摘要目的 探讨超高b值扩散加权成像(DWI)对前列腺癌的诊断效能.方法 收集2014年6月1日至2015年5月30日解放军总医院73例患者,行前列腺T2WI、常规DWI(b值为1000 s/mm2)和超高b值DWI(b值分别为2000、3000 s/mm2)检查.根据评分诊断前列腺病变,以穿刺病理结果为金标准,计算不同影像检查方法诊断前列腺癌的灵敏度、特异度、阳性预测值及阴性预测值.比较超高b值DWI和常规DWI诊断前列腺癌的灵敏度和特异度,并分析受试者工作特征(ROC)曲线下面积(AUC).结果2000、3000 s/mm2超高b值DWI诊断前列腺外周带癌的灵敏度分别为88.1 %和92.5 %,特异度分别为53.1 %和68.8 %,均高于常规DWI(均P<0.0001).2000、3000 s/mm2超高b值DWI诊断前列腺移行区癌的灵敏度分别为80.0 %和88.0 %,特异度分别为52.9 %和88.2 %,均高于常规DWI(均P<0.0001).2000、3000 s/mm2超高b值DWI间诊断前列腺外周带和移行区癌的灵敏度差异无统计学意义(均P>0.05);3000 s/mm2超高b值DWI诊断移行区前列腺癌的特异度高于2000 s/mm2(P<0.0001).3000 s/mm2超高b值DWI诊断的阳性预测值及阴性预测值均最高,外周带和移行区阳性预测值分别为86.1 %和91.7 %,阴性预测值分别为81.5 %和83.3 %.T2WI、常规DWI、超高b值DWI诊断前列腺外周带癌的AUC分别为0.591、0.553、0.698和0.806,诊断移行区癌分别为0.693、0.506、0.665和0.881,3000 s/mm2超高b值DWI的AUC均最大.结论 超高b值DWI是一种较为准确和可靠的前列腺癌诊断方法.

abstractsObjective To explore the value of ultra-high b-value diffusion-weighted imaging(DWI) in diagnosis of prostate cancer. Methods According to inclusion and exclusion criteria, 73 consecutive examinees in Chinese PLA General Hospital from June 2014 to May 2015 were screened. Written informed consent was obtained from all patients. T2WI, conventional DWI with b-value of 1 000 s/mm2and ultra-high b-value DWI with 2 000 s/mm2and 3 000 s/mm2were performed in each examinee. Images were interpreted and were corresponding to histological results conducted by ultrasound guided prostate systematic biopsy. Reference biopsy as the gold standard,the sensitivity,specificity, positive predictive value(PPV) and negative predictive value (NPV) were calculated for each image. Sensitivity and specificity differences between ultra-high b-value DWI and conventional DWI were analyzed. The areas under the curves (AUCs) between ultra-high b-value DWI and other modalities were compared. Results The sensitivity and specificity for ultra-high b-value DWI were 92.5 % and 68.8 % with b-value of 3 000 s/mm2, and they were 88.1 % and 53.1 % for 2 000 s/mm2in peripheral zone. The sensitivity and specificity for ultra-high b-value DWI were 88.0 % and 88.2 % with a b-value of 3 000 s/mm2, and they were 80.0 % and 52.9 % for 2 000 s/mm2in transition zone. The values of sensitivity for ultra-high b-value DWI were significantly higher than those for conventional DWI both in peripheral zone and transition zone (all P <0.000 1). The detection of lesions was comparable with ultra-high b-value DWI at 2 000 s/mm2and 3 000 s/mm2in peripheral zone (P >0.05), whereas the value of specificity for 3 000 s/mm2were significantly higher than that for 2 000 s/mm2in transition zone (P<0.000 1). PPV and NPV for 3 000 s/mm2were significantly higher than those for the other three modalities both in peripheral zone(86.1 % and 81.5 %) and transition zone (91.7 % and 83.3 %). In peripheral zone, the AUCs were 0.591, 0.553, 0.698 and 0.806 in T2WI, conventional DWI and ultra-high b-value DWI at 2 000 s/mm2 and 3 000 s/mm2respectively, for the diagnosis of transition zone cancer were 0.693, 0.506, 0.665 and 0.881 respectively, and the AUCs for the ultra-high b-value with 3 000 s/mm2were the largest. Conclusion Ultra-high b-value DWI is an accurate and reliable method in the diagnosis of prostate cancer.