小视野弥散加权成像定位经直肠超声引导前列腺穿刺活检术对前列腺癌的诊断价值

目的 评价小视野弥散加权成像（rFOV DWI）定位经直肠超声（TRUS）引导前列腺穿刺活检术对前列腺癌（PCa）的诊断价值。方法 收集2016年9月至2017年10月期间于TRUS引导下行前列腺穿刺活检的54例患者，术前均接受rFOV DWI检查。根据前列腺影像报告和数据系统对rFOV DWI图像进行评估，采用经会阴途径10点系统穿刺（SB）和rFOV DWI定目标穿刺（rFOV DWI-TB）相结合的穿刺方案。以穿刺病理结果为金标准，计算rFOV DWI的诊断效能，并比较SB、rFOV DWI-TB及SB联合rFOV DWI-TB在PCa检出率和穿刺点阳性率上的差异。结果 54例患者穿刺病理诊断PCa 26例，rFOV DWI诊断PCa的敏感性、特异性、阳性预测值、阴性预测值分别为80．77%、89．29%、87．50%、83．33%，rFOV DWI诊断PCa的AUC为0．916。rFOV DWI对临床显著性PCa的诊断敏感性为95%。SB、rFOV DWI-TB与SB联合rFOV DWI-TB检出率差异均无统计学意义（P>0．05），但SB联合rFOV DWI-TB的检出率显著高于SB（P=0．031）。rFOV DWI-TB穿刺点阳性率显著高于SB（χ²=124．377，P=0．000）。结论 rFOV DWI有助于术前PCa可疑病灶，特别是临床显著性PCa病灶的检出，为TRUS引导前列腺穿刺活检提供目标信息，有较高的临床应用价值。

Value of reduced field-of-view diffusion -weighted MRI for prostate cancer detection in the TRUS-guided transperineal prostate biopsy

Objective   To observe the value of reduced field-of-view diffusion-weighted MRI (rFOV DWI) for prostate cancer (PCa) detection in the TRUS-guided transperineal prostate biopsy.Methods    A total of 54 patients with suspected PCa underwent rFOV DWI before TRUS-guided prostate biopsy were prospectively enrolled in this study. All rFOV DWI data were carried out by two  independent radiologists using prostate imaging reporting and data system (PI-RADS) assessment category, and systemic 10-core biopsy (SB) combined with rFOV DWI targeted biopsy (rFOV DWI-TB) were taken. According to histopathology results, the performance of rFOV DWI was analysed. Additionally, the detection rate of PCa and the positive rate of punctures of SB, rFOV DWI-TB and SB combined with rFOV DWI-TB were compared.Results   Overall, 26 of the 54 patients (48．15%) had histologically confirmed PCa. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for detecting PCa with rFOV DWI was 80．77%, 89．29%, 87．5% and 83．33%, respectively. The ROC curve analysis revealed the AUC was 0．916. Additionally, the sensitivity for detecting clinically significant PCa with rFOV DWI was 95%. The PCa detection rate of SB, rFOV DWI-TB, and combination of SB and rFOV DWI-TB was 37．04%, 42．59% and 48．15%, respectively. The detection rate for combination of SB and rFOV DWI-TB was significantly higher than that of SB only (P=0．031). Additionally, the detection rate for rFOV DWI TB cores (78．33%) was significantly better than for SB cores (15．5%)(χ²=124．377，P=0．000).Conclusions   rFOV DWI may be useful for providing more information of PCa lesions in targeted prostate biopsy, and has potential value in clinically significant PCa detecting.