磁共振体素内不相干运动扩散加权成像在肝脏局灶性病变性质诊断中的应用价值

Application value of magnetic resonance intravoxel incoherent motion-diffusion weighted imaging in diagnosis of focal liver lesions nature

目的探讨磁共振体素内不相干运动(IVIM)扩散加权成像(DWI)在肝脏局灶性病变性质诊断中的应用价值。方法纳入47例肝脏局灶性病变患者(共50个病灶),并根据病理检查结果按病灶性质将其分为良性病灶组(n=23)和恶性病灶组(n=27)。所有患者均采用3.0T磁共振扫描仪进行肝脏常规MRI平扫和IVIM-DWI扫描。利用功能图像测量单指数模型生成表观扩散系数(ADC),功能图像测量多指数模型生成慢速表观扩散系数(sADC)、快速表观扩散系数(fADC)和灌注分数等参数,采用受试者工作特征(ROC)曲线比较3.0T磁共振IVIM-DWI各参数在肝脏局灶性病变性质诊断中的价值。结果良性病灶组的ADC与sADC均高于恶性病灶组(均P<0.05),而两组的fADC与灌注分数差异均无统计学意义(均P>0.05)。以病理检查结果为金标准,ADC诊断肝脏局灶性恶性病灶的敏感度为92.59%,特异度为95.65%,ROC曲线下面积为0.907;sADC诊断肝脏局灶性恶性病灶的敏感度为96.30%,特异度为100.00%,ROC曲线下面积为0.958;fADC诊断肝脏局灶性恶性病灶的敏感度为85.19%,特异度为91.30%,ROC曲线下面积为0.857;灌注分数诊断肝脏局灶性恶性病灶的敏感度为88.89%,特异度为89.96%,ROC曲线下面积为0.849。sADC诊断肝脏局灶性恶性病灶的ROC曲线下面积均大于其他参数(均P<0.05),且敏感度和特异度也相对较高。结论相较于3.0T磁共振IVIM-DWI中的其他参数,sADC在肝脏局灶性病变性质中诊断效能更高。

Objective To investigate the application value of magnetic resonance intravoxel incoherent motion(IVIM)-diffusion weighted imaging(DWI)in diagnosing the nature of focal liver lesions.Methods Forty-seven patients with focal liver lesions(totaling 50 lesions)were enrolled,and they were divided into benign lesion group(n=23)and malignant lesion group(n=27)according to the nature of lesions in line with the findings of pathological examination.All patients received conventional liver MRI plain scan and IVIM-DWI scan by 3.0T magnetic resonance scanner.The monoexponential model for functional image measurement was employed to generate apparent diffusion coefficient(ADC),and the multi-exponential model for functional image measurement was used to generate slow apparent diffusion coefficient(sADC),fast apparent diffusion coefficient(fADC),perfusion fraction and other parameters.The receiver operating characteristic(ROC)curve was utilized to compare the value of various IVIM-DWI parameters of 3.0T MRI for diagnosing the nature of focal liver lesions.Results The benign lesion group had higher ADC and sADC than the malignant lesion group(all P<0.05),whereas there was no statistically significant difference in the fADC or perfusion fraction between the two groups(all P>0.05).With the findings of the pathological examination as the gold standard,ADC yielded a sensitivity of 92.59%,a specificity of 95.65%and an area under the ROC curve of 0.907 for diagnosing malignant focal liver lesions;sADC yielded a sensitivity of 96.30%,a specificity of 100.00%and an area under the ROC curve of 0.958 for diagnosing malignant focal liver lesions;fADC yielded a sensitivity of 85.19%,a specificity of 91.30%and an area under the ROC curve of 0.857 for diagnosing malignant focal liver lesions;perfusion fraction yielded a sensitivity of 88.89%,a specificity of 89.96%and an area under the ROC curve of 0.849 for diagnosing malignant focal liver lesions.sADC had a larger area under the ROC curve than other parameters for diagnosing malignant focal liver lesions(all P<0.05),exhibiting relatively higher sensitivity and specificity.Conclusion Compared with other parameters of IVIM-DWI of 3.0T MRI,sADC achieves a higher diagnostic efficiency for the nature of focal liver lesions.