磁敏感成像判断大鼠肝细胞癌病理分级的价值

The Value of Susceptibility Weighted Imaging in Determining Pathologic Grade of Hepatocellular Carcinoma in Rat Model

目的 探讨磁敏感成像（SWI）技术判断肝细胞癌（HCC）病理分级的可行性。方法 建立大鼠HCC模型后，行SWI检查。完成扫描后处死大鼠，取相应病灶行病理学检查，以Edmondson-Steiner分级法作为划分HCC病理分级的标准。比较低级别和高级别HCC的瘤内磁敏感信号强度（intratumoral susceptibility signal intensity，ITSS）特征的差异，并探索ITSS特征对HCC病理分级的判断价值。结果 成功建立48只大鼠HCC模型，最终纳入分析的HCC病灶共32个，包括低级别18个（低级别组）和高级别14个（高级别组）。2组的ITSS出现率比较差异无统计学意义（P=0.113）；2组的ITSS构成成分不同（P=0.002），低级别组HCC的ITSS构成主要是微血管，而高级别组HCC的ITSS构成以出血为主。此外，2组的ITSS在肿瘤内所占比例也不同（P＜0.001），高级别组的ITSS在肿瘤内所占比例高于低级别组。当ITSS在肿瘤内所占比例得分为2分时，即至少有1个层面所占比例≥50%时，ROC曲线下面积最大，此时其灵敏度和特异度分别为85.7%（95% CI：74.9%～96.5%）及94.4%（95% CI：83.6%～100%），曲线下面积为0.917。结论 SWI能够评价HCC内的ITSS特征，并有助于区分低级别与高级别HCC。

Objective To evaluate the feasibility of susceptibility weighted imaging （SWI） in determining pathologic grade of hepatocellular carcinoma （HCC） in rat model. Methods Rat models were established first and SWI was performed before killing rats to be examined pathologically. The Edmondson-Steiner grading was used as gold reference for histological grade of HCC. The characters of intratumoral susceptibility signal intensity （ITSS） between lowand high-grade HCCs were compared. The diagnostic value of ITSS in differentiating lowfrom high-grade HCCs was evaluated. Results Forty eight rat models of HCC were successfully established. Thirty two HCCs （18 low-grade HCCs and 14 highgrade HCCs） were included finally. The incidence of ITSS between two groups was not significant （P=0.113）. Characters including component of ITSS （P=0.002） and ratio of ITSS in HCC （P〈0.001） were compared between lowand high-grade HCCs, which were both statistically significant. When score of ratio of ITSS in HCC was assessed as 2 scores, the sensitivity and specificity of ITSS in differentiating lowfrom high-grade HCCs were 85.7% （95% CI：74.9%-96.5%） and 94.4% （95% CI：83.6%-100%） respectively, and the area under roc curve （AUC） was 0.917. Conclusion SWI can evaluate characters of ITSS in HCC and can be an alternative method in grading HCC.