CONCLUSION. Coronary MDCTA has provided an opportunity for noninvasive evaluation of the coronary arteries in patients with HIES. These coronary abnormalities vary from tortuosity to ectatic dilation and focal aneurysms of the coronary arteries. Such an evaluation has potential value in identifying new aspects of this disease and thereby providing better understanding of the pathophysiology of the disorder.

MATERIALS AND METHODS. In 155 consecutively registered patients (126 men, 29 women; mean age, 58.4 years), 204 pathologically proven HCCs smaller than 3 cm were detected at multiphasic MDCT. Three radiologists in consensus classified the relative attenuation of the tumors compared with the surrounding liver parenchyma as hyperattenuation, isoattenuation, or hypoattenuation on biphasic (n = 86) and triphasic (n = 69) CT scans.

RESULTS. The prevalent enhancement patterns of HCC differed depending on tumor size. The prevalent pattern of HCC measuring 20–29 mm was arterial hyperattenuation with venous washout (47%, 47/101). The prevalent enhancement patterns of HCC smaller than 10 mm and HCC measuring 10–19 mm were isoattenuation during the arterial and portal venous phases (29%, 6/21) and hyperattenuation and isoattenuation during the arterial and portal venous phases (33%, 27/82). The typical HCC enhancement pattern (arterial hyperattenuation with venous washout) was identified in 48% (67/141) of the moderately and poorly differentiated HCCs and in 13% (8/63) of well-differentiated HCCs.

CONCLUSION. The prevalent enhancement patterns of HCC smaller than 3 cm on multiphasic MDCT scans differed depending on tumor size and cellular differentiation. HCCs smaller than 2 cm and well-differentiated HCCs frequently had atypical enhancement patterns.

CONCLUSION. High-flow hemangiomas might show relatively low signal intensity because of gadoxetic acid contrast uptake in the surrounding normal liver parenchyma during the equilibrium (3-minute delay) phase. Such findings are called pseudo washout and can mimic hypervascular hepatic tumors. However, high-flow hemangioma can be diagnosed by observing bright signal intensity on T2-weighted imaging, arterial phase–dominant enhancement, pseudo washout sign during the equilibrium phase, and isointense or slightly increased signal intensity on subtraction images.

CONCLUSION. Local evaluation of the primary tumor in patients with transitional cell carcinoma on PET is often limited by the obscuring effect of excreted FDG, but assessment of metabolic activity may still be possible through close correlation with CT images. PET/CT may also be helpful in the detection of disease outside the bladder at nodal or more distant sites and in the assessment of recurrent disease.

CONCLUSION. Early-stage findings consisted of inflammatory changes involving adjacent vertebral endplates and mimicking degenerative disk disease with inflammation. Subsequently, progression of the lesions led to complete destruction of the intervertebral joint. Knowledge of the initial features of spinal neuroarthropathy may allow earlier treatment, which may improve outcomes.

SUBJECTS AND METHODS. Eight board-certified radiologists measured tumor diameters in three planes in two consecutive MRI examinations of 22 patients with contrast-enhancing high-grade brain tumors. Products of tumor measurements were calculated, and determinations were made about tumor progression (> 25% increase in area). A variance components model was run on diameter products and the ratios of consecutive maximal diameter products. The variance components included patient examination effect, reader effect, and residual effect.

RESULTS. Complete agreement was found among readers in 10 cases (45%), all indicating stable disease. In the other 12 cases, at least one reader considered progressive disease present. The variance components model showed variance due to readers was small, indicating only modest bias among readers. The residual variance component was large (0.038), indicating that repeated measurements on the same image likely are variable even for the same reader. This variability in measurement implies that repeated measurements by the typical reader have an inherent 14% false-positive rate in the diagnosis of progression of tumors that are stable.

CONCLUSION. Our hypothesis was disproved. We found substantial interreader disagreement and indications that the very nature of the measurement method produces a high rate of false-positive readings of stable tumors. These findings should be considered in interpretation of images with this widely accepted criterion for brain tumor progression.

CONCLUSION. Malignant and benign diseases may have peritoneal involvement, which can manifest as various imaging patterns on FDG PET/CT. Awareness of these patterns and of potential interpretation issues is important to optimize diagnostic accuracy.

CONCLUSION. The division of thrombotic disorders into metabolically nonactive and active thrombus may be helpful for differential diagnosis of underlying diseases causing thrombus formation. IV contrast media administration during PET/CT makes it possible to visualize the thrombus itself and helps to distinguish between benign and malignant metabolically active thrombus.

CONCLUSION. We found that all children in our experience with occult or subtle SH type II fractures of the distal femur have posterior periosteal disruption and other MRI findings to indicate a hyperextension mechanism of injury. Direct indicators of fracture may be inconspicuous, and the presence of posterior periosteal disruption is a clue that should prompt a search for other features of this serious pediatric injury, which may be followed by limb shortening or angular deformity.

CONCLUSION. Time-resolved MRA is a useful technique with many clinical applications.

CONCLUSION. Compared with 2D FRFSE, 3D FRFSE cube provides superior image quality and improved 3D reconstructions in a shorter acquisition time and enables excellent visualization of uterine anatomy in any orientation, regardless of the original scanning plane.

CONCLUSION. Sampling was successful in 15 of 18 cases. Errors occurred only in superficial lesions biopsied via the vertical approach. The halfpipe coaxial cannula shows promise for improving positioning accuracy, avoiding target dislocation, and obviating repeated needle repositioning.

MATERIALS AND METHODS. Of 222 patients with novel S-OIV (H1N1) infection seen from May 2009 to July 2009, 66 patients (30%) who underwent chest radiographs formed the study population. Group 1 patients (n = 14) required ICU admission and advanced mechanical ventilation, and group 2 (n = 52) did not. The initial radiographs were evaluated for the pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality. Chest CT scans (n = 15) were reviewed for the same findings and for pulmonary embolism (PE) when performed using IV contrast medium.

RESULTS. Group 1 patients were predominantly male with a higher mean age (43.5 years versus 22.1 years in group 2; p < 0.001). The initial radiograph was abnormal in 28 of 66 (42%) subjects. The predominant radiographic finding was patchy consolidation (14/28; 50%) most commonly in the lower (20/28; 71%) and central lung zones (20/28; 71%). All group 1 patients had abnormal initial radiographs; extensive disease involving ≥ 3 lung zones was seen in 93% (13/14) versus 9.6% (5/52) in group 2 (p < 0.001). No group 2 patients had > 20% overall lung involvement on initial radiographs compared with 93% of group 1 patients (13/14). PEs were seen on CT in 5/14 (36%) of group 1 patients.

CONCLUSION. Chest radiographs are normal in more than half of patients with S-OIV (H1N1) and progress to bilateral extensive air-space disease in severely ill patients, who are at a high risk for PE.

CONCLUSION. The most common radiographic and CT findings in seven patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On MDCT, the ground-glass opacities and areas of consolidation had a predominant peribronchovascular and subpleural distribution, resembling organizing pneumonia.

CONCLUSION. Radiography showed peripheral lung opacities. CT revealed peripheral ground-glass opacities suggesting peribronchial injury. These imaging findings raised suspicion of S-OIV despite negative H1N1 influenza rapid antigen test results from two nasopharyngeal swabs; subsequently, those results were proven to be false-negatives by reverse transcriptase polymerase chain reaction. This case suggests a role for CT in the early recognition of severe S-OIV.

CONCLUSION. Diseases of the thoracic lymphatic system have a wide variety of unique radiographic manifestations, all of which can be explained by the underlying pathophysiology and relationship to the normal distribution of lymphatics in the chest.

MATERIALS AND METHODS. Two reviewers were blinded to the patient groups and evaluated images of 15 coronary artery segments for each patient using 320-MDCT. The images were printed on glossy paper and scored subjectively as 1 or 2, meaning of diagnostic quality, or 3, meaning poor quality.

RESULTS. No statistical difference between the groups was noted in patient age: The mean age of the patients with atrial fibrillation was 67 years (age range, 52–82 years) and that of the patients in sinus rhythm was 59 years (36–86 years) (p = 0.3). Scores of 1 and 2 (diagnostic quality) were assigned to 100% in sinus rhythm and 96% in atrial fibrillation (p < 0.05). Scores of 3 were seen only in the atrial fibrillation group (7/175, 4%). Segment 15, the distal circumflex artery, was the segment that was most frequently assigned a score of 3 (2/7, 28.6%). A discrepancy in the two reviewers' scores was seen in 25 segments (7%), requiring joint consensus. The segments that most frequently required consensus reading were segments 12 and 15. The overall mean image quality score for all three coronary arteries in atrial fibrillation was 1.25 ± 0.47 (SD) and 1.08 ± 0.26 in sinus rhythm (p < 0.001). The median effective dose was 19.28 and 13.55 mSv in the atrial fibrillation and sinus rhythm groups, respectively.

CONCLUSION. The analysis of our initial experience shows that imaging in patients with atrial fibrillation is possible using 320-MDCT, with images of most segments obtained being of diagnostic quality. Segment 15 was the most difficult to see on 320-MDCT because of the small caliber of the vessel; poor visualization of that segment mostly occurred in the setting of a dominant right coronary arterial system.

SUBJECTS AND METHODS. The cases of 28 children with ASD initially diagnosed with TTE who were scheduled for cardiac CT for evaluation for insertion of an Amplatzer septal occluder under TEE guidance were reviewed. The patients were divided into a group with small ASD (long axis < 1.5 cm) and a group with large ASD (long axis ≥ 1.5 cm). Measurements of the ASD obtained at TTE, cardiac CT, and TEE were compared. Kappa statistics were used to correlate the diagnostic value of cardiac CT assessed by two independent reviewers.

RESULTS. After cardiac CT, six patients were excluded from occluder implantation; therefore, 22 patients (seven boys, 15 girls; mean age, 4.95 years; range, 2–11 years) were included in the study. There were no significant differences in the ages and sexes of the patients in the two groups, but pulmonary-to-systemic blood flow ratio in the large-ASD group was significantly greater than that in the small-ASD group (3.54 ± 1.43 vs 1.89 ± 0.36; p = 0.001). With respect to long- and short-axis lengths of the ASD, interatrial septum, and four rims and to detection of rim deficiency, neither group had a significant difference between cardiac CT findings at ventricular end-systole and TEE findings. The long axis of the ASD in the large-ASD group measured at cardiac CT at end-systole and TEE was significantly longer than the long axis measured at TTE (p = 0.012). A high diagnostic score with good interobserver correlation ( = 0.674–0.750) validated the feasibility of cardiac CT in the assessment of ASD for closure with an Amplatzer septal occluder.

CONCLUSION. The long axis of a large ASD can be underestimated at TTE. Cardiac CT seems comparable with TEE in the assessment of ASD and is helpful in noninvasive evaluation for Amplatzer septal occluder implantation, especially for large ASD.

CONCLUSION. The nine studies reviewed showed moderate-to-good performance for decreased-purgation CTC; however, data are limited, and study design and data presentation are inconsistent. Further study of decreased-purgation CTC and standardization of terminology are needed.

SUBJECTS AND METHODS. The study included 13 patients (11 with polycystic liver disease, two with simple cysts) with 17 cysts. All patients underwent percutaneous aspiration of the liver cyst under ultrasound guidance followed by insertion of a 7-French pigtail catheter, instillation of ethanolamine oleate (10% of cyst volume), and aspiration of the ethanolamine oleate. The catheter was kept in place for 24 hours of open drainage and then removed.

RESULTS. All but one of the cysts resolved with one instillation. The one cyst, in a patient with polycystic liver disease, required two instillations 3 months apart. The mean initial volume of cysts was 589.8 mL, and the mean reduction in volume was 88.8%. Both the simple cysts resolved completely. In the cases of polycystic disease, the volume of cysts larger than 10 cm in diameter was reduced by 92.8%. Cyst resolution was gradual, and clinically significant cyst reduction was achieved within 1 year of therapy. None of the patients needed surgery. The median follow-up period was 54 months (range, 1 week–95 months). There were no significant adverse effects, and all patients had relief of symptoms after therapy.

CONCLUSION. This initial experience with a single session of percutaneous aspiration and ethanolamine oleate sclerosis resulted in sustained resolution of symptomatic polycystic liver disease with minimal morbidity, avoidance of surgery, and improvement in quality of life.

MATERIALS AND METHODS. A review of medical records yielded the cases of 46 patients, 27 with polypoid early gastric cancer and 19 with polypoid advanced gastric cancer, whose CT scans were available for review. Two radiologists retrospectively reviewed the CT images for the presence and depth of dimpling at the tumor base, the presence of vessel invagination at the dimpling site, thickening of the low-attenuating outer layer, perigastric infiltration, and transmural full-thickness enhancement of the lesion. Individual CT findings relevant as predictors were determined with univariate and multivariate analyses. Individual review of CT scans subsequently was performed by two other radiologists, who were blinded to tumor stage but aware of the results of univariate and multivariate analyses. Individual performance was evaluated with receiver operating characteristic analysis.

RESULTS. The presence of severe dimpling greater than 3.5 mm at the base of the tumor (odds ratio, 31.3) had the highest odds ratio for differentiating early from advanced gastric cancer, followed by vessel invagination (odds ratio, 12.3), the presence of dimpling (odds ratio, 9.8), perigastric infiltration (odds ratio, 5.2), and transmural full-thickness enhancement (odds ratio, 4.8). Multivariate analysis showed that the presence of dimpling greater than 3.5 mm was the only independent variable that differentiated polypoid advanced gastric cancer from polypoid early gastric cancer (p = 0.001). Subsequent differentiation of advanced from early gastric cancer with the described CT findings was very good, yielding areas under the receiver operating characteristic analysis curves of 0.827 and 0.811 for the two observers.

CONCLUSION. Greater than 3.5 mm dimpling and other ancillary CT findings are helpful in differentiating polypoid advanced gastric cancer from polypoid early gastric cancer and contribute to good individual accuracy for differentiation.

MATERIALS AND METHODS. This study investigated 78 patients who underwent diffusion-weighted imaging (DWI) with 1.5-T MRI and pathologic staging of liver fibrosis based on biopsy. DWI was performed with b values of 50 and 400 s/mm². ADCs of liver were measured using 2.0- to 3.0-cm² regions of interest in the right and left lobes of the liver; the mean ADC value was used for analysis. Pathologic METAVIR scores for liver fibrosis stage were used as a reference standard.

RESULTS. The mean ADC values for fibrosis pathologically staged using the METAVIR classification system as F0 (n = 11), F1 (n = 16), F2 (n = 10), F3 (n = 14), and F4 (n = 27) were 125.9, 105.0, 104.5, 103.2, and 99.1 x 10^-5 s/mm², respectively. The correlation between the ADC values and the degree of liver fibrosis was moderate (Spearman's test, = –0.36). There was a significant difference in ADC values between patients with nonfibrotic liver (F0) and those with cirrhotic liver (F4) (p = 0.008). The best cutoff ADC value to distinguish between these groups was 118 x 10^-5 s/mm². However, ADC values were not useful for differentiating viral hepatitis patients with F2 fibrosis or higher from those with a lower degree of fibrosis (area under the receiver operating characteristic curve [AUC] = 0.66) or for differentiating low-stage fibrosis in all patients from high-stage fibrosis in all patients (AUC = 0.54).

CONCLUSION. The ADCs in cirrhotic livers are significantly lower than those in nonfibrotic livers. However, ADC values measured using the current generation of scanners are not reliable enough to replace liver biopsy for staging hepatic fibrosis.

MATERIALS AND METHODS. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation.

RESULTS. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements.

CONCLUSION. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

MATERIALS AND METHODS. Volumes of 75, 100, and 125 mL of iopamidol, 370 mg I/mL, were administered at rates of 4, 6, and 8 mL/s. The effect of a saline chaser (50 mL of normal saline, 8 mL/s) was evaluated for each volume and rate combination. Normal, reduced (33% and 50%), and increased (25%) cardiac outputs were simulated. Peak aortic enhancement and duration of peak aortic enhancement were recorded. Analysis of variance models were run with these effects, and the estimated mean levels for the sets of factor combinations were determined.

RESULTS. Lowering the volume of contrast material resulted in reduced peak enhancement (example, -56.2 HU [p < 0.0001] with 75 vs 125 mL) and reduced duration of 75% peak enhancement (example, -9.0 seconds [p < 0.0001] with 75 vs 125 mL). Increasing the rate resulted in increased peak enhancement (example, 104.5 HU [p < 0.0001] with a rate of 8 vs 4 mL/s) and decreased duration of 75% peak enhancement (example, -13.0 seconds [p < 0.001]). Use of a saline chaser resulted in increased peak enhancement, and this increase was inversely proportional to contrast material volume. Peak enhancement increased when reduced cardiac output was simulated. Peak enhancement decreased when increased cardiac output was simulated.

CONCLUSION. Reducing contrast material volume from 125 to 75 mL, increasing the rate to 6 or 8 mL/s, and use of a saline chaser result in an aortic enhancement profile that better matches the approximately 5-second imaging window possible with 64-MDCTA of the abdomen and pelvis. Even smaller volumes of contrast material may be adequate in patients with reduced cardiac output.

CONCLUSION. The most common complications of duodenal switch surgery were bowel obstruction, followed by ventral hernias and anastomotic leaks. Only 2% of cases required repeat surgery for management.

SUBJECTS AND METHODS. Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-weighted, diffusion-weighted, 2D chemical shift, and dynamic contrast-enhanced images were acquired. After prostatectomy, the gland was sectioned transversely. Fresh slices and stained whole-mount sections with histologically defined tumor outlines were photographed. The tumor outlines were mapped onto images, and the apparent diffusion coefficient (ADC), choline-to-citrate (Cho/cit) ratio, and vascularity of the histologically defined tumor, normal peripheral zone, and central gland were quantitatively measured. Area under the receiver operating characteristics (ROC) curve (A_z) was used to determine the sensitivity and specificity of parameter combinations in cancer detection.

RESULTS. In tumor regions larger than 1 cm², the Cho/cit ratio was higher in tumor than in nontumor tissue (p < 0.001), in the peripheral zone alone (p = 0.007), and in the central gland alone (p = 0.005). ADC was lower and tumor vascularity greater in tumor than in nontumor tissue (ADC, p = 0.003; initial area under the gadolinium plasma concentration–time curve [initial gadolinium AUC], p = 0.012; forward rate constant [K^trans], p = 0.011; return rate constant [k_ep], p = 0.036). No single parameter had a significantly greater A_z (ADC, 0.71; Cho/cit ratio, 0.79; initial gadolinium AUC, 0.60; K^trans, 0.62; k_ep, 0.65). Pairs of parameters, however, did increase A_z: ADC and initial gadolinium AUC (A_z = 0.94) versus ADC (p = 0.001) and initial gadolinium AUC (p < 0.001); ADC and Cho/cit ratio (A_z = 0.94) versus ADC (p = 0.001) and Cho/cit ratio (not significant); and Cho/cit ratio and initial gadolinium AUC (A_z = 0.88) versus Cho/cit ratio (not significant) and initial gadolinium AUC (p < 0.001). All three functional techniques together had an A_z of 0.95, showing no further improvement.

CONCLUSION. The combination of two functional parameters is associated with significant improvement in prostate cancer detection over use of any parameter alone. Use of a third parameter does not increase the rate of detection.

CONCLUSION. The use of information systems to monitor a wide variety of quality metrics offers managers the opportunity to standardize radiology and departmental practices, with the goal of transforming these practices into those that are more efficient and cost-effective and of higher quality.

MATERIALS AND METHODS. The patients included in the study were outpatients who from April 2006 through July 2008 consecutively visited a single institution for MRI of the meniscus for evaluation of knee pain. For patients who underwent arthroscopy in addition to MRI, the sensitivity and specificity of MRI were calculated. Global sensitivity analysis of data on patients who did not undergo arthroscopy was performed to estimate the influence of verification bias. Global sensitivity analysis is a method for graphically determining whether a particular pair of sensitivity and specificity estimates is compatible with observed data.

RESULTS. Eighty-two patients (23%) underwent arthroscopic verification. The sensitivity and specificity of MRI were 85% and 31%. When the possibility of meniscal tears in patients who did not undergo arthroscopy was subjected to global sensitivity analysis, the sensitivity of MRI ranged from 29% to 95% and the specificity ranged from 3% to 92%. All combinations of sensitivity and specificity produced a butterfly-shaped curve, but the base case was not inside the curve.

CONCLUSION. Verification bias greatly affected assessment of the utility of MRI in the diagnosis of meniscal tear. Sensitivity and specificity from previous studies may be incompatible with our data owing to verification bias.

MATERIALS AND METHODS. A retrospective review of 1,000 consecutive MRI examinations of the shoulder was performed by consensus of two radiologists. Cysts were grouped by location into one of two groups: those within the lesser tuberosity and those adjacent to the lesser tuberosity. The rotator cuff was defined as intact, partial tear or tendinosis, or full-thickness tear. The shortest distance from the coracoid to the humeral head was measured on axial images.

RESULTS. Forty-eight patients (26 women, 22 men; age range, 35–79 years; mean age, 61 years) had cysts adjacent to or within the lesser tuberosity. Thirty-two patients (67%) had cysts just superior to the tuberosity and 16 (33%) had cysts in the lesser tuberosity, resulting in an incidence of 3.2% and 1.6%, respectively. All 16 patients (100%) with lesser tuberosity cysts had subscapularis and supraspinatus tendon abnormalities including 11 (69%) full-thickness supraspinatus tears. Patients with cysts superior to the tuberosity had 20 (63%, p = 0.004) abnormal subscapularis tendons and 28 (88%) abnormal supraspinatus tendons, including six (19%) full-thickness tears (p = 0.002). The coracohumeral distance was noted to be less than 10 mm in 10 patients (63%) with lesser tuberosity cysts as compared with 10 patients (31%, p = 0.06) with cysts superior to the tuberosity.

CONCLUSION. Cysts located within the lesser tuberosity are rare and are indicative of subscapularis and supraspinatus tendon abnormalities.

MATERIALS AND METHODS. Sixty-seven soft-tissue tumors imaged with both STIR and T1-weighted fat-suppressed contrast-enhanced sequences were evaluated. The signal-to-noise and contrast-to-noise ratios of the tumors in comparison with normal muscle, bone marrow, and fat were measured. Subjective image contrast between soft-tissue tumors and the nearest normal tissue was evaluated by two observers. The observers classified the soft-tissue tumors as benign or malignant using a 5-point scale, and sensitivity, specificity, and accuracy were calculated. The results of the two readings were assessed with receiver operating characteristic analysis.

RESULTS. The contrast-to-noise ratios of all tumors in comparison with muscle (p < 0.01), bone marrow (p < 0.05), and fat (p < 0.05) were significantly higher on the fast STIR images than on the T1-weighted fat-suppressed contrast-enhanced images. Both observers' mean ratings of benign, malignant, and all tumors in comparison with muscle on fast STIR images were significantly higher than those on T1-weighted fat-suppressed contrast-enhanced images. For both observers, the mean sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve in evaluation of the fast STIR images did not differ significantly from those in evaluation of the T1-weighted fat-suppressed contrast-enhanced images.

CONCLUSION. The fast STIR sequence is excellent for evaluation of soft-tissue tumors, and contrast-enhancement is not always needed.

SUBJECTS AND METHODS. The lateral ulnar collateral ligaments of four cadaveric elbows were imaged with a high-resolution linear-array ultrasound transducer. On localization, the ligaments were injected with 0.1% methylene blue under sonographic guidance. For confirmation of identification of the ligaments, the elbows were immediately dissected to reveal the exact location of the stain. The ligaments of both elbows of 35 healthy adult volunteers were imaged.

RESULTS. Surgical dissection confirmed injection of methylene blue into all four cadaveric ligaments. The lateral ulnar collateral ligament was identified bilaterally over the radial head in all 35 volunteers. The mean thickness of the ligament at this point was 1.2 mm in women and men. The proximal attachment of the ligament to the humerus was well visualized bilaterally in 94.3% of volunteers. The mean thickness at this point was 1.7 mm in women and 1.6 mm in men. The distal attachment on the ulna was well visualized in 90% of elbows. The ligament was hyperechoic in relation to muscle in all volunteers. Differences in ligament measurements with regard to sex and hand dominance were not significant. Ligament thickness correlated weakly with volunteer weight, height, body mass index, and age.

CONCLUSION. High-resolution ultrasound imaging is accurate for identification and measurement of normal lateral ulnar collateral ligaments. Therefore, ultrasound may prove valuable in assessment of abnormal lateral ulnar collateral ligaments.

MATERIALS AND METHODS. The study subjects were pediatric patients who had undergone one or more neuroangiographic procedures at Harborview Medical Center between December 1, 2004, and April 30, 2008. Recorded radiation doses were converted to entrance skin dose (ESD) and effective dose (ED) to indicate deterministic and stochastic damage, respectively. The Biologic Effects of Ionizing Radiation (BEIR) VII, phase 2, report was used to estimate the expected increased risk of cancer in the study population.

RESULTS. For diagnostic and therapeutic procedures, a mean ED of 10.4 and 34.0 mSv per procedure was calculated, respectively. The ESD values proved too low to cause deterministic harm. The estimated number of excess cases of malignancy projected from the total average radiation exposure was 890.6 per 100,000 exposed male children and 1,222.5 per 100,000 exposed females, an overall increase of approximately 1% to the lifetime attributable risk of cancer.

CONCLUSION. Although both angiography and CT have revolutionized the practice of medicine and confer benefits to patients, it is important that we continue to investigate the possible adverse effects of these technologies. Protocols that minimize radiation dose without compromising a study should be implemented.

MATERIALS AND METHODS. Ten patients were included who had visually normal or elevated cerebral blood volume in infarcts larger than 1.5 cm confirmed on diffusion-weighted MR images within 48 hours of perfusion CT. The cases were selected from 371 perfusion CT studies of stroke patients (99 associated with positive diffusion-weighted imaging findings) reviewed over 2.5 years on a 64-MDCT scanner. The perfusion CT images were fused to the diffusion-weighted images for measurement of cerebral blood volume, cerebral blood flow, mean transit time, time to peak, and delay in each infarct versus the contralateral hemisphere. Two neuroradiologists reviewed the images in consensus.

RESULTS. The mean time between symptom onset and perfusion CT was 3.9 days. Infarcts were in the middle cerebral artery (n = 7) and posterior cerebral artery (n = 3) distributions. Significant differences versus the contralateral finding were found in cerebral blood volume (p = 0.016; mean increase, 30.0%), mean transit time (p = 0.007; mean increase, 38.1%), time to peak (p = 0.005; mean increase, 17.7%), and delay (p = 0.030; mean increase, 124.9%). The difference in cerebral blood flow (p = 0.785; mean increase, 1.8%) was not statistically significant. Infarcts became enhanced on the dynamic perfusion CT images of eight of 10 patients and on the contrast-enhanced T1-weighted MR images of six of nine patients.

CONCLUSION. Visual inspection of cerebral blood volume and cerebral blood flow maps alone is insufficient in the evaluation of infarcts. Mean transit time, time to peak, and delay maps also should be reviewed with dynamic source images to prevent misinterpretation of findings as false-negative. This phenomenon is unlikely to occur hyperacutely (< 8 hours after onset).

SUBJECTS AND METHODS. Eighteen patients with known pulmonary nodules (nine women, nine men; mean age, 61.4 years) underwent conventional FDG PET/CT and respiratory-gated PET acquisitions during their scheduled staging examinations. Maximum, minimum, and average standardized uptake values (SUVs) and lesion size and volume were determined with and without respiratory gating. The results were then compared using the two-tailed Student's t test and the nonparametric Wilcoxon's test to assess the effects of respiratory gating on PET acquisitions.

RESULTS. Respiratory gating reduced the measured area of lung lesions by 15.5%, the axial dimension by 10.3%, and the volume by 44.5% (p = 0.014, p = 0.007, and p = 0.025, respectively). The lesion volumes in gated studies were closer to those assessed by standard CT (difference decreased by 126.6%, p = 0.025). Respiratory gating increased the measured maximum SUV by 22.4% and average SUV by 13.3% (p < 0.001 and p = 0.002).

CONCLUSION. Our findings suggest that the use of PET respiratory gating in PET/CT results in lesion volumes closer to those assessed by CT and improved measurements of tracer uptake for lesions in the lungs.

MATERIALS AND METHODS. We retrospectively compared chest ultrasound and chest CT in 19 children (nine girls and 10 boys; age range, 8 months–17 years) admitted with complicated pneumonia and parapneumonic effusion between December 2006 and January 2009. Images were evaluated for effusion, loculation, fibrin strands, parenchymal consolidation, necrosis, and abscess. In the subset of patients who underwent surgical management, imaging findings were correlated with operative findings.

RESULTS. Eighteen of 19 patients had an effusion on both chest ultrasound and chest CT. The findings of effusion loculation as well as parenchymal consolidation and necrosis or abscess were similar between the two techniques. Chest ultrasound was better able to visualize fibrin strands within the effusions. Of the 14 patients who underwent video-assisted thoracoscopy, five had surgically proven parenchymal abscess or necrosis. Preoperatively, chest ultrasound was able to show parenchymal abscess or necrosis in four patients, whereas chest CT was able to show parenchymal abscess or necrosis in three.

CONCLUSION. In our series, chest ultrasound and chest CT were similar in their ability to detect loculated effusion and lung necrosis or abscess resulting from complicated pneumonia. Chest CT did not provide any additional clinically useful information that was not also seen on chest ultrasound. We suggest that the imaging workup of complicated pediatric pneumonia include chest radiography and chest ultrasound, reserving chest CT for cases in which the chest ultrasound is technically limited or discrepant with the clinical findings.

CONCLUSION. The basic tools for coagulation assessment have not changed; however, results from subspecialty research have suggested ways in which the use of these tools can be modified and streamlined to safely reduce time and expense for the patient and the health care system.

MATERIALS AND METHODS. One hundred twenty-four patients underwent TACE using a standardized triple-drug regimen. Embolization was performed using subselective coaxial embolization technique. Fifty-six patients (group 1) received triple-drug TACE in conjunction with a nonpermanent embolic agent, microfibrillar collagen (Avitene), and 68 patients (group 2) had triple-drug TACE with a permanent embolic agent, Embosphere Microspheres.

RESULTS. Twenty-eight patients underwent liver transplantation after TACE, and survival in these patients was significantly longer than those who did not receive a transplant (p ≤ 0.001). The mean survival for the no-transplant group (n = 96) was longer in patients with Child-Pugh class A cirrhosis than in those with Child-Pugh class B cirrhosis (30.3 ± 2.92 [standard error] vs 11.6 ± 2.84 months, respectively; p < 0.001), in those with Okuda stage I versus stage II disease (31.4 ± 3.03 vs 17.4 ± 3.16 months; p = 0.002), and in those with a pre-TACE bilirubin level of less than 2.5 mg/dL (42.75 µmol/L; 28.3 ± 2.75 vs 13.2 ± 3.83 months; p = 0.007). Improved survival was seen in the no-transplant patients receiving TACE with the permanent embolic agent (group 2) than in those receiving TACE with the nonpermanent agent (group 1) out to 30 months (p = 0.002). Complications occurred in 16 patients (12.9%). The 30-day mortality was 2.4%.

CONCLUSION. Patients with hepatocellular carcinoma who underwent triple-drug TACE followed by liver transplantation showed the longest survival. Patients who did not receive a transplant and were treated with triple-drug TACE with a permanent embolic agent showed longer survival to 30 months after TACE than those receiving a nonpermanent embolic agent.

MATERIALS AND METHODS. Hemodialysis patients who underwent successful endovascular treatment of central venous obstruction were retrospectively evaluated. Stenotic lesions greater than 50% or inducing extremity swelling were subject to treatment. The primary treatment was angioplasty, and stent placement was accomplished in angioplasty-resistant obstructions. Angioplasty was the primary treatment of recurrence after stent placement. Additional stenting was reserved for angioplasty-resistant recurrences.

RESULTS. One hundred forty-seven veins in 126 patients (63 males, 63 females) between 15 and 82 years old primarily underwent 101 angioplasties and 46 stent placements. The mean follow-up was 22.1 ± 16.3 (SD) months. The average number of interventions per vein in the stent group (2.7 ± 2.4 interventions) was significantly higher than that in the angioplasty group (1.5 ± 1.0 interventions). Primary patency was significantly higher in the angioplasty group (mean, 24.5 ± 1.7 months) than that in the stent group (mean, 13.4 ± 2.0 months). Assisted primary patency of the angioplasty group (mean, 31.4 ± 2.0 months) and that of the stent group (mean, 31.0 ± 4.7 months) were equivalent. The overall mean primary patency was 21.1 ± 1.4 months, and the overall mean assisted primary patency was 31.7 ± 2.5 months. There were no significant differences in patency rates with regard to patient sex, the type of stent used, the vein or veins treated, or the type of lesions.

CONCLUSION. Endovascular treatment of central venous obstruction is a safe and effective procedure in hemodialysis patients. Stenting has a significantly lower primary patency rate than angioplasty but adds to the longevity of vein patency in angioplasty-resistant lesions; therefore, stent placement should be considered in angioplasty-resistant lesions.

MATERIALS AND METHODS. This study examined 20 radiology systems in 15 cardiac catheterization laboratories (11 used FPD and nine used II). The entrance surface doses with digital cineangiography and fluoroscopy were compared for the 20 systems using acrylic plates (20-cm thick) and a skin dose monitor.

RESULTS. For fluoroscopy, the average entrance surface doses of the 20-cm-thick acrylic plates were identical for FPD (average ± SD, 16.63 ± 7.89 mGy/min; range, 5.7–26.4 mGy/min; maximum/minimum, 4.63) and II (17.81 ± 12.52 mGy/min; range, 6.5–42.2 mGy/min; maximum/minimum, 6.49) (p = 0.799). For digital cineangiography, the average entrance surface dose of the 20-cm-thick acrylic plate was slightly lower with FPD (29.68 ± 16.40 mGy/10 s; range, 8.9–58.5 mGy/10 s; maximum/minimum, 6.57) than with II (38.50 ± 33.71 mGy/10 s; range, 15.2–117.1 mGy/10 s; maximum/minimum, 7.70), although the difference was not significant (p = 0.487).

CONCLUSION. We found that the average entrance doses of cineangiography and fluoroscopy in FPD systems were not significantly different from those in II systems. Hence, FPDs did not inherently reduce the radiation dose, although FPDs possess good detective quantum efficiency. Therefore, to reduce the radiation dose of cardiac interventional radiology systems, even FPD systems, practical measures are necessary.

MATERIALS AND METHODS. An interventional radiology database was searched to identify the cases of patients who underwent CT-guided percutaneous radiofrequency ablation of biopsy-proven renal cell carcinoma in which D5W was injected into the retroperitoneal space to displace structures away from the targeted renal tumor. The number of organs displaced and the distance between the renal tumor and adjacent organs before and after displacement with D5W were assessed.

RESULTS. The cases of 135 patients with 139 biopsy-proven renal cell carcinomas who underwent 154 percutaneous CT-guided radiofrequency ablation procedures were found in the search. Thirty-one patients with 33 renal cell carcinomas underwent 36 ablation procedures after injection of D5W into the retroperitoneal space. Fifty-five organs were displaced away from renal cell carcinoma with this technique. The average distance between adjacent structures and renal cell carcinomas before displacement was 0.36 cm (range, 0.1–1.0 cm). The average distance between structures and adjacent renal cell carcinomas after displacement was 1.94 cm (range, 1.1–4.3 cm) (p < 0.0001). The average volume of D5W used to achieve organ displacement was 273.5 mL. No complications were associated with this technique.

CONCLUSION. CT-guided injection of D5W into the retroperitoneum is an effective method for displacing vital structures away from renal cell carcinoma.

MATERIALS AND METHODS. We reviewed 545 consecutive ultrasound-guided fine-needle aspiration cytologic sampling procedures for focal pancreatic lesions from January 2004 through June 2008. The procedures were performed with a 20- or 21-gauge needle. The onsite cytopathologist evaluated the appropriateness of the sample and made a diagnosis. We reviewed the final diagnosis and the radiologic and medical records of all patients for onset of complications during or within 7 days of the procedure.

RESULTS. The study sample included 262 women and 283 men (mean age, 62 years; range, 25–86 years). The head or uncinate process of the pancreas was the location of 63.0% of the lesions, and 35.2% of the lesions were located in the body or tail of the pancreas. The site of 10 lesions (1.8%) was not specified. Sampling was diagnostic in 509 of the 545 cases (93.4%). Excluding the 36 nondiagnostic samples, ultrasound-guided fine-needle aspiration cytologic sampling had 99.4% sensitivity, 100% specificity, and 99.4% accuracy. In 537 of the 545 cases (98.5%), the procedure was uneventful. In two cases, abdominal fluid was found after the procedure that was not present before the procedure. Six patients experienced postprocedural pain without abnormal findings at subsequent imaging. No major complications occurred.

CONCLUSION. Ultrasound-guided cytologic sampling is safe and accurate for the diagnosis and planning of management of focal pancreatic lesions. With a cytologist on site, the rate of acquisition of samples adequate for diagnosis is high, reducing the need for patient recall.

MATERIALS AND METHODS. From January 2000 through December 2008, 189 transjugular intrahepatic portosystemic shunt procedures were performed with self-expanding stent-grafts. After a mean period of 43.4 ± 57 weeks, hepatic encephalopathy developed in 12 patients and did not respond to conventional medical therapy with lactulose, nonabsorbable antibiotics, and a protein-restricted diet. In all cases, shunt reduction was performed with an hourglass-shaped balloon-expandable ePTFE stent-graft inserted into the original shunt.

RESULTS. Technically successful shunt reduction with an immediate increase in portosystemic gradient was achieved in all patients. Symptoms of hepatic encephalopathy disappeared a mean of 22.3 hours (range, 18–26 hours) after the procedure. After a mean follow-up period of 73.9 ± 61.88 weeks, no recurrence of hepatic encephalopathy was found. One patient (8.3%) needed dilation of the hourglass-shaped stent-graft after 37 weeks because of recurrence of ascites. At the end of the study, five patients (41.6%) were alive in good clinical condition. Four patients (33.3%) died of cardiovascular failure 1, 2, 24, and 96 weeks after the corrective procedure. Eight months after the reduction procedure, one patient (8.3%) underwent orthotopic liver transplantation, which resulted in clinical improvement. Two patients (16.6%) were lost to follow-up 15.6 and 46.8 weeks after the procedure.

CONCLUSION. Shunt reduction with an hourglass-shaped ePTFE balloon-expandable stent-graft seems effective in reducing shunt flow and rapidly improving the patient's clinical condition. With this technique, shunt diameter can be modified on the basis of the patient's clinical condition.

CONCLUSION. The CT-guided posterolateral approach was safe, feasible, and effective for percutaneous intervention of the C2 vertebral body.

MATERIALS AND METHODS. MRI of the urethra was performed in 84 women with lower urinary tract symptoms using multiplanar T2-weighted turbo spin-echo and unenhanced and contrast-enhanced gradient-echo sequences. A dynamic true fast imaging with steady-state free precession sequence was performed during straining in the sagittal plane. Images were evaluated by two radiologists for urethral pathology and pelvic organ prolapse. MRI findings were correlated with clinical symptoms using the Fisher's exact and Mann-Whitney tests.

RESULTS. Urethral abnormalities were found in 10 of 84 patients (11.9%), including two urethral diverticula, five Skene's gland cysts or abscesses, and three periurethral cysts. Thirty-three patients (39.3%) were diagnosed with pelvic organ prolapse, of whom 29 (87.9%) were diagnosed exclusively on dynamic imaging. In 29 of 33 patients with prolapse (87.9%), the urethra was structurally normal. MRI showed 13 cystoceles and 17 cases of urethral hypermobility not detected on physical examination. Patients with a greater number of vaginal deliveries, stress urinary incontinence, frequency of voiding, and voiding difficulty were statistically more likely to have anterior compartment prolapse (p < 0.05).

CONCLUSION. Including a dynamic sequence permits both structural and functional evaluation of the urethra, which may be of added value in women with lower urinary tract symptoms. Dynamic MRI allows detection of pelvic organ prolapse that may not be evident on conventional static sequences.

MATERIALS AND METHODS. The retrospective study included 70 women with 83 suspicious breast lesions on DCE-MRI (BI-RADS 4 or 5) who underwent subsequent biopsy. DWI was acquired during clinical breast MRI using b = 0 and 600 s/mm². Apparent diffusion coefficient (ADC) values were compared for benign and malignant lesions. PPV was calculated for DCE-MRI alone (based on biopsy recommendations) and DCE-MRI plus DWI (adding an ADC threshold) for the same set of lesions. Results were further compared by lesion type (mass, nonmasslike enhancement) and size.

RESULTS. Of the 83 suspicious lesions, 52 were benign and 31 were malignant (11 ductal carcinoma in situ [DCIS], 20 invasive carcinoma). Both DCIS (mean ADC, 1.31 ± 0.24 x 10^–3 mm²/s) and invasive carcinoma (mean ADC, 1.29 ± 0.29 x 10^–3 mm²/s) exhibited lower mean ADC than benign lesions (1.70 ± 0.44 x 10^–3 mm²/s, p < 0.001). Applying an ADC threshold of 1.81 x 10^–3 mm²/s for 100% sensitivity produced a PPV of 47% versus 37% for DCE-MRI alone, which would have avoided biopsy for 33% (17/52) of benign lesions without missing any cancers. DWI increased PPV similarly for masses and nonmasslike enhancement and preferentially improved PPV for smaller (≤ 1 cm) versus larger lesions.

CONCLUSION. DWI shows potential for improving the PPV of breast MRI for lesions of varied types and sizes. However, considerable overlap in ADC of benign and malignant lesions necessitates validation of these findings in larger studies.

MATERIALS AND METHODS. The cases of all women with round, oval, or lobular palpable masses with circumscribed margins and homogeneous ultrasound echotexture for which short-term follow-up was recommended from July 1997 through December 2003 were retrospectively identified. Evaluation was by ultrasound and/or mammography and focused clinical examination. Outcome was assessed with imaging or clinical follow-up lasting at least 12 months. The cancer incidence for palpable lesions was compared with that for nonpalpable lesions recommended for short-term follow-up.

RESULTS. In 379 women, 443 palpable masses with benign features for which short-term follow-up was recommended were identified. Outcome data were available on 375 masses in 320 women. Lesions were evaluated with mammography and ultrasound (n = 186) or ultrasound alone (n = 189). Masses were typically identified only with ultrasound (n = 258, 68.8%); were oval (n = 275, 73.3%), of equal density to normal breast tissue on mammograms (n = 95 on 117 mammograms, 81.2%), and hypoechoic (n = 336 in 372 ultrasound examinations, 90.3%); and were prospectively believed to be fibroadenoma (n = 304, 81.1%). Eighty-five lesions (22.7%) were biopsied soon after evaluation, and one 1.5-mm ductal carcinoma in situ was diagnosed. At follow-up (mean, 2.7 years), 26 lesions (6.9%) had grown. Twenty-four of the 26 lesions were biopsied, and no cancer was diagnosed. The overall cancer prevalence was similar for palpable (0.3%) and nonpalpable (1.6%) masses. The cost of short-term follow-up was less than that of biopsy.

CONCLUSION. Short-term follow-up is a reasonable alternative to biopsy of palpable breast lesions with benign imaging features, particularly for young women with probable fibroadenoma.

SUBJECTS AND METHODS. Between June 2006 and December 2006, preoperative axillary sonography was performed in 191 consecutive breast cancer patients (median age, 46 years; age range, 24–79 years) who had been scheduled to undergo breast cancer surgery with sentinel node biopsy. The axillary lymph node that had the thickest cortex or that was closest to the primary tumor was prospectively classified and then removed through sonographically guided needle localization. Correspondence about and histologic results for the needle-localized nodes and the radioactive sentinel nodes were analyzed. The rate of malignancy, according to the sonographic classification, and the area under a receiver operating characteristic curve were analyzed.

RESULTS. Of the 191 needle-localized nodes, 41 (21%) had metastases and 150 (79%) did not have metastases. When a cutoff point of a cortical thickness of 2.5 mm was used, sonographic classification showed 85% (35/41) sensitivity, 78% (117/150) specificity, and an area under the curve of 0.861 (95% CI, 0.796–0.926). Of the 54 patients with metastases at sentinel node biopsy or axillary lymph node dissection, 13 (24%) had false-negative results of sonographically guided needle localization. Unsuccessful lymphatic mapping because of absent radiotracer uptake during sentinel node biopsy was found in 4% (7/191), whereas all needle-localized nodes with a cortical thickness of more than 2.5 mm were confirmed as metastases.

CONCLUSION. Sonographic classification of axillary lymph nodes is effective for predicting the presence of metastases to avoid sentinel node biopsy or to reduce unsuccessful lymphatic mapping during sentinel node biopsy.

CONCLUSION. Serum progesterone concentrations corresponding to the follicular phase of a normal menstrual cycle can aid in optimal scheduling of breast MRI examinations for premenopausal women who lack cyclical menses.

CONCLUSION. The spectrum of HHV-6 associated disorders is broad, but radiologists are frequently not familiar with these disorders. In the clinical setting of acute infection in an immunocompromised patient, the presence of one of these findings (e.g., limbic encephalitis; atypical interstitial pneumonia; pericarditis or myocarditis; or, less commonly, gastrointestinal or hepatobiliary disorders) should raise the suspicion of a possible HHV-6 related complication.

SUBJECTS AND METHODS. Patients with suspected myocardial scar were examined on a 1.5-T MR scanner for myocardial late enhancement after the administration of gadopentetate dimeglumine using a segmented 2D PSIR turbo FLASH sequence followed by a navigator-gated 3D PSIR turbo FLASH sequence. Image quality was scored by two independent readers using a 4-point Likert scale (0 = poor, nondiagnostic; 1 = fair, diagnostics may be impaired; 2 = good, some artifacts but not interfering in diagnostics; 3 = excellent, no artifacts). Scars were compared quantitatively in volume and graded qualitatively on the basis of size (area) and location.

RESULTS. Thirty-three patients were scanned using both techniques. In 25 patients, the quality of the 3D PSIR images was acceptable. Scars were detected in 12 patients. Hyperenhanced scar volumes (p = 0.43), qualitative analysis of scar area (p = 0.78), and scar location (p = 0.68) were similar for both techniques. More small hyperenhanced scars, corresponding mostly to nonischemic distribution patterns, were detected using 3D PSIR than 2D PSIR. Although 2D and 3D results were found to be highly correlated for scar volume, Bland-Altman analysis indicated a systematic smaller infarct volume on the 2D PSIR scans (R² = 0.84).

CONCLUSION. Free-breathing 3D PSIR turbo FLASH imaging is a promising technique for the assessment of left ventricular scar particularly for scar quantification and the detection of small nonischemic scars in the myocardium.

MATERIALS AND METHODS. Sixty-two patients with mechanical valves (37 single-disc, 27 bileaflet; 59 aortic, 5 mitral) were evaluated with ECG-gated 64-MDCT and transthoracic echocardiography; a subset of 10 patients underwent cinefluoroscopy. Two readers independently interpreted each study.

RESULTS. The mean age of the patients was 46.4 ± 14.4 years; 50 were men and 12 were women. There was excellent correlation, and differences between CT readers were absent to small in measuring the opening angle (r = 0.96, p < 0.001; 76.7 ± 9.0° vs 76.8 ± 9.6°, p = 0.73), annulus diameter (r = 0.96, p < 0.001; 25.9 ± 3.3 vs 25.9 ± 3.2 mm, p = 0.62), and geometric orifice area (r = 0.98, p < 0.001; 3.8 ± 0.9 vs 3.6 ± 0.8 cm², p < 0.001). There was strong correlation without difference in opening angle between CT and cinefluoroscopy (r = 0.77, p < 0.001; 79.2° ± 9.8° vs 77.2° ± 15.5°, p = 0.45). Compared with manufacturer specifications, CT reported opening angles that were smaller for single-disc valves (n = 36, 67.4° ± 5.7° vs 75°, p < 0.001) and similar for bileaflet valves (n = 42 for 21 valves, 83.8° ± 3.9° vs 85°, p = 0.05), valves, with small underestimation with CT versus specifications in annulus diameter (n = 41; r = 0.75, p < 0.001; 26.4 ± 3.0 vs 27.5 ± 3.3 mm, p = 0.003), and geometric orifice area (n = 35; r = 0.90, p < 0.001; 3.7 ± 0.7 vs 3.8 ± 0.8 cm², p = 0.04). Each disc closed fully on CT; none had more than mild regurgitation on echocardiography.

CONCLUSION. CT can measure the size and function of mechanical valves with high interobserver agreement and results similar to specifications. The opening angle with CT strongly correlates with cinefluoroscopy. CT is promising for the assessment of mechanical valves.

MATERIALS AND METHODS. We used 60 chest radiographs; 30 depicted solitary pulmonary nodules, and 30 showed no nodules. A stratified random-sampling scheme was used to select the images from the standard digital image database developed by the Japanese Society of Radiologic Technology. The mean diameter of the 30 pulmonary nodules was 14.7 ± 4.1 (SD) mm. Receiver operating characteristic analysis was used to evaluate observer performance in the detection of pulmonary nodules first on the chest radiographs without and then on the radiographs with rib suppression. Seven board-certified radiologists and five radiology residents participated in this observer study.

RESULTS. For all 12 observers, the mean values of the area under the best-fit receiver operating characteristic curve for images without and with rib suppression were 0.816 ± 0.077 and 0.843 ± 0.074; the difference was statistically significant (p = 0.019). The mean areas under the curve for images without and with rib suppression were 0.848 ± 0.059 and 0.883 ± 0.050 for the seven board-certified radiologists (p = 0.011) and 0.770 ± 0.081 and 0.788 ± 0.074 for the five radiology residents (p = 0.310).

CONCLUSION. In the detection of pulmonary nodules, evaluation of a combination of rib-suppressed and original chest radiographs significantly improved the diagnostic performance of radiologists over the use of chest radiographs alone.

CONCLUSION. There are likely thousands of people bearing radon seeds that continue to emit radiation decades after implantation. They can be identified by clinical history and emission of characteristic x-rays. Surgical removal of these sources is rarely warranted.

MATERIALS AND METHODS. We reviewed the radiologic and pathologic records of bone biopsies scheduled at our institution between 2002 and 2007. The following parameters were recorded: indication, type of primary cancer, date of diagnosis, complications of biopsy, whether the sample was of diagnostic quality, pathologic finding, and thus whether the primary malignant tumor was concordant with the lesion sampled.

RESULTS. Fifty-four of 55 patients (17 men, 37 women; mean age, 67 years) with known primary cancer and suspicious bone lesions underwent biopsy. One of the 55 patients did not undergo biopsy because a sacral insufficiency fracture was confidently diagnosed at CT. The primary malignant disease had been diagnosed up to 16 years before the new bone lesion was suspected and bone biopsy performed. Cancer types included those of genitourinary tract, breast, thyroid, gastrointestinal tract, and lung and lymphoma and myeloma. Diagnostic material was obtained in 43 of 54 cases (80%), and nondiagnostic material was obtained in 11 of 54 cases (20%). Forty-two of 43 positive biopsy findings (98%) were consistent with the primary malignant tumor. The other positive finding was a new malignant tumor. This new tumor was myelofibrosis in a man with chronic myelocytic leukemia. The primary diagnosis correlated highly with that of the new bone lesion (Spearman's test, R = 0.842; p < 0.001). No complications, including hemorrhage, infection, sinus track formation, fracture, and pneumothorax, were encountered.

CONCLUSION. In a patient with known primary malignant disease, the probability is low (2%) that biopsy of a new suspicious bone lesion will show the lesion is other than metastasis from the primary tumor.

SUBJECTS AND METHODS. Thirty-seven patients (18 men, mean age ± SD, 65.7 ± 7.8 years; 19 women, mean age, 63.8 ± 12.0 years) with clinical symptoms of osteoarthritis were studied on 3-T MRI using a 2D multiecho spin-echo sequence for T2 mapping. Meniscal signal and morphology were qualitatively graded and correlated to the T2 values of cartilage. Analysis of covariance, Bonferroni multiple comparison correction, and Spearman's correlation coefficients were used for statistical analysis.

RESULTS. Patients with meniscal tears (median ± interquartile range, 50.1 ± 6.1 milliseconds) had significantly (p = 0.021) higher T2 values of cartilage than those without meniscal tears (45.7 ± 4.8 milliseconds). T2 values of cartilage were significantly higher in the medial compartment than in the lateral compartment in patients with medial meniscal tears (p = 0.018).

CONCLUSION. T2 measurements are increased in patients with meniscal tears; this finding adds support to the theory of an association of osteoarthritis with damage to both the menisci and hyaline cartilage.

MATERIALS AND METHODS. Between December 2007 and February 2008, 45 patients (age range, 19–73 years; mean age ± SD, 45.0 ± 12.2 years) with 52 thyroid nodules were examined with conventional B-mode ultrasound and real-time freehand ultrasound elastography. All the patients were scheduled to undergo thyroid surgery because a thyroid nodule had been proven malignant on aspiration cytology. Three radiologists independently performed conventional ultrasound and elastography and analyzed the ultrasound images. Using conventional ultrasound, observers recorded the following information about nodular features: composition (solid, cystic, or mixed cystic–solid), echogenicity (hyperechoic, isoechoic, hypoechoic, or markedly hypoechoic), margin (well circumscribed, microlobulated, or irregular), calcification (negative [no calcifications]; microcalcification, macrocalcification, or mixed-type calcifications), and shape (parallel or nonparallel). Observers determined the Ueno classification and area ratio for each nodule using ultrasound elastography. Interobserver agreement was evaluated with Spearman's correlation analysis for all findings except the area ratio, for which Pearson's correlation analysis was used. A p < 0.05 was considered to indicate statistical significance.

RESULTS. Statistically significant (p < 0.05) concordance among the three radiologists was found on conventional ultrasound for most features except echogenicity and margin of thyroid nodules. The highest value of concordance on conventional ultrasound was achieved for composition (Spearman's correlation coefficient, 0.70–1.00), followed by shape (0.48–0.79) and calcification (0.47–0.62). The least concordant findings on conventional ultrasound were nodular echogenicity (0.04–0.45) and margin (0.03–0.29). However, there was no statistically significant concordance on elastography for the Ueno classification (Spearman's correlation coefficient, 0.08–0.22; p > 0.05) or the area ratio (Pearson's correlation coefficient, –0.03 to 0.23; p > 0.05).

CONCLUSION. Statistically significant concordance among radiologists about most features of malignant thyroid nodules was seen with conventional ultrasound; however, ultrasound elastography did not show reliable interobserver agreement for the diagnosis of malignant thyroid nodules.

MATERIALS AND METHODS. From October 2005 to January 2008, 35 patients with one or more HCCs and ascites were referred to our department for planning sonography of RFA. In 15 patients, RFA was determined to be unfeasible. One patient was excluded from the study because of the absence of ascites at the time of RFA. Percutaneous ultrasound-guided RFA was performed in the remaining 19 patients with 24 HCCs. The electrode tract was cauterized at the time of electrode removal. Retrospective assessments of the preprocedural platelet counts and prothrombin times were performed, and patients were evaluated for bleeding complication by checking vital signs, checking serum hemoglobin level, and using CT to determine whether the attenuation value of ascites had increased > 30 HU.

RESULTS. There were no cases of mortality or major complications that developed after RFA. No significant difference in the maximum thickness of the perihepatic ascites and in the hemoglobin level between the pre- and postprocedural measurements was detected. Hemoperitoneum as a minor complication was noted in two (10.5%) of 19 patients. However, in those two patients, vital signs were stable, follow-up laboratory data were normal, and hemoperitoneum had been completely absorbed on CT images obtained 1 month after RFA.

CONCLUSION. Percutaneous RFA for HCC can be performed safely in patients with ascites.

MATERIALS AND METHODS. We retrospectively reviewed 1,400 percutaneous CT-guided thoracic biopsies during the period from August 1993 to August 2008. A case with air embolism was considered to be a patient with hypotension during or after biopsy and with an air embolism confirmed on CT. A needle track implantation was considered to be a mass in the needle track on the postbiopsy follow-up CT.

RESULTS. There were three (0.21%) cases of air embolism. Air embolisms were confirmed in the left ventricle, coronary artery, ascending aorta, and pulmonary vein. The pulmonary venous wall was pathologically identified in one case. Although there were no fatalities, two patients needed resuscitation. Left hemiplegia occurred in one case, but it gradually disappeared. There were four (0.56%) cases of needle track implantation in 713 pathologically proven malignant thoracic biopsy cases with follow-up CT scans. Two were primary lung cancer and the others were lung metastasis (renal cell carcinoma and osteosarcoma). Implantation was found 4–7 months (mean, 5.6 months) after the biopsy, and size was 2.5–5.6 cm (mean, 3.5 cm).

CONCLUSION. The incidence of air embolism with clinical symptoms and needle track implantation complicating percutaneous thoracic biopsy is more frequent than the previously reported rate.

MATERIALS AND METHODS. Six patients with an aortic and five patients with an iliac aneurysm and 11 age-matched controls were identified in a database of 239 patients who underwent evaluations for the staging of prostate cancer. USPIO-enhanced MRI and contrast-enhanced MDCT were performed for all patients. The presence of USPIO was assessed with an iron-sensitive MRI sequence. Quantification consisted of counting the number of quadrants with USPIO-induced subendothelial signal voids. A chi-square test was used to analyze the significance of the difference between the number of USPIO-positive quadrants in the aneurysm group and that in the control group.

RESULTS. The number of USPIO-positive quadrants was significantly higher in the aneurysm than in the control group: 158 quadrants (4.2%) in the aneurysm group and 13 quadrants (0.4%) in the control group (p < 0.001). Two abdominal aortic aneurysms accounted for 90% (154/171) of all USPIO-positive quadrants.

CONCLUSION. USPIO uptake is limited or absent in the wall of normal-sized aortas and most aneurysms. However, individual abdominal aortic aneurysms exhibit high levels of USPIO uptake, indicative of extensive macrophage infiltration in the aneurysm wall. Future research should focus on the predictive value of USPIO uptake for growth and rupture of aneurysms.

MATERIALS AND METHODS. Percutaneous vertebroplasty was performed in 120 consecutive patients with 300 osteoporotic compression fractures. The cement volume injected was recorded. The cement leakage was evaluated using spinal radiography, MRI, and fluoroscopy during the procedure and CT after the procedure.

RESULTS. One hundred seven vertebrae contained intervertebral clefts, and 193 vertebrae had no clefts. The cement volume injected (± SD) was 4.0 ± 2.0 and 3.6 ± 1.6 mL into vertebrae with clefts and without clefts, respectively, with no statistically significant difference (p = 0.14). There was no statistically significant difference in the incidence of cement leakage between vertebrae with clefts (53 of 107) and those without clefts (78 of 193) (p = 0.13). Leakage occurred into the epidural veins (12 of 107), perivertebral soft tissues (7 of 107), disks (41 of 107), intervertebral foramen (1 of 107), and spinal canal (1 of 107) in fractures with clefts and into the epidural veins (47 of 193), perivertebral soft tissues (13 of 193), disks (25 of 193), paravertebral veins (5 of 193), large vein (2 of 193), lung (2 of 193), intervertebral foramen (1 of 193), and spinal canal (1 of 193) in fractures without clefts. Cement leakage into the epidural vein was significantly more frequent in vertebrae without clefts (p < 0.01). Disk leakage was significantly more frequent in vertebrae with clefts compared with those without clefts (p < 0.01).

CONCLUSION. There was no statistically significant difference in the incidence of cement leakage between vertebrae with clefts and without clefts. However, cement leakage into the epidural vein was significantly more frequent in vertebrae without clefts and disk leakage was significantly more frequent in vertebrae with clefts.

CONCLUSION. TACE using a single chemotherapeutic agent can be performed safely and effectively in HCC patients who previously underwent PVE. TACE after PVE allowed two of the patients to be downstaged so they could undergo surgical resection.

MATERIALS AND METHODS. For this study, 410 patients who underwent biopsy of a breast lesion were included: fine-needle aspiration biopsy, n = 95 patients; core biopsy, n = 84; local excision under local anesthesia, n = 72; vacuum-assisted breast biopsy, n = 100; and hookwire localization, n = 59. Information about patient age, place of residence, whether complications occurred, and type of lesion was collected.

RESULTS. Compliance was higher among women who had undergone vacuum-assisted breast biopsy than those who had undergone one of the other biopsy methods. The superiority (carryover effect) of vacuum-assisted breast biopsy persisted for 18 months after the biopsy procedure. Patient compliance for all of the other biopsy methods followed an M pattern, with the peaks corresponding to the follow-up mammography sessions. In patients who had undergone vacuum-assisted breast biopsy, a gradual decrease in compliance over time was observed. Older women were more compliant than younger women with follow-up recommendations regardless of biopsy method. A subanalysis of the vacuum-assisted breast biopsy group indicated that complications are associated with better compliance.

CONCLUSION. Women more often adhere to clinical recommendations for follow-up sessions comprising mammography. Patient age and whether biopsy complications occurred also seem to modify compliance. Further studies should assess whether superior compliance after vacuum-assisted breast biopsy persists in other settings, such as with stereotactic or ultrasound guidance, different numbers of cores, and procedures of various durations.

CONCLUSION. Overall, TR-MRA is a useful sequence for the assessment of ovarian vein reflux, which may aid the evaluation of pelvic congestion syndrome.

CONCLUSION. Adequate communication, strict workflow, and correct use of imaging protocols ensured optimal triage, diagnosis, and therapy of casualties while maintaining care for nonwar patients.

MATERIALS AND METHODS. Patient characteristics, radiology report content, additional imaging performed, final diagnosis, and diagnostic adequacy were recorded for pregnant patients consecutively referred for lung scintigraphy or pulmonary CTA according to physician preference. Measurements of pulmonary arterial enhancement were performed on all pulmonary CTA images of pregnant patients. Lung scintigraphy and pulmonary CTA studies deemed inadequate for diagnosis at the time of image acquisition were further assessed, and the cause of diagnostic inadequacy was determined. The relative contribution of the inferior vena cava to the right side of the heart was measured on nondiagnostic CTA images and compared with that on CTA images of age-matched nonpregnant women, who were the controls.

RESULTS. Twenty-eight pulmonary CTA examinations were performed on 25 pregnant patients, and 25 lung scintigraphic studies were performed on 25 pregnant patients. Lung scintigraphy was more frequently adequate for diagnosis than was pulmonary CTA (4% vs 35.7%) (p = 0.0058). Pulmonary CTA had a higher diagnostic inadequacy rate among pregnant than nonpregnant women (35.7% vs 2.1%) (p < 0.001). Transient interruption of contrast material by unopacified blood from the inferior vena cava was identified in eight of 10 nondiagnostic pulmonary CTA studies.

CONCLUSION. We found that lung scintigraphy was more reliable than pulmonary CTA in pregnant patients. Transient interruption of contrast material by unopacified blood from the inferior vena cava is a common finding at pulmonary CTA of pregnant patients.

CONCLUSION. In this article, we summarize the basic concepts, protocols, and techniques that we use for CT-guided core biopsy of lung lesions to assist radiologists in obtaining diagnostic specimens while reducing preventable complications.

CONCLUSION. With publication of the National CT Colonography Trial and the endorsement of CTC for screening by a multisociety task force that included the American Cancer Society, American College of Radiology, and U.S. Multisociety Task Force on Colorectal Cancer, the clinical validation of CTC has been completed, and CTC is now ready for widespread clinical application. Radiologists must be skilled in CTC and knowledgeable about colorectal cancer screening issues.

Methods: Clinical validation trials in both the U.S. and Europe are reviewed. Key technical aspects of the CTC examination are emphasized, including low-dose protocols, proper insufflation, and bowel preparation. Important issues of implementation are discussed, including training and certification, definition of target lesion, reporting of colonic and extracolonic findings, quality metrics, reimbursement, and cost-effectiveness.

Results: Successful validation trials in screening cohorts both in the U.S. with ACRIN® and in Germany demonstrated sensitivity of 90% or greater for patients with polyps 10 mm or greater. Proper technique is critical, including low-dose techniques in screening cohorts with upper limits in CTDI_vol of 12.5 mGy per exam. Training of new readers includes the requirement of interactive workstation training with 2-D and 3-D image display techniques. The target lesion is defined as a polyp 6 mm or greater, consistent with the American Cancer Society joint guidelines. Five quality metrics have been defined for CTC, with pilot data entered. Although the CMS national noncoverage decision in May 2009 was a disappointment, multiple third-party payers are reimbursing for screening CTC. Cost-effective modeling has shown CTC to be a dominant strategy, including in a Medicare cohort.

Conclusion: Supported by third party payer reimbursement for screening, CTC will continue to further transition into community practice and can provide an important adjunctive examination for colorectal screening.

CONCLUSION. Epiploic appendagitis is self-limited and spontaneously resolves without surgery within 5–7 days. Therefore, it is imperative for radiologists to be familiar with this entity.

MATERIALS AND METHODS. A retrospective review of 48 patients (male–female ratio, 22:26) with suspected gastrointestinal bleeding (first-episode gastrointestinal bleed, n = 19; obscure gastrointestinal bleed, n = 29) who underwent triphasic CT enterography was performed. All patients had endoscopic, pathologic, or other imaging confirmation within 3 months of triphasic CT enterography. The sensitivity and specificity of triphasic CT enterography were calculated using pathology, endoscopy, or other imaging confirmation as the reference standard. Results were retrospectively reviewed to determine the cause of missed findings at triphasic CT enterography.

RESULTS. The overall sensitivity and specificity of triphasic CT enterography for detecting gastrointestinal bleeding was 33% (7/21) and 89% (24/27), respectively. Sensitivity and specificity were higher in first-episode gastrointestinal bleed cases (42% and 100%, respectively) than in obscure gastrointestinal bleed cases (22% and 85%). In the subset of patients undergoing capsule endoscopy (n = 17), only triphasic CT enterography identified two of three bleeding sources. Triphasic CT enterography did not identify six ulcers, four vascular malformations, two hemorrhoids, a duodenal mass, and a bleeding colonic diverticulum. The missed findings at triphasic CT enterography were attributed to being CT occult (n = 9), perception errors (n = 4), and technical errors (n = 1). If perception errors are excluded, the sensitivity of triphasic CT enterography increases to 52% (11/21).

CONCLUSION. Triphasic CT enterography can be a useful and complementary test in the evaluation of clinically stable patients with suspected gastrointestinal bleeding by identifying the bleeding source in one third to one half of patients. Because of the potential for perception errors, radiologists should familiarize themselves with the appearance of bleeding sources at CT enterography.

MATERIALS AND METHODS. The images of 43 patients with liver disease who underwent 1.5-T MRI of the liver that included a multiecho T2^*-weighted sequence who also underwent concomitant liver biopsy or liver transplantation were assessed. Two independent observers measured hepatic T2^* by placing regions of interest in the hepatic parenchyma. Hepatic T2^* values were compared between patients stratified by hepatic iron grade and were correlated with histopathologic iron grade. Receiver operating characteristics analysis was performed to assess the accuracy of images obtained with the hepatic T2^*-weighted sequence in the diagnosis of iron deposition.

RESULTS. Patients with iron deposition had shorter hepatic T2^* values than did patients without iron deposition (mean T2^*, 17.7 vs 32.3 milliseconds with pooled data from both observers; p < 0.0001). Patients with iron grade 3 or greater had shorter T2^* values than those with iron grade 2 or less (10.1 vs 20.8 milliseconds; p < 0.0001). There was a strong negative correlation between hepatic T2^* and histopathologic iron grade (r = –0.849; p < 0.0001). For the prediction of iron grades 1 or greater and 3 or greater, area under the curve, sensitivity, and specificity were 0.968–0.982, 90.5–100%, and 100–97.3% at T2^* cutoffs of less than 24 and less than 14 milliseconds, respectively.

CONCLUSION. Hepatic iron overload in patients with liver disease can be assessed rapidly and accurately with MRI performed with a breath-hold T2^*-weighted sequence.

SUBJECTS AND METHODS. One hundred thirty-one consecutive patients (80 women, 51 men; age range, 18–87 years; mean age, 37 years) suspected of having appendicitis were randomly assigned to either ingest or not ingest iodinated contrast material. Thereafter, all patients underwent IV unenhanced and enhanced abdominopelvic MDCT with a 4 x 2.5 mm collimation at 120 kVp and 100 mAs_eff. Dose reduction corresponding to 30 mAs_eff was simulated. Two radiologists independently read scans during separate sessions, assessed appendix visualization, and proposed a diagnosis (i.e., appendicitis or an alternative diagnosis). The final diagnosis was based on either surgical findings or clinical follow-up. Data were analyzed by factorial analysis of multiple correspondences followed by an ascending hierarchic classification method.

RESULTS. Factorial analysis and ascending hierarchic classification revealed that, in terms of diagnostic correctness, reader influence predominated over the influence of IV and oral contrast media use and radiation dose but that correctness was also influenced by the patient's sex (p = 0.048) and was lower in cases of alternative diseases (p < 0.001). Visualization of the appendix depended predominantly on the reader rather than on the use of IV, oral, or oral and IV contrast agents or on radiation dose.

CONCLUSION. Diagnostic correctness is much more influenced by the reader than by the use of contrast medium (oral, IV, or both) or of simulated low-radiation-dose technique.

MATERIALS AND METHODS. We conducted a randomized trial of a convenience sample of adult patients presenting to an urban academic emergency department with acute nontraumatic abdominal pain and clinical suspicion of appendicitis, diverticulitis, or small-bowel obstruction. Patients were enrolled between 8 am and 11 pm when research assistants were present. Consenting subjects were randomized into one of two groups: Group 1 subjects underwent 64-MDCT performed with oral and IV contrast media and group 2 subjects underwent 64-MDCT performed solely with IV contrast material. Three expert radiologists independently reviewed the CT examinations, evaluating for the presence of appendicitis. Each radiologist interpreted 202 examinations, ensuring that each examination was interpreted by two radiologists. Individual reader performance and a combined interpretation performance of the two readers assigned to each case were calculated. In cases of disagreement, the third reader was asked to deliver a tiebreaker interpretation to be used to calculate the combined reader performance. Final outcome was based on operative, clinical, and follow-up data. We compared radiologic diagnoses with clinical outcomes to calculate the diagnostic accuracy of CT in both groups.

RESULTS. Of the 303 patients enrolled, 151 patients (50%) were randomized to group 1 and the remaining 152 (50%) were randomized to group 2. The combined reader performance for the diagnosis of appendicitis in group 1 was a sensitivity of 100% (95% CI, 76.8–100%) and specificity of 97.1% (95% CI, 92.7–99.2%). The performance in group 2 was a sensitivity of 100% (73.5–100%) and specificity of 97.1% (92.9–99.2%).

CONCLUSION. Patients presenting with nontraumatic abdominal pain imaged using 64-MDCT with isotropic reformations had similar characteristics for the diagnosis of appendicitis when IV contrast material alone was used and when oral and IV contrast media were used.

MATERIALS AND METHODS. We retrospectively reviewed CTC and OC reports from patients who had undergone both procedures as part of an established protocol. The anus-to-cecum measurement recorded on a single proprietary CTC workstation was compared with the OC cecal length for each patient. Likewise, anus-to-polyp distances were compared as measured by the radiologist and endoscopist.

RESULTS. Three hundred thirty-eight patients and 437 polyps were identified with complete data from both CTC and same-day OC. The average anus-to-cecum distance measured at CTC was 189 cm (range, 75–257 cm) and at OC, 108 cm (range, 65–150 cm). For polyps proximal to the splenic flexure (n = 145), the CTC anus-to-polyp measurement was on average 1.7 times that measured at OC. For left-sided polyps (n = 292), the CTC measurement was, on average, within 12 cm or 1.3 times that of the OC anus-to-polyp measurement. All the differences between CTC and OC measurements of cecal length and polyp distances were found to be statistically significant using a paired Student's t test of means (p < 0.001).

CONCLUSION. Anus-to-cecum and anus-to-polyp distances are disparate but comparable using a conversion factor of 0.57 for the CTC anus-to-cecum measurement and 0.59 for right-sided CTC anus-to-polyp or 0.78 for left-sided CTC anus-to-polyp measurements. These anus-to-polyp conversion factors could potentially augment current CTC guidelines for accurate and precise polyp localization and removal at endoscopy.

MATERIALS AND METHODS. The polyp population consisted of 152 polyps in 121 patients. CTC polyp findings were verified by same-day segmentally-unblinded OC. Each polyp's normalized distance along the colon centerline was computed by dividing its distance from the anorectal junction measured along the colon centerline by the length of the colon at CTC. The predicted polyp location at OC was computed by multiplying the normalized distance along the colon centerline by the colon length at OC (i.e., the distance to the cecum as determined at full colonoscope insertion). The differences between the true and predicted polyp locations at OC were compared using paired Student's t tests, linear regression, prediction interval assessment, and Bland-Altman analyses.

RESULTS. The differences between the true and predicted polyp locations at OC using the supine and prone CTC-normalized distances along the colon centerline were 2.2 ± 10.5 cm (mean ± SD; n = 136) and 1.5 ± 10.5 cm (n = 135), respectively. The predicted location was within 10 cm of its true location for 71.3% (97/136) to 74.8% (101/135) of polyps and within 20 cm of its true location for 93.3% (126/135) to 93.4% (127/136) of polyps.

CONCLUSION. By computing the normalized distance along the colon centerline of a polyp found at CTC, the location of a polyp at OC can be predicted to within 10 cm (i.e., 1 colonoscope mark) for the majority of polyps.

MATERIALS AND METHODS. At three medical centers, 1,186 patients underwent oral contrast-enhanced CTC and same-day optical colonoscopy (OC) with segment unblinding for colorectal cancer screening. One hundred eighty-five of the patients had at least one hyperplastic or adenomatous polyp 6–10 mm visible at both OC and CTC, where size was determined by a calibrated guidewire at OC. To assess flatness, the heights of the polyps at CTC were measured using a validated automated software program. The heights and height-to-width ratios of the hyperplastic polyps were compared with those of the adenomatous polyps using a Student's t test (two-tailed, unpaired, unequal variance).

RESULTS. There were 176 adenomatous and 83 hyperplastic polyps visible at segment-unblinded OC. The fraction of these polyps that were measurable at CTC using the automated software was not significantly different for adenomatous versus hyperplastic polyps (158/176 [89.8%] vs 73/87 [83.9%], respectively; p = 0.2). The average height-to-width ratios using automated width measurements were 15% less for hyperplastic polyps: 0.39 ± 0.20 (n = 158) and 0.33 ± 0.19 (n = 73) for adenomatous and hyperplastic polyps, respectively (p = 0.03). When polyps of comparable OC size or CTC width were considered, the heights of hyperplastic polyps were up to 27% less than those of adenomatous polyps.

CONCLUSION. For 6–10 mm polyps of a given size as determined by OC or a given width at CTC, hyperplastic polyps tend to be flatter (i.e., have lower height) compared with adenomatous polyps.

MATERIALS AND METHODS. The CT images of 70 patients (33 men and 37 women; mean age, 48.5 years) who underwent ventriculoperitoneal shunt placement and abdominopelvic CT because of shunt-related abdominal symptoms were reviewed retrospectively. CT images were analyzed with regard to the location of the shunting catheter tip; site, size, wall, and septa of localized fluid collection; peritoneal thickening; omentomesentery infiltration; abscess; bowel perforation; abdominal wall infiltration; and thickening of the catheter track wall.

RESULTS. The mean period between the last ventriculoperitoneal shunting operation and CT was 11 months (range, 1 week to 115 months), and the mean number of ventriculoperitoneal shunting operations undergone was 1.4 (range, 1–6). A total of 76 ventriculoperitoneal shunting catheters were introduced in 70 patients: 64 patients had a unilateral catheter inserted and six patients had bilateral catheters inserted. Sixteen patients (22.9%) were pathologically diagnosed with ventriculoperitoneal shunt–related complications: 11 cases (15.7%) of shunt infection, six cases (8.6%) of CSF pseudocyst, four cases (5.7%) of abdominal abscess, three cases (4.3%) of infected fluid collection, and one case (1.4%) of bowel perforation. Microorganisms were cultured from the tip of the shunting catheter or peritoneal fluid in 11 patients (15.7%).

CONCLUSION. On abdominopelvic CT, various intraabdominal complications secondary to ventriculoperitoneal shunt were shown, of which, shunt infection was the most common, followed by CSF pseudocyst, abscess, and infected fluid collection.

SUBJECTS AND METHODS. Dynamic gadoxetic acid–enhanced MRI of the pancreas, spleen, kidney, liver, and abdominal aorta was performed on 50 patients; dynamic gadobutrol–enhanced MRI was performed on a control group of 50 patients; and the images were compared. Dynamic imaging with a T1-weighted volumetric interpolated breath-hold examination gradient-echo sequence (TR/TE, 3.35/1.35; flip angle, 12°) was performed before and 20 (arterial phase), 55 (portal venous phase), and 90 (hepatic venous phase) seconds after bolus injection of gadoxetic acid (0.25 mmol/mL) or gadobutrol (1.0 mmol/mL). Signal-to-noise ratios and enhancement indexes were calculated for each organ and time.

RESULTS. All MR images in both groups were of diagnostic quality. During the early dynamic phases, significantly lower mean enhancement indexes were found in the gadoxetic acid group than in the gadobutrol group in the pancreas (portal venous phase, 0.66, 1.39, p ≤ 0.001; hepatic venous phase, 0.51, 1.36, p ≤ 0.001), spleen (portal venous phase, 1.54, 2.41, p ≤ 0.001; hepatic venous phase, 1.19, 2.23, p ≤ 0.001), renal cortex (portal venous phase, 1.76, 2.63, p ≤ 0.001; hepatic venous phase, 1.60, 2.63, p ≤ 0.001), and liver (portal venous phase, 0.76, 0.94, p = 0.016; hepatic venous phase, 0.76, 1.04, p ≤ 0.001). In the abdominal aorta, the mean enhancement index was greater after bolus injection of gadoxetic acid (arterial phase, 3.33, 2.24, p ≤ 0.005).

CONCLUSION. Early dynamic MRI of the upper abdominal organs, especially the spleen, pancreas, and kidney, benefits from the higher gadolinium concentration of gadobutrol than in the organ-specific contrast agent gadoxetic acid. Higher protein binding resulting in increased relaxivity of gadoxetic acid compensates for the low gadolinium concentration in the abdominal aorta.

MATERIALS AND METHODS. Using the Medicare anonymized 5% of beneficiaries complete claims file for 2005, we studied the use of relevant CT and V/Q scanning in the evaluation of patients with a diagnosis of PE and of patients with symptoms that might have been due to PE (chest pain, syncope, difficulty breathing). In 2008, we surveyed the radiology departments of Pennsylvania hospitals about the use of CT and V/Q scanning for PE, service availability hours, and what equipment was used.

RESULTS. In all data, we found that CT was used approximately six times as frequently as V/Q scanning. In the Medicare data, only small differences in frequency of use of CT and V/Q scanning were associated with hospital characteristics. Academic hospitals did not differ in a major way from other hospitals, nor did small or rural hospitals. In the survey, 97% of radiology departments reported that CT was available for evaluation of PE 24 hours a day 7 days a week. Ninety-three percent of departments reported V/Q scanning was available at some times; 77% reported V/Q available at all times.

CONCLUSION. CT was a fully disseminated and dominant technique for the diagnosis of PE by 2005, and it was readily available at small and rural hospitals. The lack of availability of off-hours V/Q scanning at a substantial fraction of hospitals may be a problem for patients with contraindications to CT.

MATERIALS AND METHODS. We analyzed non–individually identified data from the American College of Radiology's 2007 Survey of Member Radiologists and its 2003 Survey of Radiologists. Responses were weighted to be nationally representative of individual radiologists and radiology practices. We present descriptive statistics and multivariable regression analysis results on the use of EOTSs in 2007 and comparisons with 2003.

RESULTS. Overall, 44% of all radiology practices in the United States reported using EOTSs in 2007. These practices included 45% of all U.S. radiologists. Out-of-practice teleradiology had been used by 15% of practices in 2003. Regression analysis indicates that, other practice characteristics being equal, in 2007, primarily academic practices had lower odds of using EOTSs than private radiology practices. Also, large practices (≥ 30 radiologists) had lower odds of using EOTSs than practices with 15–29 radiologists. Small practices (1–10 radiologists) had high odds, but nonmetropolitan practices did not. There were no significant differences by geographic region of the United States.

CONCLUSION. Use of EOTSs was widespread by 2007, and it had been increasing rapidly in the preceding few years. Patterns of use were generally as might be expected except that nonmetropolitan practices did not have high odds of using EOTSs.

MATERIALS AND METHODS. Thirty voxelized models generated from images of patients were extended to include lung contours and were used to represent a cohort of women of various sizes. Monte Carlo simulation–based virtual MDCT scanners had been used in a previous study to estimate breast dose from simulations of a fixed-tube-current and a tube current–modulated chest CT examinations of each patient model. In this study, lung doses were estimated for each simulated examination, and the percentage organ dose reduction attributed to tube current modulation was correlated with patient size for both glandular breast and lung tissues.

RESULTS. The average radiation dose to lung tissue from a chest CT scan obtained with fixed tube current was 23 mGy. The use of tube current modulation reduced the lung dose an average of 16%. Reductions in organ dose (up to 56% for lung) due to tube current modulation were more substantial among smaller patients than larger. For some larger patients, use of tube current modulation for chest CT resulted in an increase in organ dose to the lung as high as 33%. For chest CT, lung dose and breast dose estimates had similar correlations with patient size. On average the two organs receive approximately the same dose effects from tube current modulation.

CONCLUSION. The dose to radiosensitive organs during fixed-tube-current and tube current–modulated chest CT can be estimated on the basis of patient size. Organ dose generally decreases with the use of tube current–modulated acquisition, but patient size can directly affect the dose reduction achieved.

MATERIALS AND METHODS. MR images of 63 joints in 62 patients with clinically or pathologically proven RA (36 joints in 35 patients) or tuberculous arthritis (27 joints in 27 patients) were evaluated retrospectively with regard to pattern and degree of synovial thickening, size of bone erosions, rim enhancement at bone erosions, degree of bone marrow and periarticular soft-tissue edema, and presence and number of extraarticular cystic masses. MRI findings were compared between RA and tuberculous arthritis by statistical analysis using kappa statistics, the Mann-Whitney U test, linear-by-linear association, and the chi-square test.

RESULTS. Nonuniform and greater degree of synovial thickening was more frequent in RA (p < 0.01); the thicker the synovial membrane, the greater the likelihood of RA (p < 0.01). Bone erosions of tuberculous arthritis were larger (p < 0.01), and the likelihood of tuberculous arthritis increased proportionally to the increment of size of the bone erosions (p < 0.01). Rim enhancement at bone erosion was more frequent in tuberculous arthritis (p < 0.01). Extraarticular cystic masses were more frequently seen and more numerous in tuberculous arthritis (p < 0.01).

CONCLUSION. Uniform synovial thickening, large size of bone erosion, rim enhancement at site of bone erosion, and extraarticular cystic masses were more frequent and more numerous in tuberculous arthritis. MRI may be helpful in the differentiation between RA and tuberculous arthritis.

MATERIALS AND METHODS. A total of 782 knee injuries were imaged with MDCT at a level 1 trauma center over 86 months. A total of 592 knees had a tibial plateau fracture; 381 of these fractures were managed surgically, and postoperative MDCT was performed on 36 of these knees (9%). At postoperative image analysis, an orthopedic surgeon evaluated reduction as good or suboptimal using the first postoperative radiographs. Fracture healing was determined as complete ossification, partial ossification, or nonunion on MDCT images acquired later in follow-up. The MDCT findings were compared with the radiographic findings to assess the usefulness and clinical importance of MDCT.

RESULTS. The main indications for MDCT were assessment and follow-up of the joint articular surface and evaluation of fracture healing. Orthopedic hardware caused no diagnostic problems at MDCT. Postoperative MDCT revealed additional clinically important information on 29 patients (81%), and 14 patients (39%) underwent reoperation.

CONCLUSION. Postoperative MDCT of tibial plateau fractures is performed infrequently, even in a large trauma center. When it is performed, however, because of suspicion of increasing articular step-off or fracture nonunion, postoperative MDCT reveals clinically significant information in most cases.

MATERIALS AND METHODS. Sagittal 1.5-T and 3-T MR images of 100 consecutively registered patients with symptoms were analyzed, and the Insall-Salvati index, modified Insall-Salvati index, patellotrochlear index, and patellophyseal index (ratio of the height of patella above the physeal line to the length of the patellar articular cartilage) were calculated. The upper and lower limits of 2 SDs were used to define patella alta and baja, and the correlation coefficient curves were plotted to compare techniques. The indexes in normal knees were compared with those in knees with severe chondral defects.

RESULTS. The mean patellotrochlear index was 0.49 ± 0.15 (SD) (range, 0–0.88). On the basis of calculation of 2 SDs, patella alta was determined to have a patellotrochlear index less than 0.18 and patella baja, an index greater than 0.80. Weak correlation was found between the measured patellotrochlear index and Insall-Salvati index (r = –0.224) and between the patellotrochlear index and modified Insall-Salvati index (r = –0.073). A strong correlation was found between the patellotrochlear index and patellophyseal index (r = –0.813). A statistically significant (p < 0.05) difference in the modified Insall-Salvati index and patellophyseal index was found between knees with normal and those with severe cartilage defects.

CONCLUSION. Our results indicate that the commonly used Insall-Salvati and modified Insall-Salvati indexes do not correlate with patellotrochlear articular cartilage congruence. We did find an association between the modified Insall-Salvati and patellophyseal indexes and the presence of severe chondral defects.

MATERIALS AND METHODS. T1-weighted, T2-weighted fat-saturated, and proton density–weighted fat-saturated spin-echo sequences were acquired in 15 cadaveric shoulders. Biceps tendon diameter (normal, flattened, thickened, and partially or completely torn) and signal intensity (compared with bone, fat, muscle, and joint fluid) were graded by two readers independently and in a blinded fashion. The distance of tendon abnormalities from the attachment at the glenoid were noted in millimeters. MRI findings were related to gross anatomic and histologic findings.

RESULTS. On the basis of gross anatomy, there were six normal, five flattened, two thickened, and two partially torn tendons. Reader 1 graded nine diameter changes correctly, missed two, and incorrectly graded four. The corresponding values for reader 2 were seven, one, and five, respectively, with = 0.75. Histology showed mucoid degeneration (n = 13), lipoid degeneration (n = 7), and fatty infiltration (n = 6). At least one type of abnormality was found in each single tendon. Mucoid degeneration was hyperintense compared with fatty infiltration on T2-weighted fat-saturated images and hyperintense compared with magic-angle artifacts on proton density–weighted fat-saturated images. MRI-based localization of degeneration agreed well with histologic findings.

CONCLUSION. Diameter changes are specific but not sensitive in diagnosing tendinopathy of the biceps tendon. Increased tendon signal is most typical for mucoid degeneration but should be used with care as a sign of tendon degeneration.

CONCLUSION. MDCT arthrography is an excellent tool for imaging patients with clinically suspected ulnocarpal impaction syndrome, allowing identification of the spectrum of findings and proper classification according to Palmer class II (degenerative) lesions, which directly affects management.

MATERIALS AND METHODS. Echo-planar diffusion-weighted MR images of 27 patients with glioblastoma multiforme, five patients with low-grade astrocytoma, five patients with gliomatosis cerebri, and nine patients with primary lymphoma infiltrating the corpus callosum were reviewed retrospectively. Regions of interest were drawn on apparent diffusion coefficient (ADC) maps inside the callosal tumor. ADCs were normalized by calculation of the ratio between the ADC of the tumor and the ADC of an uninvolved region of corpus callosum.

RESULTS. The mean ADC of glioblastoma multiforme was 1.13 ± 0.31 (SD) x 10^–3 mm²/s, and the mean tumor to corpus callosum ADC ratio was 1.51 ± 0.46; of low-grade astrocytoma, 1.14 ± 0.23 x 10^–3 mm²/s and 1.54 ± 0.28; gliomatosis cerebri, 1.01 ± 0.20 x 10^–3 mm²/s and 1.31 ± 0.36; and lymphoma, 0.71 ± 0.13 x 10^–3 mm²/s and 0.93 ± 0.19. The difference between the mean tumor to corpus callosum ADC ratio of lymphoma and that of all grades of astrocytoma (1.48 ± 0.43) was statistically significant (p < 0.001). The optimal ADC threshold for discriminating astrocytic tumor and lymphoma was 0.90 x 10^–3 mm²/s (sensitivity, 84%; specificity, 89%). The optimal threshold for tumor to corpus callosum ADC ratio was 1.22 (sensitivity, 73%; specificity, 100%).

CONCLUSION. The water diffusivity and the ADC ratio of the tumor to normal-appearing corpus callosum of astrocytic tumor differ significantly from those of lymphoma infiltrating the corpus callosum, allowing reliable differentiation of the two types of tumor.

MATERIALS AND METHODS. One hundred seventy-eight healthy adult patients between 20 and 40 years old and 112 pediatric patients between 2 months and 10 years old underwent cervical spine MDCT with multiplanar reconstructions. The width of the joint space between the lateral mass of C1 and the lateral mass of C2 was measured at three equidistant points on both the left and right sides on coronal reformatted images to determine the atlantoaxial interval. The distance between the lateral surface of the dens and the medial surface of the lateral mass of C1 was measured in the coronal plane to determine the lateral ADI bilaterally.

RESULTS. The upper limit of the normal range of values for the atlantoaxial interval in adults was 3.34 mm on the right and 3.39 mm on the left. The upper limit of normal for the lateral ADI was 4.67 mm on the right and 5.6 mm on the left. More than 95% of the pediatric population was found to have an atlantoaxial interval of less than 3.9 mm on either side, a right lateral ADI of less than 7.4 mm, and a left lateral ADI of less than 8.0 mm.

CONCLUSION. We propose that the obtained normal values be considered as the upper limits of the normal range for the atlantoaxial interval in adult and pediatric populations on MDCT images.

CONCLUSION. MRI may show proximal femoral abnormalities before radiography in the setting of Legg-Calvé-Perthes disease, allowing appropriate diagnosis and prompt treatment. MRI can also assess for revascularization, healing, and multiple complications.

MATERIALS AND METHODS. Study group patients (n = 43) underwent at least two two-view abdominal radiographic series within 48 hours of surgical intervention for suspected NEC complications. Control group patients (n = 86) were patients with suspected NEC who did not undergo surgery for suspected NEC complications. DAAS scores were assigned by two pediatric radiologists with 20 and 6 years' experience.

RESULTS. The initial radiographs of 26 of 43 (60.5%) patients in the study group showed fixed bowel loops (10/43, 23.3%), highly probable or definite pneumatosis (9/43, 20.9%), or portal venous gas (7/43, 16.3%). These findings had progressed to pneumoperitoneum on the follow-up series in 20 (46.5%) study group patients. Among the control group, three patients (3.5%) had highly probable or definite pneumatosis, and none had fixed bowel loops, portal venous gas, or pneumoperitoneum. Patients with higher DAAS scores were more likely to undergo surgical intervention than patients with lower scores (odds ratio, 1.69; 95% CI, 1.40–2.03). A receiver operating characteristic curve analysis showed good overall performance (c statistic = 0.83) for predicting eventual surgical intervention in the study group with higher DAAS scores.

CONCLUSION. The DAAS provides a standardized 10-point radiographic scale that increases with disease severity when using need for surgical intervention as a surrogate for severe NEC. For every 1-point increase in the DAAS score, patients were statistically significantly more likely to have severe disease as measured by need for surgical intervention.

MATERIALS AND METHODS. A search of the hospital information system was conducted to identify the cases of pediatric patients with clinically suspected or known interstitial lung disease who underwent 16-MDCT of the chest with both volumetric and axial HRCT acquisitions (both 1.25-mm slice thickness) from March 2005 to July 2008. Two pediatric radiologists reviewed the images for the presence of motion artifacts at three anatomic levels (upper, middle, and lower lung zones). Motion artifacts were given numerical grades representing no artifact to severe artifact, and the paired Student's t test was used to compare the scores for the two acquisition methods. A total motion score for each acquisition was calculated by summing the scores for each of the three lung zones, and the scores for the two imaging methods were compared. Correlation between degree of motion artifact and age was evaluated. Effective radiation doses were estimated for volumetric and axial CT acquisitions.

RESULTS. The study population consisted of 54 children (28 boys, 26 girls; mean age, 11.7 ± 3.8 years; range, 5–18 years; eight inpatients, 46 outpatients) who underwent a total of 54 MDCT chest studies with volumetric and axial HRCT acquisitions. Motion artifact scores were higher for axial than for volumetric HRCT images of the upper (1.2 vs 1.0), middle (1.6 vs 1.2), and lower (2.2 vs 1.5) lung zones (p < 0.05 at each level). The total motion score of the axial HRCT images (mean, 5; range, 1–9) was higher than that of the volumetric HRCT images (mean, 3.6; range, 1–8) (p < 0.05). Younger age correlated with higher motion artifact score on axial HRCT images (r = –0.36, p < 0.01), whereas no correlation was found between age and motion artifact score on volumetric HRCT images (r = –0.12, p = 0.38). The effective radiation doses were 0.57 mSv for axial HRCT acquisition and 7.6 mSv for volumetric acquisition. The addition of axial acquisition increased the total radiation dose of the MDCT examination 7.1%.

CONCLUSION. At CT of pediatric patients, reconstructed HRCT images from volumetric MDCT acquisition have significantly less motion artifact than images obtained with traditional axial acquisition.

CONCLUSION. Although inflammatory myofibroblastic tumors occur in various sites and the imaging characteristics are variable, tumors showed different imaging patterns that were dependent on the site at which the tumor had originated.

CONCLUSION. Familiarity with the spectrum of imaging findings in AVFs is essential for the accurate interpretation of images and facilitates diagnosis and therapeutic management. Radiologists can play a critical role in the diagnosis and treatment of AVFs. Digital angiography is helpful in elaborating a vascular map for endovascular treatment.

MATERIALS AND METHODS. Among 653 patients with symptoms of ischemia of the posterior circulation, 247 subjects with normal arteries or stenosis of the proximal vertebral artery confirmed with digital subtraction angiography were included in the study. Peak systolic velocity at the origin of the vertebral artery (PSV_origin) and in intervertebral segments of the vertebral artery (PSV_IV), end-diastolic velocity at the origin and in the intervertebral segments of the vertebral artery, and the diameter of the vascular lumen were measured. The cutoff values for the diagnosis of < 50%, 50–69%, and 70–99% stenosis were determined with receiver operating characteristics analysis.

RESULTS. The optimal cutoff values of hemodynamic parameters in evaluation of stenosis of the proximal vertebral artery for < 50% stenosis were PSV_origin ≥ 85 cm/s, PSV_origin / PSV_IV ≥ 1.3, and end-diastolic velocity at the origin ≥ 27 cm/s; for 50–69% stenosis were PSV_origin ≥ 140 cm/s, PSV_origin / PSV_IV ≥ 2.1, and end-diastolic velocity at the origin ≥ 35 cm/s; and for 70–99% stenosis were PSV_origin ≥ 210 cm/s, PSV_origin / PSV_IV ≥ 4.0, and end-diastolic velocity at the origin ≥ 50 cm/s. PSV_origin was the most useful hemodynamic parameter, having accuracy of 94.5%, 96.2%, and 88.7% for the diagnosis of < 50%, 50–69%, and 70–99% stenosis.

CONCLUSION. Color Doppler imaging is a reliable method for evaluation of vertebral artery stenosis. The results derived from this study can be used as a reference for establishing sonographic criteria for proximal vertebral artery stenosis.

CONCLUSION. MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and guide additional surgical or endovascular interventions.

CONCLUSION. Abnormal waveforms provide information for compression or obstruction of the proximal venous system in the thorax, abdomen, and pelvis. When these waveforms are abnormal, previous imaging should be reviewed or additional imaging performed to discover the cause.

MATERIALS AND METHODS. Between November 1990 and January 2008, 14 patients with fistulas between the esophagus and pulmonary parenchyma were treated with covered expandable metallic esophageal stents. The fistulas were caused by esophageal (n = 9) or bronchogenic (n = 5) carcinomas. At the time of stent placement, all patients had aspiration pneumonia and 11 had lung abscesses (79%). Technical and clinical success, fistula reopening, complications, and survival rates were evaluated.

RESULTS. Stent placement was technically successful in all cases, and there were no immediate procedural complications. Complete fistula sealing resulting in resolution of aspiration symptoms (i.e., clinical success) occurred in 12 patients (86%). During follow-up (mean survival, 100.9 ± 79.9 days; median survival, 65.5 days; range, 16–275 days), the fistula reopened in two of 12 clinical success patients. One patient (7%) experienced complications resulting from dyspnea due to tracheal compression by the esophageal stent. Although 13 patients died of aspiration pneumonia and the remaining patient died of cancer bleeding, none of the mortalities was related to the stent placement procedure.

CONCLUSION. The use of covered expandable metallic stents appears to be safe and feasible for the palliative treatment of malignant esophagopulmonary fistulas.

CONCLUSION. Diagnostic biopsy specimens can be obtained safely using simultaneous IV contrast-enhanced CT guidance during difficult biopsies of unresectable tumors encasing the celiac, superior mesenteric, or left renal arteries.

CONCLUSION. The anteromedial limb of the ascending branch was present in 14 patients and accessory gastric branches were noted in 11 patients. The use of angiography and C-arm CT of the LIPA showed 26 tumor feeders in 23 patients. The feeders were seen in the anteromedial limb (n = 12), lateral limb (n = 9), anterior limb (n = 3), and descending branch (n = 2). The anteromedial limb of the ascending branch is a common tumor feeder of the LIPA and can supply HCCs located in the right liver dome. Gastric staining is also frequently depicted on LIPA angiography and should not be confused with tumor staining.

MATERIALS AND METHODS. Ninety-six patients underwent breast DCE-MRI. The type of DCE-MRI kinetic curve was assessed qualitatively by three radiologists on two occasions. For quantitative assessment, the slope of the washout curve was calculated. Kappa statistics were used to determine inter- and intraobserver agreement for the qualitative method. Matched sample tables, the McNemar test, and receiver operating characteristic (ROC) curve statistics were used to compare quantitative versus qualitative methods for establishing or excluding malignancy.

RESULTS. Seventy-eight lesions (77.2%) were malignant and 23 (22.8%) were benign. For the qualitative assessment, the intra- and interobserver agreement was good ( = 0.76–0.88), with an area under the ROC curve (AUC) of 0.73–0.77. For the quantitative method, the highest AUC was 0.87, reflecting significantly higher diagnostic accuracies compared with qualitative assessment (p < 0.01 for the difference between the two methods).

CONCLUSION. Quantitative assessment of the type of contrast enhancement kinetic curve on breast DCE-MRI resulted in significantly higher diagnostic performance for establishing or excluding malignancy compared with assessment based on the standard qualitative method.

CONCLUSION. Hepatocellular carcinoma lesions exhibit characteristic but unusual apparent diffusion coefficient (ADC) changes during sorafenib therapy, consisting of early decrease in ADC after therapy onset followed by a reincrease. The ADC changes seem to reflect the underlying pathophysiologic mechanisms in tumor necrosis (most probably hemorrhagic) induced by this novel targeted agent early after therapy onset and may indicate tumor reactivation in the later follow-up period.

CONCLUSION. Colloid carcinomas of the pancreas appear as masses with lobulating contours, indiscrete margins, and hyperintensity on T2-weighted images (n = 8). In addition, all patients who underwent dynamic studies (n = 4) showed peripheral and internal spongelike or meshlike progressive delayed contrast enhancement.

MATERIALS AND METHODS. Over a 4-year period, 36 patients with symptomatic pericardial effusion were treated with CT-guided percutaneous placement of an indwelling pericardial catheter, for a total of 39 CT-guided tube pericardiostomy procedures. Thirty-three patients (92%) had undergone major cardiothoracic surgery, and three patients (8%) had undergone minimally invasive procedures. The medical records were retrospectively reviewed for clinical presentation, surgical history, imaging studies performed, procedural details, fluid characterization, and outcome. Charge comparison was performed with the American Medical Association Current Procedural Terminology codes and information acquired from the billing department at our facility.

RESULTS. All 39 CT-guided tube pericardiostomy procedures were performed successfully without clinically significant complications. After 33 of the 39 procedures (85%), symptoms did not recur after the catheter was removed. Three of 36 patients (8%) had a recurrence of pericardial effusion. Comparison of procedure charges showed an 89% saving over intraoperative pericardial window procedures and no significant difference compared with ultrasound-guided tube pericardiostomy. Eight patients (21% of procedures) needed pleural drainage procedures, all of which were performed in the CT suite immediately after the tube pericardiostomy procedure.

CONCLUSION. CT-guided tube pericardiostomy is a safe and effective alternative to surgical drainage in the care of patients with clinically significant pericardial effusion after cardiothoracic surgery and has the additional benefit of substantial cost savings.

SUBJECTS AND METHODS. Thirty-seven patients underwent black-blood fat-suppressed T2-weighted, rest perfusion, and late gadolinium-enhanced MRI 5.4 ± 3.1 days after the onset of acute myocardial infarction. On T2-weighted MR images, the signal intensity in relation to that of remote myocardium was determined in the late gadolinium-enhanced and periinfarction areas. Segment-based analysis was performed to determine whether the presence of microvascular obstruction influences the detection of myocardial edema.

RESULTS. The averaged signal intensity in the late gadolinium-enhanced area without microvascular obstruction was significantly higher than the signal intensity in remote normal myocardium (relative signal intensity, 1.83 ± 0.50; p < 0.001). In contrast, the signal intensity in the microvascular obstruction area on T2-weighted images was not significantly different from the signal intensity in remote myocardium (relative signal intensity, 1.14 ± 0.26). The percentages of late gadolinium-enhanced segments with high signal intensity on T2-weighted MR images were 95% (73/77) without microvascular obstruction and 30% (22/73) with microvascular obstruction.

CONCLUSION. With T2-weighted MRI, infarction-associated edema can be reliably detected in infarct lesions without microvascular obstruction. Microvascular obstruction, however, does not necessarily exhibit high signal intensity on T2-weighted MRI. Careful attention is required in interpretation of cardiac MR images of patients who have experienced acute myocardial infarction and undergone percutaneous coronary intervention. The findings on T2-weighted MR images can be substantial underestimates of the extent of acute myocardial infarction.

SUBJECTS AND METHODS. This prospective study was approved by the institutional research ethics board. Ten control subjects (five women and five men; mean age, 29.0 years) and nine patients with chronic exertional compartment syndrome (three women and six men; mean age, 33.7 years) gave informed written consent and underwent MRI of the calf muscles using an axial T2*-weighted multiecho gradient-recalled echo and a flow-sensitive alternating inversion recovery sequence with echo-planar imaging readouts before (baseline) and 3, 6, 9, 12, and 15 minutes after exercise. T2* and arterial spin labeling signal changes (T2* and ASL, respectively) over time were calculated relative to the baseline examination. T2* and ASL between patients and control subjects were compared using the Student's t test.

RESULTS. In both patients and control subjects, T2* and ASL showed a peak at 3 minutes after exercise, followed by a decrease over time. The maximum T2* was 26% and 29% for patients and control subjects, respectively. The maximum ASL was 183% and 224% for patients and control subjects, respectively. After 15 minutes, arterial spin labeling signal returned to baseline; however, T2* remained elevated (8% in patients; 10% in control subjects). No statistically significant differences between patients and control subjects in postexercise T2* and ASL were found (p = 0.21–0.98).

CONCLUSION. After calf muscle exercise, no statistically significant differences in T2* relaxation times or arterial spin labeling signal, indicative of differences in muscle oxygenation and perfusion status, were found between patients with chronic exertional compartment syndrome and control subjects.

MATERIALS AND METHODS. Twenty-eight well-preserved talus bones from the San Diego Museum of Man were assessed regarding the presence of outgrowths on the anterior aspect of the talus. The distance of the outgrowths from the talar head was measured. The results were correlated with measurements of capsular attachment on the anterior aspect of the talus derived from MR arthrographic images in 13 cadaveric ankles.

RESULTS. The average distance of capsular attachment from the talar head in the medial aspect of the bone was 10.63 mm and in the lateral part was 12.04 mm. The mean distance of bony spurs from the talar head in the medial and lateral parts of the talus was 17.2 and 12.5 mm, respectively. Medially, the talar spurs developed more proximally on the neck compared to the capsular attachment (p < 0.01). Laterally, this difference was not significant (p = 0.26).

CONCLUSION. On the medial part of the anterior talus, bone development appears to occur in an intraarticular location (i.e., osteophytes). Laterally, the outgrowths develop extraarticularly and appear to result from capsular and ligamentous traction (i.e., enthesophytes).

MATERIALS AND METHODS. First- and third-year radiology residents and an attending musculoskeletal radiologist retrospectively assessed 108 cross-table lateral knee radiographs for qualitative grading of joint fluid and quantitative measurement of the suprapatellar pouch. Qualitative and quantitative evaluation of ipsilateral knee MRI examinations performed within 1 week of radiography was performed by two attending musculoskeletal radiologists as a reference standard.

RESULTS. Qualitative visual grading of cross-table lateral radiographs had a sensitivity of 90–92%, specificity of 39–54%, and accuracy of 69–76% for joint effusion. Extrapolating from previous work showing 4 mL of fluid distends the suprapatellar pouch to 4 mm on midline sagittal MRI, the corresponding measurement on cross-table lateral radiographs was predicted to be 7 mm. Using this new criterion of effusion, sensitivity, specificity, and accuracy compared with an MR midline sagittal reference standard were 76%, 83%, and 81%, respectively. Historical data for overhead lateral radiographs had a sensitivity of 78%, specificity of 80%, and accuracy of 79%.

CONCLUSION. Qualitative visual assessment of cross-table lateral knee radiographs is highly sensitive for the detection of joint effusion. By performing quantitative evaluation with a new 7-mm criterion for suprapatellar pouch measurement, sensitivity, specificity, and accuracy are equivalent to that of overhead lateral radiography.

MATERIALS AND METHODS. One hundred eleven patients were included in this study: among 45 patients with follow-up sonography-guided FNAB, 21 underwent follow-up sonography more than 12 months after the initial sonography and 24 were followed up with sonography and sonography-guided FNAB within 12 months. Among 45 patients with follow-up sonography-guided FNAB, seven underwent thyroid surgery. Follow-up sonography results and cytopathologic results were used as reference standards.

RESULTS. There were no malignancies among 71 probably benign lesions on initial sonography. In contrast, of the 40 lesions that were suspicious malignant on sonography, eight proved to be papillary thyroid carcinoma on follow-up sonography-guided FNAB and histopathology.

CONCLUSION. Lymphocytic thyroiditis can show variable features on sonography. When a nodule shows probably benign features on sonography, follow-up with sonography is sufficient. However, if a nodule shows suspicious malignant features on sonography and shows no change or increase in size on follow-up examination, follow-up sonography-guided FNAB should be performed.

CONCLUSION. Radiologists should improve their DVT education, support ongoing clinical trials, and collaborate with DVT-focused nonradiologists in their institutions.

CONCLUSION. An understanding of the pathophysiology, natural history, and imaging features is the key to successful diagnosis and appropriate management of patients with these aortic diseases.

MATERIALS AND METHODS. This article describes a retrospective study of 48 patients (age range, 37–77 years; mean age, 61.1 years; SD, 10.3) with liver metastases from neuroendocrine tumors who underwent repetitive selective hepatic artery chemotherapy using mitomycin C alone (group 1, n = 18 patients who underwent 182 therapeutic sessions; mean, 10.11 sessions per patient) and combined mitomycin C and gemcitabine chemotherapy agents (group 2, n = 30 patients who underwent 312 therapeutic sessions; mean, 10.4 sessions per patient) with 4-week intervals between treatment sessions.

RESULTS. Both treatment protocols were well tolerated by all patients. Only minor side effects occurred in both groups, and no major complications developed. Local tumor control evaluation according to the Response Evaluation Criteria in Solid Tumors (RECIST) revealed the following for group 1: partial response, 11.1%; stable disease, 50%; and progressive disease, 38.9%. RECIST criteria for group 2 indicated partial response in 23.33%, stable disease in 53.34%, and progressive disease in 23.33%. The survival rate from the initial diagnosis to the fifth year for group 1 was 11.11% and for group 2, 46.67%. The median survival time from the initial diagnosis of group 1 was 38.67 months, whereas in group 2 it was 57.1 months.

CONCLUSION. Transarterial hepatic chemotherapy using mitomycin C and gemcitabine can be an effective therapeutic protocol for controlling local metastases and improving survival time in patients with hepatic metastases from neuroendocrine tumors.

SUBJECTS AND METHODS. From January 2005 to January 2008, among 1,837 consecutively registered patients with HCC seen at our institution, 412 had HCC and portal venous invasion; 27 of the 412 had a single HCC nodule accompanied by main portal venous tumor thrombus. Thirteen patients (10 men, three women; mean age, 70 years; range, 66–74 years) with 13 HCC nodules 3.7–5 cm in diameter extending into the main portal trunk underwent percutaneous radiofrequency ablation. Fourteen matched patients (10 men, four women; mean age, 69 years; range, 67–73 years) with 14 HCC nodules 3.6–4.8 cm in diameter extending into the main portal trunk refused radiofrequency ablation and composed the control group. Diagnosis of main portal venous tumor thrombus was made with fine-needle biopsy in all cases. Radiofrequency ablation was performed first on the main portal venous tumor thrombus and then on the HCC nodule. Efficacy of radiofrequency was defined as complete necrosis of HCC and complete recanalization of the main portal trunk and its branches. HCC necrosis was evaluated with enhanced CT. Recanalization of portal vessels was analyzed with color Doppler and contrast-enhanced ultrasound. Radiofrequency ablation was performed under ultrasound guidance with a perfused needle electrode.

RESULTS. Complete necrosis of the HCC associated with complete recanalization of the main portal vein and its branches was achieved in 10 patients (efficacy, 77%). In the other three patients, necrosis of the HCC ranged from 70% to 90%, and recanalization of the main portal trunk was not complete. No major complications occurred. In three cases, mild to moderate ascites and increased aspartate aminotransferase and alanine aminotransferase levels were found. The follow-up periods ranged from 3 to 36 months among the treated patients and 2 to 10 months among the untreated patients. The cumulative survival rate was 77% 6, 12, and 36 months after procedure in the treated group and 43% and 0% 6 and 12 months after diagnosis in the untreated group (p < 0.0001). All 10 successfully treated patients were alive and the portal system was patent at the end of the follow-up period. All three untreated patients died of progressive disease within 5 months of diagnosis.

CONCLUSION. Radiofrequency ablation can destroy both single intraparenchymal medium-sized HCCs and the accompanying main portal venous tumor thrombus with high efficacy and safety and a low rate of complications.

MATERIALS AND METHODS. Studies were performed on 80 patients (prospective ECG gating, n = 40; retrospective ECG gating, n = 40) either being evaluated for thoracic aortic aneurysm (n = 23) or aortic dissection (n = 36) or undergoing postsurgical or postintervention follow-up (n = 21). Image acquisition parameters and radiation dose (CT dose index volume [CTDI_vol] and dose–length product [DLP]) were obtained from image archival data. Contrast load and aortic attenuation values were obtained from a data registry. The comparative degrees of motion artifact and banding artifact were assessed on parasagittal maximum-intensity-projection (MIP) images and reformatted images in the plane of the aortic valve.

RESULTS. CTDI_vol and DLP in the prospective ECG-gating group was 28.8 ± 2.12 mGy (mean ± SD) and 833.7 ± 115.77 mGy/cm, respectively, which are significantly lower (p < 0.001) than those values in the retrospective ECG-gating group (74.7 ± 13.42 mGy and 2,547.3 ± 553.27 mGy/cm). The average contrast load in the prospective gating group was 109.1 ± 14.74 mL and in the retrospective gating group, 101.3 ± 10.45 mL (p < 0.05). The average aortic attenuation values (in Hounsfield units) for the prospective and retrospective ECG-gated groups were 447.6 and 350.2 HU, respectively, for the mid ascending aorta, 413.6 and 325.7 HU for the mid aortic arch, 418.2 and 327.6 HU for the mid descending aorta, and 355.0 and 306.2 HU for the supraceliac aorta. Subjective scores of motion artifact and banding artifact were equivalent between the two groups.

CONCLUSION. Compared with retrospective ECG-gated thoracic CT angiography, prospective ECG-gated thoracic CT angiography was associated with a lower radiation dose, slightly increased contrast load, increased aortic attenuation values, and equivalent image quality.

MATERIALS AND METHODS. Between October 2004 and June 2008, 14 carefully selected hemodialysis patients with hepatocellular carcinoma (five naïve, nine recurrent) underwent a total of 19 radiofrequency ablation treatments. An internally cooled or expandable electrode was used. After tumor ablation, the insertion site at the liver surface was subjected to additional ablation to reduce the bleeding risk.

RESULTS. The Child-Pugh score was 6 or better in all patients but one. The number of tumors was one or two, and the tumor diameter was 35 mm or less in all treatments. No complication such as intraperitoneal hemorrhage was found in any treatment. Local tumor progression was found after one treatment and was successfully managed with subsequent radiofrequency ablation. During the mean observation period of 343 days, there was only one death, of heart failure, among the five patients with naïve tumors.

CONCLUSION. The safety and effectiveness of radiofrequency ablation were not compromised in this series of selected patients with hepatocellular carcinoma who were undergoing hemodialysis. Radiofrequency ablation is a promising option for small hepatocellular carcinomas in patients undergoing regular hemodialysis treatments.

MATERIALS AND METHODS. A Schlieren imaging system was used to visualize the angiocatheter exit jet fluid dynamics at two different flow rates. Catheters were modified by drilling through-and-through side holes or by cutting slits into the catheters. A commercial computational fluid dynamics package was used to calculate numeric results for various vessel diameters and catheter orientations.

RESULTS. Experimental images showed that modifying standard peripheral IV angiocatheters with side holes or side slits qualitatively changed the overall flow field and caused the exiting jet to become less well defined. Numeric calculations showed that the addition of side holes or slits resulted in a 9–30% reduction of the velocity of contrast material exiting the end hole of the angiocatheter. With the catheter tip directed obliquely to the wall, the maximum wall shear stress was always highest for the unmodified catheter and was always lowest for the four-side-slit catheter.

CONCLUSION. Modified angiocatheters may have the potential to reduce extravasation events in patients by reducing vessel wall shear stress.

CONCLUSION. The DSA-guided filling-defects technique is a feasible method for tracking the sclerosing foam and should be used in the treatment of other venous disorders when using sclerosing foam with radiologic guidance.

MATERIALS AND METHODS. We retrospectively reviewed images from 115 MRI examinations of the breast performed from 1999 to 2005 for the indication of problem-solving for inconclusive findings on a mammogram. Forty-eight of the 115 women (41.8%) were at high risk. We discerned whether sonography or MRI was used as an adjunctive tool and correlated the findings with those in the pathology database.

RESULTS. The equivocal findings most frequently leading to MRI were asymmetry and architectural distortion. No suspicious MRI correlate was found in 100 of 115 cases (87%). These cases were found stable at follow-up mammography or MRI after a mean of 34 months. Fifteen enhancing masses (13%) that corresponded to the mammographic abnormality were seen on MR images. All masses identified at MRI were accurately localized for biopsy, and six malignant lesions were identified. Four of six malignant tumors were seen in one mammographic view only; two were seen on second-look ultrasound images. MRI had a sensitivity of 100% and compared with mammography had significantly higher specificity (91.7% vs 80.7%, p = 0.029), positive predictive value (40% vs 8.7%, p = 0.032), and overall accuracy (92.2% vs 78.3%, p = 0.0052). Eighteen incidental lesions (15.7%) were detected at MRI, and all were subsequently found benign.

CONCLUSION. We found breast MRI to be a useful adjunctive tool when findings at conventional imaging were equivocal. Strict patient selection criteria should be used because of the high frequency of incidental lesions seen on MR images.

MATERIALS AND METHODS. We reviewed 1,523 consecutive breast MRI examinations performed from January 1, 2003, to June 30, 2005, to identify all lesions initially detected on MRI and assessed as BI-RADS 4 or 5 for which the patient underwent subsequent imaging-guided needle or excisional biopsy. BI-RADS lesion features were recorded for each case, and the risk of malignancy was assessed using generalized estimating equations. Separate multivariate models were constructed for lesions classified as masses.

RESULTS. Included in the analysis were 258 suspicious lesions in 196 women. Among all lesions, those of 1 cm or greater were significantly more often malignant (50/147, 34%) than lesions of less than 1 cm (22/111, 20%; odds ratio, 2.09; 95% CI, 1.13–3.83). For masses, size, BI-RADS margin, and enhancement pattern predicted malignancy. In multivariate analysis of combinations of features, masses of 1 cm or greater with heterogeneous enhancement and irregular margins had a 68% probability of malignancy. Masses of 1 cm or greater with smooth margins and homogeneous enhancement had the lowest predicted probability of malignancy of 3%. BI-RADS descriptors and size were not significant predictors of malignancy for nonmasslike enhancement (NMLE).

CONCLUSION. Combinations of BI-RADS lesion descriptors can predict the probability of malignancy for breast MRI masses but not for NMLE. If our model is validated, masses with a low probability of malignancy may be eligible for short-interval follow-up rather than biopsy. Further research focused on predictive features of NMLE is needed.

SUBJECTS AND METHODS. This prospective randomized study included patients with breast cancer scheduled for conservative tumor excision and sentinel node biopsy. Patients were randomized to either radioguided localization or wire localization. Comparative radiologic, surgical, and pathologic data were collected and analyzed to establish the duration, ease of use, and accuracy of the two techniques for occult lesion localization. The effectiveness of sentinel node biopsy also was assessed. One radiologist and two surgeons participated in the study.

RESULTS. Among 134 patients, 68 were treated with wire localization and 66 with radioguided localization. The mean duration of radiologic localization was significantly shorter for radioguided localization (p < 0.001). No statistical differences were found for the other parameters studied. Radiography of the surgical specimen showed 100% lesion excision with both techniques. Complete tumor excision with tumor-free margins was achieved in 89.4% of patients who underwent radioguided localization group and 82.4% of patients who underwent wire localization. Pathologic examination showed the excised tissue volume was slightly larger (p = 0.371) and lesion concentricity slightly less (p = 0.730) with radioguided localization. The sentinel node detection rate was 91% with radioguided localization and 84% with wire localization.

CONCLUSION. The radioguided technique is as effective as the standard wire technique for localization and excision of nonpalpable breast cancer lesions and is somewhat faster and simpler to perform than wire localization.

MATERIALS AND METHODS. The study included 188,823 screening examinations of women between 50 and 64 years old; 35,204 (18.6%) mammograms were obtained using FFDM. All films were double read using a 5-point rating scale to indicate the probability of cancer. Patients with positive scores were recalled for further workup. The recall rate, cancer detection rate, and positive predictive value (PPV) of FFDM were compared with screen-film mammography.

RESULTS. The cancer detection rate was significantly higher for FFDM than screen-film mammography (6.3 vs 5.2 per 1,000, respectively; p = 0.01). The cancer detection rate for FFDM was higher than screen-film mammography for initial screening and subsequent screening, for invasive cancer and ductal carcinoma in situ, and across all age groups. The cancer detection rate for cancers presenting as microcalcifications was significantly higher for FFDM than for screen-film mammography (1.9 vs 1.3 per 1,000, p = 0.01). The recall rate was significantly higher for FFDM than screen-film mammography (4.0% vs 3.1%, p < 0.001). There was no significant difference in the PPVs of recall to assessment for FFDM and screen-film mammography (15.7% and 16.7%, p = 0.383).

CONCLUSION. FFDM resulted in significantly higher cancer detection and recall rates than screen-film mammography in women 50–64 years old. The PPVs of FFDM and screen-film mammography were comparable. The results of this study suggest that FFDM can be safely implemented in breast cancer screening programs.

MATERIALS AND METHODS. Estimated absorbed fetal dose was measured with a metal oxide semiconductor field effect transistor (MOSFET) dosimeter placed in the expected uterine location in an anthropomorphic phantom of a woman and scanned with 16- and 64-MDCT units of one vendor and a 64-MDCT unit of another vendor. A trauma chest, abdomen, and pelvis protocol and an abdomen and pelvis protocol were used. Absorbed uterine dose was measured directly from the MOSFET detector. The CTDI_vol for each protocol was recorded from the scanner console. Correlation between mean uterine dose and CTDI_vol was tested with a goodness of fit model.

RESULTS. The absorbed uterine dose ranged from 9.25 to 37.7 mGy. Absorbed fetal dose in the early first trimester correlated with CTDI_vol in a linear regression equation. For the 16-MDCT scanner, at 130 kVp, the fetal dose was 2.091 x CTDI_vol – 9.489. For the 64-MDCT scanner from the same vendor, at 120 kVp, the fetal dose was 1.113 x CTDI_vol + 1.773. For the 64-MDCT scanner from the other vendor, at 120 kVp, the fetal dose was 1.378 x CTDI_vol – 1.014. The goodness of fit results (R²) for the equations were 0.97, 0.98, and 0.99.

CONCLUSION. Estimated absorbed fetal dose during the first trimester of pregnancy is linearly associated with CTDI_vol regardless of beam energy, detector configuration, and scanner manufacturer.

MATERIALS AND METHODS. From September 2005 through December 2007, targeted ultrasound was performed for 519 suspicious MRI-detected lesions in 361 women. Retrospective review was performed to determine lesion type (mass vs nonmass), lesion descriptors, lesion size, BI-RADS category, indication for MR examination, patient age, and biopsy outcome. The results of 80 follow-up MRI examinations among 154 cases with concordant benign results on ultrasound-guided biopsy were noted.

RESULTS. A presumed ultrasound correlate was found in 290 (56%) of the 519 lesions with masses more likely than nonmass lesions to be seen with ultrasound (62% of masses and 31% of nonmass lesions). Increasing lesion size, assessment of BI-RADS category 5 versus BI-RADS category 4, rim enhancement in masses, and clumped enhancement in nonmass lesions were also significantly more likely to have an ultrasound correlate. On follow-up imaging in 80 benign, concordant ultrasound-guided biopsies, the sonographic lesion did not correspond to the MRI finding in 10. Nine of these 10 lesions underwent subsequent MRI-guided biopsy and five cancers were diagnosed.

CONCLUSION. The MR characteristics of lesions most likely to be seen with an ultrasound correlate were mass versus nonmass, increasing size, and increased level of suspicion of the lesion. Clip placement and follow-up imaging after ultrasound-guided biopsy that yields benign concordant results should be performed to detect cases in which the presumed ultrasound correlate is inaccurate to detect unsuspected false-negative biopsies.

SUBJECTS AND METHODS. Forty-five women (mean age, 46.1 years) with 52 focal mass breast lesions underwent diffusion-weighted imaging with different b values. The apparent diffusion coefficient (ADC) value of each lesion was calculated from the ADC maps done using five b values (0, 250, 500, 750, and 1,000 s/mm²) and using b values of 0 s/mm² with each other b value separately (0 and 250 s/mm², 0 and 500 s/mm², 0 and 750 s/mm², 0 and 1,000 s/mm²). The mean ADC values were correlated with imaging findings and histopathologic diagnoses. The cutoff ADC value, sensitivity, and specificity of diffusion-weighted imaging to differentiate benign and malignant lesions were calculated in all b value combinations. A p value of < 0.05 was considered statistically significant.

RESULTS. The mean ADC value was significantly lower for malignant lesions compared to benign lesions (p < 0.0001) in all b value combinations. No statistical difference was seen between the ADC obtained from different b value combinations (p = 0.2581) in the differentiation between benign and malignant lesions. The ADC calculated from b 0 and 750 s/mm² was slightly better than the other b value combinations, showing a sensitivity of 92.3% and a specificity of 96.2%.

CONCLUSION. Diffusion-weighted imaging is a potential resource as a coadjutant of MRI in the differentiation between benign and malignant lesions. Such imaging can be performed without a significant increase in examination time, especially because it can be done with lower b values.

SUBJECTS AND METHODS. Analysis was performed on images of 148 patients with histologically proven chronic hepatitis C without cirrhosis. The peak value of the C_m² (modified chi-square distribution) histogram was calculated from B-mode ultrasound images, and the resulting value was compared with the histologic fibrosis grade.

RESULTS. The peak C_m² histogram value for grade F3 fibrosis was higher than that for grades F0 and F1 (p < 0.0001) and F2 (p = 0.0003). The value for grade F2 was higher than that for grades F0 and F1 (p = 0.0027). The values gradually increased with an increase in liver fibrosis grade, although no difference was found between grades F0 and F1.

CONCLUSION. The grades of liver fibrosis in patients with chronic hepatitis C are well discriminated with the B-mode ultrasound–based analysis algorithm without discrimination between grades F0 and F1. Findings on conventional ultrasound images may reflect progression of liver fibrosis even in the absence of cirrhosis.

MATERIALS AND METHODS. The cases of 21 patients with HCC who underwent MRI after TACE were evaluated. Two independent observers calculated the apparent diffusion coefficient (ADC) of HCC and measured percentage tumor necrosis on subtraction images. The ADCs of necrotic and viable tumor tissues were compared. ADC and percentage necrosis on subtraction images were correlated with percentage necrosis found at pathologic examination. Receiver operating characteristics analysis was performed on the diagnosis of complete tumor necrosis.

RESULTS. Twenty-eight HCCs (mean diameter, 2.3 cm) were evaluated. There were significant differences between the ADC of viable tissue and that of necrotic tumor tissue (1.33 ± 0.41 vs 2.04 ± 0.38 x 10^–3 mm²/s, p < 0.0001). There was significant moderate correlation between ADC and the pathologic finding of percentage necrosis (r = 0.64, p < 0.001) and significant strong correlation between subtraction image and pathologic percentage necrosis (r = 0.89–0.91, depending on the phase; p < 0.001). In the diagnosis of complete tumor necrosis, ADC had an area under the curve, sensitivity, and specificity of 0.85, 75%, and 87.5% compared with 0.82–0.89, 100%, and 58.3–79.1% for subtraction imaging (p > 0.5 between ADC and subtraction imaging).

CONCLUSION. Compared with diffusion-weighted imaging, contrast-enhanced MRI with subtraction technique had more significant correlation with the histopathologic findings in the evaluation of necrosis of HCC after TACE. There was no difference, however, between the two methods in diagnosis of complete tumor necrosis.

SUBJECTS AND METHODS. Twenty-five patients with HCC in liver cirrhosis underwent 1.5-T MRI. T2-weighted turbo spin-echo and T1-weighted 3D gradient-echo sequences before and between 15 seconds and 20 minutes after the injection of 10 mL of Gd-EOB-DTPA were performed. Signal-to-noise ratios (SNRs) of liver parenchyma and liver-to-lesion contrast-to-noise ratios (CNRs) were calculated and plotted over time. Enhancement patterns of HCC were characterized qualitatively by two radiologists.

RESULTS. The SNR of liver parenchyma increased significantly at 15 seconds and 60 seconds after contrast injection and remained stable thereafter. HCC showed positive CNR during the arterial phase and increasingly negative CNR during the further time course (p < 0.05). The maximum absolute CNR was found at 20 minutes after contrast injection. There was no correlation between the degree of enhancement at any time point and tumor grade. On qualitative evaluation, 16 HCCs showed arterial enhancement with early washout, and five showed arterial enhancement with late washout. In the remaining four HCCs, enhancement persisted until 20 minutes. Lesion conspicuity at 20 minutes after contrast injection was at least equal to or higher than it was on the remaining sequences in 19 of the 25 patients.

CONCLUSION. After Gd-EOB-DTPA injection, most HCCs showed typical arterial enhancement with early washout. Liver-to-lesion contrast was best at 20 minutes.

MATERIALS AND METHODS. Over a 10-year period, the cases of 14 patients with histopathologically proven intraductal metastasis (n = 8) or double primary intraductal cholangiocarcinoma (n = 6) who had a history of extrabiliary malignancy were identified. Two radiologists retrospectively reviewed CT (n = 14) and MR (n = 6) images for the size and appearance of the intraductal lesion, presence of a parenchymal mass, multiplicity, attenuation on arterial and portal phase images, and presence of calcification. Clinical findings such as the location of extrabiliary malignancy and presence of Clonorchis sinensis infestation also were recorded. Univariate tests were used to differentiate the two disease entities.

RESULTS. Histopathologic confirmation was obtained by surgical resection (n = 12) or ultrasound-guided biopsy (n = 2). All intraductal metastatic lesions were of colorectal cancer, and all intraductal cholangiocarcinomas were associated with extracolonic malignant disease, including three cases of gastric cancer (p < 0.0001). All cholangiocarcinomas manifested themselves as purely intraductal masses, but five of the eight intraductal metastatic lesions were contiguous with parenchymal masses (p = 0.031). The appearance of the intraductal lesion was predominantly expansile in cases of metastasis (seven of eight cases) but not in cases of cholangiocarcinoma (one of six cases) (p = 0.026). Other findings were not statistically significant in differentiating the two disease entities.

CONCLUSION. When an intraductal lesion is found in a patient with extrabiliary malignancy, the presence of a contiguous parenchymal mass, an expansile nature of the intraductal lesion, and a history of colorectal cancer may suggest the presence of intraductal metastasis rather than double primary intraductal cholangiocarcinoma.

MATERIALS AND METHODS. Two hundred thirty consecutively registered patients underwent abdominal MRI including diffusion-weighted imaging (single-shot spin-echo echo-planar sequence) with b values of 0, 150, 500, and 1,000 s/mm². Lesions were detected by two blinded readers using only the images with a b value of 1,000 s/mm², and representative apparent diffusion coefficients were measured. Lymph nodes were not documented.

RESULTS. Fifty-two of the 230 patients had a total of 55 lesions with restricted diffusion (23.9%). The mean apparent diffusion coefficient was 809 mm²/s. Forty-three lesions (78.2%) were malignant. The 12 benign lesions were liver hemangioma, liver adenoma, autoimmune pancreatitis, pancreatic teratoma, two abscesses, three cases of inflammatory bowel wall thickening due to Crohn's disease, Bartholin cyst, hemorrhagic ovarian cyst, and renal Rosai-Dorfman disease.

CONCLUSION. Restricted diffusion is generally considered to be associated with malignant tumors because of the high cellularity of these tumors. However, in interpretation of diffusion-weighted images, it should be kept in mind that a number of benign lesions, as many as 22% in our cohort, can exhibit restricted diffusion on images with high b values, thus mimicking malignant lesions.

CONCLUSION. Knowledge of the common CT manifestations of various causes of spontaneous abdominal hemorrhage allows their accurate diagnosis and has a direct impact on clinical decision making.

SUBJECTS AND METHODS. Perfusion CT was performed on an MDCT scanner with 50 mL of iodinated contrast material injected at 4 mL/s. The quality of each functional map was rated from 0 to 3 for 123 patients with confirmed lung cancer. A subset of images was independently reviewed by two radiologists to measure interobserver and intraobserver variability. Perfusion parameters and tumor response were assessed for 35 patients with non–small cell lung cancer who underwent chemoradiation therapy. Progression-free survival and overall survival were analyzed for 22 patients who underwent repeated perfusion CT after therapy.

RESULTS. Image quality was graded 2 (moderate) or 3 (good) in 68.2% of cases. High interobserver and intraobserver correlations of perfusion parameters were found on qualified images. The patients who responded to chemoradiation therapy had significantly greater blood flow (p = 0.023) than patients who did not respond. The median progression-free survival period of the patients with an increased permeability–surface area product was 4.7 months, significantly lower than the median progression-free survival period of 19.0 months among patients with a decreased permeability–surface area product (p < 0.001). The median overall survival period was 10.6 months for the group with an increased permeability–surface area product, significantly lower than the 19.3 months for the group with a decreased permeability–surface area product (p = 0.004).

CONCLUSION. Non–small cell lung cancer with higher perfusion is more sensitive to chemoradiation therapy than that with lower perfusion. After chemoradiation therapy, findings at perfusion CT are a significant predictor of early tumor response and overall survival among patients with non–small cell lung cancer.

MATERIALS AND METHODS. Cardiac CT was performed in 35 patients with ACS: 24 patients with acute myocardial infarction (AMI) and 11 patients with unstable angina pectoris (UAP). We reconstructed 2D myocardial images at diastolic and systolic phases using the same raw data as those used for coronary CT angiography. The CT number in the myocardium was used as an estimate of ischemia. The myocardium was shown using a color scale that depicts faint low-density areas more clearly than gray scale. We evaluated the variations in myocardial enhancement during the cardiac cycle in the territory of the culprit lesion. In addition, we classified patients on the basis of the transmurality of myocardial enhancement and examined whether this feature correlates with myocardial damage.

RESULTS. Myocardial imaging at systole showed myocardial hypoenhancement in territories of the culprit lesion in 91% of patients with ACS, 96% of patients with AMI, and 75% of patients with UAP. The hypoenhancement areas at systole tended to be more extensive than those at diastole. The transmural extent of hypoenhancement at systole correlated with myocardial damage, which was shown by myocardial biomarkers.

CONCLUSION. CT myocardial imaging can be used to assess myocardial ischemia in the appropriate region of ACS with high sensitivity.

CONCLUSION. We propose a methodical diagnostic approach to determining the visceroatrial situs and cardiac configuration that predicts the probability and types of associated congenital heart disease.

CONCLUSION. The characteristic CT findings of hydrocarbon pneumonitis after diesel fuel siphonage are the presence of air–space consolidations with predominant right middle lobe involvement and areas of low attenuation within consolidation. Occasionally, bronchoalveolar lavage is needed to confirm the diagnosis of hydrocarbon pneumonitis by the presence of lipid-laden macrophages on the basis of a history of diesel fuel aspiration.

MATERIALS AND METHODS. A retrospective review of all intravascular doses of low-osmolar iodinated and gadolinium contrast materials administered from 2002 through 2006 was conducted. Adverse effects were identified through the use of radiologist and nurse event recording. Adverse effects were examined for type and severity of reaction, treatment required, and outcome.

RESULTS. A total of 456,930 contrast doses (298,491 low-osmolar iodinated, 158,439 gadolinium) were administered over the study period. A total of 522 cases of adverse effects (0.11% of total) were identified (458 low-osmolar iodinated, 64 gadolinium). The most common adverse effects were hives (274, 52.5%) and nausea (92, 17.6%). Of all adverse effects, 79 of low-osmolar iodinated and 15 of gadolinium contrast material necessitated treatment. Most treatments were performed in the radiology department alone. Only 16 cases of adverse effects necessitated transfer for further observation or treatment. Epinephrine was used to manage an adverse effect in nine instances. Thirty-two of the adverse effects of low-osmolar iodinated contrast material (6.9%) occurred in patients with a history of allergy who received premedication. Only two of these premedication reactions necessitated transfer to the emergency department. The one death in the study period occurred after administration of low-osmolar iodinated contrast material. The patient had no symptoms during the contrast administration or imaging but died suddenly within 30 minutes of receiving the dose.

CONCLUSION. Both iodinated and gadolinium contrast agents are associated with a very low rate of adverse effects. Most adverse effects are mild and can be managed in the radiology department. Transfer for additional treatment or observation is rarely needed.

CONCLUSION. Proper characterization is essential to ensure that life-threatening sequelae from Addisonian crisis are averted in infection and hemorrhage, or to identify "leave-alone" lesions such as pseudocyst and chronic calcification.

MATERIALS AND METHODS. We tabulated non–individually identified responses from the American College of Radiology 1995, 2003, and 2007 surveys of radiologists. These stratified random sample surveys had, respectively, 2,025, 1,924, and 487 responses and response rates of 75%, 63%, and 20%. Responses were weighted to make them representative of all U.S. radiologists. Respondents were assured of confidentiality.

RESULTS. Mean weekly hours worked increased from 1995 to 2003 and from 2003 to 2007. The total increase was approximately 5 hours, or 10%. Mean vacation days also increased in both subperiods, from 27 in 1995 to 39 in 2007, yielding an approximately 5% decrease in days worked per year. The overall result was a mean increase of approximately 5% in annual work hours. In 2007, the 25th percentile of weekly hours was 45, and the 75th percentile was 55. The 25th percentile of annual vacation days was 25, and the 75th percentile was 50. Full-time radiologists responding about their own weekly hours reported, at the mean, working 10% more hours than they believed was the average for other full-time radiologists in the practice.

CONCLUSION. Weekly hours and annual vacation days both have increased. The percentiles give radiologists a basis for comparison with other radiologists. Radiologists apparently often overestimate their work hours relative to the hours of others in their practices. Misperceptions of this kind might give rise to friction in radiology practices.

MATERIALS AND METHODS. Twenty metal oxide semiconductor field effect transistor dosimeters were placed in a medium-sized anthropomorphic phantom of a man. Pulmonary embolism and chest, abdomen, and pelvis protocols were used to scan the phantom three times with GE Healthcare scanners in four configurations and one 64-MDCT Siemens Healthcare scanner. Organ doses were averaged, and effective doses were calculated with weighting factors.

RESULTS. The mean effective doses for the pulmonary embolism protocol ranged from 9.9 to 18.5 mSv and for the chest, abdomen, and pelvis protocol from 6.7 to 18.5 mSv. For the pulmonary embolism protocol, the mean effective dose from the Siemens Healthcare 64-MDCT scanner was significantly lower than that from the 16- and 64-MDCT GE Healthcare scanners (p < 0.001). The mean effective dose from the GE 4-MDCT scanner was significantly lower than that for the GE 16-MDCT scanner (p < 0.001) but not the GE 64-MDCT scanner (p = 0.02). For the chest, abdomen, and pelvis protocol, all mean effective doses from the GE scanners were significantly different from one another (p < 0.001), the lowest mean effective dose being found with use of a single-detector CT scanner and the highest with a 4-MDCT scanner. For the chest, abdomen, and pelvis protocols, the difference between the mean effective doses from the GE Healthcare and Siemens Healthcare 64-MDCT scanners was not statistically significant (p = 0.89).

CONCLUSION. According to phantom data, patients are subject to different radiation exposures for similar body CT protocols depending on scanner assignment. In general, doses are lowest with use of 64-MDCT scanners.

MATERIALS AND METHODS. A retrospective analysis of 67 injection procedures of the temporomandibular joints (55% [37/67] were therapeutic injections, 27% [18/67] were diagnostic injections, and 18% [12/67] were arthrocentesis procedures), performed in 31 patients (58% [18/31] female, 42% [13/31] male; mean age, 14 years; age range, 3–34 years), was made. Seven of 38 (18%) subjects had two temporally separate procedures. Determinations of skin entry points, puncture, and injection were performed under real-time MRI. Data were assessed for rate of successful injections, quantitative and qualitative image quality, time requirements, and occurrence of complications.

RESULTS. Drug delivery was successful in all procedures. The quality of real-time FLASH 2D MR images was sufficient in all cases. Real-time MRI proved to be helpful to achieve high rates of intraarticular injections. Contrast-to-noise ratios were sufficiently high for good delineation of relevant structures. Average length of time was 25 minutes (range, 16–53 minutes). No major complications occurred.

CONCLUSION. We accept the hypothesis that real-time MRI-guided selective injection procedures of the temporomandibular joints are feasible, accurate, and safe when performed on a clinical open-bore 1.5-T MR system.

CONCLUSION. Potential postsurgical complications such as nonunion, osteolysis, infection, and heterotopic ossification are all well assessed by 3D CT.

CONCLUSION. Test characteristics for MR techniques such as MRI and MRA were relatively similar to those for CTA in diagnosis of carotid and vertebral artery dissection.

MATERIALS AND METHODS. Between January 2002 and November 2007, 2,338 ultrasound-guided thyroid, thyroid bed, and cervical lymph node FNABs were performed at a tertiary referral center. Entry criteria for our retrospective study were adult patients who underwent thyroid nodule FNAB and had previously undergone diagnostic sonography. From previous reports for 944 thyroid nodules (739 nodules in women and 205 nodules in men), four sonographic features were recorded: longest dimension, morphology, presence of microcalcifications, and presence of lymphadenopathy. The final diagnosis of each nodule was classified as benign, malignant, or nondiagnostic on the basis of surgical pathology when available and cytology otherwise and was analyzed for correlation with individual sonographic features and combinations of features.

RESULTS. The prevalence of malignancy and of nondiagnostic FNAB in this study was 11.0% and 11.8%, respectively. Statistically significant (p < 0.05) findings in malignant nodules were younger patient age (≤ 45 years; odds ratio [OR], 1.54) and solid nodule morphology (OR, 2.38). The significant predictors of a nondiagnostic-quality FNAB were older patient age (> 75 years; OR, 1.95) and a nodule ≥ 10 mm (OR, 1.45). Adding information about the other evaluated ultrasound features did not lead to a significant result.

CONCLUSION. Malignant thyroid nodules tend to be solid (86.5%). Patients older than 75 years showed a clearly increased risk of nondiagnostic FNAB, but to predict a higher risk of malignancy or of nondiagnostic FNAB using ultrasound remains difficult.

CONCLUSION. Although the radiologic differentiation from malignancy is not clearly possible, we suggest that familiarity with the manifestations of inflammatory pseudotumor can help avoid unnecessary radical surgery before histopathologic proof of malignancy.