Abstract
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Objectives Imaging agents targeting Aβ plaques in the living human brain such as F-18 florbetapir (AV-45) are valuable as biomarkers for detecting and monitoring Alzheimer disease (AD). However clearly differentiating AV-45 uptake in grey from white matters is difficult in equivocal demented subjects. The current study aimed to an improved AV-45 PET imaging reading through brain cortex guide using dual time point scanning protocol.
Methods Dual time point PET scans were performed by acquiring two 5- min-images at 0 and 50 min after tracer injection in 16 subjects (10 AD and 6 controls). The PET brain cortex segmentation was performed from early time point image. The PET segmentation map was compared to the corresponding MRI grey matter segmentation result as a gold standard. The contour of brain cortex from early PET image was overlaid to the delayed image as a reading guide. The image reading score was rated from 0 as normal to 5 as probably AD by both experienced and inexperienced nuclear medicine physicians with and without the brain cortex-contouring guide.
Results The PET brain cortex segmentation was successfully performed in all subjects. The segmentation map showed high correlation to the corresponding MRI derived grey matter map. The correlation of AV-45 PET rating score between experienced and inexperienced physicians was improved with the aid of a brain cortex-contouring guide.
Conclusions The dual time point image protocol showed promising in providing additional brain cortex-contouring information which can improve the AV-45 PET reading consensus for inexperienced physicians