Objective. To compare magnetic resonance imaging (MRI), conventional radiography, and ultrasonography in identifying bone erosions in patients with juvenile idiopathic arthritis (JIA), and to determine the validity and reliability of an MRI scale in detecting and grading joint damage. Methods. In 26 JIA patients, the clinically more affected wrist was studied with MRI, radiography, and ultrasonography, coupled with standard clinical assessment and biochemical analysis. MR images were assessed independently by 2 readers according to an apposite devised scoring system. Results. Of 26 patients, 25 (96.1%) had 1 or more erosions as detected by MRI, whereas conventional radiography and ultrasonography revealed erosions in 13 (50%) of 26 and 12 (50%) of 24 patients, respectively. The ability of MRI to detect erosive changes was significantly higher with respect to conventional radiography (P ‫؍‬ 0.002 with Bonferroni correction [P B ]) and ultrasonography (P B ‫؍‬ 0.0002) in the group of patients with <3 years' disease duration. Ultrasonography and conventional radiography were of equivalent value for the detection of destructive changes. Wrist MRI score correlated highly with radiographic erosion score (r s ‫؍‬ 0.82) and with wrist limited range of motion score (r s ‫؍‬ 0.69). The interreader intraclass correlation coefficient (ICC) for MRI score was excellent (0.97); intrareader ICCs were good for both investigators (0.97 and 0.79). Conclusion. MRI seems to be a powerful tool to detect early structural damage in JIA. The proposed MRI scale for bone erosions appears promising in terms of reliability and construct validity. The pathophysiologic meaning and the prognostic value of bone erosions revealed only by MRI remain to be established in longitudinal studies.

Objective. To determine the efficacy of dynamic gadolinium-enhanced magnetic resonance imaging (MRI) of the wrist in the evaluation of disease activity in patients with rheumatoid arthritis (RA).Methods. Thirty-six patients with RA (with different degrees of disease activity) and 5 healthy controls were studied. MRI was performed with a low-field (0.2T), extremity-dedicated machine. After an intravenous bolus injection of gadolinium-diethylenetriamine pentaacetic acid, 20 consecutive fast spin-echo images of 3 slices of the wrist were obtained every 18 seconds.Results. The curves of synovial membrane enhancement identified the following 2 groups: controls and RA patients in remission, and RA patients with active or intermediately active disease. Both the rate of early enhancement (REE) and relative enhancement (RE) were significantly higher in patients with active RA than in those with inactive RA and controls. The REE and RE were significantly correlated with the number of swollen joints (P < 0.00001 and P ‫؍‬ 0.003, respectively), the number of tender joints (P < 0.00001 and P ‫؍‬ 0.004, respectively), the Ritchie index (P ‫؍‬ 0.0002 for both REE and RE), the Disease Activity Score (P ‫؍‬ 0.0004 and P ‫؍‬ 0.0008, respectively), the Health Assessment Questionnaire (HAQ) (P ‫؍‬ 0.0002 and P ‫؍‬ 0.0007, respectively), early morning stiffness (P ‫؍‬ 0.001 and P ‫؍‬ 0.009, respectively), the C-reactive protein level (P ‫؍‬ 0.015 and P ‫؍‬ 0.03, respectively), the erythrocyte sedimentation rate (P ‫؍‬ 0.03, RE only), and ␣2 globulins (P ‫؍‬ 0.036 and P ‫؍‬ 0.028, respectively).Conclusion. Our data support use of dynamic MRI for discriminating active from inactive RA. Enhancement curves are associated not only with laboratory and clinical indicators of inflammation, but also with the HAQ, a relevant predictor of RA functional outcome. This technique can be repeated frequently and is an excellent candidate for the ideal method for the followup of patients with RA.

Our initial results show that MRI can detect intra- and extra-mural lesions of CD. The high concordance observed between MRI, endoscopy, US and Doppler US findings suggests that MRI is at least comparable for diagnostic capability with these techniques offering, thanks to multiplanar projections, an improved visualisation of the bowel without ionising radiation.

DCE-MRI represents a promising method for the assessment of disease activity in JIA, especially in patients with wrist arthritis. As far as we know, this study is the first to demonstrate the feasibility, reliability and construct validity of DCE-MRI in JIA. These results should be confirmed in large-scale longitudinal studies in view of its further application in therapeutic decision making and in clinical trials.