GLENOID LABRAL TEARS - PROSPECTIVE EVALUATION WITH MR-IMAGING, MR ARTHROGRAPHY, AND CT ARTHROGRAPHY

OBJECTIVE. We prospectively compared MR imaging, MR arthrography, and CT arthrography to determine the sensitivity of each technique in dete cting glenoid labral tears and in determining whether the labrum is de tached or degenerated. SUBJECTS AND METHODS. Thirty patients 19-39 yea rs old (mean, 27 years old) who had either signs and symptoms of shoul der instability or shoulder pain of unexplained origin were referred f or diagnostic imaging. Each patient underwent MR imaging, followed by MR arthrography after intraarticular injection of 25 ml of a dilute so lution of gadopentetate dimeglumine. Twenty-eight of thirty patients u nderwent CT arthrography after intraarticular injection of air and rad iographic contrast material. Each patient also underwent arthroscopy o r open surgery. RESULTS. At surgery, labral tears were found in 28 pat ients; a detached fragment was found in 26 patients. The labrum was fo und to be degenerated in 18, A labral tear was detected on MR images i n 26 (93%) of 28, on MR arthrograms in 27 (96%) of 28, and on CT arthr ograms in 19 (73%) of 26. A detached labral fragment was detected on M R images in 12 (46%) of 26, on MR arthrograms in 25 (96%) of 26, and o n CT arthrograms in 13 (52%) of 25. Labral degeneration was detected o n MR images in two (11%) of 18, on MR arthrograms in 10 (56%) of 18, a nd on CT arthrograms in four (24%) of 17. MR arthrography was the best of the three imaging techniques for showing the inferior part of the glenoid labrum and inferior glenohumeral ligament. CONCLUSION. MR arth rography and MR imaging both showed labral tears with greater sensitiv ity than CT arthrography did. MR arthrography was the most sensitive o f the three techniques for detecting a detached labral fragment and la bral degeneration. Furthermore, MR arthrography afforded the best visu alization of the inferior part of the labrum and the inferior glenohum eral ligament. MR imaging and MR arthrography also enabled direct visu alization of rotator cuff disease and other unsuspected associated abn ormalities.