Guido Hugo Jajamovich PhD, Abstract Co-Author: Nothing to Disclose

Wei Huang, Abstract Co-Author: Nothing to Disclose

Cecilia Besa MD, Abstract Co-Author: Nothing to Disclose

Xin Li, Abstract Co-Author: Nothing to Disclose

Aneela Afzal, Abstract Co-Author: Nothing to Disclose

Bachir Taouli MD, Presenter: Research Grant, General Electric Company Consultant, Bayer AG

DCE-MRI can be used to quantify liver tumor perfusion parameters with the use of pharmacokinetic models, such as the Tofts model (TM) and two-compartment Shutter-Speed model (SSM). The TM assumes infinitely fast equilibrium inter-compartmental water exchange kinetics, while the SSM introduces the mean intracellular water molecule lifetime, ti, to account for the transcytolemmal exchange. In this study, the TM and SSM are applied to estimate perfusion parameters of liver parenchyma and hepatocellular carcinoma (HCC).

In this prospective IRB approved study, 9 cirrhotic patients with 12 HCC lesions (mean size 6.4 cm, range 1-13 cm) underwent DCE-MRI. 5 patients were scanned twice for test-retest evaluation. Data was acquired using axial 3D-FLASH sequence covering the whole liver (temporal resolution 1.9-2.5s, 100 volumes acquired) before and after injection of 0.05 mmol/kg of Gd-BOPTA. Liver, portal vein, abdominal aorta and HCCs mean concentrations time-courses were obtained by placing ROIs. Liver and HCC parameters Ktrans, ve and kep for TM and SSM and ti for SSM were compared using Wilcoxon test. Reproducibility was assessed by computing the coefficient of variation (CV).

ve and kep for TM and Ktrans and ti for SSM showed significant differences between liver and HCC (p <0.03). Ktrans, ve and kep for TM were significantly different when compared with their SSM counterparts (p <0.005). Parameter reproducibilities were better in liver parenchyma (CV range 17.4-32.3) compared to HCC (range 37.7-62.6) for both models, while TM demonstrated generally better reproducibility than SSM.

Initial data shows different perfusion parameters when computed with the TM and SSM, with differences observed for Ktrans and ti between liver and HCC for the SSM. The SSM showed worse reproducibility than TM.

Substantial differences in ti (mean intracellular water molecule lifetime) were observed between liver parenchyma and HCC which may reflect differences in metabolic activities, suggesting potential utility for HCC characterization.

Jajamovich, G, Huang, W, Besa, C, Li, X, Afzal, A, Taouli, B, Hepatocellular Carcinoma Perfusion Quantification with Tofts vs. Two-Compartment Shutter-speed Models. Initial Experience.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013751.html