The usefulness of virtual MR arthroscopy as an adjunct to conventional MR arthrography in detecting anterior labral lesions of the shoulder

OBJECTIVE. The objective of this study was to investigate the usefulness of virtual MR arthroscopy as an adjunct to conventional MR arthrography in detecting various antero-inferior glenoid labral lesions. MATERIALS AND METHODS. The study group was composed of 28 patients(22 men and six women; mean age, 25 years) who underwent direct MR arthrography of the shoulder as well as arthroscopy due to recurrent shoulder dislocations. MR arthrography examinations were reviewed retrospectively with radiologists blinded to the arthroscopic diagnoses. Virtual MR arthroscopy was produced from fat-suppressed 3D gradient-recalled echo MR arthrography using volume-rendering software. The sensitivity, specificity, and accuracy for diagnosis were calculated. The diagnostic performances were validated by receiver operating characteristic curve analysis. RESULTS. The structure of the glenoid labrum was well visualized in a 3D perspective, and characterization of the injured anterior glenoid labrum was aided by adjunct use of virtual MR arthroscopy. The accuracy for detecting classic Bankart, anterior labroligamentous periosteal sleeve avulsion, and Perthes lesions improved to 85.7%, 85.7%, and 92.9%, respectively, with adjunct virtual MR arthroscopy with MR arthrography versus 78.6%, 82.1%, and 89.3%, respectively, with MR arthrography alone. A statistically significant improvement of the diagnostic capability of MR arthrography with adjunct virtual MR arthroscopy was proven for the detection of a classic Bankart lesion(p <5). ONCLUSION. Having a 3D perspective to validate chronic recurrent glenoid labral injuries of the shoulder facilitated understanding of the anatomic relationships and helped diagnosis. Adjunct virtual MR arthroscopy is potentially useful for detecting and characterizing chronic recurrent glenoid labral lesions to improve diagnosis.