目的 应用磁共振扩散张量成像技术 (diffusion tensor im aging DTI),对阿尔茨海默病 (Alzheimer'sdisease AD )患者顶叶及胼胝体膝部脑白质损伤的情况与临床认知评价之间的关系进行初步研究。方法 对 22例AD 患者和 22例健康老年...目的 应用磁共振扩散张量成像技术 (diffusion tensor im aging DTI),对阿尔茨海默病 (Alzheimer'sdisease AD )患者顶叶及胼胝体膝部脑白质损伤的情况与临床认知评价之间的关系进行初步研究。方法 对 22例AD 患者和 22例健康老年人进行脑部 DTI 扫描后,测量顶叶和胼胝体膝部的各向异性分数值 (fractional anisotropyFA ),应用成组 t检验对 AD 组和正常对照组的相应区域进行比较,并用部分相关性检验对 AD 患者脑中各部位相应取值与临床认知评价量表之间的关系进行统计。结果 AD 患者左侧顶叶 FA 值与记忆相关量表评分呈正相关。胼胝体膝部 FA 值与 M M SE 评分呈正相关。结论 DTI 技术能够在一定程度上反映 AD 患者脑白质受损情况与认知功能缺损的关系。展开更多
To denoise the diffusion weighted images （DWls） featured as multi-boundary, which was very important for the calculation of accurate DTIs （diffusion tensor magnetic resonance imaging）, a modified Wiener filter was...To denoise the diffusion weighted images （DWls） featured as multi-boundary, which was very important for the calculation of accurate DTIs （diffusion tensor magnetic resonance imaging）, a modified Wiener filter was proposed. Through analyzing the widely accepted adaptive Wiener filter in image denoising fields, which suffered from annoying noise around the edges of DWIs and in turn greatly affected the denoising effect of DWIs, a local-shift method capable of overcoming the defect of the adaptive Wiener filter was proposed to help better denoising DWIs and the modified Wiener filter was constructed accordingly. To verify the denoising effect of the proposed method, the modified Wiener filter and adaptive Wiener filter were performed on the noisy DWI data, respectively, and the results of different methods were analyzed in detail and put into comparison. The experimental data show that, with the modified Wiener method, more satisfactory results such as lower non-positive tensor percentage and lower mean square errors of the fractional anisotropy map and trace map are obtained than those with the adaptive Wiener method, which in turn helps to produce more accurate DTIs.展开更多
文摘目的 应用磁共振扩散张量成像技术 (diffusion tensor im aging DTI),对阿尔茨海默病 (Alzheimer'sdisease AD )患者顶叶及胼胝体膝部脑白质损伤的情况与临床认知评价之间的关系进行初步研究。方法 对 22例AD 患者和 22例健康老年人进行脑部 DTI 扫描后,测量顶叶和胼胝体膝部的各向异性分数值 (fractional anisotropyFA ),应用成组 t检验对 AD 组和正常对照组的相应区域进行比较,并用部分相关性检验对 AD 患者脑中各部位相应取值与临床认知评价量表之间的关系进行统计。结果 AD 患者左侧顶叶 FA 值与记忆相关量表评分呈正相关。胼胝体膝部 FA 值与 M M SE 评分呈正相关。结论 DTI 技术能够在一定程度上反映 AD 患者脑白质受损情况与认知功能缺损的关系。
基金Project(2009AA04Z214) supported by the National High Technology Research and Development Program of ChinaProject(07JJ6133) supported by the Natural Science Foundation of Hunan Province, China
文摘To denoise the diffusion weighted images （DWls） featured as multi-boundary, which was very important for the calculation of accurate DTIs （diffusion tensor magnetic resonance imaging）, a modified Wiener filter was proposed. Through analyzing the widely accepted adaptive Wiener filter in image denoising fields, which suffered from annoying noise around the edges of DWIs and in turn greatly affected the denoising effect of DWIs, a local-shift method capable of overcoming the defect of the adaptive Wiener filter was proposed to help better denoising DWIs and the modified Wiener filter was constructed accordingly. To verify the denoising effect of the proposed method, the modified Wiener filter and adaptive Wiener filter were performed on the noisy DWI data, respectively, and the results of different methods were analyzed in detail and put into comparison. The experimental data show that, with the modified Wiener method, more satisfactory results such as lower non-positive tensor percentage and lower mean square errors of the fractional anisotropy map and trace map are obtained than those with the adaptive Wiener method, which in turn helps to produce more accurate DTIs.
