1 First Department of Radiology, Istituto Nazionale Tumori Fondazione G. Pascale, Via Mariano Semmola, Naples 80131, Italy.
AJR Am J Roentgenol. 2015 May;204(5):1000-7. doi: 10.2214/AJR.14.12509.
Irreversible electroporation is a new ablation modality. Our purpose was to describe the MRI findings after irreversible electroporation treatment of hepatocellular carcinoma (HCC).
In an 18-month period, we treated 24 HCC lesions in 20 patients who were not candidates for surgery. MRI was performed before and 1 month after irreversible electroporation. We used the liver-specific contrast medium gadoxetic acid. We evaluated the size, shape, signal intensity (T1-weighted, T2-weighted, and diffusion-weighted imaging), dynamic contrast enhancement pattern, and signal behavior during the liver-specific phase. Changes in the perilesional parenchyma, perfusion abnormalities, and complications were also recorded.
According to the modified Response Evaluation Criteria in Solid Tumors system, 22 of 24 lesions had a complete response, and two lesions showed a partial response and were retreated. The lesions showed a mean size increase of 10%, with a round or oval shape. On the T1-weighted images, we observed a hyperintense core and a hypointense rim. On the T2-weighted sequences, the signal was heterogeneously hypointense. On diffusion-weighted images, 83% of lesions showed restricted diffusion, with b values of 0-800 s/mm(2), whereas in 17% of the lesions, the signal was not clearly discernible for different b values. The apparent diffusion coefficient values did not show statistically significant differences between the baseline (800-1020 × 10(-3) mm(2)/s) and the reassessment after 1 month (900-1100 × 10(-3) mm(2)/s). The necrotic area did not show a signal increase after contrast material injection. Perfusion abnormalities, such as areas of transient hepatic intensity difference, were present in the tissue adjacent to six treated lesions. In two patients, a reduced or absent concentration of the contrast medium was observed during the liver-specific phase around the ablation zone. One patient had an arteriovenous shunt and another had biliary duct dilatation.
MRI detects characteristic morphologic and functional changes after irreversible electroporation treatment.
不可逆电穿孔是一种新的消融方式。本研究旨在描述肝癌（HCC）接受不可逆电穿孔治疗后的 MRI 表现。
在 18 个月的时间内，我们对 20 名不适合手术的 HCC 患者的 24 个病灶进行了治疗。患者治疗前后均行 MRI 检查，包括钆塞酸二钠增强 MRI。我们评估了病灶的大小、形态、信号强度（T1WI、T2WI 和弥散加权成像）、动态对比增强模式以及肝胆特异期的信号行为。同时还记录了病灶周围肝实质的变化、灌注异常和并发症。
根据改良实体瘤疗效评价标准，24 个病灶中 22 个完全缓解，2 个部分缓解并再次治疗。病灶平均增大 10%，呈圆形或椭圆形。T1WI 上病灶呈高信号，中央呈高密度，周围呈低信号。T2WI 上病灶呈不均匀低信号。DWI 上 83%的病灶呈弥散受限，b 值为 0-800 s/mm(2)，17%的病灶在不同 b 值上信号不清晰。ADC 值在基线（800-1020×10(-3)mm(2)/s）和 1 个月后复查时（900-1100×10(-3)mm(2)/s）之间无统计学差异。注射造影剂后坏死区未见信号增高。在 6 个治疗病灶周围的组织中可见到短暂性肝内信号差异区等灌注异常。2 例患者在消融区周围的肝胆特异期观察到造影剂浓度降低或缺失。1 例患者存在动静脉分流，另 1 例患者胆管扩张。
MRI 可检测到 HCC 接受不可逆电穿孔治疗后的特征性形态和功能改变。
