Traverse and rotate CT scanner having rotational step through a multiple of the fan angle

摘要

In a medical radiographic apparatus, of the type in which a fan of radiation and detectors receiving the radiation along pencil beams in the fan are traversed laterally in relation to a slice of the patient's body and orbited about an axis intersecting the slice, an angular step between each lateral scan is usually substantially equal to the angle subtended by the radiation at its source. It is proposed to arrange the angular step to be a multiple of the angle subtended by the fan, thus leaving gaps in the range of angular position taken by beams of the fan. The gaps are filled in the course of an extended orbital motion.