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.