Sang Ho Lee PhD, Presenter: Nothing to Disclose

Koichi Hayano MD, Abstract Co-Author: Nothing to Disclose

Dushyant V. Sahani MD, Abstract Co-Author: Research Grant, General Electric Company

Andrew X. Zhu MD, PhD, Abstract Co-Author: Nothing to Disclose

Hiroyuki Yoshida PhD, Abstract Co-Author: Patent holder, Hologic, Inc Patent holder, MEDIAN Technologies

Parameter values differ substantially between standard and WX PKMs. The results suggest that DCE-MRI data are water-exchange sensitive.

DCE-MRI data have often been analyzed using standard pharmacokinetic models (PKMs) that assume a fast water exchange limit (FXL). Recently, it has been demonstrated that deviations from the FXL model occur when contrast agent arrives at the target tissue. However, the analysis has not been reported in the liver tumor with dual blood supply. The aim of this study was to compare kinetic parameters between 5 different standard dual-input PKMs and their corresponding water exchange-modified (WX) versions obtained from DCE-MRI of advanced hepatocellular carcinoma (HCC).

BF (P<0.003), BFPV (P<0.03), BV (P<0.001), and PS (P<0.022) were statistically significantly different for the pairwise comparison with all models except the AATH model, γ (P<0.023) with the TK and ETK models, BFA (P<0.008) with all models except the ETK model, MTT (P<0.05) with the 2CX and DP models, vI (P<0.012) with all models, and E (P=0.021) with only the DP model, respectively. No parameter was consistent over all PKM pairs.

T1-weighted DCE-MRI of 20 patients was performed on a Siemens Avanto 1.5T with 2 consecutive 7s acquisitions during breath-holds that repeated 10 times with a break of 21s between them over a 4 minute period. The arterial and portal input curves were modeled by a sum-of-exponentials function. Total hepatic blood flow (BF), arterial fraction (γ), arterial BF (BFA), portal BF (BFPV), blood volume (BV), mean transit time (MTT), permeability-surface area product (PS), fractional interstitial volume (vI), and extraction fraction (E) were estimated by fitting data to analytic solutions of 5 different FXL PKMs: the Tofts-Kety (TK), extended TK (ETK), two compartment exchange (2CX), adiabatic approximation to the tissue homogeneity (AATH), and distributed parameter (DP) models, and their WX PKMs using a 2-site exchange model for the TK model and a 3-site 2-exchange model for the ETK, 2CX, AATH, and DP models. Paired comparison of parameters within HCC between FXL and WX PKMs was evaluated using Wilcoxon signed-rank test for each parameter and for each PKM pair.

Lee, S, Hayano, K, Sahani, D, Zhu, A, Yoshida, H, Comparison of Standard and Water-exchange-modified Dual-input Pharmacokinetic Models for DCE-MRI in Advanced Hepatocellular Carcinoma.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006291.html