Evaluation of preoperative MR imaging of rotator cuff and labral lesions of the shoulder

Background. MR imaging is the method of choice in the diagnostic of soft tissue structures. As to shoulder injuries it is widely used for the diagnosis of rotator cuff and labral lesions. An evaluation of MR imaging is done by correlation of the preoperative imaging to the results of shoulder arthroscopy. Methods. From 8/2003 to 8/2007 162 arthroscopic shoulder examinations with 161 patients were performed. In 146 patients MR imaging was done before surgery. MR imaging was performed using established examination protocols with transverse, paracoronal and parasagittal scans in nonenhanced T1 and T2 contrast. The retrospective study embraced 146 patients (60 female, 86 male, mean age 52 years). The MR imaging was done because of clinical aspects of the examination, after shoulder injury or in the case of longlasting shoulder pain without diagnosis. MR imaging is correlated to the arthroscopic findings. The statistic evaluation is done with chi(2) test and contingence tables. Results. A transmural rotator cuff tear was diagnosed by MR imaging in 76 patients. By shoulder arthroscopy 82 transmural cuff tears could be found. One tear described by MR imaging could not be certified by arthroscopy. 7 lesions were not described preoperatively, 4 of the subscapularis tendon and one of the supraspinatus tendon. This means a sensitivity of MR imaging of 0.90 and a specifity of 0.91. Discussion. Native MR imaging is a reliable diagnostic procedure for the evaluation of transmural rotator cuff tears. Labral lesions however and especially SLAP lesions can not always be found by a routine native MRI. Here special scans, for instance in ARBER position or contrast enhanced techniques should be taken in consideration to improve the correlation to arthroscopic results.