MR DIAGNOSIS OF SUPERIOR LABRAL ANTERIOR-POSTERIOR (SLAP) INJURIES OFTHE GLENOID LABRUM - VALUE OF ROUTINE IMAGING WITHOUT INTRAARTICULAR INJECTION OF CONTRAST MATERIAL

OBJECTIVE. Superior labral anterior posterior (SLAP) lesions are pecul iar types of tears that involve the superior and anterior aspects of t he glenoid labrum and extend posteriorly. The biceps tendon may also b e involved In the injury. There have been conflicting reports in the l iterature about the value of MR imaging in depicting these injuries. S ome authors have advocated imaging in special planes and, more recentl y, the use of intraarticular injection of contrast material to facilit ate the diagnosis of SLAP injuries. Symptoms of SLAP injury of the gle noid labrum are nonspecific, acid patients are often imaged according to routine imaging protocols that include images in axial, oblique cor onal, and oblique sagittal planes using spin-echo pulse sequences. Int raarticular injection of contrast material is not part of routine MR i maging of the shoulder. We sought to determine the value of routine MR imaging without intraarticular contrast enhancement in the diagnosis of SLAP injuries of the glenoid labrum. MATERIALS AND METHODS. The MR images of eight patients with arthroscopically proved SLAP lesions wer e selected for this study. The MR imaging appearance of the glenoid la brum, biceps tendon attachment, and rotator cuff tendons were retrospe ctively evaluated in the axial, oblique coronal, and oblique sagittal planes in each case. The findings were correlated with the surgical ob servations. RESULTS. All eight patients showed an abnormal labrum on t he coronal MR images, on 88% of the axial images, and on 50% of the sa gittal images. An oblique or horizontal linear focus of increased sign al was seen to traverse-the labrum in 50% of the cases on sagittal ima ges. Fifty percent of the cases also showed an intraarticular body, pr esumably representing the displaced fragment of a bucket-handle tear, on all imaging planes (the MR ''Cheerio'' sign). CONCLUSION. Routine M R imaging of the shoulder without intraarticular injection of contrast material is useful in the diagnosis of SLAP injuries of the glenoid l abrum.