The Experimental Study On MR Perfusion Imaging In Valuation Of Radiofrequency Ablation Of Liver VX2 Tumor In Rabbits

Objective：To evaluate the effect of radiofrequency ablation of liverVX2 tumor in rabbits on MR Perfusion Imaging(PWI),and to investigatequantitative evaluation of perfusion parameter on malignant potency.Materials and Methods：21 New Zealand White rabbits were randomlydivided into three groups(group A, group B and group C) after wereimplanted liver VX2 tumors, Radiofrequency Ablation(RFA) Treat wasperformed by CT-guided on VX2 tumors. Rabbits in eachgroup ,respectively,was porformed unenhance MRI and PWI before RFA and1 w ,2 w and 3 w after RFA , and all were killed after MR examination.Themorphological changes of the tumor and hepatic tissue were also investigatedunder light microscope ,and positive enhance integral and maximum slop ofincrease were measured by Functool software of GE ADW 4.4 workstation．Results：Under CT-guided New Zealand White rabbits hepatic VX2tumors model achievement ratio is 90.0%(27/30). 21 rabbits hepatic VX2tumors model have tumor FRA and follow-up examination. Group A has 1rabbit died from anesthetic accident in the tumor of radio frequency ablation,and 3 rabbits(group B has 1 rabbit and group C have 2 rabbits) died fromsecondary infection follow-up .17 rabbits successfully finish MR examination.Rabbits hepatic VX2 tumors in the RFA central zones were gray and noresidual hepatic VX2 tumors,then in the RFA border zones were dark red and have some residual hepatic VX2 tumors. Before RFA all of Rabbits hepaticVX2 tumors positive enhance integral and maximum slop of increase oftumor center、tumor border and normal hepatic tissue are 54.11±24.92 and47.01±15.82、40.92±20.95 and33.61±12.15、31.73±18.56 and 35.39±15.08,then after RFA are 13.93±7.19 and 10.59±8.56、29.39±19.91 and26.80±14.73、36.03±23.16 and 34.01±19.93. The difference weresignificant in positive enhance integral and maximum slop of increase oftumor center before and after RFA(P<0. 05). The difference were significantin positive enhance integral and maximum slop of increase of tumor centerbefore and after RFA in group A and B .Conclusions：The method of under CT-guided making is simple，traumais small and the occurrence rate is very high. PWI can both reveal the changesof tumor before and after RFA ,and PWI has the potential to evaluate theeffects of RFA. Dynamic observe the PWI quantificational standard oftumor can accurately evaluate the effect of tumor FRA .