16-Slice MDCT Arthrography of the Shoulder: Accuracy for Detection of Glenoid Labral and Rotator Cuff Tears

PURPOSE: We wanted to determine the diagnostic accuracy of 16-slice MDCT arthrography (CTA) for glenoid labral and rotator cuff tears of the shoulder. MATERIALS AND METHODS: We enrolled forty-five patients who underwent arthroscopy after CTA for pain or instability of the shoulder joint. The CTA images were analyzed for the existence, sites and types of glenoid labral tears and the presence and severity of rotator cuff tears. We determined the sensitivity, specificity and accuracy of CTA for detecting glenoid labral and rotator cuff tears on the basis of the arthroscopy findings. RESULTS: At arthroscopy, there were 33 SLAP lesions (9 type I, 23 type II and 1 type III), 6 Bankart lesions and 31 rotator cuff lesions (21 supraspinatus, 9 infraspinatus and 1 subscapularis). On CTA, the sensitivity, specificity and accuracy for detecting 24 SLAP lesions, excluding the type I lesions, were 83%, 100% and 91%, the total rotator cuff tears were 90%, 100% and 98%, the full thickness supraspinatus tendon tears were 100%, 94% and 96%, and the partial thickness supraspinatus tendon tears were 29%, 100% and 89%, respectively. CONCLUSION: 16-slice MDCT arthrography has high accuracy for the diagnosis of abnormality of the glenoid labrum or rotator cuff tears and it can be a useful alternative to MRI or US.

Anterior Labral Tear: Diagnostic Value of MR Arthrography of the Shoulder

PURPOSE: To assess the accuracy of magnetic resonance(MR) arthrography in the diagnosis of anterior labral tear of the shoulder. MATERIALS AND METHODS: Between Semptember 1996 and February 2000, MR arthrography of the shoulder was performed in 281 patients with a history of shoulder pain or instability. Among this total, only 157 shoulders in 154 patients who underwent arthroscopy or open surgery 0 to 230 (average, 20.9) days after MR arthrography were included in this study; the subjects comprised of 150 males and 4 females with an average age of 23.3 years. MR arthrographs of these 154 patients were analyzed for the presence of anterior labral tears, and the findings were correlated with the arthroscopic and surgical findings. Anterior labral tear was classified as A to D according to its location, as determined by arthroscopy and surgery. (A=4 to 6 o 'clock direction, anteroinferior; B=2 to 4 o 'clock direction, central; C=12 to 2 o 'clock direction, anterosuperior; D= SLAP lesions). The retrospective analysis of MR arthrographs showing false-positive and negative findings was also undertaken. RESULTS: In the diagnosis of anterior labral tear, MR arthrography showed a sensitivity of 94%, a specificity of 90% and an accuracy of 91%. Anterior labral tears were confirmed by arthroscopy or surgery in 62 of the 157 shoulders (39%). Among 62 lesions, two (3%) were observed in area A, 32(52%) in area A+B, nine (15%) in area A+B+C, one(2%) in area A+B+D, 13(21%) in area A+B+C+D, two (3%) in area B+C, one(2%) in area B+D, and two(3%) in area C. Among ten false-positive cases, seven were focal lesions (two, three and two lesions in area A, B and C, respectively), and in the remaining three cases, located in area A+B, MR arthrography revealed thickening and deformation. All four false negatives were focal lesions (two in area A and two in area C). CONCLUSION: Other than in focal lesions, in which accuracy was relatively low, MR arthrography showed high sensitivity, specificity and accuracy in the diagnosis of anterior labral tear of the shoulder.

Subchondral Cysts of the Humeral Head: MR Imaging Findings

PURPOSE: To evaluate the findings of subchondral cyst of the humeral head, as seen on shoulder MRarthrography MATERIALS AND METHODS: Sixty-three patients( M:F=62:1 ; mean age 23 years) who underwent shoulder MRarthrography between September 1996 and May 1998 were retrospectively reviewed. No patient had a history of eithershoulder dislocation or certain diseases known to be commonl accompanied by subchondral cysts. All MR images wereobtained using a 1.5 Tesla unit after intraarticular injection of 20ml of diluted contrast material. T1 andT2-weighted axial, oblique coronal, and oblique sagittal images were analysed for the presence, location, number,shape, size, and connection to the joint cavity of subchondral cysts. RESULTS: We identified 58 subchondral cystsin 43(71.7%) of 63 cases. All were located in the posterolateral portion of the humeral head, and on the physealline. Twenty-eight patients(65.1%) had one cyst, and 15(34.9%) had two. Thirty-four cysts(58.6%) were round orovoid in shape and, 2-8mm in diameter(average, 3.9mm) ; 24(41.4%) were lobulated and 3-10mm in diameter(average5.3mm). Fifty-three cysts(91.4%) were connected to the joint cavity. CONCLUSIONS: In symptomatic patients, the incidence of subchondral cyst of the humeral head was 71.7%. All were located in the posterolateral portion, andon the physeal line. Most subchondral cysts were connected with the joint cavity.

Analysis of shoulder MR imaging using Receiver Operating Characteristic curve

PURPOSE: To assess the utility of shoulder MRI by using ROC (receiver operating characteristic) curve in theevaluation of rotator cuff tear, anterior labral tear, superior labral tear and Hill-Sachs Lesion. MATERIALS AND METHODS: We evaluated 38 arthroscopically confirmed patients who had undergone shoulder MRI. According to thesignal intensity of the rotator cuff, as seen on T2 and proton density imaging, a five-stage grading system wasdevised. Labral tears were graded according to the separation of the labium; this was based on gleaned,morphologic and signal intensity changes of the labrum : six grades of anterior labral tear and three grades ofsuperior labral tear. Hill-sachs lesion was also classified into four grades according to morphologic and signalchanges of the humeral head. These findings were reviewed by two musculoskeletal radiologists and ROC curves andareas under the curve (Az) was abtained. RESULTS: The ratio of area under the curve of rotator cuff tear,anterior labral tear, superior labral tear and Hill-Sachs lesion were 82.4%, 88.%%, 62.4% and 91.3%, respectively. CONCLUSION: The Accuracy of shoulder MRI using ROC curve was relatively high in rotator cuff tear, anteriorlabral tear and Hill-Sachs lesion, but low in superior labral tear.