US4653080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray diagnostic apparatus
Assignee: Toshiba Corp
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Filing: 1984-01-31
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Granted: 1987-03-24
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Expires: 2004-01-31
Abstract
Abstract An X-ray diagnostic apparatus comprises, an X-ray radiation source for generating an X-ray and projecting the same toward an object, an X-ray detector for detecting the X-ray which has transmitted through the object to derive a total X-ray intensity signal of the object including a primary X-ray signal component and a scattered X-ray signal component, a signal processor which processes the X-ray intensity signal detected from the X-ray detector in such a manner that a scattered X-ray intensity distribution which is pre-calculated based upon the X-ray intensity signal is eliminated from an X-ray intensity distribution obtained from the X-ray intensity signal so as to derive a distribution function of the primary X-ray signal component without adverse influences on the scattered X-ray signal component, and a monitor for displaying a distribution from based upon the distribution function of the primary X-ray signal component.
Inventors
- 👤 Katsuya Kikuchi
- 👤 Michitaka Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:40
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/52; A61B6/5258; A61B6/5282; H; H04; H04N; H04N23/00; H04N23/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
166 words
An X-ray diagnostic apparatus comprising: an X-ray radiation source for generating X-rays and projecting the same toward an object; X-ray detector means for detecting the X-rays which have been transmitted through the object to derive an X-ray intensity signal of the object including a primary X-ray signal component and a scattered X-ray signal component; signal processor means for processing the X-ray intensity signal detected from the X-ray detector means, said signal processor means including: first memory means for storing a response function of a scattered X-ray intensity response containing a spatial spread of the amount of the scattered X-ray; means for calculating a scattered X-ray intensity distribution based upon said function stored in the first memory means and a parameter determined by X-ray radiographic conditions; and means for subtracting said calculated scattered X-ray intensity distribution from said X-ray intensity signal of said X-ray detector means so as to derive X-ray intensity signals due to a primary X-ray without adverse influence of the scattered X-ray signal component.
Claim 2
Dependent Claim
166 words
An X-ray diagnostic apparatus comprising: an X-ray radiation source for generating X-rays and projecting the same toward an object; X-ray detector means for detecting the X-rays which have been transmitted through the object to derive an X-ray intensity signal of the object including a primary X-ray signal component and a scattered X-ray signal component; signal processor means for processing the X-ray intensity signal detected from the X-ray detector means, said signal processor means including: first memory means for storing a response function of a scattered X-ray intensity response containing a spatial spread of the amount of the scattered X-ray; means for calculating a scattered X-ray intensity distribution based upon said function stored in the first memory means and a parameter determined by X-ray radiographic conditions; and means for subtracting said calculated scattered X-ray intensity distribution from said X-ray intensity signal of said X-ray detector means so as to derive X-ray intensity signals due to a primary X-ray without adverse influence of the scattered X-ray signal component.
Claim 3
Dependent Claim
43 words
An apparatus as claimed in claim 1, further comprising: A/D converter means for converting the X-ray intensity signal of the object derived from the X-ray detector means into a corresponding digital X-ray intensity signal to be processed in said calculating and subtracting means.
Claim 4
Dependent Claim
84 words
An apparatus as claimed in claim 2, wherein the signal processor means further includes: second memory means for temporarily storing the digital X-ray intensity signal derived from the A/D converter means; means for averaging the digital X-ray intensity signal with respect to an entire X-ray projection area; and second means for calculating an averaged digital value of primary X-ray intensity in response to the averaged digital X-ray intensity signal by way of an approximation on the averaged digital value of the primary X-ray intensity.
Claim 5
Dependent Claim
128 words
An apparatus as claimed in claim 3, wherein said second means for calculating includes: a function converter in which the averaged digital value of the primary X-ray intensity derived from the second arithmetic means is raised to a predetermined power; a first multiplier in which the averaged digital value of the primary X-ray intensity is multiplied by a constant; a second multiplier in which the output of the first multiplier is multiplied by the predetermined power; a third multiplier in which the output of the second multiplier is multiplied by the predetermined values derived from the first memory means; and fifth arithmetic means for calculating the output of the third multiplier and the output of the first multiplier so as to derive the digital scattered X-ray intensity signal.
Claim 6
Dependent Claim
40 words
An apparatus as claimed in claim 1, further comprising: a grid which is provided in front of the X-ray detector means in such a manner that a part of the X-ray transmitted through the object is absorbed by the same.
Claim 7
Dependent Claim
39 words
An apparatus as defined in claim 1, further comprising: monitor means for displaying a radiographic image corresponding to said X-ray intensity signal of the primary X-ray data from based upon the response function of the primary X-ray signal component.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |