Background: 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. The aim of this
study was to determine whether partial volume correction (PVC) improves the precision
of measures of tau deposits in early AD.
Materials and Methods: 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.
Results: 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 no 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, no correlation was found between atrophy and tau deposits, even after PVC.
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
Biography: Graduated with a degree in Medicine at Kanazawa University School of
Medicine in 1979. Then finished the doctor’s course at Graduate School of Kanazawa
University School of Medicine in 1983. He specializes in radiology especially in nuclear
medicine. He was a Rotary Foundation scholar from 1984 to 1985 at Montreal
Neurological Institute. In 1993, he became head of department of radiology at National
Center Hospital of Neurology and Psychiatry. In 2004, he became Professor and Chair,
department of nuclear medicine, Saitama Medical University and returned to National
Center of Neurology and Psychiatry in 2012 as director general of integrative brain
imaging center. Currently serves as visiting Professor of Saitama Medical University and
Tohoku University. He is a board certified specialist of Radiology, Nuclear Medicine, and