US4577222A
Expired / Lapsed
US
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Apparatus and method for cross sectional imaging of a body
Assignee: Thomson CSF Broadcast Inc
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Filing: 1982-11-26
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Granted: 1986-03-18
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Expires: 2002-11-26
Abstract
Abstract The disclosure is directed to a method and apparatus for generating a processed image of a cross-section through a body. Fluoroscopic tomography is achieved wherein a series of video frames of a cross-section of a body can be viewed in real time. In this manner, for example, one can monitor the progress of a bolus of contrast material moving through a blood vessel in the cross-section being viewed. In a form of the disclosure, a recorded series of frames of a principal plane of a body being imaged can be processed to obtain a corresponding series of frames that represent a plane of interest that is spaced from the principal plane, thereby avoiding the necessity of re-exposure for each new plane to be viewed. In accordance with the disclosed method, a body is disposed between a combination of a source of radiation and an associated detector, such that a beam of radiation from the source impinges angularly on the body and passes through to the detector. Relative rotational motion is effected between the beam and the body, such that a principal plane of interest in the body remains substantially in focus during the relative rotational motion. A series of frames of electronic video signals are derived from the detector, at different rotational positions, the frames representing images of the radiation transmission characteristics of the body at a series of successive times. The series of frames are temporally filtered and then displayed. In a preferred embodiment, the temporal filtering step comprises filtering the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially the temporal frequency of the movement of a bolus of contrast material through the region being imaged.
Inventors
- 👤 Robert A. Kruger
- 👤 James A. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:51
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/481; A61B6/02; A61B6/027; A61B6/50; A61B6/504; G; G06; G06T; G06T12/00; G06T12/10
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
157 words
A method for generating a processed image of a cross-section through a body, comprising the steps of: disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; temporally filtering said series of frames by combining successive frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other; and displaying the temporally filtered series of frames.
Claim 2
Independent Claim
157 words
A method for generating a processed image of a cross-section through a body, comprising the steps of: disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; temporally filtering said series of frames by combining successive frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other; and displaying the temporally filtered series of frames.
Claim 3
Dependent Claim
29 words
The method as defined by claim 1, further comprising the step of injecting a bolus of contrast medium into the body before deriving the frames of electronic video signals.
Claim 4
Dependent Claim
23 words
The method as defined by claim 1, wherein said temporal filtering step comprises applying said series of frames to a recursive filtering system.
Claim 5
Dependent Claim
23 words
The method as defined by claim 2, wherein said temporal filtering step comprises applying said series of frames to a recursive filtering system.
Claim 6
Dependent Claim
48 words
The method as defined by claim 2, wherein said temporal filtering step comprises filtering the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of the bolus through the region being imaged.
Claim 7
Dependent Claim
48 words
The method as defined by claim 4, wherein said temporal filtering step comprises filtering the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of the bolus through the region being imaged.
Claim 8
Dependent Claim
22 words
The method as defined by claim 6, wherein said recursive filtering system includes a pair of recursive filters having different temporal characteristics.
Claim 9
Independent Claim
220 words
A method for generating a processed image of one or more cross-sections through a body, comprising the steps of: injecting a bolus of contrast medium into the body; disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane in said body remains substantially in focus during said relative potational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images 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 principal plane and adjacent planes; implementing geometrical transformation to different pixel positions of video signal levels of frames of the sequence, the geometrical transformation of a pixel being a function of relative rotational angle associated with its frame, and the distance between a plane of interest to be imaged and the principal plane; temporally filtering the series of geometrically transformed frames; and displaying the temporally filtered series of geometrically transformed frames.
Claim 10
Independent Claim
220 words
A method for generating a processed image of one or more cross-sections through a body, comprising the steps of: injecting a bolus of contrast medium into the body; disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane in said body remains substantially in focus during said relative potational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images 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 principal plane and adjacent planes; implementing geometrical transformation to different pixel positions of video signal levels of frames of the sequence, the geometrical transformation of a pixel being a function of relative rotational angle associated with its frame, and the distance between a plane of interest to be imaged and the principal plane; temporally filtering the series of geometrically transformed frames; and displaying the temporally filtered series of geometrically transformed frames.
Claim 11
Dependent Claim
42 words
The method as defined by claim 8, wherein said temporal filtering comprises combining successive geometrically transformed frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other.
Claim 12
Dependent Claim
23 words
The method as defined by claim 8, wherein said temporal filtering step comprises applying said series of frames to a recursive filtering system.
Claim 13
Dependent Claim
22 words
The method as defined by claim 10, wherein said recursive filtering system includes a pair of recursive filters having different temporal characteristics.
Claim 14
Dependent Claim
48 words
The method as defined by claim 8, wherein said temporal filtering step comprises filtering the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of the bolus through the region being imaged.
Claim 15
Dependent Claim
55 words
The method as defined by claim 10, wherein said step of implementing geometrical transformations to different pixel positions of video signal levels of frames of the sequence, comprises assigning modified pixel addresses to said video signal levels, and applying said modified pixel addresses to the recursive filtering system in conjunction with said video signal levels.
Claim 16
Dependent Claim
165 words
Apparatus for generating a processed image of a cross-section through a body, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; means for temporally filtering said series of frames by combining successive frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other; and means for displaying and/or recording the temporally filtered series of frames.
Claim 17
Dependent Claim
165 words
Apparatus for generating a processed image of a cross-section through a body, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; means for temporally filtering said series of frames by combining successive frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other; and means for displaying and/or recording the temporally filtered series of frames.
Claim 18
Dependent Claim
16 words
Apparatus as defined by claim 14, wherein said temporal filtering means comprises a recursive filtering system.
Claim 19
Dependent Claim
52 words
Apparatus as defined by claim 14, wherein said temporal filtering means is operative to filter the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of a bolus of contrast material through the region being imaged.
Claim 20
Dependent Claim
231 words
Apparatus for generating a processed image of one or more cross-sections through a body into which a bolus of contrast material has been injected, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images 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 principal plane and adjacent planes; means for implementing geometrical transformation to different pixel positions of video signal levels of frames of the sequence, the geometrical transformation of a pixel being a function of relative rotational angle associated with its frame, and the distance between a plane of interest to be imaged and the principal plane; means for temporally filtering the series of geometrically transformed frames; and means for displaying and/or recording the temporally filtered series of geometrically transformed frames.
Claim 21
Dependent Claim
231 words
Apparatus for generating a processed image of one or more cross-sections through a body into which a bolus of contrast material has been injected, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images 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 principal plane and adjacent planes; means for implementing geometrical transformation to different pixel positions of video signal levels of frames of the sequence, the geometrical transformation of a pixel being a function of relative rotational angle associated with its frame, and the distance between a plane of interest to be imaged and the principal plane; means for temporally filtering the series of geometrically transformed frames; and means for displaying and/or recording the temporally filtered series of geometrically transformed frames.
Claim 22
Dependent Claim
16 words
Apparatus as defined by claim 17, wherein said temporal filtering means comprises a recursive filtering system.
Claim 23
Dependent Claim
52 words
Apparatus as defined by claim 17, wherein said temporal filtering means is operative to filter the series of frames of video signals with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of a bolus of contrast material through the region being imaged.
Claim 24
Dependent Claim
51 words
Apparatus as defined by claim 17, wherein said means for temporally filtering the series of geometrically transformed frames comprises means for combining successive geometrically transformed frames of the series with a weighting for each combination that depends on when the frames being combined occur in time with respect to each other.
Claim 25
Independent Claim
164 words
A method for generating a processed image of a cross-section through a body, comprising the steps of: injecting a bolus of contrast medium into the body; disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; temporally filtering said series of frames with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of the bolus through the region being imaged; and displaying the temporally filtered series of frames.
Claim 26
Independent Claim
164 words
A method for generating a processed image of a cross-section through a body, comprising the steps of: injecting a bolus of contrast medium into the body; disposing the body between a combination of a source of radiation and an associated detector, such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; deriving from the detector, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; temporally filtering said series of frames with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of the bolus through the region being imaged; and displaying the temporally filtered series of frames.
Claim 27
Dependent Claim
166 words
Apparatus for generating a processed image of a cross-section through a body, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; means for temporally filtering said series of frames with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of a bolus of contrast material through the region being imaged; and means for displaying and/or recording the temporally filtered series of frames.
Claim 28
Dependent Claim
166 words
Apparatus for generating a processed image of a cross-section through a body, comprising: a combination of a source of radiation and an associated detector mechanically coupled together and positioned such that a beam of radiation from said source impinges angularly on said body and passes through to said detector; means for effecting relative rotational motion between said beam and said body such that a principal plane of interest in said body remains substantially in focus during said relative rotational motion; means for generating from the detector output, at different rotational positions, a series of frames of electronic video signals that represent images of the radiation transmission characteristics of the body at a series of successive times; means for temporally filtering said series of frames with a filter function having a temporal frequency response that corresponds substantially to the temporal frequency of the movement of a bolus of contrast material through the region being imaged; and means for displaying and/or recording the temporally filtered series of frames.
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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |