3-DIMENSIONAL MRI OF THE GLENOID-LABRUM

The objective of this study was to assess the accuracy of three-dimens ional (3D) magnetic resonance imaging (MRI) reformation in the evaluat ion of tears of the glenoid labrum complex (GLC). Fifty-five shoulders were evaluated by MRI using standard spin-echo sequences. Gradient-re focused-echo axial projections were used to assess the GLC on the two- dimensional (2D) studies. Three-dimensional Fourier transform multipla nar gradient-recalled imaging with a resolution of 0.7 mm was also per formed in all patients. Independent analyses of the anterior and poste rior labra were performed in a blinded manner for both the 2D and 3D s tudies by three experienced musculoskeletal radiologists. Observations of the imaging studies were compared with the videoarthroscopic findi ngs. The appearance of the GLC was rated on a scale of 0 to 4 (0-2=nor mal, 3, 4=abnormal or tom). The diagnostic confidence was averaged fro m the three reader's scores. Anterior labral tears were effectively de tected with sensitivities of 89% and 96% and specificities of 96% and 100% (P<0.0001) for the 2D and 3D studies, respectively. For posterior labral tears, the sensitivity and specificity of the 2D method were 4 7% and 98%, respectively. The sensitivity and specificity of the 3D vo lume sequence were 53% and 98%, respectively. The lower sensitivity of both imaging methods for detecting posterior labral tears may be infl uenced by the smaller number (n=5) of arthroscopically confirmed cases in our study and reflects the difficulty of viusalizing the posteroin ferior borders of the GLC with present MRI techniques.