Diagnostic Accuracy of Ultrasonography Compared with Magnetic Resonance Imaging for Rotator Cuff Pathologies of the Shoulder: A Cross-Sectional Study

Open Access

Abstract

Background: Rotator cuff disorders are common causes of shoulder pain and functional impairment. Accurate imaging is important for identifying tendon abnormalities and guiding appropriate management. Ultrasonography (USG) is a readily available, non-invasive, and cost-effective imaging modality, whereas magnetic resonance imaging (MRI) provides comprehensive multiplanar assessment of soft-tissue structures. This study evaluated the diagnostic accuracy of USG compared with MRI for detecting rotator cuff pathologies of the shoulder. Methods & Materials: This cross-sectional study included 40 participants with clinically suspected shoulder musculotendinous pathology. We compared USG findings with MRI findings to detect rotator cuff abnormalities, particularly involving the supraspinatus, subscapularis, and infraspinatus tendons. Diagnostic performance was assessed using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy, and Cohen's kappa agreement. Results: The mean age of participants was 50.1 ± 10.8 years, and 70.0% were male. USG demonstrated high diagnostic performance for supraspinatus abnormalities, with sensitivity ranging from 91.7% to 100.0%, specificity from 95.5% to 97.2%, and accuracy from 95.0% to 97.5%. For subscapularis lesions, sensitivity ranged from 92.9% to 100.0%, specificity from 96.2% to 100.0%, and accuracy from 95.0% to 100.0%. Infraspinatus lesions showed comparatively lower sensitivity, particularly for partial-thickness tears (66.7%) and tendinosis (75.0%), although specificity remained high. Conclusion: USG demonstrated high diagnostic accuracy and substantial-to-almost-perfect agreement with MRI for most rotator cuff pathologies. It may therefore serve as a useful first-line imaging modality, while MRI remains valuable for equivocal or complex lesions.