Magnetic resonance imaging provides accurate and precise volume determination of the regenerating mouse liver

Abstract

Direct and repetitive noninvasive determination of the time course and the strain-specific hepatic regenerative capacity after partial hepatectomy can extend our knowledge about the basic mechanisms of liver regeneration and repair. The aim of this study was to develop a magnetic resonance (MR)-based volumetric procedure to measure the hepatic volume in the regenerating mouse liver. In Balb-C mice (n = 14), varying amounts of liver tissue were resected and MR imaging was performed 24 hours later in a 1.5 Tesla Magnet Unit. Three dimensional (3D) T1- (volumetric interpolated breath-hold examination [VIBE] sequence) and T2-weighted images were acquired with continuous 1-mm thin slices. Animals with and without intravenous administration of paramagnetic contrast agents were compared. Immediately after MR examination, mice were euthanized and livers were weighted. The liver volume was determined on MR images using Cavalieri's method and linear regression analysis was performed from the data obtained. Correlation coefficients between the liver volume measured by MR and the liver weight were 0.98 (T1) and 0.94 (T2) in the group without paramagnetic contrast injection and 0.70 (T1) and 0.96 (T2) after paramagnetic contrast application. We conclude that MR-based liver volumetry allows precise liver volume measurement during hepatic regeneration after partial hepatectomy in mice and can be a valuable tool with regard to experimental hepatology.