Diagnostic Accuracy of Ultrasonography in Detection of Destructive Changes in Small Joints of Hands in Patients of Rheumatoid Arthritis: A Comparison with Magnetic Resonance Imaging.

Background: Ultrasonography can be used in early Rheumatoid Arthritis to determine and to follow parameters of joint inflammation, such as effusion, synovitis, and marginal erosion that can be radiologically occult. We therefore planned a study to investigate whether Ultrasonography could provide information on signs of inflammation and destruction in Rheumatoid Arthritis affected finger joints that was not available with Radiography and compared it to the information provided by Magnetic resonance imaging.
Study Design: Hospital Based Descriptive Study.
Methods: The study included 30 patients fulfilling American College of Rheumatology 2010 criteria of Rheumatoid Arthritis with no erosions present on radiographs of hands. Erosion, Synovial thickening/vascularity, effusion and Tenosynovitis of Flexor tendon sheath / Extensor tendon sheath were assessed on both Ultrasonography and Magnetic resonance imaging.
Stastical Analysis: Considering Magnetic resonance imaging as gold standard sensitivity, specificity, positive predictive value, negative predictive value and kappa value of Ultrasonography were calculated. Kappa value was calculated by kappa statistics to show agreement between the two modalities.
Results: Ultrasonography and Magnetic resonance imaging had near perfect agreement for detecting synovial thickening and vascularity, substantial agreement for detecting effusion, Flexor tendon sheath / Extensor tendon sheath inflammation, and only moderate agreement for detecting erosions in Metacarpophalangeal and Proximal interphalangeal joints.
Conclusion: The early diagnosis of Rheumatoid Arthritis by Ultrasonography and MRI is very important to early treatment of Rheumatoid Arthritis. Ultrasonography is a reliable method for assessing inflammatory activity and destructive changes in small joints of hand as the Ultrasonographic findings are comparable to those of MRI.