正常前列腺组织IVIM-DWI的可重现性研究及年龄相关性分析

The reproducibility of IVIM-DWI in normal prostate and age-related analysis

目的：探讨体素内不相干运动扩散加权成像（IVIM-DWI）各相关参数在正常前列腺组织中的可重现性，并分析其随年龄的变化趋势。材料与方法将66名符合纳入标准的各年龄段健康志愿者分成三组（A组，15～30岁，13名；B组，31～50岁，25名；C组，≥51岁，28名），在3.0 T磁场强度下对志愿者行IVIM-DWI扫描，休息30 min后行第二次IVIM-DWI扫描（b值0、25、50、75、100、150、200、400、600、800、1000、1200、1500、2000、3000 s/mm2），应用双指数模型对信号衰减进行分析得出slow ADC值，fast ADC值及f值。采用配对样本t检验研究前后两次扫描之间的差异，探讨各参数的可重现性；采用方差分析（ANOVA）及LSD法对各参数在不同年龄段正常前列腺组织中的差异进行比较，分析其随年龄的变化趋势。结果 A组健康志愿者前列腺中央腺fast ADC值两次测量数据差异有统计学意义（P=0.022），其余各参数两次测量数据差异没有统计学意义；slow ADC值外周带A、B组及A、C组间差异有统计学意义，B、C组间差异无统计学意义，中央腺A、C组及B、C组间差异有统计学意义，A、B组间差异无统计学意义；fast ADC值外周带及中央腺各组两两间均无显著性差异；f值外周带各组两两间均有显著性差异，中央腺A、C组及B、C组间差异有统计学意义，A、B组间差异无统计学意义；前列腺外周带及中央腺slow ADC值、f值总体上随年龄段升高呈上升趋势。结论不同年龄段正常前列腺组织的IVIM-DWI各相关参数总体上具有良好的可重现性；应用影像学手段，通过对IVIM-DWI相关参数的分析，可以定量的反映前列腺随年龄升高而发生的各种细胞水平的变化，为前列腺疾病的诊断及定量分析提供可靠的依据。

Objective：To investigate the reproducibility of the intravoxel incoherent motion diffusion weighted imaging （IVIM-DWI） derived parameters, and analyze the change of the IVIM-DWI derived parameters of normal prostate in different age groups. Materials and Methods：Sixty-six volunteers conformed to the standards were divided into three groups （group A, 15—30 years, 13. Group B, 31—50 years, 25. Group C,≥51 years, 28） and underwent the scanning of IVIM-DWI with 15 b-factors from 0 to 3000 （0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500, 2000, 3000 s/mm2） twice with an interval of 30 minutes using 3.0 T MRI device, the biexponential ifts were applied to ifgure out the slow ADC, fast ADC and f values. The reproducibility of every parameters were investigated by the paired t-test. The differences of every parameters in normal prostate between the three age groups were assessed using one-way analysis of variance （ANOVA） and the least significant difference （LSD） t-test. Results： Slow ADC, fast ADC and f values showed good reproducibility in both peripheral zone （PZ） and central gland （CG） of three age groups, except fast ADC in CG of group A （P=0.022）. The slow ADC and f values of the prostate peripheral zone and central gland had the upward tendency with age increasing. Slow ADC showed signiifcant difference between group A and B, group A and C, while had no signiifcant difference between group B and C in PZ, and slow ADC showed signiifcant difference between group A and C, group B and C, while had no signiifcant difference between group A and B in CG. Fast ADC in both PZ and CG between three age groups had no signiifcant different. F value show signiifcant difference between three age groups in PZ, while in CG f value show signiifcant difference between group A and C, group B and C, while had no signiifcant difference between group A and B. Conclusions：In general, a good reproducibility of IVIM-DWI derived parameters in normal prostate of three age groups was observed. IVIM-DWI technology relfected the age-related change of prostate tissues in the celluar level, and the derived parameters could set a reliable reference to the quantitative analysis of prostate diseases.