Rofo 2009; 181 - A13
DOI: 10.1055/s-0028-1124044

Quantification of perfusion and endothelial permeability in inflammatory joint diseases

S Weckbach 1, SP Sourbron 2, M Notohamiprodjo 2, H Hatz 3, MF Reiser 2, C Glaser 2
  • 1Department of Clinical Radiology, University Hospital Mannheim, Medical Faculty Mannheim – University of Heidelberg, Mannheim/Germany
  • 2Department of Clinical Radiology, University Hospitals – Grosshadern, Ludwig-Maximilians-University Munich/Germany
  • 3Klinik Feldafing, Feldafing/Germany

Purpose: The possibility to directly measure capillary blood flow and permeability would be of advantage for therapy control studies in inflammatory joint diseases. The Tofts-model (used to quantify perfusion so far) does not produce direct measurements of capillary blood flow. The purpose was to test a standard two-compartment-model for direct measurement of blood flow and permeability and to analyze it considering explanatory power and plausibility compared to the Tofts-model.

Materials and Methods: Dynamic ce-MRI of the hands of 5 patients with rheumatoid arthritis were acquired at 3T (TWIST, 1.5×0.52 mm3) over 5min with a temporal resolution of 2.5sec. Arterial input functions were measured in the radial artery and 4 ROIs were set in muscle and inflammatory tissue. Pixel- and ROI enhancement curves were fitted to a standard two-compartment-model and the TOFTS-model. Plasma volume (PV), extraction flow (EF) and interstitial volume were calculated with both models, additionally plasma transit time and plasma flow (PF) with the standard model. The results were analyzed and compared regarding explanatory power and plausibility.

Results: Pixelwise analysis of different inflammatory ROIs resulted in intraindividually varying perfusion characteristics of up to 30% difference. Both models result in comparable values for EF whereas the Tofts-model does not produce values for PF and in some cases unphysiological (negative) values for PV. Perfusion parameters correlated well with laboratory inflammation parameters and clinical activity scores.

Conclusion: By using a two-compartment model and a MR-sequence with high temporal resolution a separate quantification of blood flow and permeability in patients with inflammatory joint diseases seems possible with plausible results. Now future measurements with a larger patient cohort need to be carried out to verify these first data.