Abstract
The purpose of this study was to investigate the efficiency of radial plane of MR arthrogram (R-MRA) for labral lesions of the shoulder. 64 shoulders were examined and all patients had either signs and symptoms of labral lesions. There were 53 men and 11 women, aged 15-45 years old (mean, 21.5 years old), with 48 right and 16 left shoulder abnormalities. The patients were referred to us because of a recurrent dislocation (32 cases), a superior labral abnormality (24 cases), a traumatic first dislocation (6 cases), a recurrent dislocation with a superior labral abnormality (2 cases). Each patient underwent R-MRA after intra-articular injection of 10ml of 0.5% mepivacaine. R-MRA was performed with 1.0-T system (Siemens Harmony). All patients were supine with the humerus in the neutral position. After a radial localizing imaging, intensity and morphological changes in the labrum through all the o'clock positions of the glenoid rim in T2 star images by the FRASH method were evaluated. Labral lesions of all patients were categorized according to Kim and Yamasaki's classification, and the findings on the R-MRA were correlated with the arthroscopical findings. This study showed 68% of sensitivity, 92.7% of specificity, and 82.7% of accuracy through all the o'clock positions of the glenoid rim on the radial plane of MRA. A radial MRA was useful to diagnose the labral leision of the shoulder precisely and from all viewpoints. Though 0.5% mepivacaine is cheaper than gadopentetate meglumine, it did not influenced the enhancement effect.
