Low-cost high-resolution animal SPECT imaging on a clinical SPECT scanner

In order to develop animal SPECT imaging technology with low cost, we propose a dedicated multi-pinhole collimator design scheme on a clinical SPECT scanner to achieve high resolution. Based on the proposed design one can also optimize current system design for different application purposes. This work is focused on achieving half-mm SPECT imaging resolution on a single-head clinical SPECT scanner. A seven-pinhole collimator and a four-degree-of-freedom motion control stage are assembled. High accuracy geometrical calibration is performed by scanning a point source in a hybrid orbit, which consists of three circular orbits in different axial positions and a helical orbit. The system matrix is derived from Monte-Carlo simulation and denoised by fitting each point spread function (PSF) to a 2D Gaussian function. Point source studies show a promising 0.5 mm reconstruction resolution is achievable in the studied system. Preliminary ultra micro hot rod phantom experiments demonstrate the smallest 0.75 mm hot rods are identifiable. The proposed technology is attractable for its low cost, high resolution and fine feasibility.