扩散加权成像ADC值评估睾丸生精功能的初步研究

目的评价MR扩散加权成像(DWI)睾丸ADC值对评估生精功能的价值。方法本研究纳入睾丸穿刺活检证实生精功能减低者为病例组A组(n=18),年龄20~40岁,平均(28.1±5.1)岁;以精液检查正常者为对照组,按年龄段设立3个对照组:对照组B(n=18),年龄20~30岁,平均(25.4±3.1)岁;对照组C(n=22),年龄31~40岁,平均(35.4±3.3)岁;对照组D(n=16),年龄41~50岁,平均(43.4±4.3)岁。均采用3.0 T MR机行睾丸常规平扫及DWI序列扫描,DWI扫描采用EPI序列(b值分别取0,900,4000),ADC图自动生成。由同一位医生在影像工作站采用手动选取尽可能大的兴趣区测量双侧睾丸ADC值。采用独立样本t检验,比较病例组与对照组、各对照组之间的ADC值;通过ROC曲线分析,计算诊断睾丸生精减低时的ADC最佳临界值。结果病例组A组睾丸平均ADC值(0.479±0.025)mm~2/s,对照组B为(0.446±0.018)mm~2/s,对照组C为(0.458±0.033)mm~2/s,对照组D为(0.468±0.033)mm~2/s。3个对照组进行组间ADC值的比较均有明显统计学差异(P0.001),表明尽管生精功能还能保持正常范围,但随年龄增长睾丸ADC值逐渐增高。而病例组睾丸平均ADC值明显高于所有对照组(P0.001)。通过ROC分析,本组诊断睾丸生精功能减低时的ADC最佳临界值为0.473 mm~2/s,敏感度及特异度分别是84.1%和73.7%。结论采用MR扩散加权成像(DWI)睾丸ADC值测量能有效对睾丸生精功能进行初步评估。

Diffusion-weighted MRI with ADC analysis of testicular spermatogenic function: preliminary study

Objective To assess the efficacy of diffusion-weighted MR imaging (DWI) for evaluating testicular spermatogenic function.Methods 18 men (mean age:28.1±3.7 years,range:20-40 years) with testicular spermatogenesis hypofunction confirmed by percutaneous testes biopsy,volunteers with normal semen analysis including 18 young men (mean age:25.4±3.1 years,range:20-30 years),22 middle-aged men (mean age:35.4±3.3 years,range:31-40 years),and 16 older men (mean age:43.4±4.3 years,range:41-50 years) were included in the study.All subjects underwent conventional 3 T MRI and DWI using EPI sequence with b values of 0,900,and 4000 s/mm2.The ADC values were measured by placing the largest possible regions of interest on the testes without including necrosis and testicular edge on the automatically generated ADC maps.Testicular ADC values in each group were compared and the optimal cutoff value for diagnosing testicular spermatogenesis hypofunction was determined using ROC curve analysis.Results Average testicular ADC value in group A,group B,group C and group D were (0.479±0.025),(0.446±0.018),(0.458±0.033),and (0.468±0.033) mm2/s,respectively.The average ADC values of the three control groups were significantly different (P＜0.001) and increased with age from (0.446±0.018) mm2/s in young,(0.458±0.033) mm2/s in middle-aged,to (0.468±0.033) mm2/s in older men.The average ADC values of patients with testicular spermatogenesis hypofunction (0.479±0.025) mm2/s were significantly higher than those in each control group (P＜0.001).The optimal cutoff value of testicular ADC value for diagnosing testicular spermatogenesis hypofunction by ROC analysis was 0.473 mm2/s with 84.1％ sensitivity and 73.7％ specificity.Conclusion The testicular ADC values are useful for differentiating testicular spermatogenesis hypofunction from normal.