Feasibility Study of Multi Laue Lens Based SPECT with a Dedicated 3D Reconstruction Algorithm: A First Monte Carlo Study

Abstract The development of in-vivo imaging techniques has significantly advanced biomedical science and cancer diagnosis, yet their limited spatial resolution constrains their utility in small-animal studies and early-stage tumor detection. This study introduces a novel SPECT system employing X-ray and gamma-ray focusing optics—traditionally used in astronomy—to enhance spatial resolution in small object imaging at sub-millimeter scales without compromising sensitivity. Our innovative design utilizes an array of Laue lenses, eliminating the need for traditional collimators such as parallel or pinhole collimators, thereby achieving ultra-high spatial resolution. A custom Monte Carlo simulation models the system's spatial resolution and sensitivity, supported by a tailored 3D reconstruction algorithm that complements the system’s geometry. Findings reveal that our proposed system can achieve a spatial resolution of 0.1 mm full width at half maximum (FWHM) and a sensitivity of 1,670 cps/µCi. This setup allows the discrimination of adjacent volumes as small as 0.113 nL, far surpassing the capabilities of existing SPECT systems, including the SIEMENS parallel LEHR and multi-pinhole (5-MWB-1.0) Inveon SPECT, which are limited to a 2 mm resolution due to inherent resolution-sensitivity trade-offs. The proposed design could revolutionize SPECT imaging, significantly impacting transgenic animal research and early-stage tumor detection with its sub-millimeter resolution.