IVIM-DWI和定量DCE-MRI鉴别前列腺癌和前列腺增生——灌注系数的相关性研究

目的 分析体素内不相干运动磁共振扩散加权成像(IVIM-DWI)和磁共振动态增强扫描(DCE-MRI)定量参数对前列腺癌和前列腺增生鉴别诊断的价值,探讨二者灌注系数的相关性,并对两种不同方法进行评价和比较。方法 回顾性分析经病理学证实的31例前列腺癌患者和52例前列腺增生患者。所有患者均行前列腺IVIM-DWI和DCE-MRI检查,其中IVIM-DWI采用10个b值(b=10、20、30、50、80、100、200、400、1000、1500 s/mm2),将所得图像通过工作站后处理,计算出病变组织的纯水分子扩散系数D值及灌注分数f值;同时将DCE-MRI扫描所得图像利用定量分析软件测量出病灶组织的参数值,即容积转运参数Ktrans值、速率常数Kep值及血管外细胞外容积分数Ve值。利用两独立样本t检验分别计算各参数在前列腺癌组和增生组间的差异;利用Person相关分析对两种不同检查方法中的灌注系数进行相关性分析;并对有鉴别诊断价值的参数行受试者特性曲线(ROC曲线),评价各参数值的诊断效能。结果 前列腺癌组的D值明显低于前列腺增生组,差异有统计学意义(P0.01);前列腺癌组的f值及Ktrans、Kep、Ve值明显高于前列腺增生组,差异有统计学意义(P0.01),且f值与Kep值呈正相关(P0.05),其相关系数为0.368。对D、f值及Ktrans、Kep、Ve值分别行ROC曲线得出:Kep的曲线下面积(AUC)最大(0.991,P0.01),相应的敏感度和特异度分别为90.91%、100%。结论IVIM-DWI和DCEMRI定量分析对前列腺良恶性疾病的诊断及鉴别诊断均有价值,两种不同检查方法的灌注系数呈正相关。DCE-MRI的诊断效能优于IVIM-DWI。

Correlation of perfusion fraction between IVIM-DWI and quantitative DCE-MRI for diagnosis of prostate cancer and hyperplasia

Objective To assess the diagnostic value of parameters derived from Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and dynamic contrast-enhanced (DCE)-MRI in prostate cancer and benign prostate hyperplasia and to explore the correlation of perfusion fraction between IVIM-DWI and DCE-MRI. Methods 83 patients with histologically confirmed prostate cancer (31) and prostate hyperplasia (52) underwent IVIM-DWI and DCE-MRI. The IVIM-DWI was performed with 10 b-values (10,20,30,50,80,100,200,400,1000, and 1500 s/mm2) to calculate the values of D and f. The values of Ktrans, Kep and Ve were measured on DCE-MRI. All parameters between prostate cancer and hyperplasia were compared by two independent sample t-test . The correlation of perfusion fraction between the two methods was analyzed by Pearson correlation . The diagnostic performance of different parameters was evaluated by receiver operating characteristic (ROC) curve analysis. Results The D value of prostate cancer was significantly lower than that of hyperplasia (P<0.01). The values of f and Ktrans, Kep, Ve were significantly higher in cancer than hyperplasia (P<0.01). F and Kep were positively correlated(r=0.368). With ROC curve analysis for the values of D, f,Ktrans, Kep, Ve, the area under the ROCcurve of Kep was 0.991, significantly (P<0.01) larger than that of D, f,Ktrans, and Ve with 90.91%diagnostic sensitivity and 100%specificity. Conclusion Both IVIM-DWI and DCE-MRI can improve the differential diagnosis of prostate disease with positive correlation of the perfusion fractions. DCE-MRI has better diagnostic performance than IVIM-DWI.