| 本文已被：浏览 2502次 下载 2658次 |
码上扫一扫！ |
| 3-T MR扩散加权成像诊断前列腺癌最优b值探究 |
| 阳青松1,王振1,陈玉坤1,陈录广1,马超1,高旭2,王燕2,余勇伟3,陆建平1* |
|
|
(1. 第二军医大学长海医院影像医学科, 上海 200433;
2. 第二军医大学长海医院泌尿外科, 上海 200433;
3. 第二军医大学长海医院病理科, 上海 200433
*通信作者) |
|
| 摘要: |
| 目的 以磁共振超声融合靶向穿刺联合系统穿刺病理结果为金标准,探究3-T MR 扩散加权成像(DWI)诊断前列腺癌的最优b值。方法 前瞻性招募临床拟诊为前列腺癌的患者43例,于穿刺前行包括常规T2WI及10个b值(0、50、100、150、200、500、800、1 000、1 500、2 000 s/mm2)DWI在内的MR检查。采用DWI联合T2WI对病灶进行分析判断,根据MR诊断结果选择穿刺方式。MR提示有可疑病灶者行靶向穿刺联合系统穿刺,未提示可疑灶者行单纯系统穿刺。选择病理确诊为前列腺癌的患者,测量不同b值病灶及正常组织的DWI信号强度。采用Wilcoxon Signed Ranks非参数配对检验分析不同b值病灶和正常组织信号强度差异是否具有统计学意义,采用受试者工作特征(ROC)曲线计算各b值诊断曲线下面积(AUC)、敏感性和特异性。结果 入组病例共43例,22例确诊为前列腺癌,16例为良性前列腺增生,5例为前列腺炎。在确诊为前列腺癌的22例中,16例病灶在b值为1 500 s/mm2 DWI上显示较为清晰,6例病灶在b值为2 000 s/mm2 DWI上显示较为清晰。Wilcoxon Signed Ranks结果显示当b值为500 s/mm2时病灶和正常组织信号强度差异无统计学意义(P=0.236),在其他b值图像上病灶和正常组织信号强度差异均有统计学意义(P<0.000 1)。ROC曲线分析提示b 值为 1 500 s/mm2 时AUC最大(0.933)。当诊断的信号强度cut-off值为49.2时,诊断的敏感性和特异性分别为0.909和0.909。结论 3-T MR DWI在b值为1 500 s/mm2时具有最佳显示病灶能力,在b值为500 s/mm2时无法区分诊断前列腺癌与正常组织。 |
| 关键词: 前列腺肿瘤 鉴别诊断 磁共振成像 扩散加权成像 信号强度 |
| DOI：10.3724/SP.J.1008.2015.00402 |
| 投稿时间：2015-01-29修订日期：2015-03-09 |
| 基金项目:上海市卫生和计划生育委员会项目(M20140149). |
|
| Investigation of the optimal b value in diffusion weighted MR imaging for diagnosis of prostate cancer at 3-T |
| YANG Qing-song1,WANG Zhen1,CHEN Yu-kun1,CHEN Lu-guang1,MA Chao1,GAO Xu2,WANG Yan2,YU Yong-wei3,LU Jian-ping1* |
(1. Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;
2. Department of Urology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;
3. Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
*Corresponding author) |
| Abstract: |
| Objective To investigate the optimal b value in diffusion weighted MR imaging for diagnosis of prostate cancer at 3-T while using magnetic resonance/transrectal ultrasound (MR/TRUS) fusion-guided biopsy and system biopsy pathological findings as reference standard. Methods Forty-three consecutive patients were enrolled in this prospective study; they were suspected to have prostate cancer and underwent T2WI and diffusion-weighted MRI with 10 b-values (0,50,100,150,200,500,800,1 000,1 500,and 2 000 s/mm2) prior to biopsy. DWI combined with T2WI analysis was used for detecting prostate cancer. The biopsy modality was decided by the MRI results: patients had suspicious lesions took MR/TRUS fusion-guided biopsy and system biopsy and those had no suspicious lesions took system biopsy only. The signal intensity of prostate cancer lesions and normal prostate tissue on DWI of different b values were measured. Statistical analyses were performed by a Wilcoxon Signed Ranks test to compare the signal intensities between prostate cancer and normal prostate tissue. Receiver operating characteristics (ROC) were used to calculate the AUC, sensitivity, and specificity, so as to determine the optimal b value for revealing prostate cancer on DWI. Results Twenty-two of the 43 patients were diagnosed as prostate cancer, with 16 diagnosed as benign prostate hyperplasia (BPH) and 5 as prostatitis. Among the 22 prostate cancer patients b=1 500 s/mm2 and b=2 000 s/mm2 DWI images provided the best lesion visibility in 16/22 and in 6/22 patients, respectively. Wilcoxon Signed Ranks test showed that the signal intensities of the lesions and the normal tissues were significantly different(P<0.000 1) at all b values but when at 500 s/mm2 (P=0.236). ROC curve indicated that the optimal signal intensity contrast was obtained at b=1 500 s/mm2 (P<0.000 1, AUC=0.933), and the signal intensity cut-off value was 49.2, with the sensitivity and specificity being 0.909 and 0.909, respectively. Conclusion A b value of 1 500 s/mm2 is optimal for 3-T DWI to visualize prostate cancer lesions, and b=500 s/mm2 has the lowest diagnosis efficiency. |
| Key words: prostatic neoplasms differential diagnosis magnetic resonance imaging diffusion weighted imaging signal intensity |
