Radiation scanning method and apparatus

A method of radiation scanning for producing an image of the internal structure of an object along a pencil beam of radiation comprising the steps of:

• directing a beam of X-radiation along a path through the object to produce scattered radiation from each point of the object along the path of the beam;
• locating along a path perpendicular to the beam a means having the characteristics of an optical slit sufficiently narrow in its dimension parallel to the axis of the beam to have the effect of an image forming aperture and a dimension perpendicular to the axis of the beam substantially wider than the narrow dimension of the slit;
• passing the scattered radiation through the means to establish in a plane in space parallel to the axis of the beam, an array of scattered radiation reversed in positions relative to their points of origin along the axis of the beam and subtending a wide angle of scattered radiation perpendicular to the beam from each point along the beam;
• successively detecting continguous narrow elongated bands of the array of scattered radiation perpendicular to the axis of the beam at the plane in space, the bands each being delimited by a solid angle defined solely by the dimensions of the means and its spacing from the object;
• and
• producing discrete signals corresponding to the radiant energy in each band.

Apparatus for producing cross-sectional X-rays of human bodies comprising

• A source of X-radiation for forming a pencil beam of radiation;
• means for directing said pencil beam sequentially and successively through contiguous regions of the body to produce scattered radiation from each point of the body to be investigated;
• radiation detector means positioned to detect scattered radiation produced by directing each said pencil beam of radiation through the object;
• aperture defining means disposed between the object to be examined and said radiation detector means defining a slit having its elongated dimension extending transverse to the axis of said pencil beam of radiation for passing to said radiation detector means that part of the radiation which is scattered from each point of the object along the path of said pencil beam and which lies within a predetermined solid angle defined solely by the position of said slit relative to the object and by the dimensions of said slit;
• said elongated dimension of said slit being at least an order of magnitude greater than the narrow dimension of said slit;
• said detector means including means for examining bands of the scattered radiation passed through said aperture defining means to produce signals representative of the scattered radiation in each band whereby the structure of the object lying along the path of the beam of radiation through the object may be determined.