Goetz Hannes Welsch MD, Presenter: Nothing to Disclose

Philipp Schlechtweg, Abstract Co-Author: Nothing to Disclose

Nina Renner MD, Abstract Co-Author: Nothing to Disclose

Rolf Janka MD, PhD, Abstract Co-Author: Consultant, Siemens AG

Siegfried Trattnig MD, Abstract Co-Author: Nothing to Disclose

Georg Schett MD,PhD, Abstract Co-Author: Nothing to Disclose

To assess the feasibility of imaging the biochemical and micro-structural changes of articular cartilage in the small finger joints of patients with rheumatoid arthritis (RA) as well as to correlate these findings to clinical parameters.

During an initial feasibility study five young patients with RA (33.8±4 years) and five age and sex matched volunteers (31.2±5 years) where included. The following clinical study included 20 patients with RA (52.6±14 years). High resolution MRI was performed on a 3 T MRI using two 4-cm loop coils, covering the metacarpophalangeal (MCP) joints 2-3. Besides morphological MRI, a 3D dual-flip-angle gradient-echo technique was used for T1dGEMRIC (TR:15 ms; TE:3.83 ms; voxel size:0.26x0.26x1.5mm; acquisition time:3:42 minutes). Quantitative T1dGEMRIC mapping was performed with a delay of 30 minutes after i.v. administration of 0.2 mmol/kg Gd(DTPA)2-. Region-of-interest analysis was performed on the distal cartilage layer of the metacarpal bone and the proximal cartilage layer of the proximal phalanx; intra- and inter rater agreement was assessed (intraclass correlation coefficient). At the day of MRI, disease-specific characteristics were evaluated including: DD: disease duration; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; DAS 28: Disease Activity Score; RF: rheuma factor; CCP: cyclic citrullinated peptide. Statistical testing was performed on basis of analysis of variance and Pearson correlation.

The feasibility study revealed significantly lower T1 values in young RA patients (527±101ms) compared to the control group (642±61ms) (p<0.05), as well as good intra- and inter rater agreement of 0.836 – 0.849. The clinical study revealed a clear decrease in T1 values related to the disease duration with 568±112ms (DD<5years, n=12) and 487±178ms (DD≥5 years, n=8) (p<0.05). The correlation with the disease-specific characteristics revealed significant correlations in between the T1 dGEMRIC values and the RF as well as the CCP (Pearson~0.400), with decreased T1 values in RF or CCP positive patients.

Our data shows that biochemical T1 mapping using dGEMRIC is feasible in small finger joint of patients with RA revealing changes in the micro-structural properties of articular cartilage.

Ongoing RA and positive RF as well as CCP seems to be associated with proteoglycan loss of articular cartilage in the MCP joints of patients with RA.

Welsch, G, Schlechtweg, P, Renner, N, Janka, R, Trattnig, S, Schett, G, Imaging of Micro-structural Cartilage Changes in the Finger Joints of Patients with Rheumatoid Arthritis by Means of Delayed Gadolinium MRI of Cartilage (dGEMRIC): Initial Clinical Results.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034463.html