Abstract
The recent advent of tau-specific positron emission tomography (PET) has enabled in vivo assessment of tau pathology in Alzheimer’s disease (AD). However, because PET scanners have limited spatial resolution, the measured signals of small brain structures or atrophied areas are underestimated by partial volume effects (PVEs). The aim of this study was to determine whether partial volume correction (PVC) improves the precision of measures of tau deposits in early AD. We investigated tau deposits in 18 patients with amyloid-positive early AD and in 36 amyloid-negative healthy controls using 18F-THK5351 PET. For PVC, we applied the SPM toolbox PETPVE12. The PET images were then spatially normalized and subjected to voxel-based group analysis using SPM12 for comparison between the early AD patients and healthy controls. We also compared these two groups in terms of brain atrophy using voxel-based morphometry of MRI. We found widespread neocortical tracer retention predominantly in the posterior cingulate and precuneus areas, but also in the inferior temporal lobes, inferior parietal lobes, frontal lobes, and occipital lobes in the AD patients compared with the controls. The pattern of tracer retention was similar between before and after PVC, suggesting that PVC had little effect on the precision of tau load measures. Gray matter atrophy was detected in the medial/lateral temporal lobes and basal frontal lobes in the AD patients. Interestingly, only a few associations were found between atrophy and tau deposits, even after PVC. In conclusion, PVC did not significantly affect 18F-THK5351 PET measures of tau deposits. This discrepancy between tau deposits and atrophy suggests that tau load precedes atrophy.
Highlights
Alzheimer’s disease (AD), the most common form of progressive degenerative dementia, is characterized by cognitive deterioration and behavioral impairment
We evaluated the correlation of atrophy and 18F-THK5351 retention obtained from the same regions of interest (ROIs) using multiple regression models among AD patients and healthy controls respectively
The early AD patients showed significantly increased tau deposits on 18F-THK5351 positron emission tomography (PET) data before and after partial volume correction (PVC) compared with the healthy controls (Figures 1, 2, 3 and Tables 2, 3)
Summary
Alzheimer’s disease (AD), the most common form of progressive degenerative dementia, is characterized by cognitive deterioration and behavioral impairment. The recent advent of tau-specific positron emission tomography (PET) has enabled in vivo assessment of tau pathology in AD, which will aid in early detection, disease staging, and treatment development (Holtzman et al, 2016). Because PET scanners have limited spatial resolution, the measured signals of small brain structures such as cortical gray matter are underestimated by partial volume effects (PVEs) (Matsuda et al, 2002; Yanase et al, 2005; Gonzalez-Escamilla et al, 2017). AD is characterized by progressive brain atrophy and PVEs are estimated to be even more severe in AD patients (Scheltens et al, 1992; Schroeter et al, 2009; Rullmann et al, 2016). The aim of the present study was to determine whether PVC improves the precision of 18F-THK5351 PET measures of tau deposits in early AD
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
