GB754694A - Method and apparatus for taking x-ray photographs - Google Patents

Abstract

754,694. X-ray apparatus. PAATERO, Y. V. Oct. 28, 1954, No. 31231/54. Class 98 (1). A radiograph of a curved layer within an object is made by moving the object relative to a fixed X-ray source, and moving a film having substantially the same contour as the layer with the same linear speed as the layer, the X-rays being directed through the object, and then through means for restricting them to a narrow beam, on to the film. The method is described with reference to the radiography of the jaw. As shown in Fig. 1, a chair for a patient is supported on a dome 16 mounted on a base 1 for rotation by an electric motor 17 driving a gear mounted on base 1 and engaging teeth 19 on the inside of the base of the dome. Supports 23 fixed to the dome carry a neckring 24, centred on the axis of rotation of the chair, and having removable part 24a so that the neck of the patient can be inserted in the ring. A slide 27 is movable backwards and forwards in'a slot in a frame 25. Two ear rods 28 are threaded on a rod 29 which has oppositely threaded ends and is journalled in slide 27. Rods 28 slidably engage a rod 31 fixed to the'slide, so that by turning the threaded rod 29 the ear rods are moved outwards or inwards. The seat 20 is vertically adjustable by a hand wheel 21 to bring the patient to a height where the ear rods are adjusted to insert pins at their lower ends into the patient's ears. A frame 3 hinged at 2 to the base 1 supports a rod 4 carrying the rotatable cassette table 5 and fixed but adjustable shutters 12 defining a slot 13. A film support 6 is curved to the shape of the jaw and hinged for a degree of adjustment to allow for individual variations in the shape of the jaw, and has a rubber apron for holding a film to its curved surface. The film support is carried by the table 5 which, by its weight acting around pivot 2, is held in edge-to-edge contact with neck-ring 24 so that when the chair and patient are rotated, table 5 turns in the opposite direction. An X-ray tube (not shown) directs a beam through the patient's head and through slit 13 on to the film in holder 6. The jaw is thus scanned on to a film of similar shape moving at the same linear speed. Specifications 653,401 and U.S.A. Specifications 2,613,726, 2,684,446 also are referred to.