Presentation Information
[POS-57]Contrast Recovery Method for Early-Phase Positron Emission Tomography Images
*Masashi Kameyama1 (1. Tokyo Metropolitan Institute for Geriatrics and Gerontology (Japan))
Keywords:
tracer kinetics,positron emission tomography
Positron Emission Tomography (PET) is a powerful imaging technique that visualizes molecular activity in the body. In brain imaging, it is commonly used to detect pathological changes in neurodegenerative diseases such as Alzheimer's disease. Although standard PET imaging focuses on scans acquired 30–60 minutes after tracer injection, early-phase PET images—acquired within 10 minutes—can provide valuable information about cerebral blood flow (CBF). This dual-use capability makes early-phase imaging attractive for both diagnostic and research purposes.
However, for tracers with low permeability-surface area product (PS), such as [18F]MK6240, the image contrast in early-phase scans may be significantly reduced due to insufficient tracer delivery to the brain. To address this issue, we propose a novel mathematical correction method to enhance contrast in early-phase images.
The key idea is to first estimate the PS value of the tracer by comparing it with that of water, which rapidly and freely distributes in brain tissue. We analyzed the relationship between the K1values (initial uptake rates) of water and the tracer using Bland-Altman analysis, a statistical method for comparing two measurement techniques. The slope of the Bland-Altman plot provides an estimate of the tracer's PS value.
Using this estimated PS, we then apply a modified version of the Lassen's correction method, originally developed for cerebral blood flow estimation. This enables image contrast recovery using referencing a region region.
However, for tracers with low permeability-surface area product (PS), such as [18F]MK6240, the image contrast in early-phase scans may be significantly reduced due to insufficient tracer delivery to the brain. To address this issue, we propose a novel mathematical correction method to enhance contrast in early-phase images.
The key idea is to first estimate the PS value of the tracer by comparing it with that of water, which rapidly and freely distributes in brain tissue. We analyzed the relationship between the K1values (initial uptake rates) of water and the tracer using Bland-Altman analysis, a statistical method for comparing two measurement techniques. The slope of the Bland-Altman plot provides an estimate of the tracer's PS value.
Using this estimated PS, we then apply a modified version of the Lassen's correction method, originally developed for cerebral blood flow estimation. This enables image contrast recovery using referencing a region region.