Small-animal molecular imaging with portable devices on clinical pinhole single-photon emission computed tomography systems

摘要

Objectives: We have developed a portable system compatible with various clinical gamma cameras to perform three-dimensional (3D) small-animal molecular imaging. The spatial resolution of this system is close to that of commercial animal imaging systems, although its cost is much lower. Methods: The portable system consists of a rotating stage, a leveling plate, a line source phantom, and a calibration phantom. To obtain high-resolution single-photon emission computed tomography (SPECT) images, we developed several methods for system alignment and applied geometric calibration. The projections of the subject were reimaged according to the calibration parameters and reconstructed by the 3D ordered subsets expectation maximization (OS-EM) algorithm. Results: The resulting images of the microdeluxe phantom showed 2.4-mm cold rods. The image quality of phantom scanning was stable when the portable system was applied to various gamma cameras from different manufacturers. The resultant images of a ~(99m)Tc-MDP bone scan of a mouse showed details of the spine, femur, pelvis, and tail. Furthermore, a radiopharmaceutical study of ~(99m)Tc-HYNIC-Annexin V on a liver inflammation-induced mouse was carried out to demonstrate the feasibility of this system for small-animal molecular imaging. Conclusions: The newly developed portable system was compatible with various gamma cameras and enabled successful performance of small-animal molecular imaging.