MR相位差增强成像技术对健康成人视辐射的初步研究

Preliminary study of the optic radiation in healthy adults using MR phase-difference enhanced imaging

目的探讨相位差增强成像(PADRE)技术显示正常成人视辐射的可行性。方法采用3.0T MR对35名健康志愿者视辐射行弥散张量成像(DTI)和PADRE技术成像,以DTI视辐射神经纤维束显示为"金标准",对PADRE技术成像的血管增强(VE)、组织增强(TE)及相位增强(Padre)3种模式重建图像中视辐射的显示情况分别进行评分,并测算其相位值,统计学分析分别采用Wilcoxon符号秩和检验和t检验。结果以DTI神经纤维束追踪作为参照,PADRE技术可清晰显示35名健康志愿者的视辐射,VE图像表现为平行侧脑室的低信号带,TE及Padre图像Padre中视辐射可分为两层结构:内侧的低信号带(内矢状层)和外侧的更低信号带(外矢状层),VE、TE及Padre图像中视辐射(内外矢状层)平均评分值分别为0±0、1.90±0.30、1.83±0.38,三者之间比较差异具有统计学意义,TE和Padre对视辐射(内外矢状层)的显示优于VE(Z值分别为-11.533、-11.392,P值均<0.01),内、外矢状层的相位值分别为-0.151±0.119,-0.441±0.099,其差异具有统计学意义(t=-15.945,P<0.01)。结论高分辨率PADRE技术可以显示视辐射,并可区分内、外矢状层,为活体视辐射成像提供了一种新方法。

Objective To assess the feasibility of delineating the optic radiation in healthy adults using phase-difference enhanced imaging（ PADRE） technique. Methods Diffusion tensor imaging and high-resolution PADRE raw images were acquired from thirty-five healthy volunteers using a 3T MR system. Diffusion tensor tractography and vessel enhancement（ VE）,tissue enhancement（ TE） and Padre images were reconstructed and the delineations of the optic radiations were scored respectively. The phase values of optic radiations were calculated. Wilcoxon tests and paired t tests were used. Results Based on the location of optic radiation on the diffusion tensor tractography,in all 35 healthy subjects,the optic radiations were depicted as hypointense bands parallel to the lateral ventricles in PADRE images. The mean scores were 0 ± 0,1. 90 ± 0. 30,1. 83 ± 0. 38 in VE,TE and Padre images,which demonstrated significant differences. TE and Padre images were superior to the VE images in delineating optic radiations（ Z =-11. 533,Z =-11. 392,both P〈0. 01）. Phase values of the internal sagittal stratum and external sagittal stratum were（-0. 151 ± 0. 119）,（-0. 441 ± 0. 099） radians respectively,and there was statistical difference（ t =-15. 945,P〈0. 01）. Conclusion The PADRE technique can delineate the optic radiation and identify the internal sagittal stratum and external sagittal stratum,which may provide a novel tool for imaging optic radiation in vivo.