Isolated peroneal tenosynovial lipoma arborescens: multimodality imaging features.

Synovial lipoma arborescens is a rare and benign fatty proliferative lesion of the synovium that is most commonly seen within the suprapatellar pouch of the knee, but increasingly reported to involve tendon sheaths, including those of the ankle. We present the third known case of tenosynovial lipoma arborescens isolated to the peroneal tendon sheath without ankle joint involvement. To our knowledge, this is the first to report this entity utilizing a unique combination of radiographic, sonographic, and MR imaging, along with intraoperative and histologic correlation. Knowledge of this case is important when interpreting radiographic or sonographic images of this condition to raise the possibility of the rare entity of lipoma arborescens involving the peroneal tendon sheath.

Accuracy of non-arthrographic 3T MR imaging in evaluation of intra-articular pathology of the hip in femoroacetabular impingement.

OBJECTIVE: To investigate the accuracy of non-arthrographic 3-T MRI compared to hip arthroscopy in the assessment of labral and cartilaginous pathology in patients with suspected FAI. MATERIALS AND METHODS: Following IRB approval and waived consent, 42 consecutive cases of suspected FAI with non-arthrographic 3-T MRI and arthroscopy of the hip were reviewed. High-resolution TSE MR imaging was evaluated in consensus by two musculoskeletal radiologists, blinded to arthroscopic findings, for the presence of labral tears and articular cartilage lesions. Acetabular cartilage was categorized as normal, degeneration/fissuring, delamination, or denudation. MRI findings were compared to arthroscopy. Sensitivity, specificity, accuracy, and predictive values for MRI were calculated using arthroscopy as the standard of reference. RESULTS: Forty-two hips in 38 patients with a mean age of 29 (range 13-45 years) were assessed. Mean interval between MRI and arthroscopy was 154 days (range 27-472 days). MRI depicted 41 cases with labral tears (sensitivity 100%, specificity 50%, accuracy 98%, PPV 98%, NPV 100%), 11 cases with femoral cartilage abnormalities (sensitivity 85%, specificity 100%, accuracy 95%, PPV 100%, NPV 94%), and 36 cases with acetabular cartilage lesions (sensitivity 94% specificity 67%, accuracy 90%, PPV 94%, NPV 67%). Of the 36 cases with acetabular cartilage lesions on MRI, 7 were characterized as degeneration/fissuring, 26 as delamination, and 3 as denudation, with discordant results between MRI and arthroscopy for grading of articular cartilage in ten cases. CONCLUSION: Non-arthrographic 3-T MR imaging is a highly accurate technique for evaluation of the labrum and cartilage in patients with clinically suspected FAI.

MR imaging of the spine and sacroiliac joints for spondyloarthritis: influence on clinical diagnostic confidence and patient management.

PURPOSE: To quantify the effect of magnetic resonance (MR) imaging of the spine and sacroiliac joints on clinical diagnostic confidence and to determine if MR imaging affects treatment of patients with axial spondyloarthritis. MATERIALS AND METHODS: This prospective observational study was approved by the research ethics board and included 55 consecutive patients referred by three rheumatologists for MR imaging of the spine and sacroiliac joints. Measures of diagnostic confidence for clinical features (inflammatory back pain, mechanical back pain, muscular back pain, radicular back pain, spondylitis, sacroiliitis, and other) and overall diagnoses were made by using a Likert scale both before and after MR imaging. Proposed treatment was similarly recorded before and after MR imaging interpretation. The McNemar test was performed to determine the change in diagnostic confidence and consequent effect on patient treatment. RESULTS: Diagnostic confidence for specific clinical features improved significantly after MR imaging for inflammatory back pain (14% vs 76%, before vs after; P < .001), mechanical back pain (4% vs 49%, P < .001), spondylitis (7% vs 76%, P < .001) and sacroiliitis (9% vs 87%, P < .001). Confidence for overall diagnoses also improved significantly after MR imaging for ankylosing spondylitis (29% vs 80%, P < .001), undifferentiated spondyloarthritis (58% vs 93%, P < .001) and osteoarthritis (29% vs 64%, P < .001). Of the 23 patients for whom tumor necrosis factor-α inhibitor (TNFi) therapy was recommended before MR imaging, 12 (52%) were prescribed TNFi therapy after MR imaging. Of the 32 patients for whom TNFi therapy was not recommended before MR imaging, 10 (31%) patients were prescribed TNFi therapy after MR imaging. Overall, 22 (40%) patients had a change in treatment recommendation regarding TNFi therapy after MR imaging. CONCLUSION: MR imaging of the spine and sacroiliac joints significantly influences the diagnostic confidence of rheumatologists regarding clinical features and overall diagnoses of axial spondyloarthritis, and consequently significantly affects treatment plans.

MRI of the metatarsophalangeal joints: improved assessment with toe traction and MR arthrography.

OBJECTIVE: This study evaluates the impact of toe traction and direct MR arthrography on the assessment of articular cartilage and plantar plates of the first and second metatarsophalangeal joints. MRI of five cadaveric feet was obtained utilizing four techniques: before arthrography without and with traction and after arthrography without and with traction. CONCLUSION: The combination of toe traction and MR arthrography is perceived to be superior in the articular cartilage and plantar plate evaluation.

Radiology-pathology conference: cutaneous angiosarcoma of the leg.

Cutaneous angiosarcoma is a rare aggressive vascular neoplasm with a poor prognosis, seen usually in the elderly population in a background of chronic lymphedema. We present a case of cutaneous angiosarcoma of the leg without any chronic lymphedema with clinicoradiological and histological correlation.

The utility of multidetector computed tomography for detection of parathyroid disease in the setting of primary hyperparathyroidism.

PURPOSE: The aim of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) in the detection of parathyroid adenoma and hyperplasia in the setting of primary hyperparathyroidism. METHODS: Records of 48 patients with biochemically confirmed primary hyperparathyroidism, who underwent preoperative imaging with 16- or 64-slice contrast-enhanced MDCT and subsequent successful parathyroidectomy over a 3-year period, were reviewed. Two radiologists, blinded to the operative and histologic findings, independently evaluated multiplanar computed tomographic images for all patients. RESULTS: On pathologic examination, 63 abnormal glands were confirmed in 41 female and 7 male patients (mean age, 63 years). Of the 63 abnormal glands, 40 were adenomatous and 23 were hyperplastic. MDCT demonstrated an 88% (95% confidence interval [CI], 77%-99%) positive predictive value for localizing abnormal hyperfunctioning parathyroid glands. The sensitivity of MDCT in detecting single-gland disease was 80% (95% CI, 68%-92%); whereas the specificity for ruling out hyperfunctioning parathyroid tissue, either adenomatous or hyperplastic, was 75% (95% CI, 51%-99%). The sensitivity for exclusively localizing parathyroid hyperplasia was 17% (95% CI, 2%-33%). The parathyroid adenomas were substantially larger and heavier than their hyperplastic counterparts, with an average weight of 1.51 g (range, 0.08-6.00 g) and 0.42 g (range, 0.02-2.0 g) for adenoma and hyperplasia, respectively. CONCLUSIONS: Contrast-enhanced MDCT demonstrated an 88% positive predictive value for localizing adenomatous and hyperplastic parathyroid glands. The poor sensitivity for detection of multigland disease was likely a result of the smaller size and weight of the abnormal hyperplastic glands.