64-slice MDCT arthrography in shoulder instability: our experience.

PURPOSE: This study was performed to assess the diagnostic accuracy of air-contrast 64-slice multidetector computed tomography (MDCT) arthrography in the evaluation of glenohumeral joint instability by comparison with conventional arthroscopy. MATERIALS AND METHODS: Fifty patients with a history of shoulder instability underwent MDCT arthrography with thin collimation scans. The raw data were transferred to a workstation and processed using multiplanar reformation (MPR) and volume rendering (VR) algorithms. All patients subsequently underwent conventional arthroscopy. The results of the two techniques were compared and their sensitivity and specificity calculated. RESULTS: We diagnosed eight anterosuperior labrum lesions (group 1), 32 anteroinferior labrum lesions (group 2) and two posterior labrum lesions (group 3). Overall sensitivity and specificity (groups 1, 2, 3) were 88% and 100%, respectively. In group 1, sensitivity was only 66% (four false negatives), whereas in groups 2 and 3, it was 94% (two false negatives) and 100%, respectively. The labrum lesions were also found to be associated, with 100% sensitivity and specificity, with 20 lax capsules, 17 Hill-Sachs lesions, five Bankart lesions, two Perthes lesions and three complete rotator-cuff tears. CONCLUSIONS: Air-contrast MDCT arthrography is fast, reproducible, well tolerated and very accurate in the evaluation of lesions causing shoulder instability.

US evaluation and diagnosis of rupture of the medial head of the gastrocnemius (tennis leg).

PURPOSE: The aim of this study is to demonstrate the diagnostic accuracy of ultrasonography (US) in the diagnosis of rupture of the medial head of the gastrocnemius muscle, also called "tennis leg" (TL). MATERIALS AND METHODS: Thirty-five consecutive patients with acute traumatic injury of the calf underwent US examination. There were 25 men and 10 women; mean age 47.5 years (range 35-60 years). All examinations were performed using a 5-12 MHz broadband electronic linear array probe. RESULTS: Thirty-three out of 35 patients had TL; 24 cases of partial rupture and nine cases of complete rupture were diagnosed. In the remaining two cases, both with symptoms suggesting TL, one patient had a tear of the proximal musculotendinous junction and one had a ruptured Baker's cyst. Fluid collections caused by the muscular rupture were visible as hypoechoic areas; in 80% of cases associated by a hyperechoic oval area due to hematoma and local inflammation. The degree of fluid collection in the patients with complete rupture (6-16 mm; mean: 9.7 mm) was significantly greater than the one seen in patients with partial rupture (4-8 mm; mean: 6.8 mm). CONCLUSIONS: US is the imaging modality of choice in clinical suspicion of TL, both in the initial workup of the patient and in the follow-up. US is easy to perform and is particularly useful to distinguish TL from other pathologies, especially ruptured Baker's cyst and deep vein thrombosis, which require a different therapeutic management.