Sylvain Prévost1, Etienne Rousseau2. 1. Department of Nuclear Medicine and Radiobiology, Centre de recherche CHUS, Universite de Sherbrooke, Sherbrooke, Canada. sylvain.prevost@usherbrooke.ca. 2. Department of Nuclear Medicine and Radiobiology, Centre de recherche CHUS, Universite de Sherbrooke, Sherbrooke, Canada.