Sources of artifacts in rotational scanography.

The images produced in rotational scanography, currently under investigation at several institutions, may contain several kinds of artifacts. The sources of such artifacts are: 1. vertical and horizontal misalignment of the focal spot with the axis of rotation; 2 misalignment of the primary and secondary slits; 3 a density gradient due to slit cut-off; 4 vibration of the x-ray tube during rotation; 5. A density gradient due to variation in motor speed; 6. radiographic striations due to ripple of the tube output. Striations are present even if a 12-pulse generator is used, but they disappear if a constant potential generator is employed.