ABSTRACT
Background@#and Purpose To determine the imaging characteristics and cutoff value of18F-florapronol (FC119S) quantitative analysis for detecting β-amyloid positivity and Al- zheimer’s disease (AD), we compared the findings of FC119S and 18F-florbetaben (FBB) positron-emission tomography (PET) in patients with cognitive impairment. @*Methods@#We prospectively enrolled 35 patients with cognitive impairment who underwent FBB-PET, FC119S-PET, and brain magnetic resonance imaging. We measured global and vertex-wise standardized uptake value ratios (SUVRs) using a surface-based method with the cerebellar gray matter as reference. Optimal global FC119S SUVR cutoffs were determined using receiver operating characteristic curves for β-amyloid positivity based on the global FBB SUVR of 1.478 and presence of AD, respectively. We evaluated the global and vertex-wise SUVR correlations between the two tracers. In addition, we performed correlation analysis for global or vertex-wise SUVR of each tracer with the vertex-wise cortical thicknesses. @*Results@#The optimal global FC119S SUVR cutoff value was 1.385 both for detecting β-amyloid positivity and for detecting AD. Based on the global SUVR cutoff value of each tracer, 32 (91.4%) patients had concordant β-amyloid positivity. The SUVRs of FC119S and FBB had strong global (r=0.72) and vertex-wise (r>0.7) correlations in the overall cortices, except for the parietal and temporal cortices (0.4
ABSTRACT
Background@#and PurposeWe aimed to determine the effect of demographic factors on cortical thickness and brain glucose metabolism in healthy aging subjects. @*Methods@#The following tests were performed on 71 subjects with normal cognition: neurological examination, 3-tesla magnetic resonance imaging, 18F-fluorodeoxyglucose positron-emission tomography, and neuropsychological tests. Cortical thickness and brain metabolism were measured using vertex- and voxelwise analyses, respectively. General linear models (GLMs) were used to determine the effects of age, sex, and education on cortical thickness and brain glucose metabolism. The effects of mean lobar cortical thickness and mean lobar metabolism on neuropsychological test scores were evaluated using GLMs after controlling for age, sex, and education. The intracranial volume (ICV) was further included as a predictor or covariate for the cortical thickness analyses. @*Results@#Age was negatively correlated with the mean cortical thickness in all lobes (frontal and parietal lobes, p=0.001; temporal and occipital lobes, p<0.001) and with the mean temporal metabolism (p=0.005). Education was not associated with cortical thickness or brain metabolism in any lobe. Male subjects had a lower mean parietal metabolism than did female subjects (p<0.001), while their mean cortical thicknesses were comparable. ICV was positively correlated with mean cortical thickness in the frontal (p=0.016), temporal (p=0.009), and occipital (p=0.007) lobes. The mean lobar cortical thickness was not associated with cognition scores, while the mean temporal metabolism was positively correlated with verbal memory test scores. @*Conclusions@#Age and sex affect cortical thickness and brain glucose metabolism in different ways. Demographic factors must therefore be considered in analyses of cortical thickness and brain metabolism.
ABSTRACT
Background@#and Purpose This study aimed to determine the neuropsychological differences between patients with early-stage Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB) with a Clinical Dementia Rating (CDR) score of ≤1. @*Methods@#We examined 168 patients with AD (126 with CDR score=0.5, 42 with CDR score=1) and 169 patients with DLB (104 with CDR score=0.5, 65 with CDR score=1) whose diagnoses were supported by 18F-flobetaben positron-emission tomography (PET) and 18F-N-(3-fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane PET. Neuropsychological test scores were compared after controlling for age, sex, and education duration. Using a cutoff motor score on the Unified Parkinson’s Disease Rating Scale of 20, patients with AD were further divided into AD with parkinsonism (ADP+ , n=86) and AD without parkinsonism (ADP− , n=82). @*Results@#At CDR scores of both 0.5 and 1, the DLB group had lower scores on the attention (digit-span forward at CDR score=0.5 and backward at CDR score=1), visuospatial, and executive (color reading Stroop test at CDR score=0.5 and phonemic fluency test, Stroop tests, and digit symbol coding at CDR score=1) tests than the AD group, but higher scores on the memory tests. The ADP− and ADP+ subgroups had comparable scores on most neuropsychological tests, but the ADP+ subgroup had lower scores on the color reading Stroop test. @*Conclusions@#Patients with DLB had worse attention, visuospatial, and executive functions but better memory function than patients with AD. Parkinsonism was not uncommon in the patients with AD and could be related to attention and executive dysfunction.