EP0223432A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
X-ray radiography system
Assignee: Individual
•
Filing: 1986-10-22
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Granted: —
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Expires: 2006-10-22
Abstract
Abstract A method and device for producing flux equalized x-ray images for medical radiography through the use of a scanning fan shaped x-ray beam (7) and a feedback control system (30) which regulates the beam intensity at a multiple number of points along the fan beam to compensate for the x-ray attenuation variations of the patient (18).
Inventors
- 👤 Shih-Ping Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 06:22
CPC Classifications
G; G21; G21K; G21K1/00; G21K1/10; A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/06; A61B6/40; A61B6/4035; A61B6/54; A61B6/542; A61B6/544; G21K1/02; G21K1/04; H; H05; H05G; H05G1/00; H05G1/08; H05G1/26; H05G1/30; H05G1/36; H05G1/38; H05G1/42; H05G1/44; H05G1/60
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
176 words
X-ray scanning apparatus of the type having an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object and a detector located on the opposite side of the object for detecting the x-ray flux passing through the object, wherein the improvement comprises: a detector which includes an array of detectors located across the x-ray fan beam for detecting the x-ray flux passing through the object at multiple points across the fan beam and for outputting electrical signals representative of the detected flux at such points; an x-ray flux modulator for modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; a feedback circuit supplied with the output electrical signals of the detector array for controlling the flux modulator so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 2
Dependent Claim
176 words
X-ray scanning apparatus of the type having an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object and a detector located on the opposite side of the object for detecting the x-ray flux passing through the object, wherein the improvement comprises: a detector which includes an array of detectors located across the x-ray fan beam for detecting the x-ray flux passing through the object at multiple points across the fan beam and for outputting electrical signals representative of the detected flux at such points; an x-ray flux modulator for modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; a feedback circuit supplied with the output electrical signals of the detector array for controlling the flux modulator so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 3
Dependent Claim
32 words
X-ray scanning apparatus as recited in claim 1 wherein the x-ray modulator selectively varies the cross-sectional area of the x-ray fan beam at each of said points to control the flux density.
Claim 4
Dependent Claim
26 words
X-ray scanning apparatus as recited in claim 1 further comprising means for creating a visually perceptible image of the x-ray fan beam passing through the object.
Claim 5
Dependent Claim
23 words
X-ray scanning apparatus as recited in claims 3 or 13 wherein the imaging means is located between the object and the detector array.
Claim 6
Dependent Claim
23 words
X-ray scanning apparatus as recited in claims 3 or 13 wherein the detector array is located between the object and the imaging means.
Claim 7
Dependent Claim
124 words
X-ray scanning apparatus as recited in claim 1 wherein the x-ray source simultaneously generates and scans both a monitoring x-ray fan beam and a plurality of imaging x-ray fan beams over the object, the monitoring beam proceeding the imaging beams and wherein the flux modulator separately modulates each imaging x-ray beam at multiple points across it and the detector array scans the object on the side opposite from the x-ray source in alignment with the monitoring beam, the detector array including a time delay circuit for delaying the output signals to the flux modulator to compensate for the difference in time between the passage of the monitoring beam over a particular point and the subsequent passage of the imaging beams over the same point.
Claim 8
Dependent Claim
45 words
X-ray scanning apparatus as recited in claims 1 or 13 wherein the flux modulator comprises a plurality of bundles of x-ray opaque rods, the rods being selectively extendable into the path of the x-ray beam in response to the output signals from the detector array.
Claim 9
Dependent Claim
46 words
X-ray scanning apparatus as recited in claim 7 wherein each rod bundle is positioned to regulate the x-ray beam flux over a different discrete area of the x-ray beam which impacts on the detector whose output signal controls the position of the rods of that bundle.
Claim 10
Dependent Claim
39 words
X-ray scanning apparatus as recited in claim 8 wherein the rods are oscillated into and out of the path of the beam at a rate which is controlled by the magnitude of the output signal of the corresponding detector.
Claim 11
Dependent Claim
36 words
X-ray scanning apparatus as recited in claim 8 wherein the rods are extended into the path of the beam to a length which is controlled by the magnitude of the output signal of the corresponding detector.
Claim 12
Dependent Claim
39 words
X-ray scanning apparatus as recited in claims 1 or 13 further comprising a prescatter collimator and a postscatter collimator and means for moving both collimaters and the detector array in unison and in alignment to sweep over the object.
Claim 13
Dependent Claim
23 words
X-ray scanning apparatus as recited in claims 1 or 13 wherein the flux modulator is interposed between the x-ray source and the object.
Claim 14
Dependent Claim
174 words
X-ray flux control apparatus for use with an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object, such as a patient, means for visually imaging the x-ray fan beam passing through the patient, wherein the flux control apparatus comprises: a detector which includes an array of detectors located across the x-ray fan beam for detecting the x-ray flux passing through the object at multiple points across the fan beam and for outputting electrical signals representative of the detected flux at such points; an x-ray flux modulator for modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; a feedback circuit supplied with the output electrical signals of the detector array for controlling the flux modulator so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 15
Dependent Claim
174 words
X-ray flux control apparatus for use with an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object, such as a patient, means for visually imaging the x-ray fan beam passing through the patient, wherein the flux control apparatus comprises: a detector which includes an array of detectors located across the x-ray fan beam for detecting the x-ray flux passing through the object at multiple points across the fan beam and for outputting electrical signals representative of the detected flux at such points; an x-ray flux modulator for modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; a feedback circuit supplied with the output electrical signals of the detector array for controlling the flux modulator so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 16
Dependent Claim
43 words
X-ray flux control apparatus as recited in claim 13 wherein the x-ray modulator selectively varies the cross-sectional area of the x-ray fan beam in the direction of the scan movement of the beam at each of said points to control the flux density.
Claim 17
Dependent Claim
127 words
X-ray flux control apparatus as recited in claim 1 further comprising means for dividing the x-ray fam bean into both a monitoring x-ray fan beam and a plurality of imaging x-ray fan beams over the object, the monitoring beam proceeding the imaging beams and wherein the flux modulator separately modulates each imaging x-ray beam at multiple points across it and the detector array scans the object on the side opposite from the x-ray source in alignment with the monitoring beam, the detector array including a time delay circuit for delaying the output signals to the flux modulator to compensate for the difference in time between the passage of the monitoring beam over a particular point and the subsequent passage of the imaging beams over the same point.
Claim 18
Independent Claim
162 words
A method for modulating the flux intensity of an x-ray scanning apparatus of the type having an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object and a detector located on the opposite side of the object for detecting the x-ray flux passing through the object, wherein the flux modulation method comprises the steps of: detecting the x-ray flux passing through the object at multiple points across the fan beam and outputting electrical signals representative of the detected flux at such points; modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; and controlling the flux modulator in response to said electrical signals so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 19
Independent Claim
162 words
A method for modulating the flux intensity of an x-ray scanning apparatus of the type having an x-ray source for generating a fan beam and for scanning the x-ray fan beam over an object and a detector located on the opposite side of the object for detecting the x-ray flux passing through the object, wherein the flux modulation method comprises the steps of: detecting the x-ray flux passing through the object at multiple points across the fan beam and outputting electrical signals representative of the detected flux at such points; modulating the intensity of the x-ray fan beam at a multiple number of points across the fan beam; and controlling the flux modulator in response to said electrical signals so as to modulate the flux of the beam at multiple points across it, the full spectrum of the beam being modulated substantially equally at each particular point, so that the flux detected by the array will be substantially equal across the beam.
Claim 20
Dependent Claim
38 words
The x-ray flux modulation method as recited in claim 16 wherein the modulating step comprises the step of selectively varying the cross-sectional area of the x-ray fan beam at each of said points to control the flux density.
Claim 21
Dependent Claim
35 words
The x-ray flux modulation method as recited in claim 16 further comprising the step of imaging the x-ray fan beam passing through the object onto high contrast x-ray film, having a gamma greater than three.
Claim 22
Dependent Claim
127 words
An x-ray scanning method comprising the steps of simultaneously generating and scanning both a monitoring x-ray fan beam and a plurality of imaging x-ray fan beams over an object, the monitoring beam preceding the imaging beams, detecting the monitoring beam passing through the object, at multiple points across the monitoring beam in a direction perpendicular to the scan direction and generating output signals represenative of the flux magnitude at such points, delaying the output signals to compensate for the difference in time between the passage of the monitoring beam over a particular point and the subsequent passage of the imaging beams over the same point, and separately modulating each imaging x-ray beam at multiple points across the imaging x-ray beam in response to the delayed output signals.
Claim 23
Dependent Claim
127 words
An x-ray scanning method comprising the steps of simultaneously generating and scanning both a monitoring x-ray fan beam and a plurality of imaging x-ray fan beams over an object, the monitoring beam preceding the imaging beams, detecting the monitoring beam passing through the object, at multiple points across the monitoring beam in a direction perpendicular to the scan direction and generating output signals represenative of the flux magnitude at such points, delaying the output signals to compensate for the difference in time between the passage of the monitoring beam over a particular point and the subsequent passage of the imaging beams over the same point, and separately modulating each imaging x-ray beam at multiple points across the imaging x-ray beam in response to the delayed output signals.
References Cited (Backward Citations)
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