Objective: The purpose of our study was to prospectively compare the diagnostic accuracy of 3D isotropic indirect MR arthrography with conventional sequences of indirect MR arthrography for the diagnosis of labral and rotator cuff lesions on a 3-T MR unit.
Subjects and methods: Thirty-six consecutive patients who were scheduled for shoulder arthroscopic surgery at our institution underwent indirect MR arthrography. Both conventional sequences and an additional 3D isotropic sequence were obtained 1 day before arthroscopic surgery. Two musculoskeletal radiologists prospectively evaluated the images in consensus for the presence of superior and anterior labral lesions and subscapularis and supraspinatus-infraspinatus tendon tears using the conventional sequences and the 3D isotropic sequence. We analyzed the statistical difference between the sensitivities and specificities of both methods using arthroscopic findings as the reference standard.
Results: Surgical findings confirmed the presence of 23 superior labral lesions, eight anterior labral lesions, 21 subscapularis tears, and 24 supraspinatus-infraspinatus tears. The sensitivity and specificity of the conventional sequences were 74% and 54% for superior labral lesions, 88% and 96% for anterior labral lesions, 67% and 85% for subscapularis tendon tears, and 96% and 75% for supraspinatus-infraspinatus tendon tears. The sensitivity and specificity of the 3D isotropic sequence were 70% and 85% for superior labral lesions, 100% and 100% for anterior labral lesions, 67% and 85% for subscapularis tendon tears, and 96% and 67% for supraspinatus-infraspinatus tendon tears. No statistically significant difference was seen in sensitivities and specificities for both methods.
Conclusion: Three-dimensional isotropic MR arthrography sequences with multiplanar reconstruction can provide a similar capability for the diagnosis of labral and rotator cuff lesions as conventional MR arthrography sequences but in a shorter imaging time.