联合应用MR波谱分析与扩散加权成像定量指标行前列腺癌定量诊断  

Study of quantitative diagnosis for prostate cancer combined MR spectroscopy and diffusion weighted imaging

作　　者：郭雪梅[1] 王霄英[1] 李飞宇[1] 蒋学祥[1] 

机构地区：[1]北京大学第一医院放射科北京大学前沿交叉学科研究院功能成像研究中心,100034

出　　处：《中华放射学杂志》2010年第4期387-391,共5页Chinese Journal of Radiology

基　　金：基金项目：2007年度高等学校博士学科点专项科研基金新教师项目（20070001748）

摘　　要：目的以前列腺六分区为基础，量化分析并验证MRS与DWI两种功能成像的定量指标在联合诊断前列腺癌时的权重大小。方法搜集2006年2月至2007年7月间前列腺MR检查数据库中患者资料，并以接受前列腺MR检查的不同时间段，将入选前列腺检查患者分为2组，分别用于定量分析和验证结果，第1组为从2006年2月至12月期间、第2组为从2007年1月至7月期间的患者。每例患者在行常规MRI后，均进行MRS和DWI检查，测量MRS可用体素的（胆碱＋肌酸）／枸橼酸盐（CC／C）值和分区内最小ADC值（ADCmini）。以CC／C≥0．911作为阳性体素标准，计算前列腺MRS六分区内阳性体素比（PVR）。采用聚类分析中的线性判别，计算第1组分区内PVR和ADCmini合用时各自所占的权重。将第2组分区内PVR和ADCmini代入公式，采用ROC分析比较单独及联合诊断的诊断效能。结果第1组和第2组均有40例患者，非前列腺癌20例，前列腺癌20例。由第1组病例得出的联合诊断线性判别公式为DWI和MRS联合诊断的非标准化线性判别值（D）：3．264×ADCmini-0．205×PVR-4．407，分区内PVR和ADCmini的曲线下面积（Az）分别为0．769和0．910，联合诊断的Az为0．909。第2组病例分区内PVR和ADCmini的乜分别为0．838和0．912，联合诊断的Az为0．915。2组的联合诊断效能与单独使用DWI的诊断效能差异均无统计学意义（x2值分别为0．32和1．50，P值均〉0．05）。结论DWI对前列腺癌的诊断效能高于MRS，联用2种功能参数不能明显提高总体的诊断效能。Objective To quantitatively analyze and testify the diagnostic value of combined MRS and DWI for prostate cancer based on sextant localization. Methods Patients who underwent prostate MR examinations in our hospital had MRS and DWI scanning in addition to conventional MRI. The （choline ＋ creatine）/citrate （CC/C） value in each measurable voxel and the minimal ADC value （ADCminl） in each sextant were measured. Taking CC/C of no less than 0. 911 as the cutoff value for prostate cancer, the ratios of positive voxel （PVR） in sextants were calculated. The selected patients were divided into 2 groups according to the date of examination, for the quantitative analysis and the verification respectively. Group 1 was from Feb, 2006 to Dec, 2006, and group 2 from Jan, 2007 to Jul, 2007. The diagnostic efficacy of PVR, ADCmini and their combination was tested by ROC analysis. Results There were 40 patients in group 1 and group 2 respectively for the linear discrimination of the cluster analysis, including 20 patients with prostate cancer and 20 patients without prostate cancer. The linear discrimination equation calculated from group 1 was ＇ D = 3. 264 × ADCmini - 0. 205 × PVR - 4. 407 . The areas under curve （Az） of ROC for PVR, ADCmini and D were 0.769, 0.910 and 0.909, respectively. In group 2, the Az of ROC for PVR, ADCmini and D were 0. 838, 0. 912 and 0. 915, respectively. There were no statistical difference between ADCmini -alone and D in both groups（ X2 = 0. 32 and 1.50, P 〉 0. 05 ）. Conclusions Quantitative prostate DWI had higher diagnostic value than MRS. The combined use of MRS and DWI was not superior to the DWI-alone in the diagnostic efficacy of prostate cancer.

关 键 词：前列腺癌 磁共振波谱学 

分 类 号：R445.2[医药卫生—影像医学与核医学]