射频消融治疗肝脏恶性肿瘤急性热损伤的MRI表现及疗效判定

目的探讨肝脏恶性肿瘤射频消融后急性热损伤的MRI表现及疗效判定。方法回顾性分析MRI引导下158例共266个肝脏恶性肿瘤病灶的射频消融术后即刻MRI表现。结果147个原发性肝癌及59个肝转移癌病灶消融后表现为T2WI低信号、T1WI低信号；2个原发性肝癌及55个肝转移癌病灶消融后表现为T2WI呈稍高信号，T1WI低信号；3个原发性肝癌消融后T2WI呈低信号，而T1WI呈高信号。瘤周消融带均呈短T1短T2信号，周边见薄环状长T2-信号环绕。151个原发性肝癌及106个转移癌病灶被瘤周消融带完全包绕，1个原发性肝癌及8个肝转移癌病灶未完全被瘤周消融带包绕。结论肝脏恶性肿瘤射频消融后急性热损伤的即刻MRI表现具有特征性，据以评价疗效确切、可靠。

MRI findings of acute thermal damage and effect assessment after radiofrequency ablation of malignant hepatic tumors

Objective To explore MRI features of acute thermal damage and assess effect of radiofrequency ablation （RFA） for malignant hepatic tumors. Methods A total of 158 patients with 266 malignant liver lesions underwent MRI guided RFA, and MRI features immediately after RFA were retrospectively analyzed. Results After RFA, hypo-intensity both on T2WI and T1WI were observed in 147 primary hepatic carcinoma lesions and 59 hepatic metastasis lesions, slightly hyper-intensity on T2WI and hypo-intensity on T1WI were found in 2 primary hepatic carcinomas and 55 liver metastases, while hypo-intensity on T2WI and hyper-intensity on T1WI were found in 3 primary hepatic carcinoma. All peritumoral ab- lation zone demonstrated hyperqntensity on T1WI and hypo-intensity with a thin rim of high signal intensity on T2WI. To- tally 151 primary hepatic and 106 hepatic metastasis lesions＇were completely surrounded by peritumoral ablation zone, and 1 primary hepatic carcinoma and 8 liver metastases were not completely surrounded. Conclusion MRI features of acute thermal damage immediately after RFA for malignant hepatic tumors have characteristics, which might be used to evaluate the curative effect of RFA exactly and reliably.