Conceptual design of a compact positron tomograph for prostate imaging

Abstract

Summary form only received as follows. The authors present a conceptual design of a compact positron tomograph for prostate imaging, using a pair of external curved detector banks placed above and below the patient. The lower detector bank is fixed below the patient bed, and the top bank adjusts vertically for maximum sensitivity and patient access. Each bank is composed of 40 HR+PET block detectors, forming two arcs (44 cm minor, /spl sim/60 cm major axis) that are tilted to minimize attenuation and positioned as close as possible to the patient to improve sensitivity. The individual detectors are angled to point towards the prostate to minimize resolution degradation in that region. Inter-plane septa extend /spl sim/5 cm beyond the scintillator crystals to reduce random and scatter backgrounds. A patient is not fully encircled by detector rings in order to minimize cost, causing incomplete sampling due to the side gaps. Monte Carlo simulation (including randoms and scatter) demonstrates the feasibility to detect a spherical tumor of 2.5 cm diameter with a tumor to background of 2:1, requiring a number of counts that should be achievable with a 2 minute scan after a 10 mCi injection (e.g. carbon-11 choline).