The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity

Abstract

We present the design of a positron emission tomograph (PET) with flexible geometry dedicated to in vivo studies of small animals (TierPET). The scanner uses two pairs of detectors. Each detector consists of 400 small individual yttrium aluminum perovskite (YAP) scintillator crystals of dimensions 2 x 2 x 15 mm3, optically isolated and glued together, which are coupled to position-sensitive photomultiplier tubes (PSPMT's). The detector modules can be moved in a radial direction so that the detector-to-detector spacing can be varied. Special hardware has been built for coincidence detection, position detection, and real-time data acquisition, which is performed by a PC. The single-event data are transferred to workstations where the radioactivity distribution is reconstructed. The dimensions of the crystals and the detector layout are the result of extensive simulations which are described in this report, taking into account sensitivity, spatial resolution and additional parameters like parallax error or scatter effects. For the three-dimensional (3-D) reconstruction a genuine 3-D expectation-maximization (EM)-algorithm which can include the characteristics of the detector system has been implemented. The reconstruction software is flexible and matches the different detector configurations. The main advantage of the proposed animal PET scanner is its high flexibility, allowing the realization of various detector-system configurations. By changing the detector-to-detector spacing, the system is capable of either providing good spatial resolution or high sensitivity for dynamic studies of pharmacokinetics.

MicroPET II: design, development and initial performance of an improved microPET scanner for small-animal imaging

“…Dedicated small-animal PET systems have been developed by a number of groups and companies (for example, Bloomfield et al (1997), Cherry et al (1997), Del Guerra et al (1998), Jeavons et al (1999), Knoess et al (2003), Lecomte et al (1996), Seidel et al (2002), Tai et al (2001), Watanabe et al (1997), Weber et al (1997), Ziegler et al (2001)) and have been successfully used in biomedical research over the past ten years. Applications of interest have included drug and tracer development, longitudinal studies of animal models of human disease, and imaging of gene expression, gene therapy, protein function and cell trafficking (Budinger et al 1999, Cherry and Gambhir 2001, Phelps 2000.…”

Molecular imaging with copper-64

“…Furthermore, the ability to genetically manipulate these animals has allowed researchers to develop more clinically relevant animal models of human disease. In keeping with the advances in the genetic and biochemical field, dedicated animal systems have also been built for MR, CT, PET and SPECT [13][14][15][16][17][18][19][20][21]. The ability to non-invasively and quantitatively study drug targets in animal models with higher resolution molecular imaging devices accelerates both the identification of potential targets, and their screening and validation.…”

Quantification of D2 Receptor Binding in the Rat Striatum Using Small Animal PET - The Impact of the Reference Tissue on the Binding Potential of [18F]N-Methyl-Benperidol

“…The small animal tomograph ("TierPET", Zentrallabor für Elektronik', Forschungszentrum Jülich GmbH, Jülich, Germany) was described in detail elsewhere [39]. Axial as well as transaxial field of view had a diameter of 40 mm.…”