Objective: To explore the value of ultrahigh b-value DWI in diagnosis of prostate cancer. Methods: From October 2015 to October 2016, a total of 84 cases from Affiliated Changshu Hospital of Soochow University(39 cases of prostate cancer with a total of 57 lesions, 45 cases of benign prostate hyperplasia) were examined with T(2)WI, high b-value DWI (b=1 000 s/mm(2)) and ultrahigh b-value DWI (b=2 000 s/mm(2)) .Three image sets were rated respectively based on PI-RADS V2 by two radiologists and the scores were compared with biopsy results.The differences of the area under the ROC curve (AUC) among the three groups of each observer were compared by Z test. Results: The difference of AUC between ultrahigh b-value DWI and T(2)WI in the diagnosis of peripheral and transitional zone cancer was statistically significant between the two observers (P=0.009 9, 0.008 2, 0.010 8 and 0.004 5 respectively), and there was no significant difference of AUC between ultrahigh b-value DWI and high b-value DWI in the diagnosis of peripheral and transitional zone cancer.The inter-reader agreement was found to be perfect for all lesions, peripheral zone lesions and transition zone lesions at ultrahigh b-value DWI (kappa values were 0.738, 0.709 and 0.768 respectively). Conclusion: The diagnostic performance of ultrahigh b-value DWI is superior to high b-value DWI and T(2)WI in both peripheral zone and transition zone cancers.
目的： 探讨超高b值扩散加权成像(DWI)定性诊断前列腺癌的价值。 方法： 回顾性分析2015年10月至2016年10月常熟市第一人民医院84例患者(39例前列腺癌，共57个病灶；45例前列腺良性增生)T(2)加权成像(T(2)WI)、高b值DWI(b＝1 000 s/mm(2))和超高b值DWI(b＝2 000 s/mm(2))成像。两位观察者基于前列腺影像报告和数据系统第2版(PI－RADS V2)评分标准分别对三组序列进行评分诊断，并与穿刺活检病理结果对照。绘制每位观察者三组序列诊断前列腺癌的受试者工作特征(ROC)曲线，采用Z检验比较每位观察者三组序列间ROC曲线下面积(AUC)差异。 结果： 两位观察者超高b值DWI与T(2)WI诊断外周带和移行带癌的AUC差异有统计学意义(P值分别为0.009 9、0.008 2、0.010 8和0.004 5)，与高b值DWI诊断外周带和移行带癌的AUC差异无统计学意义。超高b值DWI上两位观察者诊断所有部位、外周带和移行带癌均具有较高的一致性(kappa值分别为0.738、0.709和0.768)。 结论： 超高b值(b＝2 000 s/mm(2))DWI对外周带和移行带癌的诊断能力优于高b值(b＝1 000 s/mm(2))DWI和T(2)WI。.
Keywords: Magnetic resonance imaging; Prostatic neoplasms; Ultrahigh b-value.