Performance evaluation on reconstructions in a stationary multi-pinhole SPECT

Stationary multi-pinhole SPECT system allows acquisition of multiple projections at the same time such that the high-resolution kinetic information can be obtained without rotating the camera. In this case, image reconstruction can be performed on the data collected without rotating detector heads and enable dynamic data acquisition as PET does. To achieve high resolution stationary multi-pinhole SPECT and larger FOV, a larger detector surface is necessary. Limited detector size lead to smaller number of pinholes, and may further result in confined field-of-view (FOV). In stationary multi-pinhole SPECT system, angular sampling is constrained by number of pinholes. The limited angular scanning is not sufficient to provide angular sampling data around the object, and finite angular sampling and insufficient sampling coverage can result in streak artifact and/or geometric distortion. We are developing a stationary multi-pinhole SPECT system based on a clinical three-head SPECT system. Three multi-pinhole collimators covered by the 3 detector heads were designed with 27 pinholes focusing on FOV center to achieve high sensitivity and high resolution. The goal of this paper is to evaluate different reconstruction approaches from sparse or insufficient projection data in the stationary multi-pinhole SPECT system from simulated data.