A method of computed tomography includes illuminating an object with a cone of illumination, wherein the object is between a source of the cone of illumination and a two-dimensional photo-detector array. The method includes shielding the photodetector array from the collimator shield that includes a slit defined therethrough and moving the slit of the collimator shield across the photodetector array in a direction perpendicular to the slit to expose the photodetector array to the cone of illumination through the slit as the slit scans across the photodetector array to acquire a two-dimensional image of the object. The method includes rotating the object to a new rotational position and repeating movement of the slit to expose the photodetector and rotating the object along the axis until the object has been imaged from multiple rotational positions to form a three-dimensional model of the object.