RESUMO
Rotator cuff muscles tears are among the most common problems of shoulder joint. This disorder is diagnosed most commonly by imaging methods especially ultrasound and MRI. According to previous studies, both of these methods have high diagnostic value. Because of small sample sizes and inappropriate gold standards in these studies and also lack of enough studies in our country we decided to conduct this study to compare ultrasound and MRI for diagnosis of rotator cuff muscles tears. We performed shoulder ultrasonography and MRI for 100 patients before shoulder surgery in this descriptive analytical study. The results of ultrasonography and MRI were reported separately by 2 radiologists. Using SPSS 19 software, data were analyzed by McNamara's test. 27 of 100 patients that underwent surgery had tears in rotator cuff muscles [20 with complete tear and 7 with partial tear]. Sensitivity, specificity, positive predictive value and negative predictive value were 92.6%, 95.9%, 89.3% and 97.2% for ultrasonography, and 96.3%, 97.3%, 95.9% and 98.6% respectively for MRI. There was no significant difference between the two methods [P>0.05]. According to the results of this study both of these methods have high accuracy in the diagnosis of rotator cuff muscles tears and can be used for patient evaluation