Abstract: The method of the imaging system based on the M-M coded method is discussed, and the model of the imaging system based on the M-M coding method is established through Monte Carlo software MCNP. Using radiation sources of different energies at different positions to irradiate coding collimators with different thicknesses, it is determined that the optimal thickness of the coded collimator is 10mm by analyzing and explaining the reconstructed image SNR obtained. Then the response of the imaging system based on the optimal parameters of coded mask to the single-point source, multi-point source and extended source was simulated. The reconstructed image SNR of the single-point source reached 40.36, and the imaging system also successfully reconstructed the shape of the extended source. There are no fluctuating sidelobes in the background of reconstructed images of point and extended source. The above results prove the excellent performance of the M-M coded method, and it has the potential to replace MURA or URA in special scenarios. This article can lay the foundation for the subsequent development of coded aperture gamma camera based on M-M coded method.

Key words: M-M coding mode, Monte Carlo simulation, gamma camera, gamma ray detection, field of view