US4953087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-dimensional images obtained from tomographic data having unequally spaced slices
Assignee: General Electric Co
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Filing: 1988-10-24
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Granted: 1990-08-28
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Expires: 2008-10-24
Abstract
Abstract Three-dimensional representations of the surface of a structure located in a three-dimensional space are formed from tomographic data collected in a medical diagnostic imaging system. The images include structures of specific interest displayed at a high resolution and adjacent structures to improve the perception of the structures of interest displayed at a low resolution. Total examination time is reduced because the total number of slices needed to form the image is reduced. A plurality of slices of different spacings are obtained and divided into first and second space portions (associated with different slice spacings). An interpolation factor which varies as a function of slice spacing is used in the dividing step to establish selected dimensions of first and second three-dimensional elements. The location of each of the first and second elements is specified as a function of the interpolation factor and the first and second three-dimensional elements which contain a portion of the surface are identified.
Inventors
- 👤 Carl R. Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:54
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G06; G06T; G06T17/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
195 words
A method for generating a three-dimensional representation of the surface of a structure located in a three-dimensional space comprising the steps of: obtaining a plurality of slices at a first slice spacing which collectively contain a first portion of said space; obtaining a plurality of slices at second slice spacing which collectively contain a second portion of said space, said second slice spacing being different from said first slice spacing; dividing said first and second space portions respectively into sets of first and second three-dimensional spatial elements; selecting an interpolating factor which varies as a function of said slice spacing for use in said dividing step to establish a specified relationship between a selected dimension of a first three-dimensional element and a selected dimension of a second three-dimensional element; specifying the location of each of said first and second three-dimensional elements in said space as a function of said interpolation factor; identifying each of said first and second three-dimensional elements which contains a portion of said surface, and generating a data element representing each of said portions; and displaying an image of said surface from said data elements, said image including a plurality of pixels.
Claim 2
Independent Claim
195 words
A method for generating a three-dimensional representation of the surface of a structure located in a three-dimensional space comprising the steps of: obtaining a plurality of slices at a first slice spacing which collectively contain a first portion of said space; obtaining a plurality of slices at second slice spacing which collectively contain a second portion of said space, said second slice spacing being different from said first slice spacing; dividing said first and second space portions respectively into sets of first and second three-dimensional spatial elements; selecting an interpolating factor which varies as a function of said slice spacing for use in said dividing step to establish a specified relationship between a selected dimension of a first three-dimensional element and a selected dimension of a second three-dimensional element; specifying the location of each of said first and second three-dimensional elements in said space as a function of said interpolation factor; identifying each of said first and second three-dimensional elements which contains a portion of said surface, and generating a data element representing each of said portions; and displaying an image of said surface from said data elements, said image including a plurality of pixels.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein said interpolating factor is selected to establish a substantially equal relationship between said selected dimensions of said first and second three-dimensional elements.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said method includes application of the dividing cubes method to determine said surface.
Claim 5
Dependent Claim
226 words
The method of claim 1 wherein said method is performed using the dividing cubes method and includes the steps of: (a) calculating gradient vectors at a plurality of data points in contiguous slices of said space at said first and second slice spacings, each slice being at a relative location denoted as z k within an (x,y,z,) coordinate system, the location of each data point being denoted as (i,j,k) within said coordinate system, each data point having a value f(i,j,k), and each gradient vector having components g x , g y , and g z calculated according to the formula: g x (i,j,k)=[f(i+1,j,k)-f(i-1,j,k)]c 1 g y (i,j,k)=[f(i,j,+1,k)-f(i,j-1,k)]c 2 g z (i,j,k)=[f(i,j,k+1)-f(i,j,k-1)]c 3 where c 1 =1/(2*PIXEL x ), c 2 =1/(2*PIXEL y ), and c 3 =1/(z k +1-z k -1) where PIXEL x and PIXEL y are the data point spacings within each slice in the x and y directions, respectively; (b) subdividing each kth marching cube in the z-direction by an interpolation factor C(k) such that a subcube size of (z k +1-z k )/C(k) projects to not more than one of said image pixels, each of said first and second three-dimensional elements comprising one of said subcubes; and (c) generating interpolated data points in each kth marching cube, said interpolated data points each having a location in z given by z.sub.k +{K(z.sub.k +1-z.sub.k)/C(k)}.
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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) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |