[18F]FDG Revisited: A New Perspective on the Temporal Dynamics of Brain Glucose Metabolism

• DOI: 10.20944/preprints202502.0892.v1
• Publication Date: 2025-02-14T05:07:59Z
• Authors: Andreas Hahn; Pia Falb; Matej Murgas; Sebastian Klug; Murray Reed; Godber Godbersen; Magdalena Ponce d...; Christian Milz; Marcus Hacker; Dan Rujescu; Rupert Lanzenberger
• Keywords: Dynamics; Carbohydrate Metabolism

[18F]FDG positron emission tomography (PET) is extensively utilized to assess brain glucose metabolism, typically through static images reflecting radiotracer accumulation of up one hour. In comparison, functional PET (fPET) enables investigation dynamics occuring within seconds. However, the physiological mechanisms supporting these rapid changes in metabolism necessitate further attention allow accurate interpretation function and their clinical implications. This work highlights candidate driving signal at high temporal resolution, offering complementary insights existing interpretations.At rest, metabolic demands are closely matched by supply across blood-brain barrier (BBB), regulated transporter 1 (GLUT1). During neuronal activation, both transport phosphorylation hexokinase elevated meet increased energy requirements. Simulations indicate that increases primarily driven BBB (K1 k2 a two-tissue compartment model), with slower subsequent activity (k3). Mechanisms include concentration gradient towards GLUT1 intrinsic properties, but only minor effects blood flow. Conversely, moment-to-moment fluctuations [18F]FDG, as investigated molecular connectivity, reflect temporally synchronized via demands.We emphasize that, particularly during strong coupling between underpin fPET signal. Considering alterations numerous disorders, stimulation-induced connectivity represent promising opportunity investigate underlying pathophysiological processes.