Tomographic evaluation of a dual-head positron emission tomography system

Abstract

In this paper we present the performance evaluation results, in the planar and tomographic modes, of a low-cost positron emission tomography camera dedicated to small-animal imaging. The system consists of two pixelated Lu2SiO5 crystals, two Hamamatsu H8500 position sensitive photomultiplier tubes, fast amplification electronics and an FPGA-USB-based read-out system. The parameters that have been studied are (i) saturation as a function of the head distance and photon acceptance angle, (ii) effect of the number of projections and half or complete head's rotation, (iii) spatial resolution as a function of the head distance, (iv) spatial resolution as a function of acceptance angle, (v) system's sensitivity as a function of these parameters and (vi) performance in small mice imaging. Image reconstruction has been carried out using open source software developed by our group (QSPECT), which is designed mainly for SPECT imaging. The results indicate that the system has a linear response for activities up to at least 2 MBq, which are typical in small-animal imaging. Best tomographic spatial resolution was measured to be ∼2 mm. The system has been found suitable for imaging of small mice both in the planar and tomographic modes.

¹⁷⁶Lu effect on the minimum detectable activity limits for a dual head, LSO: Ce based, PET system

“…The small animal PET prototype camera, which was used as reference, has been extensively presented previously [3], [6], [7]. In brief, it consists of two LSO:Ce based heads, the crystal arrays have 20×20 pixels and H8500 Hamamatsu PSPMTs.…”

Effect of 176Lu intrinsic radioactivity on dual head PET system imaging and data acquisition, simulation, and experimental measurements

“…The full characterization of the system performance has been published. 11,12 In brief, it consists of two detector heads, which include a 20 × 20 array of 2 × 2 × 10 mm 3 LSO:Ce crystals coupled via a 2 mm thick glass light guide to a Hammamatsu H8500 photomultiplier tube.…”

Influence of Rotation Increments on Imaging Performance for a Rotatory Dual-Head PET System

“…Nevertheless, how to determine the rotation increments is also an open problem. Efthimiou et al have evaluated the performance of a rotatory dual-head system by a series of angles [17], and in their work the system response matrix (SRM) is geometrically estimated which is not accurate and is apt to cause depth of interaction (DOI) blurring near the field of view (FOV) boundaries [8, 13, 17]. …”