A Simple Low-Dose X-Ray CT Simulation From High-Dose Scan

Low-dose X-ray computed tomography (CT) simulation from a high-dose scan is required in optimizing radiation dose to patients. In this paper, we propose a simple low-dose CT simulation strategy in the sinogram domain using the raw data from high-dose scan. Specially, a relationship between the incident fluxes of low- and high-dose scans is first determined according to the repeated projection measurements and analysis. Second, the incident flux level of the simulated low- dose scan is generated by properly scaling the incident flux level of the high-dose scan via the determined relationship in the first step. Third, the low- dose CT transmission data by energy integrating detection is simulated by adding a statistically independent Poisson noise distribution plus a statistically independent Gaussian noise distribution. Finally, a filtered back-projection (FBP) algorithm is implemented to reconstruct the resultant low- dose CT images. The present low- dose simulation strategy is verified on the simulations and real scans by comparing it with the existing low- dose CT simulation tool. Experimental results demonstrated that the present low- dose CT simulation strategy can generate accurate low- dose CT sinogram data from high-dose scans in terms of qualitative and quantitative measurements.