Ahn M I, Park Y H, Yim J I, Yoo J
Department of Diagnostic Radiology, St. Vincent's Hospital, Catholic University of Korea, Suwon, Korea.
Invest Radiol. 1998 Oct;33(10):723-9. doi: 10.1097/00004424-199810000-00002.
The authors assessed the sequential sonographic and computed tomographic (CT) findings and their correlations with pathologic findings of the normal rabbit liver after percutaneous ethanol injection (PEI).
In 30 anesthetized rabbits, 1 mL of ethanol was injected percutaneously under sonographic guidance. The animals were divided into five groups of six rabbits each according to the times of sonography and CT examinations after PEI: day 1 (immediately after), day 3, week 1, week 2, and week 4. The radiologic findings were analyzed regarding echogenicity (sonography) and density patterns before and after contrast administration (CT). The relations between radiologic findings and pathologic findings were examined using statistical analysis. The lesion size was measured using sonography and CT and compared with the actual size of the pathologic specimen.
Sonography and CT showed various radiologic findings according to the time elapsed after PEI. The livers were hyperechoic in 100% (6/6) of the rabbits on day 1; this changed to isoechoic (67%, 12/18) or slightly hypoechoic (22%, 4/18) after week 1 through week 4 after PEI on sonography. CT scanning showed well-defined, hypodense lesions with no contrast enhancement in 100% (6/6) of the rabbits on day 1, and the lesions were slightly hypodense and relatively poorly defined in 88% (21/24) after day 3. Peripheral enhancement was noted in 83% (15/18) after week 1. Histopathologic examination revealed thrombosis and atrophic hepatic cell cords correlating well with hyperechogenicity on sonography and very low density on CT immediately after PEI. Coagulation necrosis was a main pathologic finding in the central portion of the lesions after day 3 and correlated with the CT findings of central low density without contrast enhancement. After week 1, peripheral granulation tissue and fibrosis were correlated with peripheral contrast enhancement on CT. Lesion size was largest in the week 1 group, and the size difference was statistically significant between the week 1 group and the day 1 group.
Sonographic and CT findings of the PEI-treated normal rabbit liver varied with time in a predictable manner and correlated with pathologic findings. After a week, the PEI-treated normal liver shows perilesional enhancement that is nodular and irregular (particularly until 2 weeks); this must be taken into account when evaluating the therapeutic effect after PEI using conventional CT studies. Although long-term data are missing, control CT scans for residual tumor should not be performed before the second week after PEI because of the difficulty discerning enhancing tumor from enhancing fibrosis.
作者评估了经皮乙醇注射（PEI）后正常兔肝脏的超声及计算机断层扫描（CT）的连续检查结果及其与病理结果的相关性。
对30只麻醉兔在超声引导下经皮注射1 mL乙醇。根据PEI后超声和CT检查时间将动物分为五组，每组6只兔：第1天（注射后即刻）、第3天、第1周、第2周和第4周。分析放射学检查结果，包括超声检查的回声性以及CT检查在对比剂注射前后的密度模式。采用统计分析研究放射学检查结果与病理结果之间的关系。使用超声和CT测量病变大小，并与病理标本的实际大小进行比较。
根据PEI后的时间推移，超声和CT显示出各种放射学表现。第1天，100%（6/6）的兔肝脏呈高回声；PEI后第1周~第4周，超声检查显示肝脏变为等回声（67%，12/18）或轻度低回声（22%，4/18）。CT扫描显示，第1天100%（6/6）的兔肝脏有边界清晰的低密度病变，无对比剂增强；第3天后，88%（21/24）的病变呈轻度低密度且边界相对不清。第1周后，83%（15/18）的病变出现周边强化。组织病理学检查显示，血栓形成和肝细胞索萎缩与PEI后即刻超声检查的高回声性及CT检查的极低密度密切相关。第3天后，凝固性坏死是病变中央部分的主要病理表现，与CT检查显示的中央低密度且无对比剂增强相关。第1周后，周边肉芽组织和纤维化与CT检查的周边对比剂增强相关。病变大小在第1周组最大，第1周组与第1天组之间的大小差异具有统计学意义。
PEI处理后的正常兔肝脏的超声和CT表现随时间以可预测的方式变化，并与病理结果相关。1周后，PEI处理后的正常肝脏显示出周边强化，呈结节状且不规则（特别是在2周内）；在使用传统CT研究评估PEI后的治疗效果时必须考虑到这一点。尽管缺乏长期数据，但由于难以区分强化的肿瘤与强化的纤维化，PEI后第2周前不应进行用于评估残留肿瘤的对照CT扫描。
