General Electric Company

James A McFaul

David Leo McDaniel

Carl C Scheid

Norbert Joseph Pelc

Barry F Belanger

David M Barrett

Gary S Keyes

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.

Scanning mammography system with improved skin line viewing

The brightness of an X-ray video image during fluorography is maintained at a substantially constant level by a control circuit which varies the X-ray dose in relation to changes in the average brightness of the X-ray image. Selected picture elements of the image which lie within a defined region in the image and which have a brightness above a given level are used to derive the average X-ray image brightness. The brightness of the selected picture elements are summed and the number of such picture elements counted. The summation of the brightness and the picture element count are both scaled by a factor of 2.sup.n to reduce the size of the numbers of the complexity of the averaging circuitry. The scaled brightness summation is divided by the scaled picture element count and the result is stored as the average X-ray image brightness.

Automatic brightness compensation for fluorography systems

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. The attenuation is achieved by moving collimators into the beam so as to reduce the radiation directed towards the second segments. The beam is scanned over the target and continuously adjusted in accordance with the radiation detected in each of the segments of the beam. In this manner, each area of the target receives just sufficient radiation to provide proper imaging without overexposing area of the target which have less attenuation than other areas.

Mammographic apparatus with collimated controllable X-ray intensity and

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. In another form, the X-ray beam is collimated into a point source by the use of an X-ray impervious disk positioned adjacent to and overlaying an X-ray window in the X-ray source.

Scanning mammography system with reduced scatter radiation

A scanning type radiographic imaging system is disclosed which employs novel means to produce comparable radiation intensity in the object regions being radiographed. Such result is achieved with variable radiation attenuating elements having their attenuation controlled during this scanning process with novel feedback control means. The feedback control is produced with a stationary detection unit having circuit means which generates the electrical control signals.

Growing community of inventors

Waukesha, WI, United States of America

James A McFaul