2 results about "Pinhole collimator" patented technology

This invention provides a dual-aperture multi-pinhole collimator, comprising: a collimator plate; and multiple pinholes of two different apertures spaced apart on the collimator plate. During a single imaging process, radioactive rays passing through the imaging fields of different apertures simultaneously form corresponding and non-overlapping projection responses on the detector. Of the two apertures, the first aperture is smaller than the second aperture. The first aperture is determined based on the desired system spatial resolution, and the second aperture is determined based on the desired detection efficiency. This invention also proposes a SPECT imaging system based on the aforementioned multi-pinhole collimator. Its imaging module obtains imaging results from the data required for tomographic reconstruction using an improved MLEM iterative algorithm. The improved MLEM iterative algorithm introduces weighting factors into the original MLEM iterative algorithm, weighting the projection data of the dual-aperture pinholes and the corresponding system transmission matrix elements respectively. This invention improves detection sensitivity while maintaining spatial resolution.

The application provides an inorganic scintillation crystal performance test system and method based on an adjustable pinhole collimator, and solves the problem that existing inorganic scintillation crystal performance test systems are mostly limited to the research of specific crystals and radioactive sources and are not universal in radiation detection macroscopic applications. The system comprises a base, a radioactive source, a radioactive source limiting unit, a collimation assembly, a collimation adjusting unit, a detector position adjusting unit and a rear-end test unit. Through the use of the system core structure, the collimation assembly composed of multiple pinhole collimators, the radioactive source radiation is accurately injected into the scintillation crystal at a certain angle, reducing the interference caused by scattering and environmental background, and combining standard scintillation crystals and standard radioactive sources of the same kind, the activity and energy consistency of the radioactive source is calibrated with high precision and sensitivity, and then flexible matching of various types of radioactive sources is realized, and the objective conditions of the numerous radiation isotopes in the application environment are restored as much as possible.