Construction of a Multipinhole SPECT System

Recently, functional imaging of small animals using the high-resolution nuclear medicine imaging such as animal PET and animal SPECT is becoming a valuable tool for studying various in-vivo animal models, in particular imaging varieties of molecular events. The popularity of using nuclear medicine imaging for the animal imaging is mainly due to the relatively high sensitivity, a full quantitative tomographic capability, and the ability to extend small animal imaging assays directly into human applications. In SPECT, the high-resolution is achieved by the use of smaller pinhole collimators. In biomedical studies of small animals, characterization of biodistribution and pharmacokinetics is important not only in determining localization of a new drug, but also in quantifying the physiological function of a targeted tissue or organ through the tracer distribution. To determine the biodistribution and pharmacokinetics of a tracer through imaging, the imaging system must have the capability of high-resolution and dynamic data acquisition. In many animal SPECT systems developed in the past few years, only few can achieve the capability of dynamic data acquisition, in particular, as we know, very few of them can accommodate for whole body or larger organ scan. Recently, a 3-head clinical SPECT system from Chang Gung Memorial Hospital was transferred to Chang Gung University for teaching and research use. With the need for a static (dynamic) scan in high-resolution and high-sensitivity animal SPECT system, and development platform for various research studies, here we propose a 3-year grant to construct and develop a multipinhole SEPCT system by modifying this clinical 3-head SPECT system. Our goal is to construct a larger FOV multipinhole SPECT while at the same time achieving high-resolution and sensitivity, and most importantly, without the need to move any camera head, so a dynamic acquisition for real kinetic study is possible. The larger FOV can be achieved by using a larger distance from pinhole to the detector and by using a new reconstruction algorithm for truncated projection data. Also we will build up a data processing platform with multipinhole and truncated reconstruction methods. We will also develop point-source-based system matrix for multipinhole reconstruction using Monte Carlo software. This development will serve as a platform for further research study in hardware and software design of a multipinhole SPECT system, and also the experience will be shared to the research community.

Project ID:PC9801-2495
External Project ID:NSC97-2314-B182-029-MY3