MR diagnosis of labral tears of the shoulder: value of T2*-weighted gradient-recalled echo images made in external rotation.

OBJECTIVE

Because several studies have shown that conventional MR imaging can fail to diagnose a significant percentage of labral tears, some authors have proposed obtaining T2*-weighted gradient-recalled echo images with the humerus in external rotation. The purpose of our study was to determine whether the diagnostic accuracy of detecting anteroinferior labral tears by MR imaging would be improved by adding a T2*-weighted gradient-recalled echo sequence with the humerus in external rotation.

MATERIALS AND METHODS

The study included 24 patients for whom axial MR images of the shoulder were obtained with the humerus in both the neutral position and external rotation. Two observers interpreted the images made in the neutral position and then noted any change in their interpretations after viewing findings on the external-rotation images. MR results were correlated with surgical findings. At surgery, 14 anteroinferior labra were found to be torn and 10 were found to be intact.

RESULTS

Both observers identified one patient for whom a surgically proved labral tear was seen only on the external-rotation images. The sensitivity increased from 0.43 to 0.50 (p = .35) for observer 1 and from 0.36 to 0.43 (p = .35) for observer 2. The specificity of 0.90 for both observers remained unchanged. The accuracy improved from 0.62 to 0.67 for observer 1 and from 0.55 to 0.62 for observer 2.

CONCLUSION

The addition of external-rotation T2*-weighted gradient-recalled echo images to the MR examination for tears of the anteroinferior labrum leads to a small but statistically insignificant increase in diagnostic sensitivity. We conclude that the small increase in sensitivity does not justify the routine use of this sequence.