METHOD, PROCESSOR AND COMPUTED TOMOGRAPHY (CT) MACHINE FOR GENERATING IMAGES UTILIZING HIGH AND LOW SENSITIVITY DATA COLLECTED FROM A FLAT PANEL DETECTOR HAVING AN EXTENDED DYNAMIC RANGE

摘要

A method, processor and computed tomography (CT) machine for generating images utilizing high and low sensitivity data collected from a flat panel detector having an extended dynamic range. Hardware modifications for extending the dynamic range include grouping pixel rows and pixel columns into clusters of two. The sensitivity of the rows/columns is modified by positioning optical masks that have different transparencies for different rows/columns. Software modifications for extending the dynamic range include taking two correlated exposure scan measurements at each angle and combining the two data sets into one scan prior to image reconstruction. This method uses a spatially varying pixel exposure method where several adjacent pixels are clustered and each cluster has a different sensitivity. The signals of these clusters are combined to form one image effectively producing an increased dynamic range. The flat panel imager may be an a-Si:H based flat panel detector for use in X-ray imaging, including cone beam computer tomography (CBCT).