Mammographic apparatus with collimated controllable X-ray intensity and plurality filters
First Claim
1. A method of improving imaging in an X-ray mammography machine having a controllable X-ray source for generating an X-ray beam of selected radiation intensity and a target area for the X-ray beam, the method comprising the steps of:
- directing the X-ray beam in a preselected configuration onto a part of the target area;
detecting the radiation intensity of the X-ray beam in each of a plurality of substantially equal segments of the target area;
identifying at least one segment of lowest radiation intensity;
adjusting the X-ray source to establish a predetermined radiation intensity in the identified at least one segment;
identifying other segments each having a radiation intensity greater than a predetermined percentage of the predetermined radiation intensity in the identified at least one segment; and
attenuating the radiation intensity directed toward the identified other segments.
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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. 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.
64 Citations
20 Claims
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1. A method of improving imaging in an X-ray mammography machine having a controllable X-ray source for generating an X-ray beam of selected radiation intensity and a target area for the X-ray beam, the method comprising the steps of:
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directing the X-ray beam in a preselected configuration onto a part of the target area; detecting the radiation intensity of the X-ray beam in each of a plurality of substantially equal segments of the target area; identifying at least one segment of lowest radiation intensity; adjusting the X-ray source to establish a predetermined radiation intensity in the identified at least one segment; identifying other segments each having a radiation intensity greater than a predetermined percentage of the predetermined radiation intensity in the identified at least one segment; and attenuating the radiation intensity directed toward the identified other segments. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 19)
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12. A mammography machine comprising:
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a controllable X-ray source for generating an X-ray beam of preselected X-ray radiation intensity; first collimating means positioned in a path of said X-ray beam for collimating said beam into a fan shape; means coupled to said X-ray source for effecting movement of said source for causing said fan-shaped beam to scan across a target area; detection means positioned for receiving said X-ray radiation passing through the target area and for producing signals indicative of the intensity of said radiation, said detection means comprising a plurality of uniformly spaced detector elements, each element extending in a direction corresponding to the direction of movement of said beam, each of the signals representing radiation intensity at a corresponding one of said elements; and means responsive to a one of said signals from said detection means indicative of a minimum radiation intensity for controlling said X-ray source to establish a constant X-ray radiation intensity passing through the target area at each position of said scanning fan shaped X-ray beam. - View Dependent Claims (13, 14, 15, 16)
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17. A method for generating a collimate scanning X-ray beam over a predetermined target area from an X-ray source having a selected axis in an X-ray system having at least one collimator associated with the X-ray beam, the method comprising the steps of:
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rotating the X-ray source to a predetermined angular orientation with respect to the predetermined target area; energizing the X-ray source to cause the X-ray beam to illuminate a portion of the predetermined target area; initiating pivotable motion of the x-ray source generally about the selected axis at least substantially simultaneously with the occurrence of the energizing step; passing the X-ray beam through the at least one collimator to shape the X-ray beam into a predetermined configuration at the predetermined target area; moving the at least one collimator at least generally concurrently with the pivotable motion of the X-ray source such that the illuminated portion of the predetermined target area maintains a constant dimension; detecting the radiation intensity of the X-ray beam in each of a plurality of substantially equal segments of the predetermined target area; identifying at least one segment of lowest radiation intensity; adjusting the X-ray source to establish a predetermined radiation intensity in the at least one segment; identifying other segments each having a radiation intensity greater than a predetermined percentage of the predetermined radiation intensity established in the at least one segment; attenuating the radiation intensity directed toward the other segments; and terminating energization of the X-ray source when the predetermined target area has been illuminated by the X-ray beam. - View Dependent Claims (18, 20)
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Specification