Publication date: Jul 15, 2025

In neuroinflammation, activated astrocytes, called reactive astrocytes, highly express monoamine oxidase B (MAO-B). [F]SMBT-1 is a novel PET tracer developed for imaging neuroinflammation, with highly selective binding to MAO-B. The quantification method for [F]SMBT-1 PET imaging has not been established, although some human studies using [F]SMBT-1 PET imaging have already been conducted. In this study, we explored the most appropriate method for quantifying [F]SMBT-1 PET. Dynamic PET scanning of [F]SMBT-1, accompanied by serial arterial blood sampling, was performed in healthy elderly subjects. With PET and blood data, the total distribution volumes (Vts) in the brain regions were calculated using a one-tissue compartment model (1TCM), a two-tissue compartment model (2TCM), and Logan graphical analysis. Standardized uptake values (SUVs) and SUV ratio-1 (SUVR-1) were determined for different time frames and reference regions. The values of the χ criterion and Akaike’s Information Criterion (AIC) in the brain regions were lower in 2TCM than in 1TCM, suggesting that 2TCM was a better model in terms of curve fitting. However, the very high coefficient of variation (%COV) for parameters such as K1, k2, k3, and k4 in 2TCM suggests that these parameters may not have been properly estimated. SUVs, especially at 50-70 and 70-90 min post-injection, were strongly correlated with Vt (r = 0. 9188-0. 9445, p 

Semantics

Original Article