Apparatus for examining a body by radiation such as X or gamma radiation

Apparatus for examining a body by means of penetrating radiation, such as X- or .gamma. - radiation, including source means for producing a substantially planar, sectoral-shaped swath of radiation directed towards the body, the plane of the swath being arranged to define a plane of interest in the body, detector means disposed to receive radiation emergent from the body, the source means and the detector means being disposed on opposite sides of an aperture in which the body can be inserted, collimator means disposed between the source means and the detector means and having a plurality of apertures formed therein through which respective finger-like beams of the radiation can pass such that the beams traverse respective linear paths, in said plane of interest, through the body, said detector means including a respective detector device for each of said beams, each device comprising a scintillator, adapted to scintillate in response to the impact of said radiation, and having a planar output surface through which light can emerge, and a photomultiplier tube having a planar photo-sensitive target juxtaposed with, and substantially parallel to, said output surface;

• said tube being of larger dimensions, measured in a direction extending across the width of said swath, than said output surface;
• wherein adjacent scintillators are placed substantially in contact with one another and, in order to adapt the apparatus to accommodate the tubes of adjacent detector devices in said juxtaposed relationship with their respective scintillators, notwithstanding said larger dimensions of said tubes as compared with said scintillators, the output surface of adjacent scintillators are disposed in different planes.