Assessment of Hepatic Perfusion in Transplanted Livers by Pharmacokinetic Analysis of Dynamic Magnetic Resonance Measurements

OBJECTIVE:The purpose of this study was to validate the assessment of hepatic perfusion by pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance image series. MATERIALS AND METHODS:Dynamic measurements were performed with a saturation recovery turbo fast low angle shot (ie, FLASH) sequence over the course of approximately 4 minutes in 17 patients with transplanted livers. By pharmacokinetic analysis using an open 2-compartment model, we estimated and correlated an amplitude of signal enhancement, A, and the perfusion rate, kp, with invasive perfusion measurements from implanted thermo-diffusion probes (FTDP). RESULTS:Data analysis for segment IV of the transplanted livers yielded a mean blood flow of 81 ± 19 mL/min/100g and a mean perfusion rate of 13 ± 6 minutes. There was a significant correlation between FTDP and kp (rS = 0.64, P = 0.01) but not with A. CONCLUSIONS:Although our open 2-compartment model oversimplifies the complexity of hepatic perfusion, it allows a numerically robust estimation of regional blood flow per unit of blood volume. Thus, dynamic magnetic resonance imaging represents a noninvasive method to assess hepatic perfusion rate which can be visualized in color coded images.