Scatter Correction Using Pair-Wise Fan Beam Consistency Conditions

Due to wide cone angle, the artifacts caused by scatter radiation are inevitable in flat detector CT reconstructed images. Cupping and streak artifacts are the main manifestations of scatter artifacts which will degrade low contrast resolution and Hounsfield unit accuracy. Scatter artifacts can be mitigated by subtracting the two-dimensional distribution of scatter radiation from the measured projections. Convolution-based scatter modeling can be used for the approximate scatter estimation with a high degree of computational efficiency. In this paper, we propose an algorithm to optimize the scatter kernel parameters by enforcing pair-wise fan beam consistency conditions on cone beam projections. The proposed method does not require prior Monte-Carlo simulation, additional reconstruction, or calibration experiments. Our results from the simulated datasets show the reduction of artifacts after the minimization of scatter-induced data inconsistency.