A new design for a SPECT small-animal imager

Abstract

We demonstrate, using computer models, the feasibility of a new SPECT system for imaging small animals such as mice. This system consists of four modular scintillation cameras, four multiple-pinhole apertures, electronics, and tomographic reconstruction software. All of these constituents have been designed in our laboratory. The cameras are 120mm×120mm with a resolution of approximately 2mm, the apertures can have either single or multiple pinholes, and reconstruction is performed using the OS-EM algorithm. One major advantage of this system is the design flexibility it offers, as the cameras are easy to move and the aperture s are simple to modify. We explored a number of possible configurations. One promising configuration had the four camera faces forming four sides of a cube with multiple-pinhole apertures employed to focus the incoming high-energy photons. This system is rotated three times, so that data are collected from a total of sixteen camera angles. It is shown that this hybrid system has some superior properties to single-aperture-type systems. We conclude that this proposed system offers advantages over current imaging systems in terms of flexibility, simplicity, and performance.

T-SPECT: a novel imaging technique for small animal research

“…In an attempt to address this problem we introduce collimators with multiple pinholes. Two such systems were described previously in [6] and [7]. The system we describe here is a modification of a multipinhole approach developed previously in our group [8].…”

Gamma Radiation Imaging System via Variable and Time-Multiplexed Pinhole Arrays

“…The stationary imagers gather the projection data simultaneously within a short scan time, and are non-multiplexing pinhole systems (have no overlapping projections). Meikle and Wilson suggested systems that perform SPECT from multiplexed projection data, with overlapping pinhole projections consisting of one or more multipinhole detectors rotating around the object [10][11][12]. Wilson who used a synthetic collimator, introduced another method [13].…”

CdZnTe strip detector SPECT imaging with a slit collimator

“…This research is directed towards building a small animal SPECT imager using a CdZnTe detector and a slit collimator to achieve both high spatial resolution and excellent energy resolution (Gagnon et al 2001). The idea of using a slit collimator was inspired by the recent applications of pinhole collimators in small animal SPECT imaging (Weber et al 1994, Jaszczak et al 1994, Habraken et al 2001, McElroy et al 2002, Wilson et al 2002, Wu et al 2002, Beque et al 2003, Schramm et al 2003, Song et al 2003. With a pinhole collimator, the image spatial resolution depends on both the pinhole size and the image magnification factor due to the imaging geometry.…”