Image-intensifier-based volume tomographic angiography imaging system: geometric distortion correction

An image intensifier-based rotational volume tomographic angiography imaging system has been constructed. The system consists of an x-ray tube and an image intensifier that are separately mounted on a gantry. This system uses an image intensifier coupled to a TV camera as a 2D detector so that a set of 2D projections can be acquired for a direct 3D reconstruction. Although an image intensifier offers good detection quantum efficiency and possibly results in a better low contrast resolution than a fluorescent screen, it introduces two types of distortion: S distortion and pincushion distortion. To obtain accurate reconstructions, these distortions must be corrected prior to 3D reconstruction. Techniques for the correction of these distortions have been developed. These techniques were tested using experimental data acquired with the image intensifier-based volume tomographic angiography imaging system. The results indicate that the distortion correction techniques work well.