The Value Of MR Imaging In Primary Hepatocellular Carcinomaand Radiofrequency Ablation For Hepatocellular Carcinoma

Objective To evaluate the characteristics of MR imaging in primary hepatocellular carcinoma before and after radiofrequency ablation.Materials and methods There were25lesiongs of24patients who had undergone conventional MR imaging, dynamic contrast-enhanced MR imaging and diffusion MR imaging on a SIEMENS3.0T scanner， were confirmed primary hepatocellular carcinoma according to clinical pathologic diagnostic standard before radiofrequency ablation in2days. Follow-up MRI after1months of radiofrequency ablation.Before and after radiofrequency ablation, anatomizing MR imaging maps and ADC measurements on primary hepatocellular carcinoma, edges of the tumor and the rest of liver.Statistical method is repetitive measure analysis of variance.Results Before radiofrequency ablation,the lesion of hepatocellular carcinoma presented as patchy low intensity on T1WI and high signal on T2WI; high signal on DWI，low intensity on ADC map. On DCEMRI, transient hepatic tumour enhanced in hepatic arterial phase,washed out in portal venous phase and equilibrium phase.After radiofrequency ablation, signal of the lesions increased on T1WI and ADC map,decreased on T2WI and DWI in varying degrees. All the lesions were without enhancement. Paired t-test presented:after radiofrequency ablation, the ADC differences of lesion were significant （t=-4.049，P＜0.01）, the ADC differences of lesion borders were significant （t=-2.217，P＜0.05）. the ADC differences of recurrence and residual lesions were significant （P＜0.05）. Before radiofrequency ablation,the numerical value of ADC on tumour，border，the rest liver step up,which were（0.86705±0.14728）×10-3mm2/s,（1.07806±0.23537）×10-3mm2/s,（1.25944±0.17809）×10-3mm2/s; the numerical value of ADC on treatment region was （1.18284±0.3517）×10-3mm2/s,on its border was （1.21421±0.25481）×10-3mm2/s,on the rest liver was（1.20954±0.17337）×10-3mm2/s.Multiple comparisons presented statistically significant difference(P＜0.05）. After radiofrequency ablation, the ADC differences were not significant （P>0.05）. The ADC differences presented statistically significant difference (P＜0.05）on tumour and border after radiofrequency ablation.But the difference was not significant （P>0.05） after treatment. Conclusion MR imaging is one of diagnostic criterias for primary hepatocellular carcinoma；but also a method to assess curative effect of radiofrequency ablation...