LAUSR

[18F]-fluoroethoxybenzovesamicol ([18F]-FEOBV) is a vesamicol analogue selectively binding the vesicular acetylcholine transporter (VAChT), a protein expressed uniquely by cholinergic neurons1. Non-invasive and short duration PET imaging acquisition protocols allowing accurate quantification of VAChT are preferred in patients with dementia because of their limited ability to lay still during prolonged imaging sessions. Recently, Aghourian et al. reported in vivo quantification of brain cholinergic denervation in patients with Alzheimer’s disease (AD) using simplified and non-invasive [18F]-FEOBV PET imaging2. These authors applied an abbreviated and non-invasive 30-minute imaging protocol with white matter as a reference region to estimate regional gray matter VAChT binding. The white matter reference region was chosen based on non-specific binding patterns of timeactivity curves during late uptake (3–3.5 hours) scan phases. This approach departs from previously used cerebellar gray matter reference regions3. This is appropriate as the cerebellar cortex contains cholinergic nerve terminals resulting in specific VAChT uptake4. Furthermore, cholinergic terminal changes may occur in cerebellar cortices in neurodegenerative disorders, potentially further invalidating the use of this reference