Tamotsu Kamishima, Presenter: Nothing to Disclose

To assess the usefulness of contrast-enhanced MR imaging of the hand in the evaluation of the pannus in patients with rheumatoid arthritis (RA) before and after the treatment with infliximab.

Thirteen rheumatoid patients (2 men and 11 women, age ranged 25-71 with a mean of 51.8) unresponsive to MTX were included in the study. Before scheduled dosage, the patients were examined clinically, serologically, and by MR imaging. They were reexamined at 6 (n=1), 14 (n=1), 22 (n=7) or 30 (n=4) weeks after the initial treatment. MR imaging was performed with a 0.3 Tesla system (HITACHI MRP7000). After a manual intravenous contrast injection, spin-echo T1-weighted images of the hand were obtained 4 minutes after the administration of contrast. In addition to subjective comparison between images obtained before and after treatment (improved, worsened, and no change), signal intensity of pannus and adjacent bone was measured before and after the administration of contrast to investigate the treatment effect on pannus. Relative enhancement value was defined as signal intensity of pannus relative to that of bone, where signal intensity of the bone was utilized as an internal standard. The value was compared with ACR core set results obtained at the time of imaging evaluation.

In one patient, subjective comparison turned out to be “improved”, while all the others were “no change”. Relative enhancement value improved after treatment by more than 50% in 3 patients (23%), exacerbated by more than 50% in 4 patients (31%), while others (46%) had no significant change. Patients who had relative enhancement included ACR 70 and ACR 20 responders, on the other hand, no responder was seen among those who had exacerbated pannus enhancement.

MR imaging appear to be able to monitor the treatment effect on pannus by measuring the extent of contrast enhancement. This may be a sensitive method with a possibility of offering a useful clue on whether further treatment is to be continued, especially when no ACR core set improvement is seen after several sessions of treatment.

Kamishima, T, Effect of Treatment with Infliximab on Patients with Rheumatoid Arthritis Evaluated by Contrast-enhanced MR Imaging.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4419276.html