Objective To study the value of relative cerebral blood flow(rCBF)changes in patients with amnestic-type mild cognitive impairment (aMCI)and mild Alzheimer disease(AD) using MRI pulsed arterial spin labeling(PASL).Methods A prospective study recruited 37 aMCI patients (aMCI group),30 mild AD patients(mild AD group) and 30 healthy volunteers (normal control group) from March 2011 to December 2013,MRI using PASL for cerebral perfusion imaging was performed and data of rCBF were collected.Taking age as covariate,analysis of variance (ANONA)was carried out to assess the difference of rCBF among all the three groups,then Bonferroni was done between every two groups.A follow-up examination using PASL was performed in the seventeen patients of the aMCI group.And paired t-test was used for comparing the longitudinal change of their rCBF data.Results Compared with the normal control group,the aMCI group showed significant increase of rCBF in bilateral posterior cingulate cortices and precuneus (cluster number 2 785,P＜0.05).While the mild AD group showed decrease of rCBF in the left inferior and superior parietal lobes,the angular,middle frontal lobe,as well as the right superior temporal lobe (cluster number 3 459-5 206,P＜0.05).When compared with the aMCI group,the mild AD group showed regional hypoperfusion in bilateral middle frontal lobes,the left precuneus,the right postcentral and inferior parietal lobe (cluster number 3 236-19 863,P＜0.05).In the longitudinal study of the 17 aMCI patients,an increased rCBF was found to coexist with reduced rCBF in the left inferior frontal and lateral occipital cortex,bilateral frontal poles and paracingulate gyrus,with hyperperfusion dominated.Increased rCBF was also detected in the left temporal lobe,the angular gyrus and precuneus,while decreased rCBF was present in the left putamen,the operculum and right corpus callosum (P＜0.05).Conclusions ASL perfusion imaging is a valuable method for dynamic monitoring of the cerebral perfusion changes in aMCI and AD patients.PASL will assist in finding a useful imaging biomarker for early diagnosis of AD.

Objective To evaluate the role of local gyrification index (LGI) in the early diagnosis of Alzheimer disease(AD). Methods Thirty‐five amnestic‐type mild cognitive impairment patients (aMCI group), 34 mild AD patients (mild AD group) and 33 healthy volunteers (normal control group) were studied. All patients underwent high resolution MRI examination and mini‐mental state examination (MMSE). Using surface‐based morphometry, the FreeSurfer was employed to access LGI of vertex over every participant′s whole cortical surface, then we calculated the mean LGI (mLGI) of each subject′s left and right hemisphere separately. Taking age, gender and educational year as covariance, analysis of covariance was used to compare the difference of mLGI of left and right brain among 3 groups, then Bonferroni was done between every two groups. Analysis of covariance was applied to compare the difference of LGI of every participant among 3 groups, and Monte Carlo method was employed to perform multiple comparison corrections. The correlations between the MMSE scores and LGIs of the three groups were analyzed. Results Compared with normal control group(left 3.03±0.12,right 3.02±0.13), the mLGI of hemispheres in mild AD group(left 2.94±0.11,right 2.93±0.10) decreased respectively(P<0.05). The difference of mLGI of hemispheres between aMCI group(left 2.96 ± 0.10, right 2.96 ± 0.09) and normal control group had no statistical significance(P>0.05). The difference of mLGI of hemispheres between aMCI group and mild AD group also had no statistical significance(P>0.05). The aMCI group showed decrease of LGI in some brain regions located at the right temporal lobe, bilateral frontal and parietal lobe compared with the normal control group. While compared with aMCI group, decreased LGIs was presented in some brain regions located at bilateral temporal, occipital, frontal lobe and the right parietal lobe of mild AD group. There was a positive correlation between MMSE scores and LGIs of some brain regions in the bilateral temporal, occipital lobe, the left frontal lobe and the right parietal lobe in the three groups. Conclusion LGI is conductive in the early diagnosis of AD and can serve as an imaging marker for monitoring disease progresses.

Objective:To investigate the relationship between abdominal visceral adipose tissue (VAT) and cardiometabolic risk (CMR) through quantitative computed tomography (QCT).Methods:The present study included 76226 participants. Abdominal fat areas were measured using the QCT Pro Model 4 system. Cardiometabolic indices were collected, including systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, triglyceride, and low-density and high-density lipoprotein cholesterols CMR score was the sum of abnormal blood pressure, fasting glucose, triglyceride, and high-density lipoprotein cholesterol. Restricted cubic spline and ordered logistic regression models were applied.Results:The mean age was 50±13 years and the percentage of men was 58.8%. The level of VAT area was higher in men than in women (191.7±77.1 cm 2 vs 116.4±56.2 cm 2, P<0.0001 for all). After adjustment for age, the cardiometabolic indices except high-density lipoprotein cholesterol increased with increasing VAT area. When VAT area was 300 cm 2, age-adjusted odds ratios and 95% confidence intervals of a CMR score ≥ 1 were 14.61 (13.31, 16.04) for men and 5.46 (4.06, 7.36) for women, and the age-adjusted probability of a CMR score ≥ 3 was 31.7% for men and 31.3% for women. Conclusions:QCT-derived VAT is closely related to CMR. The findings suggest that measurement of visceral fat is recommended for the management of abdominal obesity in subjects who agree to undergo lung cancer screening via low-dose CT without additional radiation exposure.