Myocardial Blood Flow at Rest and Stress Measured with Dynamic Contrast-Enhanced MRI: Comparison of a Distributed Parameter Model with a Fermi Function Model

PurposeTo assess the feasibility of simultaneously measuring blood flow (F-b), Gd-DTPA extraction fraction (E), and distribution volume (v(d)) in healthy myocardium at rest and under adenosine stress using dynamic contrast-enhanced MRI. MethodsSixteen volunteers were examined at 1.5 T and 11 returned for a repeat study. The data were analyzed using a distributed parameter (DP) 2-region model to arrive at estimates of F-b, E, blood volume, and interstitial volume. For comparison, estimates of F-b were also obtained using a Fermi function model. ResultsDP model fits were successful in 49 of the 54 data sets. Estimates obtained using DP and Fermi models did not differ for either rest F-b or myocardial perfusion reserve though DP estimates of stress F-b were lower than Fermi estimates. The repeatability of the DP parameters F-b, E, and v(d) was better than or equal to the repeatability of Fermi-F-b. E at rest and under stress was estimated to be 66% and 57%, respectively. ConclusionThe results suggest that characteristics of the microvasculature of healthy myocardium can be reliably determined using dynamic contrast-enhanced MRI at rest and under stress and that delivery of Gd-DTPA to the myocardium is not flow-limited. Magn Reson Med 70:1591-1597, 2013. (c) 2013 Wiley Periodicals, Inc.