精囊的磁共振扩散成像初步研究

目的评价磁共振扩散成像对精囊病变的鉴别诊断价值.方法 75例患者行MR扩散成像检查,使用回波平面扩散张量成像序列检查,b值为0和1 000.测量其精囊、膀胱、盆底脂肪和直肠内气体的ADC值.40例获最终诊断结果,其中10例为前列腺癌侵犯精囊,9例为前列腺癌内分泌治疗后改变,9例为良性前列腺增生患者,12例为无前列腺和精囊症状的健康志愿者.结果 40例患者中36例(90%)获得精囊的ADC值.前列腺癌侵犯精囊的ADC值为[0.30±0.08(均值±标准差)]×10-3 mm2/s (n=8),较前列腺癌内分泌治疗后精囊的ADC值低(P<0.05).前列腺癌内分泌治疗后精囊的ADC值为(0.46±0.17)×10-3 mm2/s (n=8),较前列腺增生患者的精囊ADC值低(P<0.05).前列腺增生患者的精囊ADC值为(0.96±0.10)×10-3mm2/s (n=8),健康志愿者的精囊ADC值为(0.97±0.33)×10-3mm2/s (n=12),二者无显著性差异(P>0.05).各组间膀胱、盆底脂肪和直肠内气体的ADC值无显著性差异(P>0.05).结论 ADC值可用于精囊病变的鉴别诊断.

Diffusion-weighted MR imaging in seminal vesicle gland

Objective To evaluate whether apparent diffusion coefficients (ADCs) calculated from diffusion-weighted echo-planar magnetic resonance images can be used to differentiate seminal vesicle lesions.Methods Diffusion-weighted echo-planar MR imaging was performed in 75 patients.Images were obtained with a diffusion-weighted factor,factor b,of 0 and 1 000 s/mm²,and an ADC map was constructed.Forty patients which who had the definite diagnosis were divided into 4 groups:Group 1,seminal vesicles invaded by prostate adenocarcinoma (PCa) (n=10),Group 2,seminal vesicles after anticancer endocrine therapies (n=9),Group 3,seminal vesicles in benign prostate hyperplasia (BPH) patients (n=9) and Group 4,normal seminal vesicles (n=12).Diffusion tensor study was performed with an echo-planar sequence with the following parameters:TR=8000 ms; TE=79.2 ms; matrix 128×128; slice:n=18; slice thickness:3 mm with no gap; FOV 13 cm×13 cm; acquisition time:3 min 44 s.During the MR studies,two experienced radiologists evaluated the quality of diffusion-weighted MR images and determined by consensus whether they were acceptable for further analyses.One radiologist measured the ADC value of Group 2,3,4.In Group 1,corresponding area of low signal on MR T2 images were measured.The ADCs of the bladder,fat in the bottom of the pelvis and air in the rectum were also measured.Each area was measured 3 times randomly,and the mean value was calculated.Results Acceptable images for ADC measurement were obtained in 36 (90%) of the 40 patients.The mean ADC of Group 1,(0.30±0.08 [mean±standard deviation])×10^-3 mm²/s (n=8),was significantly smaller (P<0.05) than that of Group 2.The mean ADC of Group 2,(0.46±0.17)×10^-3mm²/s (n=8),was significantly smaller (P<0.05) than that of Group 3.The mean ADC of Group 3,(0.96±0.10)×10^-3mm²/s (n=8),was not significantly different (P>0.05) from that of Group 4,(0.97±0.33)×10^-3mm²/s (n=12).No significant differences were seen in the mean ADCs of bladder,pelvic fat and the air among the four groups.Conclusion Measurement of ADCs may be used to characterize seminal vesicle lesions.