Ct And Mri Demonstrations And Pathologic Analysis Of Rabbits With Hepatic Neoplasm Treated With Cryoablation

Objective:To describe the appearance of CT,MRI and pathology about rabbits with hepatic tumors treated with cryoablation on follow-up helical CT technology,to distinguish the radiologic-histopathologic correlation and characterize the imaging appearance of local tumor recurrence in the rabbit model.Methods:Hepatic cryoablation was performed in 17 rabbits with VX-2 tumors and in twelve healthy rabbits. Liver imaging was performed with CT,MRI one day prior to cryoablation and on the third day, seventh day,fourteenth day, twenty-first day, twenty-eighth day after cryoablation. Imaging findings were analysed comparatively with histopathologic finding.Results:1. all cryolesions exhibited arterial phase rim enhancement and noenhancement of central foci at CT,but showed diverse imging characters on the thirdly day,seventh day,fourteenth day,twenty-first day following cryoablation. and after 28days,normal control group has no longer enhancement sign; meanwhile tumors without cryoablated wholly show pearly rim enhanced imaging findings at the cryolesion periphery,and arterial phase pearly rim enhancement was growing bigger than before and further mergerd each other.2. All cryolesions exhibited various signal intensity characters at MRI imaging,but show diverse imging characters on the third day,and on the first,second,third week following cryoablation. and after four weeks, low signal intensity was seen at T2-weighted MR imaging at the cryolesion periphery if the tumor was totally ablated;meanwhile the other has high signal imaging findings. Areas of high signal intensity on T2-weighted MR images correlated with liquefaction necrosis,blood lake,granulation tissue and remnant tumor. High signal intensity findings on T2-weighted MR images should be evidence of residual tumor four weeks after cryoablation.Conclusion:1. Transverse contrast-enhanced arterial-phase and portal venous phase CT scans obtained four weeks after cryoablation show a large peripheral enhanced nodule that suggests recurrent tumor,which is helpful to distinguish correctly wether tumor was totally removed.2. High signal intensity findings shown at T2-weighted MR imaging at the cryolesion periphery were believed as an useful way to distinguish resiue and recurrent tumor four weeks after cryoablation.