Diagnostic value of proton magnetic resonance spectroscopy in mild cognitive impairment

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 (mI/NAA). Then the differences between the ratios were compared in each group. Results: Circled Digit OneThe NAA/Cr ratios of the subcortical white matter of left middle frontal gyrus, left hippocampus and right hippocampus 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). Circled Digit TwoThe mI/Cr ratios of the subcortical white matter of left middle frontal gyrus, 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). Circled Digit ThreeThe mI/NAA ratios of the subcortical white matter of left middle frontal gyrus, 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 gyrus 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). Conclusion: The NAA/Cr ratios of the subcortical white matter of left middle frontal gyrus and bilateral hippocampus detected with 1H-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.