Novel methods for iterative reconstruction and noise estimation in CT imaging

Computed tomography (CT) has become an important clinical imaging modality, and has been extended into a wide range of usage with the development of novel CT scanners such as dual energy CT (DECT). However, the imaging dose during CT scanning increasingly raises public concern. Iterative reconstruction algorithms have shown promise on improving quality of CT images with reduced radiation. In the first part of this study, a novel iterative reconstruction method is developed to enable a new data acquisition scheme for potential reduction in imaging dose and engineering cost of DECT. As iterative CT reconstruction continues to advance, the spatial distribution of noise standard deviation (STD) and accurate noise power spectrum (NPS) on the reconstructed CT images become important for method evaluation as well as optimization of algorithm parameters. In the second part of this study, a practical method for pixel-wise calculation of noise statistics on an iteratively reconstructed CT image is developed, which enables accurate calculation of noise STD for each pixel and NPS.Ph.D