Felker Ely R, Dregely Isabel, Chung Dong Jin, Sung Kyunghyun, Osuagwu Ferdnand C, Lassman Charles, Sayre James, Wu Holden, Lu David S
1 Department of Radiology, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Ste 1638, Los Angeles, CA 90095.
2 Department of Pathology, David Geffen School of Medicine, Los Angeles, CA.
AJR Am J Roentgenol. 2017 May;208(5):1141-1146. doi: 10.2214/AJR.16.17207. Epub 2017 Feb 8.
The purpose of this study is to evaluate the MRI appearance of the irreversible electroporation zone in porcine liver, with histopathologic correlation.
Nine irreversible electroporation ablations were percutaneously created in two Yorkshire pigs. Irreversible electroporation was performed with a bipolar 16-gauge electrode with 3-cm exposure tip and fixed 8-mm interpolar distance. Gadoxetate disodium-enhanced 3-T MRI was performed 50 hours after irreversible electroporation. Livers were harvested immediately after MRI for histopathologic analysis. Ablation zone size was measured on each pulse sequence and correlated with pathologic ablation zone size. Qualitative MRI features of the ablation zone were assessed, and contrast-to-noise ratios (CNRs) were calculated. Statistical analysis included Pearson correlation and t tests.
Histopathologically, three distinct layers were present in the irreversible electroporation ablation zone: an inner layer of coagulative necrosis (hyperintense at T1- and T2-weighted imaging and nonenhancing), a middle layer of congestion and hemorrhage (hypointense at T1-weighted imaging, hyperintense at T2-weighted imaging and DWI, and progressively enhancing but hypointense at the hepatobiliary phase), and a peripheral layer of inflammation (hyperintense at the arterial phase but isointense at all other sequences). The hepatobiliary phase ablation zone size showed the highest correlation with the pathologic ablation zone size (r = 0.973). This correlation was significant (p < 0.001). T2-weighted imaging had the highest lesion-to-normal tissue CNR.
The irreversible electroporation ablation zone contains three distinct histopathologic zones, each with unique MRI features. T2-weighted imaging had the highest CNR, and the hepatobiliary phase had the strongest correlation with ablation zone size.
本研究旨在评估猪肝不可逆电穿孔区域的MRI表现，并与组织病理学结果进行相关性分析。
在两头约克夏猪身上经皮进行了9次不可逆电穿孔消融。使用双极16号电极进行不可逆电穿孔，电极尖端暴露3 cm，极间距离固定为8 mm。在不可逆电穿孔后50小时进行钆塞酸二钠增强3-T MRI检查。MRI检查后立即摘取肝脏进行组织病理学分析。在每个脉冲序列上测量消融区大小，并与病理消融区大小进行相关性分析。评估消融区的定性MRI特征，并计算对比噪声比（CNR）。统计分析包括Pearson相关性分析和t检验。
组织病理学上，不可逆电穿孔消融区存在三个不同的层：内层为凝固性坏死（在T1加权和T2加权成像上呈高信号，无强化），中层为充血和出血（在T1加权成像上呈低信号，在T2加权成像和DWI上呈高信号，在肝胆期逐渐强化但呈低信号），外层为炎症（在动脉期呈高信号，但在所有其他序列上呈等信号）。肝胆期消融区大小与病理消融区大小的相关性最高（r = 0.973）。这种相关性具有统计学意义（p < 0.001）。T2加权成像的病变与正常组织的CNR最高。
不可逆电穿孔消融区包含三个不同的组织病理学区域，每个区域具有独特的MRI特征。T2加权成像的CNR最高，肝胆期与消融区大小的相关性最强。
