Dual-energy CT: a new imaging modality for bone marrow oedema in rheumatoid arthritis

Active joint inflammation is a key feature in rheumatoid arthritis (RA). Treatment guidelines for RA,1 including ‘Treat-to-Target’ strategies,2 stress the importance of abrogation of inflammation. MRI clearly demonstrates bone marrow oedema lesions (BMEL) as a sign of inflammation.3 Dual-energy CT (DECT) scanners could provide a new approach to visualise BME.4–7 We investigated if DECT could visualise BME of the hand and wrist in patients with active RA, with MRI-proven BME as a gold standard. Institutional review board approval was obtained. Twenty consecutive patients with active clinical synovitis of a metacarpophalangeal, proximal interphalangeal or wrist joint provided written informed consent and were included; 9 men and 11 women with a mean age of 60.7 (±10.3) years. Thirteen patients were ACPA positive and 8 were ACPA and RF positive; mean tender joint count and swollen joint count were both 5.9. Mean DAS28 was 4.37 (±1.4). The mean disease duration was 6.6 (±6.1) years. Seventeen patients were treated with conventional disease-modifying antirheumatic drugs, 7 were also treated with biologicals. DECT was performed on a dual-source CT, data were post-processed with SyngioVia ‘Bone Marrow Oedema’ application (see the online supplementary text). Images were presented as colour-coded maps. …