结直肠癌原发灶与肝转移灶的扩散成像比较

Comparing Primary Lesions of Colorectal Cancers with Its Hepatic Metastases in DWI Sequence

目的探讨结直肠癌原发灶与其肝转移灶之间在常规磁共振序列、扩散加权成像(DWI)及表观扩散系数(ADC)上的不同。方法对经病理或临床证实的85例结直肠癌患者及23例结直肠癌肝转移患者的磁共振表现进行回顾性分析,并以病灶T1WI-r SI、T2WI-r SI、DWI-r SI平均信号强度、ADC值作为评价标准。统计学方法采用两独立样本t检验、Mann-Whitney秩和检验及受试者工作特征(ROC)曲线图。结果结直肠癌原发灶与肝转移灶在T1WIr SI、T2WI-r SI、DWI-r SI平均信号强度及ADC之间具有显著差异(Z=-7.333,P<0.05;t=6.112,P<0.05;t=-3.892,P<0.05;t=7.518,P<0.05)。在结直肠癌肝转移灶的诊断中DWI-r SI与常规序列相对信号强度下的曲线面积(AUC)分别为0.940、0.786;在结直肠癌原发灶的诊断中DWI-r SI与常规序列相对信号强度的AUC分别为0.843、0.847。结论结直肠癌原发灶与肝转移灶之间在不同MRI序列存在信号差异,说明两者之间在其生物学特性上存在差异。DWI序列在对结直肠癌肝转移灶的诊断准确性高于常规序列,在原发灶的诊断准确性上相近。

Objective To explore differences of primary lesions of colorectal cancer and its hepatic metastases in conventional MRI sequences,diffusion weighted imaging（ DWI） and apparent diffusion coefficient（ ADC）. Methods MR images of 85 cases of colorectal cancer and 23 cases of hepatic metastases of colorectal cancer were retrospectively studied.All cases were confirmed by pathology or clinical evaluation. Evaluation standards were the average signal of T1WI-r SI,T2WI-r SI,DWI-r SI and ADC value. Statistical methods employed were two independent sample t-test,the Mann-Whitney rank and the ROC curve. Results Primary lesions of colorectal cancer of T1WI-r SI（ P 〈 0. 05）,T2WI-r SI（ P 〈 0. 05）and ADC values（ P 〈 0. 05） were significantly higher than that of hepatic metastases of colorectal cancer. The DWI-r SI（ P〈 0. 05） of hepatic metastases of colorectal cancer were significantly higher than that of primary lesions of colorectal cancer. Area under the curve（ AUC） of the conventional MRI and DWIBS diagnostic accuracy rate of hepatic metastases of colorectal cancer and primary lesions were 0. 786,0. 940 and 0. 847,0. 843 respectively. Conclusion The statistical differences of T1WI-r SI,T2WI-r SI,DWI-r SI and ADC values between primary lesions of colorectal cancer and hepatic metastases of colorectal cancer showed significant differences in the biological characteristics. DWI sequence showed higher diagnostic accuracy rate than conventional MRI sequences of hepatic metastases of colorectal cancer. The diagnostic accuracy rates of DWI sequences and conventional MRI sequences in primary lesions of colorectal cancer were close.