Single Photon Emission Computed Tomography (SPECT) is still the mainstay for cardiac screening. Current state of the art cardiac SPECT systems (Spectrum-Dynamic's D-SPECT and GE's Discovery NM530) use CZT semiconductor detectors which results in a number of cost-performance tradeoffs. They are based on the use of large collimator holes (compared with collimators used in standard dual head gamma camera) to increase the system sensitivity that may result in poor image resolution when no resolution recovery applied. The main objective of this project is to develop a high-sensitivity and high-spatial resolution SPECT system for cardiac applications. To make such an organ-specific SPECT system widely available however, the development cost has to be practical so that the system acquisition by the medical centers, hospitals and even physician offices is not cost-prohibitive. It should be mentioned that the CZT-based systems are much more expensive than a standard dual head gamma-camera. In this grant we plan to improve the performance of Cardiac SPECT without increasing the development cost. In order to achieve our goals we envision a SPECT system build from 8-10 mm thick conventional scintillators (CsI:Tl or NaI:Tl) with one-sided readout using silicon multipliers (SiPM) arrays. Owing to their high density, availability, and price which is at least an order of magnitude smaller than CZT, CsI (or NaI) is an attractive scintillator to use for out project. Our goal is to achieve high spatial image resolution and 0.1% scanner sensitivity which is about 10-times larger than dual-head gamma camera. We will utilize laser-induced optical barriers (LIOB) technique to fabricate the scintillator arrays.
The focus of this research proposal is to develop a high-performance and cost-effective stationary SPECT system dedicated to cardiac imaging. The detector system follows a body-contouring geometry which can provide an order of magnitude larger system sensitivity compared to the standard dual-head gamma cameras.