弥散加权成像的不同定量参数值在直肠癌术前评估中的应用价值

The application value of different quantitative parameters of diffusion weighted imaging in preoperative evaluation of rectal cancer

目的探讨不同表观扩散系数(ADC)值在直肠癌术前评估中的价值。方法109例直肠癌患者,术前均行常规MRI及扩散加权成像(DWI)序列扫描。比较不同分组的ADC最大值、最小值、平均值和差值。绘制各参数受试者工作特征(ROC)曲线,通过比较ROC曲线下面积(AUC)明确诊断效能。结果不同ADC参数值组间一致性为0.845~0.907。未突破组的ADC平均值高于突破组(AUC=0.727,P=0.003)。无淋巴结转移的ADC最大值、最小值和平均值均高于有淋巴结转移组(AUC=0.651、0.678、0.787,P<0.001)。无脉管或神经束膜侵犯的ADC最大值、最小值和平均值均高于有脉管或神经束膜侵犯(AUC=0.719、0.665、0.744,P<0.05)。结论ADC定量参数值可用于术前评估直肠癌的分期、淋巴结转移和脉管或神经束膜侵犯且ADC平均值诊断效能较高。

Objective To investigate the application value of different quantitative parameters of apparent diffusion coefficient(ADC)measured by diffusion weighted imaging(DWI)in preoperative rectal cancer.Methods One hundred and nine patients with rectal cancer were collected retrospectively.All patients received preoperative magnetic resonance imaging(MRI)and DWI scanning.The maximum,minimum,average,and different values of ADC were compared among different groups.The receiver operating characteristic(ROC)curve of each parameter of ADC was analyzed,and the area under the ROC curve(AUC)was calculated to evaluate the diagnostic performance of each parameter for preoperative rectal cancer.Results The agreement between different ADC parameter values was 0.845~0.907.The average ADC value in the non-breakthrough group was significantly higher than that of the breakthrough group(AUC=0.727,P=0.003).The maximum,minimum and average values of DAC without lymph node metastasis were significantly higher than those with lymph node metastasis(AUC=0.651,0.678 and 0.787,P<0.001).The maximum,minimum and average values of DAC without vascular or perineurial invasion were significantly higher than those with vascular or perineurial invasion(AUC=0.719,0.665 and 0.744,P<0.05).Conclusion Different quantitative parameters of ADC can be used to evaluate different stages,lymph node metastasis and vascular or perineurial invasion in preoperative rectal cancer.The diagnostic efficiency of average ADC value is higher.