Noise removal from once-beam CT images and reduction of patient dose

摘要

Cone-beam CT and 4-D CT, which are expected as diagnostic equipments of the future, have disadvantage to increase patient dose. If we reduce the patient dose, quantum mottle will increase and image will be degraded. We investigated the relation between a patient dose and the noise characteristic of a cone-beam CT images for the 3-D phantom. Moreover, we developed the method to remove the noise from CT projections, considering the relation of the coefficient between wavelet-decomposition levels. Our preliminary results show that noise can be removed efficiently with saving the edge of an image and that its possibility of patient dose reduction.