Imaging of Knee Joint Pathologies: A Comparative Study of Ultrasound and Magnetic Resonance Imaging

Background: Magnetic resonance imaging (MRI) has been accepted as the best non-invasive imaging modality for the evaluation of knee joint pathology but the advantages of ultrasound (US) over magnetic resonance imaging (MRI) are that the ultrasound is readily available, cheap and offers real-time imaging. Aim: To assess the accuracy of ultrasound in diagnosing knee joint pathologies using MRI as a reference. Materials And Methods: 50 patients were evaluated prospectively over a period of 1.5 years by USG followed by MRI of the affected knee. Accuracy of USG was calculated with MRI as reference. Results: In our study, the majority of patients were in age group 21-30 years. Perfect agreement was noted between ultrasound and MRI for detecting Baker’s cyst. Near perfect agreement was noted between ultrasound and MRI for detecting joint effusion, soft tissue edema and osteophytes. Substantial agreement was noted between ultrasound and MRI for Collateral ligaments tear and Meniscal injuries. Moderate agreement was noted between ultrasound and MRI for PCL tear. Fair agreement was noted between ultrasound and MRI for ACL tear. Conclusion: Knee USG has high accuracy in diagnosing pathologies like knee joint effusion, synovitis, popliteal/baker’s cysts, soft tissue edema/cellulitis, arthritic changes, collateral ligament and meniscal tears. Keywords: Knee joint pathologies, Ultrasound, MRI, Ligaments