SAT0391 Does dynamic contrast-enhanced mri provide better separation of active early rheumatoid arthritis patients and healthy controls than conventional MRI?. (23rd January 2014) - Axelsen, M.B.
Abstract : Objectives: To identify the MRI parameter that best separates healthy controls from early RA patients. Patterns of enhancement from conventional MRI and dynamic contrast enhanced (DCE)-MRI of healthy controls and of early RA patients with active disease undergoing treatment were compared. Methods: Conventional and DCE-MRI of the wrist and the 2nd-5th metacarpophalangeal (MCP) joints was performed once in 26 healthy controls, age 47.5 (24-64) years (median (range)), and before and after 6 and 12 months of DMARD treatment in 14 early RA patients (age 39 (26-63) years; disease duration <6 months), using a 1.0T Siemens Impact whole body MRI unit (Siemens, Erlangen, Germany). DCE-MRI was obtained in 1 preselected coronal slice covering the wrist and the 2nd-5th MCP-joints. The dynamic sequences were analyzed using Dynamika v. 4.2 (Image Analysis Ltd., Leeds, UK): Regions of interest were drawn delineating the individual joints. The number of enhancing voxels (Nvoxel), the average initial rate of enhancement (IRE, %/s), the average maximal enhancement (ME), MExNvoxel and IRExNvoxel were calculated for the combined examined areas (wrist and 2nd-5th MCP-joint). The conventional contrast-enhanced MR-images were evaluated by the OMERACT RA MRI (RAMRIS) synovitis score. Results: 16 of 26 (61.5%) healthy controls and 13 of 14 (92.9%) RA patients at baseline showed enhancement (Number of enhancing voxels (Nvoxel) median 3 and 362, respectively). Healthy controls values were lower than baseline RA values for all parameters (Mann-Whitney, all p<0.001 (except for ME p=0.003)), Table 1 . At baseline only 1 patient had a baseline RAMRIS below the 95th percentile of the controls, the numbers were 3 for Nvoxel, MExNvoxel and IRExNvoxel and 9 and 10 for IRE and ME, respectively. RAMRIS, Nvoxel, IRExNvoxel (trend) but not IRE, ME, and MExNvoxel decreased from baseline to 6 months after start of treatment (Wilcoxon signed rank test, p=0.003, 0.038, 0.050, 0.26, 0.374, and 0.051). Conclusions: RAMRIS synovitis scoring of conventional contrast-enhanced MRI and, to a lesser extent 1 slice DCE-MRI analysis of number of enhancing voxels, best discriminated early RA patients from healthy controls. Both parameters decreased during treatment, ie. showed sensitivity to change. Disclosure of Interest: M. B. Axelsen Grant/Research support from: Abbott, B. Ejbjerg: None Declared, M. Hetland: None Declared, K. Hørslev-Petersen Grant/Research support from: Abbott, U. Lauridsen: None Declared, O. Majgaard: None Declared, M. Boesen Consultant for: Image Analysis, O. Kubassova Shareholder of: and director of Image Analysis, H. Bliddal Grant/Research support from: Abbott, M. Østergaard Grant/Research support from: Abbott