The effect of source position accuracy on image quality in helical MDCT 3D image reconstruction

Image reconstruction in helical CT assumes that the source position at which each view is acquired is accurately reported to the image reconstruction algorithm. However, in practical situations this is not always the case. Hardware, instrumentation and bandwidth limitations along with manufacturing tolerances limit the accuracy at which source positions may be recorded. This study simulates scans under the conditions of positional reporting errors in combination with errors in the time moments at which positions are reported. The resulting image quality is evaluated and the deviations from images obtained under ideal conditions are characterized using pixel to pixel differences and mutual information between image pairs.