MR diffusion-weighted imaging of rabbit liver VX-2 tumor

AIM: To investigate the implanting method of rabbit liver VX-2 tumor and its MR diffusion-weighted imaging (DWI)characteristics.METHODS: Thirty-five New Zealand rabbits were included in the study. VX-2 tumor was implanted subcutaneously in 14 rabbits and intrahepatically in 6 for pre-experiments.VX-2 tumor was implanted intrahepatically in 12 rabbits for experiment and three were used as the control group.DWI, T1- and T2-weighted of MRI were performed periodically in 15 rabbits for experiment before and after implantation. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC)values. The statistical significance was calculated by analysis of variance (ANOVA) of the randomized block design using SPSS10.0 software.RESULTS: The successful rate of subcutaneous implantation of VX-2 tumor was 29% (4/14) while that of intrahepatic implantation of it was 33% (2/6) in the preexperiment.The successful rate of intrahepatic implantation of VX-2 tumor in the experiment was 83% (10/12) and 15 tumors grew in 10 successfully implanted rabbits. The. DWI signal of VX-2 tumor was high and became lower when the b value increased step by step. The signal of VX-2 tumor on the map of ADC was low. When the b value was 100 or 300 s/mm2, the ADC value of normal groupand VX-2 tumor group was respectively 2.57±0.26,1.73±0.31, 1.87±0.25 and 1.57±0.23 mm^2/s. Their distinction was significant (F= 43.26, P