大鼠肝硬化背景下肝结节MR征象与病理分型

MR imaging of the nodules in TAA-induced rat liver cirrhosis model

目的 探讨硫代乙酰胺（TAA）诱导大鼠肝硬化背景下肝结节的MR表现与病理分型的相关性。方法 选取实验性SD雄性大鼠84只,采用硫代乙酰胺（TAA）腹腔定点注射,200~240mg/kg,3次/周,于注射后第6~30周末分批做磁共振成像检查,肝标本观察其大体形态并做HE染色病理检查,取病理证实的直径≥3mm肝结节作为MR观察对象,分析比较磁共振各序列对肝结节的检出率。结果 84只实验大鼠中,MRI观察到56枚直径≥3mm肝结节,其中,直径3~5mm结节41个,5~10mm结节10个,10mm以上结节5个;病理诊断再生结节12个,低级退变结节24个,高级退变结节15个,癌结节5个。磁共振各序列以T1WI及DWI检出率最高,定性诊断率以磁共振信号I、II型最高,增强扫描强化方式有利于肝硬化结节与癌结节鉴别,但高级退变结节与癌结节强化方式有重叠,需结合其他序列。结论 TAA诱导大鼠肝硬化背景下的直径≥3mm的肝结节模型,能够为MR各序列影像所识别,综合序列判断对肝结节有鉴别诊断价值。

Objective To deeply explore relevance of MR imagings and pathological classification on thioacetamide（TAA）induced rat liver nodules under the background of liver cirrhosis.Methods We selected 84 experimental SD male rats,used thioacetamide（TAA）intraperitoneal injection,200~240mg/kg,3times/week,6~30batches for the weekend magnetic resonance imaging.The pathological observation on the liver specimen showed that intrahepatic nodules were msrthan 3mm in diameter as research materials;The nodule detection rate of each scanning sequence was determined and the MRI findings were retrospective analyzed.Results A total of 56 hepatic nodnles were≥ 3mm in diametes in the experimental rats,among them,3~5mm nodules were 41,5~10mm nodules were 10,more than 10 mm nodules were 5;Regenerative nodules were 12,low-grade dysplastic nodules were 24,high-grade dysplastic nodules were 15,and carcinoma nodules were 5.T1 WI and DWI sequence had the highest detection rate,qualitative diagnosis rate of nodules at the highest of type I,II,schedule of enhancement was helpful to differentiate malignant from benign,but high-grade dysplastic nodules and carcinoma nodule identification were difficult,sometimes needed to be combined with other sequences.Conclusion Liver nodules model（diameter≥3 mm）under the background of TAA induced rat liver cirrhosis is suitable for MR imaging studies.