Evaluating The Effect Of HIFU Treatment For Rabbit VX2 Liver Tumor By MR LAVA Enhancement Scanning

Objective: To evaluate the effect of HIFU treatment for rabbit VX2 liver tumor by using MR LAVA sequence enhancement scanning Method: Rabbit VX2 liver tumor model was established. T1WI,T2WI and LAVA sequence enhancement scanning were taken before and after HIFU (on 1,3,7,14 and 21 days after HIFU treatment). The enhancement changes were studied on every time point and correlated with their corresponding pathology.Result: 56 of 60 New-Zealand rabbits were successfully implanted with VX2 liver tumor before HIFU treatment. The successful rate was 93%; 6 rabbits were executed to investigate the blood supply of VX2 liver tumor; only 45 in 50 VX2 liver tumor were undergone all the examinations after HIFU treatment(successful rate: 75%) Three enhancement patterns(annular, nonuniform and uniform) were noted before HIFU,pathology showed the carcinoma were the well-differentiated prickle cell carcinoma in all patterns. For 38 annular enhancement VX2 liver tumor (38/56,68%) , pathology confirmed less blood vessel structure in the tumor center and more blood vessel structure in the periphery; uniform enhancement VX2 liver tumor (6/56, 11%), demonstrated abundant blood vessel structure in the tumor parenchymatous tissue; nonuniform enhancement VX2 liver tumor (12/56,21%) showed affluence blood vessel structure and also zone of necrosis inside the tumor. After HIFU ,VX2 liver tumors showed low signal on T1WI and mixed signal on T2WI and three enhancement patterns were noted(annular, nonuniform and non enhanced). For 9 annular enhancement VX2 liver tumor (20%), pathology confirmed non enhancement in the tumor center was coagulation necrosis and the enhancement section was composed by inflammatory cell with blood vessel structure. 20 non enhancement VX2 liver tumor (44%) showed total coagulation necrosis. 16 nonuniform enhancement VX2 liver tumor (36%) demonstrated coagulation necrosis in non enhancement section and tumour cell with affluence blood vessel structure in enhancement section.Conclusion: MR LAVA sequence enhancement scanning can be a new way with faster scanning speed and shorter scanning time. It can reflect the pre-and post-HIFU pathology and can be the effective way to evaluate the effect of HIFU treatment in rabbit VX2 liver tumor model.