JUVENILE CHRONIC ARTHRITIS OF THE HIP - VALUE OF CONTRAST-ENHANCED MR-IMAGING

Objective: The purpose of this of this study was to assess the value o f contrast-enhancement in MR diagnosis of hip joint disease in patient s with juvenile chronic arthritis. Patients and methods: Fourteen hips in seven children (four girls, three boys; mean age, 11 years; range, 7-17 years) with juvenile chronic arthritis for a mean duration of se ven years (range, 3-15 years) were imaged on a 0.5T MR unit, One patie nt had an MR scan repeated after an 8-month interval, Axial and corona l T1-weighted spin-echo, and axial gradient-echo sequences were perfor med. T1 weighted axial sequences were repeated immediately after 0.1 m mol/kg of intravenous gadopentetate dimeglumine, Patients were assesse d clinically for pain in the hip, range of motion at the hip joint, ha emoglobin and erythrocyte sedimentation rate. Two radiologists, unawar e of the patients symptoms, jointly assessed the unenhanced and contra st-enhanced scans for synovial hypertrophy (pannus), cartilage destruc tion and joint effusion. Results: Pannus was underestimated on 75% of unenhanced MR scans (95% binomial confidence intervals 54% to 93%), En hancing pannus was seen in 14 of the 16 hip MR scans, Enhancing pannus was associated with articular cartilage destruction in all cases, and joint pain in 13 of 14 scans. Joint effusions were overestimated on u nenhanced scans in all cases, Pannus could only reliably be distinguis hed from joint effusion after contrast enhancement, Both cases of locu lated joint effusion were only seen after contrast enhancement. Conclu sion: Contrast-enhancement is recommended to aid MR detection of disea se activity and extent in children with juvenile chronic arthritis of the hip.