An analytic model for the performance of cone beam microtomography is described. The maximum power of a microfocus X-ray source is assumed to be approximately proportional to the focal spot size. Radiation flux penetrating the specimen is predicted by a semi-empirical relation which is valid for X-ray energies less than 20 keV. Good signal to noise ratio is predicted for bone specimens of 0.1 to 10 mm when scanned at the optimal energy. A flux of about 1 X 10 1°p hotons/mm 2/s is identified for 0.2 mm specimens. Cone beam volumetric microtomography is found to compare favorably with synchrotron based methods.
The resolution of 2D imaging systems is frequently described by experimental estimates of the point, line, or edge spread function. It is shown that a response function across the normal to a boundary between two homogeneous volumes can provide a measure of resolution. The set of surface boundary voxels is determined by applying a simple threshold. The normal distance of every voxel to the surface is computed and an accumulator bin is incremented by the voxel's gray level. This results in an aggregate surface response function, which is related to 3D point, line, and plane spread functions. This method can be applied to general boundary interfaces where precise surface normals are known, such as those on a sphere or plane. Results of applying this method to volumetric cone beam x-ray CT data are shown.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.