Diagnostic accuracy of ultrasound in rotator cuff and associated non-rotator cuff pathologies of shoulder joint compared to magnetic resonance imaging

Abstract

Objectives: The present study was carried out to evaluate diagnostic accuracy of ultrasound (US) in delineating various rotator cuff and associated non rotator cuff pathologies (RCPs) of shoulder joint compared to Magnetic Resonance Imaging (MRI). Methods: Fifty consecutive symptomatic subjects in age-group 18-75 years (mean ±SD: 56.0±13.6 years; 39-male, 11-female) were evaluated. US performer and MRI reporting radiologists were blinded to results of each-other. The sensitivity, specificity, and accuracy of US was measured for diagnosing various musculo-tendinous pathologies of shoulder against MRI gold standard. Results: MRI detected RCPs in all subjects while US was abnormal in 46(92%) cases. Supraspinatus was the most frequently affected tendon. Remarkably, 28% patient had polytendon abnormalities. US showed sensitivity of 84% and specificity of 87.5% for tendinosis; sensitivity of 78.1% and specificity of 94.4% for partial thickness tear (PTT) and 100% sensitivity and specificity for diagnosing full thickness tear. However, sensitivity of US for diagnosing PTT of infraspinatus tendon, subscapularis tendinosis and teres-minor atrophy was low. US had high specificity for diagnosing non-RCPs but sensitivity was low. Conclusions: A normal shoulder US may not rule out with certainty some rotator cuff and associated non-rotator cuff abnormalities. It is suggested to search for polytendon abnormalities which may be missed.