Changes And Characteristics Of Cerebral Blood Perfusion Of Mild Cognitive Impairment Patients Transforming Alzheimer’s Disease

Objective:To investigate the imaging characteristics and abnormal changes of brain cerebral blood perfusion of mild cognitive cmpairment(MCI)patients transforming Alzheimer’s disease(AD)by using arterial spin labeling(ASL),and to further clarify the imaging biomarker for early diagnosis of AD.Methods:Elderly patients with self-reported cognitive impairment were recruited from various communities in Nanchong City.According to the diagnostic criteria of MCI and AD,the participants were divided into normal control group(NC),MCI group and AD group.Finally,19 AD patients,28 MCI patients and 28 NC subjects were enrolled.All subjects underwent a systematic neuropsychiatric scale assessment,routine MRI scan and 3D-ASL scan.The cerebral blood flow(CBF)images were obtained by 3D-ASL post-processing software of MRI.The comparisons of the CBF among NC,MCI,and AD were conducted by using Analysis of Variance(ANOVA)and independent sample T test,to identify the characteristics of cerebral blood perfusion of each group.Furthermore,the correlation coefficient between the CBF values of the brain regions showed significant difference among groupsand behavioral scales were calculated.Results:Significantly different CBF were observed among NC,MCI and AD groups in the bilateral hippocampus,insula,thalamus,inferior frontal gyrus,middle frontal gyrus,superior temporal gyrus,left parietal lobe,middle temporal gyrus,superior temporal gyrus,lingual gyrus,parahippocampal gyrus,pallidum,putamen and right precuneus(P<0.05).Compared with the NC subjects,the MCI patients showed significantly increased CBF in the bilateral middle frontal gyrus,precuneus,hippocampus,thalamus,left middle temporal gyrus,inferior temporal gyrus,insula,parahippocampal gyrus,pallidum,putamen,right inferior frontal gyrus and right anterior cingulate gyrus(P<0.05).Compared with the MCI patients,the AD patients showed significantly increased CBF in the bilateral superior frontal gyrus,hippocampus,left parahippocampal gyrus,right superior temporal gyrus,middle temporal gyrus,anterior cingulate gyrus,insula and right amygdala;and showed significantly decreased CBF in the bilateral precuneus,parietal lobe,left middle temporal gyrus,insula and thalamus(P<0.05).The CBF values of the brain regions showed significant differences between MCI and AD were extracted to calculate the correlation coefficients with behavioral scales.Then the significant positive correlation between MMSE and the CBF values of bilateral middle temporal gyrus,left superior frontal gyrus,parahippocampal gyrus,right insula and right amygdala;N5 and the CBF values of left thalamus,right superior frontal gyrus,right superior temporal gyrus and right amygdala;N7 and the CBF values of left middle temporal gyrus and left parahippocampal gyrus;BNT and the CBF values of left middle temporal gyrus,left parahippocampal gyrus and right middle temporal gyrus;AFT and the CBF values of left parahippocampal gyrus and right middle temporal gyrus;STT-A and the CBF value of bilateral middle temporal gyrus;STT-B and the CBF value of left middle temporal gyrus.Conclusion:The characteristics of cerebral blood perfusion detected by ASL may be valuable for the diagnosis of AD and MCI,and can be used to assess the prognosis of disease and clarify the transformation.