肝细胞癌冷冻治疗术后完全消融早期MRI特征

目的探讨氩氦刀冷冻治疗肝细胞癌(HCC)术后完全消融的MRI表现。方法回顾性分析经随访证实氩氦刀冷冻治疗消融完全的48例HCC患者术前及术后2~7天MRI资料,测量冷冻治疗前后病灶及其周围肝实质ADC值。结果消融后,38例T1WI呈高信号,26例T2WI呈低信号;增强扫描动脉期瘤结节均未见强化,但9例瘤结节出现门静脉晚期及延迟期强化;消融区周边均可见环形强化,25例可见消融区相邻肝包膜下斑片状强化;30例可见瘤结节周边消融区肝实质内穿行小血管强化,7例可见周围肝实质强化。冷冻治疗前后肿瘤ADC值分别为(0.80±0.33)×10-3 mm2/s、(1.26±0.54)×10-3 mm2/s,差异有统计学意义(P0.01)。结论 MRI可用于评价氩氦刀治疗肝癌的早期疗效,冷冻消融后肿瘤及周围肝实质延迟持续强化并不一定代表肿瘤残留,术后ADC值的变化可用于预测早期疗效。

Early MRI features of hepatocellular carcinoma after successful cryoablation

Objective To study the early MRI findings of hepatocellular carcinoma (HCC) after successful cryoablation. Methods Totally 48 patients (48 lesions) were reviewed retrospectively before and after successful cryoablation of HCC. The ADC values of lesions and peritumoral liver parenchyma pre- and post-cryoablation were measured and analyzed. Results Thirty-eight lesions appeared hyperintense on T1WI and 26 lesions appeared hypointense on T2WI after 2-7 days post-procedure. All the lesions were non-enhanced during the arterial phase, but 9 lesions enhanced during the venous and delayed phases. Enhanced rim around the cryoablation zone appeared in all the cases and undercapsule cloudy enhancement appeared in 25 cases. Crisscrossing small vessels were found in peritumoral liver parenchyma in 30 cases during delayed phases and peritumoral liver parenchyma enhancement were found in 7 cases. The ADC values of lesions before and after cryoablation were (0.80±0.33)×10^-3 mm²/s and (1.26±0.54)×10^-3 mm²/s (P<0.01). Conclusion MRI can be used to evaluate the early therapeutic effect after cryoablation. The delayed enhanced tumor and peritumoral liver parenchyma do not indicate residual viable tumor. The raised ADC values may be used to predict the early therapeutic effect.