ABSTRACT
BACKGROUND AND PURPOSE: While AD can be definitively confirmed by postmortem histopathologic examination, in vivo imaging may improve the clinician's ability to identify AD at the earliest stage. The aim of the study was to test the performance of amyloid PET using new processing imaging algorithm for more precise diagnosis of AD. METHODS: Amyloid PET results using a new processing imaging algorithm (MRI-Less and AAL Atlas) were correlated with clinical, cognitive status, CSF analysis, and other imaging. The regional SUVR using the white matter of cerebellum as reference region and scores from clinical and cognitive tests were used to create ROC curves. Leave-one-out cross-validation was carried out to validate the results. RESULTS: Forty-four consecutive patients with clinical evidence of dementia, were retrospectively evaluated. Amyloid PET scan was positive in 26/44 patients with dementia. After integration with 18F-FDG PET, clinical data and CSF protein levels, 22 of them were classified as AD, the remaining 4 as vascular or frontotemporal dementia. Amyloid and FDG PET, CDR 1, CSF Tau, and p-tau levels showed the best true positive and true negative rates (amyloid PET: AUC = .85, sensitivity .91, specificity .79). A SUVR value of 1.006 in the inferior frontal cortex and of 1.03 in the precuneus region was the best cutoff SUVR value and showed a good correlation with the diagnosis of AD. Thirteen of 44 amyloid PET positive patients have been enrolled in clinical trials using antiamyloid approaches. CONCLUSIONS: Amyloid PET using SPM-normalized SUVR analysis showed high predictive power for the differential diagnosis of AD.
Subject(s)
Alzheimer Disease/diagnostic imaging , Aniline Compounds , Positron Emission Tomography Computed Tomography/methods , Stilbenes , Aged , Alzheimer Disease/pathology , Female , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging , Male , Retrospective Studies , Sensitivity and SpecificityABSTRACT
PURPOSE: To assess the brain core temperature of Alzheimer disease (AD) patients in comparison with healthy volunteers using diffusion-weighted thermometry. MATERIALS AND METHODS: Fourteen AD patients (3 men, 11 women; age range 60-81 years, mean age 73.8 ± 6.1 years) and 14 healthy volunteers, age and sex-matched (mean age 70.1 ± 6.9 years; range 62-84 years; 5 men, 9 women) underwent MR examination between February 2014 and March 2016. MR imaging studies were performed with a 1.5-T MR scanner. Brain core temperature (T: °C) was calculated using the following equation from the diffusion coefficient (D) in the lateral ventricular (LV) cerebrospinal fluid: T = 2256.74/ln (4.39221/D) - 273.15 using a standard DWI single-shot echo-planar pulse sequence (b value 1000 s/mm2). Statistical analysis was performed using a nonparametric Wilcoxon rank-sum test to compare the patient and control groups regarding LV temperatures. RESULTS: There was no significant difference (P = 0.1937) in LV temperature between patients (mean 37.9 ± 1.1 °C, range 35.8-39.2 °C) and control group (38.7 ± 1.4 °C, range 36.9-42.7 °C). CONCLUSIONS: Brain core temperature in AD patients showed no significant alterations compared to healthy volunteers.
