1. ¹CHU de Bordeaux, Bordeaux, France
2. ²CNRS UMR5231, Bordeaux, France
3. ³Université de Bordeaux2, Bordeaux, France
4. ⁴Institute for NeuroDegenerative Disorders, New Haven, Connecticut, USA
5. ⁵EPHE, Bordeaux, France

Correspondence: Dr O Barret, Service de Médecine nucléaire, UMR-CNRS 5231, Hôpital Pellegrin, Place Amélie Raba Léon, Bordeaux 33076, France. E-mail: olivier.barret@imf.u-bordeaux2.fr

Received 1 April 2008; Revised 25 April 2008; Accepted 28 April 2008; Published online 28 May 2008.

Abstract

Dementia with Lewy Body and Alzheimer's disease exhibit degeneration of the cholinergic neurons, and currently, the primary target of treatment is the cholinergic neurotransmitter system. [¹²³I]-IBVM is a highly selective radioligand for in vivo visualization of the vesicular acetylcholine transporter (VAChT) using single photon emission computed tomography. This study compares different noninvasive methods using the occipital cortex as a reference region for the quantification of [¹²³I]-IBVM binding in six older, healthy volunteers: two kinetic analyses based on one-tissue (1TCM) or two-tissue compartment model (2TCM), one linear and one multilinear analysis, and a simplified peak equilibrium analysis. Time–activity curves were well described by a 1TCM for all regions. The 2TCM converged reliably only in the striatum. Goodness of fit was not improved by using a 2TCM as compared with a 1TCM. The multilinear analysis gave binding potentials similar to the 1TCM while being more robust. The peak equilibrium method might prove to be a useful simplified analysis. The binding potentials obtained with reference region methods strongly correlated with results from invasive blood-sampling analysis. Noninvasive quantification of [¹²³I]-IBVM data provides reliable estimates of VAChT binding, which is most valuable to study neurodegenerative diseases with specific cholinergic alteration.