肝肿瘤射频消融术后MRI表现及其临床意义

目的探讨肝肿瘤经皮射频消融(RFA)治疗后的MRI表现,并分析其临床意义。方法收集59例接受经皮RFA的肝肿瘤患者(82个病灶),其中36例术前接受MR检查,回顾性分析其MRI资料,分析病灶大小、信号及强化方式等变化特点。结果 RFA治疗后2个月内病灶完全坏死区呈等或稍短T1短T2信号,偶呈稍长或长T2信号,增强扫描无明显强化;2个月后完全坏死区呈短T2信号,增强扫描无强化。残存病灶呈长T2信号,增强扫描动脉期明显强化;复发病灶消融区范围较前增大,呈长T2信号。富血供病灶动脉期可见厚薄不均、环状或不规则结节状强化,乏血供病灶消融区边缘不光整。结论肝肿瘤RFA术后具有特征性MRI表现,能有效判断肿瘤残存和(或)复发,对于指导临床进一步治疗有重要意义。

Appearances and clinical significances of MRI in liver neoplasms treated with radiofrequency ablation

Objective To observe the MRI appearances of hepatic tumors treated with percutaneous radiofrequency ablation (RFA), and to analyze their clinical significances. Methods Totally 59 patients with 82 liver tumor lesions were treated with RFA were collected, among them 36 underwent MR before RFA, and the MRI findings were analyzed retrospectively, including the size, signal intensity, the enhancement of the lesions and so on. Results Within 2 months after RFA, the completely necrotic areas were slightly hyperintensity or homogeneous on T1WI and hypointensity on T2WI, which occasionally present as slightly hyperintensity or hyperintensity on T2WI. The completely necrotic zones showed as hypointensity areas without contrast enhancement on contrast-enhanced T1WI. Two months later, the completely necrotic areas were hypointense on T2WI, and showed as hypointense areas without enhancement. The residual tumors were hyperintensity on T2WI, and obvious enhancement in the arterial phase was noticed. The relapsed lesions were hyperintensity on T2WI, and the areas were enlarged. The hypervascular tumors showed uneven rim or irregular nodular enhancement in the arterial phase, and the edges of hypovascular tumors revealed irregular areas. Conclusion Hepatic tumors treated with RFA have characteristic MRI appearances, which are helpful to the detection of residual and/or relapse tumors and are important for further treatment.