Reactive synovitis of the knee joint : MR imaging appearance with arthroscopic correlation

• Published in: Skeletal radiology Vol. 29; no. 10; pp. 577 - 582
• Main Authors: BREDELLA, Miriam A, TIRMAN, Phillip F. J, WISCHER, Thorsten K, BELZER, John, TAYLOR, Andrew, GENANT, Harry K
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.10.2000; Springer Nature B.V
• Subjects: Adult; Arthritis; Arthroscopy; Biological and medical sciences; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Knee; Knee Injuries - complications; Knee Joint - pathology; Magnetic Resonance Imaging; Male; Medical sciences; Osteoarticular system. Muscles; Pain management; Prospective Studies; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Sensitivity and Specificity; Synovial Membrane - pathology; Synovitis - etiology; Synovitis - pathology; Knee; Human; Synovitis; Methodology; Diseases of the osteoarticular system; Lower limb; Test reliability; Nuclear magnetic resonance imaging; Trauma; Knee disease; Accuracy; Sensitivity; Specificity; Association; Arthropathy; Medical imagery; Diagnosis; Technique
• ISSN: 0364-2348; 1432-2161
• DOI: 10.1007/s002560000259

To evaluate the use of routine MR imaging sequences in detecting and characterizing secondary reactive synovitis of the knee joint using arthroscopy as the standard of reference. Fifty consecutive patients with a history of knee pain who were referred for MR imaging and subsequently underwent arthroscopy of the knee comprised the study group. MR images were evaluated for the presence and appearance of synovitis reflected in synovial thickening and irregularity. Synovial thickening was graded on MR imaging as follows: 0=normal, 1=thin line of increased signal intensity, 2=increased signal intensity with frond-like or hair-like projections and a granular appearance of joint fluid. Standard knee imaging protocols were used. The sensitivity, specificity, and accuracy of MR imaging in detecting synovitis compared with arthroscopy were 88%, 97%, and 95%, respectively. Grade 1 synovitis was best seen on proton-density-weighted images, demonstrating increased signal intensity of the synovium against the relatively low signal intensity of the joint fluid. Grade 2 synovitis was best seen on proton-density images and T2-weighted spin echo and fast spin echo images with fat saturation, demonstrating a granular and linear hair-like appearance of joint fluid. Axial and sagittal imaging planes were most helpful in the diagnosis of synovitis. Routine MR pulse sequences are useful in identifying the presence and extent of synovial abnormalities. The detection of different stages of synovial pathology should become an important part of the evaluation of the post-traumatic patient as treatment may be altered as a result.