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 000s/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 500s/mm2 DWI上显示较为清晰,6例病灶在b值为2 000s/mm2 DWI上显示较为清晰。Wilcoxon Signed Ranks结果显示当b值为500s/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 500s/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 500s/mm2时具有最佳显示病灶能力,在b值为500s/mm2时无法区分诊断前列腺癌与正常组织。
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 T2 WI and diffusion-weighted MRI with 10b-values（0,50,100,150,200,500,800,1 000,1 500,and 2 000s/mm^2）prior to biopsy.DWI combined with T2 WI analysis was used for detecting prostate cancer.The biopsy modality was decided by the MRI results：patients had suspicious lesions took MR/TRUS fusionguided 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 5as prostatitis.Among the 22 prostate cancer patients b=1 500s/mm^2 and b=2 000s/mm^2 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 500s/mm^2（P=0.236）.ROC curve indicated that the optimal signal intensity contrast was obtained at b=1 500s/mm^2（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 500s/mm^2 is optimal for 3-T DWI to visualize prostate cancer lesions,and b=500s/mm^2 has the lowest diagnosis efficiency.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2015年第4期402-406,共5页
Academic Journal of Second Military Medical University
基金
上海市卫生和计划生育委员会项目(M20140149)~~
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
prostatic neoplasms
differential diagnosis
magnetic resonance imaging
diffusion weighted imaging
signal intensity
