US4536790A
Expired / Lapsed
US
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Apparatus and method for fluoroscopic imaging of a body
Assignee: Thomson CSF Broadcast Inc
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Filing: 1982-11-26
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Granted: 1985-08-20
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Expires: 2002-11-26
Abstract
Abstract The disclosure is directed to a method and apparatus for generating a processed video image of a fluid-carrying vessel in a body, and can also be used to obtain information concerning the flow rate of blood in the vessel. In the disclosed method, a contrast medium is injected into the body, typically into the vessel to be imaged or leading into the vessel to be imaged. A source of X-radiation is directed at the body, and radiation which passes through the body is detected and converted into a series of frames of electronic video signals, preferably in digital form. The frames represent images of the radiation transmission characteristics of the body at a series of successive times. Each frame includes an array of pixels, the video level at each pixel of a frame being determined by the radiation transmissivity of the body through an elemental region thereof. A processed video image can then be displayed which has a video parameter, such as luminance, that depends, at each pixel, on a time-representative value for the pixel. This processed image shows the progress of the contrast material, as a function of time, through the vessel of interest.
Inventors
- 👤 Robert A. Kruger
- 👤 Wayne Bateman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:43
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/30; H04N5/32; H04N5/3205
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
155 words
A method for generating a processed video image of a fluid-carrying vessel in a body, comprising the steps of: injecting a contrast medium to pass into the vessel; irradiating the body; detecting radiation which passes through the body and generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; storing, for each pixel, a time-representative value which depends on the determined time; and displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 2
Independent Claim
155 words
A method for generating a processed video image of a fluid-carrying vessel in a body, comprising the steps of: injecting a contrast medium to pass into the vessel; irradiating the body; detecting radiation which passes through the body and generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; storing, for each pixel, a time-representative value which depends on the determined time; and displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 3
Dependent Claim
15 words
The method as defined by claim 1, wherein said video parameter is video luminance level.
Claim 4
Dependent Claim
212 words
The method as defined by claim 1, wherein said steps of determining the time at which the video signal level at each pixel is indicative of maximum opacification, and storing a time-representative value for each pixel, includes the steps of: generating time-representative values as a function of time during the sequence; storing a video frame in a first frame store; comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of the video frame stored in the first frame store; selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; re-storing the selected video signal levels in the first frame store; storing the current time-representative value, in response to an occurrence indication, at the corresponding pixel of a second frame store synchronized with the first frame store; and repeating the comparing and subsequent steps for subsequent generated frames; whereby the processed video image will be represented by the time-representative values in the second frame store.
Claim 5
Dependent Claim
212 words
The method as defined by claim 2, wherein said steps of determining the time at which the video signal level at each pixel is indicative of maximum opacification, and storing a time-representative value for each pixel, includes the steps of: generating time-representative values as a function of time during the sequence; storing a video frame in a first frame store; comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of the video frame stored in the first frame store; selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; re-storing the selected video signal levels in the first frame store; storing the current time-representative value, in response to an occurrence indication, at the corresponding pixel of a second frame store synchronized with the first frame store; and repeating the comparing and subsequent steps for subsequent generated frames; whereby the processed video image will be represented by the time-representative values in the second frame store.
Claim 6
Dependent Claim
70 words
The method as defined by claim 4, wherein the initial reference values in said second frame store are representative of a selected video level, and wherein said occurrence indication is generated only when the video signal level of the pixel of the generated frame is lower by at least a predetermined amount than the video signal at the corresponding pixel of the video frame stored in the first frame store.
Claim 7
Dependent Claim
47 words
The method as defined by claim 1, further comprising the steps of determining a travel path distance between selected pixels in said vessel on the processed video image; and determining a travel time between said pixels along said path from the time-representative values stored in conjunction therewith.
Claim 8
Dependent Claim
47 words
The method as defined by claim 2, further comprising the steps of determining a travel path distance between selected pixels in said vessel on the processed video image; and determining a travel time between said pixels along said path from the time-representative values stored in conjunction therewith.
Claim 9
Dependent Claim
27 words
The method as defined by claim 6, further comprising the step of deriving flow rate in said vessel from said travel path distance and said travel time.
Claim 10
Dependent Claim
27 words
The method as defined by claim 7, further comprising the step of deriving flow rate in said vessel from said travel path distance and said travel time.
Claim 11
Dependent Claim
156 words
Apparatus for generating a processed video signal representative of an image of a body, comprising: a source of radiation directable at the body; means for detecting radiation which passes through the body and for generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; means for determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; means for storing, for each pixel, a time-representative value which depends on the determined time; and means for displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 12
Dependent Claim
156 words
Apparatus for generating a processed video signal representative of an image of a body, comprising: a source of radiation directable at the body; means for detecting radiation which passes through the body and for generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; means for determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; means for storing, for each pixel, a time-representative value which depends on the determined time; and means for displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 13
Dependent Claim
14 words
Apparatus as defined by claim 10, wherein said video parameter is video luminance level.
Claim 14
Dependent Claim
210 words
Apparatus as defined by claim 10, wherein said means for determining the time at which the video signal level at each pixel is indicative of maximum opacification, and the means for storing a time-representative value for each pixel, comprise: means for generating time-representative values as a function of time during the sequence; a first frame store; a second frame store synchronized with the first frame store; means for comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of a video frame stored in the first frame store, and for selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; means for generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; means for re-storing the selected video signal levels in the first frame store; and means responsive to occurrence indications for storing the current time-representative value at the corresponding pixel of the second frame store; whereby the processed video image will be represented by the time-representative values in the second frame store.
Claim 15
Dependent Claim
210 words
Apparatus as defined by claim 11, wherein said means for determining the time at which the video signal level at each pixel is indicative of maximum opacification, and the means for storing a time-representative value for each pixel, comprise: means for generating time-representative values as a function of time during the sequence; a first frame store; a second frame store synchronized with the first frame store; means for comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of a video frame stored in the first frame store, and for selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; means for generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; means for re-storing the selected video signal levels in the first frame store; and means responsive to occurrence indications for storing the current time-representative value at the corresponding pixel of the second frame store; whereby the processed video image will be represented by the time-representative values in the second frame store.
Claim 16
Dependent Claim
179 words
For use in conjunction with an imaging system, including a source of radiation directable at a body; detection means for detecting radiation which passes through the body; and a display; an apparatus for generating a processed video signal representative of an image of the body; comprising: means for detecting radiation which passes through the body and for generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; means for determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; means for storing, for each pixel, a time-representative value which depends on the determined time; and means for displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 17
Dependent Claim
179 words
For use in conjunction with an imaging system, including a source of radiation directable at a body; detection means for detecting radiation which passes through the body; and a display; an apparatus for generating a processed video signal representative of an image of the body; comprising: means for detecting radiation which passes through the body and for generating a series of frames of electronic video signals that represent an image of the radiation transmission characteristics of the body at a series of successive times, each frame including an array of pixels, the video signal level at each pixel being determined by the radiation transmissivity of an elemental region of the body; means for determining the time at which the video signal level at each pixel is indicative of maximum opacification of the elemental body region corresponding to the pixel; means for storing, for each pixel, a time-representative value which depends on the determined time; and means for displaying a processed video image which has a video parameter that depends, at each pixel, on the time-representative value for the pixel.
Claim 18
Dependent Claim
14 words
Apparatus as defined by claim 14, wherein said video parameter is video luminance level.
Claim 19
Dependent Claim
210 words
Apparatus as defined by claim 14, wherein said means for determining the time at which the video signal level at each pixel is indicative of maximum opacification, and the means for storing a time-representative value for each pixel, comprise: means for generating time-representative values as a function of time during the sequence; a first frame store; a second frame store synchronized with the first frame store; means for comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of a video frame stored in the first frame store, and for selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; means for generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; means for re-storing the selected video signal levels in the first frame store; and means responsive to occurrence indications for storing the current time-representative value at the corresponding pixel of the second frame store; whereby the processed video image will be represented by the time-representative values in the second frame store.
Claim 20
Dependent Claim
210 words
Apparatus as defined by claim 15, wherein said means for determining the time at which the video signal level at each pixel is indicative of maximum opacification, and the means for storing a time-representative value for each pixel, comprise: means for generating time-representative values as a function of time during the sequence; a first frame store; a second frame store synchronized with the first frame store; means for comparing the video signal level at each pixel of a generated frame with the video signal level at the corresponding pixel of a video frame stored in the first frame store, and for selecting at each of said pixels a video signal level representative of the lower of the compared video signal levels; means for generating an occurrence indication whenever the video signal level of the pixel of the generated frame is lower than the video signal level of the pixel of the video frame stored in the first frame store; means for re-storing the selected video signal level in the first frame store; and means responsive to occurrence indications for storing the current time-representative value at the corresponding pixel of the second frame store; whereby the processed video image will be represented by the time-representative values in the second frame store.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |