氢质子磁共振波谱在轻度认知障碍中的诊断价值

Diagnostic value of proton magnetic resonance spectroscopy in mild cognitive impairment

目的探讨氢质子磁共振波谱分析(1H-MRS)在轻度认知功能障碍(MCI)诊断中的应用价值。方法回顾性分析22例MCI患者接受1H-MRS检查的资料,并与18例年龄、性别、受教育程度相匹配的认知功能正常的健康体检者进行对照。所有受检者均为右利手,采用激励回波采样模式检测,计算双侧大脑额中回皮质下白质区和双侧海马的N-乙酰天冬氨酸/肌酸(NAA/Cr)、肌醇/肌酸(mI/Cr),肌醇/NAA(mI/NAA)等的比值,并比较各组比值间的差异。结果①MCI组的左额中回皮质下白质、左海马、右海马NAA/Cr比值分别为(1.29±0.18)、(1.30±0.18)、(1.20±0.23),均低于对照组的(1.83±0.14)、(1.54±0.22)、(1.37±0.16),差异均有统计学意义(P<0.05);MCI组的右额中回皮质下白质NAA/Cr比值为(1.32±0.19),低于对照组的(1.35±0.24),差异无统计学意义(P>0.05)。②MCI组的左额中回皮质下白质、左海马、右海马mI/Cr比值分别为(0.66±0.12)、(1.02±0.14)、(0.68±0.06),均高于对照组的(0.56±0.09)、(0.89±0.09)、(0.52±0.05),差异均有统计学意义(P<0.05);MCI组的右额中回皮质下白质mI/Cr比值为(0.56±0.08),低于对照组(0.58±0.07),差异无统计学意义(P>0.05)。③MCI组的左额中回皮质下白质、左海马、右海马mI/NAA比值分别为(0.52±0.12),(0.80±0.15),(0.59±0.13),均高于正常对照组的(0.30±0.04),(0.59±0.10),(0.39±0.06),差异均有统计学意义(P<0.05);MCI组的右额中回皮质下白质mI/NAA比值为0.44±0.09,与正常对照组的0.44±0.11比较,差异无统计学意义(P>0.05)。结论1H-MRS检测MCI患者的左额中回皮质下白质、双侧海马NAA/Cr比值低于正常对照组,mI/Cr和mI/NAA比值高于正常对照组。这些指标的变化可为MCI的早期诊断提供依据。

Objective To investigate the application value of proton magnetic resonance spectroscopy （1H-MRS） in the diagnosis of mild cognitive impairment （MCI）. Methods The clinical data of 22 patients with MCI who received 1H-MRS examination were analyzed retrospectively, and they compared with 18 age-, sex- and educational level-matched healthy subjects without cognitive impairment. A stimulated echo acquisition mode was used to detect and calculate the ratios such as bilateral frontal subcortical white matter, N-acetylaspartate/creatine （NAA/Cr） of bilateral hippocampus, myoinositol/creatine （ mI/Cr）, and myoinositol N-acetyl aspartate （ml/NAA）. Then the differences between the ratios were compared in each group. Results ①The NAA/Cr ratios of the subcortical white matter of left middle frontal gyrus, left hippocampus and right hippoeampus in the MCI group were 1.29 ±0.18, 1.30 ±0.18, and 1.20 ± 0.23, and they were all lower than 1.83 ±0. 14, 1.54± 0.22, and 1.37 ± 0.16 in the control group.There were significant differences （P 〈 0.05 ） ; the NAA/Cr ratio of the subcortical white matter of right middle frontal gyrus in the MCI group was 1.32 ±0.19, and it was lower than 1.35 ±0.24 in the control group. There was significant difference （P 〉 0.05 ）. @The mI/Cr ratios of the subcortical white matter of left middle frontal gyms, left hippocampus and right hippocampus in the MCI group were 0.66 ± 0.12, 1.02 ± 0.14, and 0.68 ± 0.06, and they were higher than 0.56 ±0.09, 0. 89 ± 0.09, and 0.52 ± 0.05 in the control group. There were significant differences （ P 〈 0.05 ）. The mI/Cr ratio in the subcortical white matter of right middle frontal gyrus in the MCI group was 0.56 ± 0.08, and it was lower than 0.58± 0.07 in the control group. There was significant difference （ P 〉 0.05 ）. ③The mI/NAA ratios of the subcortical white matter of left middle frontal gyms, left hippocampus and right hippocampus in the MCI group were 0.52 ± 0.12, 0.80 ± 0.15, and 0.59 ± 0.13, and they were higher than 0.30 ± 0.04, 0.59 ± 0. 10, and 0.39 ± 0.06 in the control group. There were significant differences （ P 〈 0.05 ）. The mI/NAA ratio of the subcortical white matter of right middle frontal gyms in the MCI group was 0.44 ± 0.09, and it was lower than 0.44 ± 0.11 in the control group. There was significant difference （ P 〉 0.05 ）. Conelusion The NAA/Cr ratios of the subcortical white matter of left middle frontal gyms and bilateral hippocampus detected with 1 H-MRS are lower than the control group, and those of mI/Cr and mI/NAA are higher than the control group. The changes of these indicators can provide the basis for the early diagnosis of MCI.