American Association of Physicists in Medicine, 33rd Annual Meeting, San Francisco, California, 28 July-1 August. Medical Physics, 18(3):660, May/June 1991.
X-ray computed tomography performed with contiguous thin slices can produce three-dimensional object descriptions with nearly isotropic voxels. The pixel noise in each slice is attributable to x-ray quantum noise with spatial correlation arising from the reconstruction algorithm. Systematic slice-to-slice noise can be controlled by quantitative calibration of each slice with Z axis smoothing of calibration coefficients. Unexpected noise can be produced by interference of object structure and the Z axis response function if the slice profile and table increment are not matched. This noise is not apparent in uniform objects but noticeable for complex objects such as cancellous bone. Control of all factors can produce precision in serial volume of interest measurements less than .3% when the serial 3D data is aligned by rotation/translation interpolation.