US4468697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for and method of X-ray image processing
Assignee: US Philips Corp
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Filing: 1982-08-26
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Granted: 1984-08-28
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Expires: 2002-08-26
Abstract
Abstract A device for and method of X-ray processing in which a constant adjustable signal value is subtracted from a video signal of an X-ray image in order to correct the video signal for the effects of inherent scatter. The adjustable signal value depends on the X-ray tube voltage, the nature of the object to be examined, the field size etc. so that it is preferably dependent on the X-ray exposure parameters. The video signal is preferably converted into a logarithmic value by means of a logarithmic table which is dependent on the adjustable signal value (or actually on the exposure parameters).
Inventors
- 👤 Leonardus A. J. Verhoeven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:21
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/30; H04N5/32; H04N5/3205
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
206 words
A method for making X-ray images of objects comprising the steps of: storing, in a memory, a plurality of X-ray exposure programs, wherein each exposure program includes the values of a multiplicity of exposure parameter settings which are suitable for producing X-ray images of a particular class of objects and the level of X-ray scatter in the object is determined by a combination of the values of at least two of said parameter settings, and an associated scatter radiation compensation value; selecting one of said programs from said memory for producing an image of a particular object and adjusting the values of exposure parameter settings of X-ray aparatus to the values specified in said selected program; irradiating said particular object with said X-ray apparatus in accordance with said selected values and producing an electric video signal which is representative of the amplitude of X-radiation which has passed through the object; subtracting the value of said associated scatter radiation compensation signal from the amplitude of the video signal to generate a difference signal and generating a display signal which is proportional to the logarithm of the difference signal; and producing a display having pixels whose brightness is proportional to a corresponding instantaneous amplitude of said display signal.
Claim 2
Independent Claim
206 words
A method for making X-ray images of objects comprising the steps of: storing, in a memory, a plurality of X-ray exposure programs, wherein each exposure program includes the values of a multiplicity of exposure parameter settings which are suitable for producing X-ray images of a particular class of objects and the level of X-ray scatter in the object is determined by a combination of the values of at least two of said parameter settings, and an associated scatter radiation compensation value; selecting one of said programs from said memory for producing an image of a particular object and adjusting the values of exposure parameter settings of X-ray aparatus to the values specified in said selected program; irradiating said particular object with said X-ray apparatus in accordance with said selected values and producing an electric video signal which is representative of the amplitude of X-radiation which has passed through the object; subtracting the value of said associated scatter radiation compensation signal from the amplitude of the video signal to generate a difference signal and generating a display signal which is proportional to the logarithm of the difference signal; and producing a display having pixels whose brightness is proportional to a corresponding instantaneous amplitude of said display signal.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein each exposure program in the memory further includes a table of values of the logarithms corresponding to values of an associated difference signal.
Claim 4
Dependent Claim
53 words
The method of claim 1 wherein the program contains the values of at least two of the hardness of X-rays, the size of an irradiated field, the thickness and/or composition of the object, the distance between the object and an image forming device, and the distance between the object and a scatter grid.
Claim 5
Dependent Claim
205 words
Apparatus for making X-ray of objects comprising: a memory which contains a plurality of X-ray exposure programs, wherein each exposure program includes the values of a multiplicity of exposure parameter settings which are suitable for producing X-ray images of a particular class of objects and the level of X-ray scatter in the object is determined by a combination of the values of at least two of said parameters, and an associated scatter radiation compensation signal value; X-ray exposure means comprising X-ray source means for directing X-radiation through the object and image forming means for producing a video signal representative of the amplitude of X-rays which have passed through the object; means for selecting a particular program from the memory and for adjusting the X-ray exposure means in accordance with the values of the parameter settings in said selected program; means which subtract the value of said scatter radiation compensation signal from said video signal to produce a difference signal; means which produce a display signal having an amplitude which is representative of the logarithm of the difference signal; and means which produce a visual display wherein the brightness of points in the display is proportional to the amplitude of corresponding points in the display signal.
Claim 6
Dependent Claim
205 words
Apparatus for making X-ray of objects comprising: a memory which contains a plurality of X-ray exposure programs, wherein each exposure program includes the values of a multiplicity of exposure parameter settings which are suitable for producing X-ray images of a particular class of objects and the level of X-ray scatter in the object is determined by a combination of the values of at least two of said parameters, and an associated scatter radiation compensation signal value; X-ray exposure means comprising X-ray source means for directing X-radiation through the object and image forming means for producing a video signal representative of the amplitude of X-rays which have passed through the object; means for selecting a particular program from the memory and for adjusting the X-ray exposure means in accordance with the values of the parameter settings in said selected program; means which subtract the value of said scatter radiation compensation signal from said video signal to produce a difference signal; means which produce a display signal having an amplitude which is representative of the logarithm of the difference signal; and means which produce a visual display wherein the brightness of points in the display is proportional to the amplitude of corresponding points in the display signal.
Claim 7
Dependent Claim
52 words
The apparatus of claim 4 wherein the memory program further includes a table containing the values of the logarithms of corresponding values of the associated difference signal and wherein the means for producing the display signal selects a value from said table in accordance with the corresponding value of the difference signal.
Claim 8
Dependent Claim
45 words
The apparatus of claim 4 wherein each program contains the values of at least two of: the hardness of the X-ray, the size of the irradiated field, the composition and/or thickness of the object, and the distance between the object and the image forming means.
Claim 9
Dependent Claim
28 words
The apparatus of claim 6 further comprising a scatter grid and wherein the program further contains the value of the distance between the object and the scatter grid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |