Eccentric source collimator assembly for rotating source CT scanner

A radiographic scanner comprising:

• a scan circle for receiving of an object to be examined;
• radiation detection means at least partially encircling the scan circle;
• a source of a fan pattern of generally continuous radiation, said source disposed to irradiate at least a part of said radiation detection means with radiation which has traversed the scan circle;
• and
• a collimator comprising a plurality of vanes, each of said vanes disposed radially relative to a geometric center and displaced from each other to form apertures therebetween, said collimator disposed with said geometric center displaced from said source.

A radiographic scanner comprising:

• a scan circle adapted to receive an object to be examined;
• a source of a fan pattern of generally continuous radiation, said source being mounted for rotational movement about the scan circle, in the plane of the scan circle;
• a radiation detector means for detecting radiation from the source which has traversed the scan circle, said detector means disposed at least partially encircling the scan circle;
• and
• a radiation shield at least a part of which is disposed in a circular arc segment in the plane of the scan circle and is disposed eccentrially about said source, said radiation shield having a plurality of apertures therein for collimating the fan pattern of radiation into a plurality of diverging finger beams.

A radiographic scanner comprising:

• a scan circle adapted to receive an object to be examined;
• a source of a fan pattern of generally continuous radiation said source being mounted for rotational movement about the scan circle;
• a radiation detection means for detecting radiation from the source which radiation has traversed the scan circle, said detector means disposed at least partially encircling the scan circle;
• and
• a collimator mechanism for dividing the fan pattern of radiation into a plurality of divergent finger beams, the collimator mechanism comprising a radiation shield disposed between the source and the scan circle, said radiation shield having a plurality of apertures therein, the width of each finger beam being determined by the effective width of the corresponding aperture, the effective widths of said apertures being sized such that the finger beams have different widths with the finger beams of the widest width traversing the scan circle near its center and the finger beams of narrowest width traversing the scan circle near its periphery.