嗅觉脑功能MRI对阿尔茨海默病的早期诊断

Olfactory Functional MRI in the Early Diagnosis of Alzheimer Disease

目的探讨嗅觉功能MRI早期诊断阿尔茨海默病(AD)的价值。资料与方法 14例正常老年人(NC)、11例轻度认知障碍(MCI)患者及12例AD患者进行MMSE、MOCA及CDR量表评分,采用西门子3.0T磁共振扫描仪、32通道头线圈以事件相关设计的方式进行嗅觉fMRI扫描,64位Matlab7.11.0及SPM8软件进行数据处理,选择双侧初级嗅觉皮层(POC)为感兴趣区(ROI),统计ROI内激活体素数量并进行分析,比较3组间ROI内的激活体素数量,分析受试者ROI内的激活体素数量与MMSE和MOCA评分的相关性。结果 NC组、MCI组和AD组POC内激活体素数分别为201±114、88±102、45±60,AD组激活水平显著低于MCI组及NC组,MCI组显著低于NC组,差异有统计学意义(H=13.272,P<0.01)。控制年龄因素时,受试者初级嗅觉皮层内的激活范围与MMSE评分(r=0.447,P<0.05)及MOCA评分(r=0.421,P<0.05)呈正相关。结论嗅觉功能MRI可以反映AD病理改变造成的嗅觉功能损害,可能成为早期诊断AD的新方法,具有重要研究价值。

Purpose To investigate the value of olfactory functional MRI （fMRI） in early diagnosing Alzheimer disease （AD）. Materials and Methods Fourteen normal elderly people （NC group）, eleven mild cognitive impairment （MCI group） and twelve AD patients （AD group） underwent MMSE, MOCA and CDR grade. All subjects were scanned by Siemens 3.0T MRI scanner, with 32 channel head coil in event-related design, all data were processed with 64 bit Matlab 7.11.0 and SPM8 software. Primary olfactory cortex （POC） was selected as the region of interest （ROI）, the quantity of activated voxels was calculated and analyzed, the correlation between the quantity of activated voxels and MMSE as well as MOCA scores was also analyzed. Results The quantity of activated voxels in POC of NC group, MCI group and AD group was 201±114, 88±102 and 45±60, respectively. The activated level of AD group was obviously less than that of MCI group and NC group, and MCI group was statistically less than NC group （H=13.272, P＆lt;0.01）. There was a positive correlation between the activated voxels and the MMSE score （r=0.447, P＆lt;0.05） as well as MOCA （r=0.421, P＆lt;0.05） score under the control factor of age. Conclusion Olfactory fMRI can reflect the olfactory defect caused by the pathological change of AD, which is a potential new method for early diagnosing AD.