基于MR三维梯度回波与扩散加权成像序列的脑表面重组技术比较

目的 使用MR三维梯度回波（3D flash）序列和扩散加权成像（DWI）序列的扫描图像进行脑表面三维重组，对两种方法显示脑表面结构的能力、价值与限度及临床应用等进行比较和探讨。方法 对30名正常人行头颅3D flash和DWI检查。通过容积重组显示脑表面解剖结构。同一组医生对两种方法重组图像进行评价和评分，并比较结果。结果 基于3D flash重组的各脑表面结构清楚显示，平均得分均在2．50分以上。基于DWI的重组图像能够较好地显示中央前回、中央后回、顶上小叶、额上回、中央前沟、中央沟、中央后沟、顶间沟及额上沟等结构，平均得分2．60～2．75分，缘上回、角回、额中回、额下回、颞上回、外侧沟和额下沟等结构显示较差，平均得分1．67～2．48分，颞中回、颞下回、颞上沟及颞下沟等显示很差，平均得分仅0．88～1．27分。比较两种方法的平均得分，基于3D flash重组优于基于DWI的三维重组，差异有统计学意义，P值均〈0．01。结论 基于3D flash重组能够显示真实的脑表面主要脑沟、脑回和脑裂，对脑解剖形态的研究和定位诊断有重要意义。基于DWI的三维脑表面重组能比较满意地显示顶叶、额叶的主要表面结构，扫描和重组快速，有一定实用价值。

Three-dimensional reconstruction of brain surface anatomy: technique comparison between flash and diffusion-weighted imaging

Objective To compare two methods 3D flash and diffusion-weighted images(DWI)in reconstructing the brain surface anatomy,and to evaluate their displaying ability,advantages,limitations and clinical application.Methods Thrity normal cases were prospectively examined with 3 D flash sequence and echo-planar DWI.Three-dimensional images were acquired with volume-rendering on workstation.Brain surface structures were evaluated and scored by a group of doctors.Results Main structures of brain surface were clearly displayed on three-dimensional images based on 3D flash sequence.Average scores were all above 2.50.For images based on DWI,precentral gyrus,postcentral gyrus,superior parietal lobule, superior frontal gyrus,precentral sulcus,central sulcus,postcentral sulcus,intraparietal sulcus and superior frontal sulcus were best shown with average scores between 2.60-2.75,However,supramarginal gyrus, angular gyurs,middle frontal gyrus,inferior frontal gyrus,superior temporal gyrus,lateral sulcus,inferior frontal sulcus could not be well shown,with average scores between 1.67-2.48.Middle temporal gyrus, inferior temporal gyrus,superior temporal sulcus and inferior temporal sulcus can only get scores from 0.88 to 1.27.Scores of images based on 3D flash were much higher than that based on DWI with distinct differentiations,P values were all below 0.01.Conclusion Three-dimensional images based on 3D flash can really display brain surface structures.It is very useful for anatomic researches.Three-dimensional reconstruction of brain surface based on DWI is a worthy technique to display brain surface anatomy, especially for frontal and parietal structures.