阿尔茨海默病和轻度认知功能障碍患者的磁共振酰胺质子转移成像初步研究

A preliminary study on amide proton transfer MR imaging of Alzheimer＇s disease and mild cognitive impairment in elder patients

目的评价磁共振酰胺质子转移（APT）成像技术在诊断阿尔茨海默病（AD）和遗忘型轻度认知功能障碍（aMCI）患者脑异常改变的可行性，并进一步探讨该技术的临床应用价值。方法21例AD患者（AD组）、11例aMCI患者（aMCI组）和19例年龄及性别相阪配的健康对照者（对照组）进行头颅常规磁共振结构像和APT成像检查。在斜轴位APT像上测量双侧海马、颞叶白质、枕叶白质和大脑脚的酰胺质子（3．5ppm处）不对称磁化转移率（MTRasym）。采用单因素方差分析比较3组间各脑结构MTRasym（3．5ppm）值的差异。以年龄和受教育时间为控制变量，采用偏相关分析比较所有受试者各脑结构MTRasym（3．5ppm）值与简易精神状态量表（MMSE）评分的相关性。结果正常对照组、MCI组和AD组双侧海马的MTRasym（3．5ppm）值依次增高，右侧：（0．86±0．32）％、（1．15±0．31）%和（1．42±0．35）％（F=13．712，P=0．000）；左侧：（0．84±0．31）％、（1．14±0．32）％和（1．39±0．33）％（F=12．835，P=0．000）。双侧海马的MTRasym（3．5ppm）值均与MMSE评分呈负相关（右侧r=-0．595，P=0．000；左侧r=0．552，P=0．000）。结论APT成像能够敏感地显示AD和MCI患者海马区基于蛋白增加的脑代谢异常。

Objective To evaluate the feasibility of amide proton transfer （APT） MR imaging for the detection of cerebral metabolite abnormalities in patients with Alzheimer＇s disease （AD） and amnestic mild cognitive impairment （aMCI）, and to explore its clinical utility. Methods Totally 21 AD patients, 11 aMCI patients and 19 age- and sex-matched normal controls underwent APT and structural MR imaging. The magnetic resonance ratio asymmetry （MTRasym） values at 3.5 ppm of bilateral hippocampi, temporal white matter regions, occipital white matter regions and cerebral peduncles were measured on the oblique axial APT MR images. The differences in MTRasyrn （3.5 ppm） values of the cerebral structures among the three groups were compared by using one-way ANOVA. After adjusting for age and years of education, partial correlation analysis was used to investigate the associations between mimi-mental state examination （MMSE） scores and the various MR imaging measures among all the groups. Results MTRasym （3.5ppm） in bilateral hippocampi showed a consistently increasing trend from normal controls to MCI and to AD , right： （0.86 ± 0.32）%,（ 1.15±0.31）% and （1.42±0.35）% （F=-13. 712,P=0.000）; left： （0. 84 ± 0. 31） % , （1. 14±0.32）% and （1.39±0.33）% （F=12.835,P=0.0000）. MTRasym （3.5 ppm） values of bilateral hippocampi were significantly negatively correlated with MMSE scores （right： r=- 0. 595, P =0. 000 ; left： r= -0. 552, P= 0. 000）. Conclusions APT MR imaging can sensitively show abnormal cerebral metabolites because of the increased proteins and peptides in the hippocampus in patients with AD and MCI. which suggests the technique is a useful tool to diagnose early AD and monitor the disease.