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.

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.

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. 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. 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.

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.