基于PI-RADS V2研究多参数MRI诊断早期前列腺癌的价值

目的 基于前列腺影像报告和数据系统第2版(PI-RADS V2)探讨多参数MRI对早期前列腺癌(PCa)的诊断价值.方法 回顾性纳入27例行MRI检查[T2WI、扩散加权成像(DWI)、动态增强(DCE)]的早期PCa患者,2位放射科医师在不提供任何临床资料的情况下参照PI-RADS V2分析T2WI、DWI和DCE图像,按12分区法对前列腺各个分区出现癌的可能性进行评分.共组成4种方案.方案1:T2WI;方案2:T2WI+DWI;方案3:T2WI+DCE;方案4:T2WI+DWI+DCE.根据影像评分和病理结果对照,计算4种方案对早期PCa癌区和非癌区的平均PI-RADS V2评分并采用独立样本t检验比较,绘制受试者工作特征(ROC)曲线并采用Z检验比较曲线下面积(AUC)的差异,取约登指数最大值所对应的PI-RADS V2评分为界值,统计4种方案的敏感度、特异度及准确度.结果 27例早期PCa患者共纳入324区,119个癌区和205个非癌区,其中64个外周带癌区,55个移行区癌区.在方案1~4中,早期PCa癌区的PI-RADS V2评分分别为3.13±1.19、3.27±1.15、3.28±1.23、3.33±1.16,非癌区的PI-RADS V2评分分别为1.98±0.90、1.91±0.91、2.03±0.99、1.94±0.96,2组间PI-RADS V2评分在每种方案的差异均有统计学意义(P<0.05).各方案诊断早期PCa的AUC从大到小依次为:方案4(0.819)、方案2(0.810)、方案3(0.772)、方案1(0.765),各方案间的AUC差异均无统计学意义(P>0.05).方案1~4均以PI-RADS V2评分≥4分为临界值,诊断的敏感度分别为45.40%、56.30%、59.70%、61.34%;特异度分别为95.10%、96.10%、89.80%、96.60%;准确度分别为76.85%、81.48%、78.70%、83.65%.结论 多参数MRI有助于提高早期PCa的检出及诊断准确度,其中以T2WI+DWI+DCE的诊断价值最高.PI-RADS V2是一种评价早期PCa较好的半定量方法.

Evaluation of multiparametric MRI in diagnosing early prostate cancer:a study based on PI-RADS version 2

Objective To investigate the diagnostic value of multiparametric MRI in early prostate cancer(PCa) based on PI-RADS version 2.Methods 27 surgically-proved early PCa patients were collected in this retrospective study.T2WI,DWI and DCE were evaluated by two blinded radiologists.By 12 sub-region classification method the possibility of the presence of cancer at each sub-region was scored according to the PI-RADS V2.The receiver operating characteristic (ROC) curve was used to analyze the diagnosic efficacy of the following 4 protocols:T2WI alone(protocol 1),T2WI+DWI(protocol 2),T2WI+DCE(protocol 3),T2WI+DWI+DCE(protocol 4).The sensitivity,specificity and accuracy for each protocol were calculated.The average scores of cancerous sub-regions and non-cancerous sub-regions were calculated and the independent sample t test was used to compare the four protocols.Results 324 sub-regions were analyzed in 27 early PCa patients and then divided into 119 cancerous sub-regions and 205 non-cancerous sub-regions,including 64 peripheral zone cancerous sub-regions and transition zone cancerous sub-regions.In protocol 1-4, the average scores of cancerous sub-regions in orderwere 3.13±1.19,3.27±1.15,3.28±1.23, 3.33±1.16,respectively.Non-cancerous sub-regions's scores in order were 1.98±0.90,1.91±0.91, 2.03±0.99,1.94±0.96 respectively and there were significant differences among each protocol (P<0.05).The area under the ROC curve of the 4 protocols for region-based analysis were displayed in descending order: protocol 4 (0.819), protocol 2 (0.810), protocol 3 (0.772), protocol 1 (0.765) and there were no significant differences between any two protocols (P>0.05).In four protocols, the sensitivity in order were 45.40%, 56.30%, 59.70%, 61.34%, while the specificity in order were 95.10%, 96.10%, 89.80%, 96.60%, and the accuracy in order were 76.85%, 81.48%, 78.70%, 83.65%.Conclusion Multiparametric MRI can improve the diagnostic accuracy for the detection of early PCa, and T2WI+DWI+DCE is with the highest value.The PI-RADS V2 system is a better semi quantitative method for evaluation of early PCa.