Abstract: A method and apparatus for improving skin line viewing in a medical X-ray diagnostic system having an X-ray source for generating a scanning X-ray beam to image a target. In one form, the apparatus includes a first collimator positioned in the X-ray beam and having a rectangular shaped slit for passing the beam. A second collimator is positioned adjacent the first collimator and includes a plurality of spaced attenuation plates which can be moved over the slit in the first collimator. The attenuation plates are angles and tapered with respect to the slit. Control means is provided for locating the target within the slit and continuously driving the second collimator attenuation plates so as to intersect the edge of the target aligned with the slit.

Abstract: 1. A diagnostic x-ray machine including a reciprocating grid reduces grid lines, in the radiographic image, formed as a result of velocity variations in the reciprocation of the grid, principally at the points of grid reversal. An x-ray source produces a beam of x-ray radiation along a major axis directed through the body and to the grid. A reciprocating mechanism moves the grid within a plane perpendicular to the major axis between a first limit and a second limit and the x-ray beam is modulated synchronously with the grid motion to reduce the grid image at points of grid speed variation.

Abstract: A method and apparatus for improving imaging in an X-ray mammography machine having a controllable X-ray source incorporates apparatus for directing the X-ray beam in a preselected configuration onto at least a portion of a target area. The creation intensity of the beam is detected in each of a plurality of substantially equal segments of the target area and a first segment of lowest radiation intensity is identified. The X-ray source is adjusted to establish a predetermined radiation intensity in the identified first segment. Second segments are then identified each having a radiation intensity greater than a predetermined percentage of the radiation intensity in the identified first segment. The radiation intensity directed toward the identified second segments is then automatically attenuated by a control system responsive to the radiation intensity detected in the second segments.

Abstract: A multi-zoned x-ray exposure detector for a scanning fan beam x-ray system comprises an electron emitter which upon exposure to x-rays emits electrons into a channel defined by an isolation walls. The channel contains air which is ionized. The isolation walls extend parallel to the direction of the sweeping fan beam behind the electron emitter. Within each channel formed by the isolation walls, is a collection electrode biased in voltage with respect to the electron emitter to collect the ions. The intersection of the beam and the channel defines a zone in which exposure may be determined.The current from the collection electrode is amplified by an amplifier to produce a signal related to x-ray exposure of each zone.

Abstract: Method and apparatus for minimizing scatter in an X-ray imaging system of the type including a controllable source of X-ray radiation and means for collimating the X-ray radiation into a fan-shaped beam and effecting scanning of the X-ray beam across a target area. The improved system includes a grid assembly extending in a transverse direction across the target area and having a relatively narrow width in the beam scanning direction. A drive is coupled to the grid removing the grid in synchronism with the X-ray beam and an X-ray impervious belt is coupled to the grid and extends in a transverse direction across the target area and is movable with the grid for covering the target area outside the grid to prevent scatter radiation from impinging on X-ray film located beneath the grid. In one form, the grid includes a plurality of air interspersed septa to allow reduced beam energy.