基于前列腺影像报告和数据系统评估T2WI联合分段读出弥散加权成像诊断早期前列腺癌的价值

Evaluation of T2WI and readout-segmented echo-planar imaging in diagnosing early prostate cancers:a study based on PI-RADS system

目的：比较分段读出平面回波成像（readout-segmented echo-planar imaging, RS-EPI）与单次激发平面回波成像（single-shot echo-planar imaging, SS-EPI）在早期前列腺癌诊断中的价值。材料与方法回顾性纳入20例行3.0T MRI SS-EPI和RS-EPI检查的早期前列腺癌患者。两位影像科医生在不提供任何临床资料的情况下参照PI-RADS标准分析T2WI、RS-EPI和SS-EPI图像，按六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5种方案：方案1：T2WI；方案2：SS-EPI；方案3：RS-EPI；方案4：T2WI＋SS-EPI；方案5：T2WI＋RS-EPI。采用受试者工作特征（receiver operating characteristic, ROC）曲线比较5种方案的诊断效能。结果方案1～5的曲线下面积分别为0.789、0.790、0.874、0.838、0.881，由高到低的顺序为T2WI＋RS-EPI＞RS-EPI＞T2WI＋SS-EPI＞SS-EPI＞T2WI。方案1与方案3、方案4、方案5，方案2与方案3、方案4，方案4与方案5之间ROC曲线下面积差异有统计学意义（P＜0.05）。方案1与方案2，方案3与方案4、方案5之间ROC曲线下面积差异无统计学意义（P＞0.05）。结论 T2WI联合应用DWI可提高早期前列腺癌的诊断效能，T2WI联合RS-EPI的诊断效能高于T2WI联合SS-EPI，更利于临床早期前列腺癌的诊断。

Objectives：To compare the clinical utility of readout-segmented echo-planar imaging （RS-EPI） with single-shot echo-planar imaging （SS-EPI） in diagnosing early prostatic cancers. Materials and Methods： Twenty surgically-proved early prostate cancer patients were collected in this retrospective study. T2WI, RS-EPI and SS-EPI were evaluated by two blinded radiologists. By using 6 sub-region classiifcation method the possibility of the presence of cancer at each sub-region was scored according to the PI-RADS system. The receiver operating characteristic （ROC） curve was used to analyze the diagnostic efifcacy of the following 6 protocols： T2WI alone （protocol 1）, SS-EPI alone （protocol 2）, RS-EPI （protocol 3）, a combination of T2WI and SS-EPI （protocol 4） and a combination of T2WI and RS-EPI （protocol 5）. Results：The area under the ROC curve （Az） of protocol 1 to protocol 5 for region-based analysis were 0.789, 0.790, 0.874, 0.838, 0.881, respectively. ROC analysis revealed signiifcant differences between protocol 1 and 3, 4, 5, and between protocol 2 and 3, 4, and between protocol 4 and 5 （P〈0.05）. While the difference between protocol 1 and 2, between 3 and 4, 5 has no statistical significance （P〉0.05）. Conclusions：The combination of T2WI and DWI can improve the diagnosis ability of early prostate cancers. Combination of T2WI and RS-EPI is a more effective approach than combination of T2WI and SS-EPI for the detection of early prostate cancers.