Quantitative Total-Body Imaging of Blood Flow with High Temporal Resolution Early Dynamic ¹⁸F-Fluorodeoxyglucose PET...

Area of Science:

• Nuclear Medicine
• Physiology
• Medical Imaging

Background:

• Quantitative total-body blood flow imaging traditionally relies on short-lived cyclotron-produced tracers like 15O-water or 11C-butanol.
• Previous attempts using 18F-fluorodeoxyglucose (FDG) were restricted to tissues with high extraction fractions.
• The need for a widely available radiotracer for blood flow assessment is critical for broader clinical and research applications.

Purpose of the Study:

• To develop and validate an early-dynamic 18F-FDG PET method for quantitative total-body blood flow imaging.
• To assess blood flow by deriving the vascular transit time of 18F-FDG using high temporal resolution kinetic modeling.
• To compare the novel 18F-FDG method against a reference tracer (11C-butanol) in a pilot study.

Main Methods:

• Utilized high temporal resolution (1-2 second frames) reconstruction of the first two minutes of dynamic PET scans.
• Employed a distributed kinetic model (adiabatic approximation to the tissue homogeneity model; AATH) to directly estimate blood flow.
• Validated the method by analyzing total-body dynamic PET scans from human participants scanned with both 18F-FDG and 11C-butanol, and compared with literature values.

Main Results:

• Demonstrated quantitative agreement between 18F-FDG derived blood flow and 11C-butanol measurements (Pearson R=0.955, p<0.001).
• Parametric imaging visually corroborated the regional blood flow estimations across the body.
• The method accurately resolved a wide range of physiological blood flow values in healthy participants, consistent with literature.

Conclusions:

• Total-body blood flow imaging is feasible using early-dynamic 18F-FDG PET with high-temporal resolution kinetic modeling.
• This method facilitates efficient single-tracer imaging of both blood flow and metabolism.
• Potential for significant research and clinical impact in oncology, cardiovascular disease, pain medicine, and neuroscience.