US4914589A
Expired / Lapsed
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Three-dimensional images obtained from tomographic data using a variable threshold
Assignee: General Electric Co
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Filing: 1988-10-24
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Granted: 1990-04-03
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Expires: 2008-10-24
Abstract
Abstract Three-dimensional images are formed from tomographic data collected in a medical diagnostic imaging system. The images include structures of specific interest having voxel densities not confined to a single, exclusive area of the image histogram. A variable threshold dependent on the particular voxel locations is used in extracting the 3-D surface definition in order to eliminate partial volume artifacts in the 3-D image.
Inventors
- 👤 Carl R. Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:32
CPC Classifications
G; G06; G06T; G06T12/00; G06T12/30; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/563
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
82 words
A method for extracting a surface within a plurality of two-dimensional tomographic slices, each slice including a plurality of voxels, said method comprising the steps of: acquiring voxel densities within said slices such that all slices are substantially parallel and spaced along a z-axis; and identifying at least portions of each voxel containing said surface according to an identification criterion, the criterion, applied to each respective voxel being dependent on the location along said z-axis of the respective slice containing said voxel.
Claim 2
Independent Claim
82 words
A method for extracting a surface within a plurality of two-dimensional tomographic slices, each slice including a plurality of voxels, said method comprising the steps of: acquiring voxel densities within said slices such that all slices are substantially parallel and spaced along a z-axis; and identifying at least portions of each voxel containing said surface according to an identification criterion, the criterion, applied to each respective voxel being dependent on the location along said z-axis of the respective slice containing said voxel.
Claim 3
Dependent Claim
52 words
The method of claim 1 wherein said identifying step comprises the steps of: selectively weighting said voxel densities by a weighting coefficient, said weighting coefficient having a value for applying to each respective slice which is dependent on the location of said respective slice; and comparing said voxels to a predetermined threshold.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein said value of said coefficient is further dependent on the location of a respective voxel within each respective slice.
Claim 5
Dependent Claim
40 words
The method of claim 1 wherein said identifying step comprises comparing said voxels to a variable threshold, said threshold having a value for comparing to voxels within each respective slice which is dependent on the location of said respective slice.
Claim 6
Dependent Claim
25 words
The method of claim 4 wherein said value of said threshold is further dependent on the location of a respective voxel within each respective slice.
Claim 7
Dependent Claim
91 words
Apparatus for extracting a surface within a plurality of two-dimensional tomographic slices, each slice including a plurality of voxels, said apparatus comprising: data means for storing voxel densities of said slices arranged according to location within substantially parallel slices which are spaced along a z-axis; and identifying means coupled to said data means for identifying at least portions of each voxel containing said surface according to an identification criterion, the criterion applied to each respective voxel being dependent on the location along said z-axis of the respective slice containing said voxel.
Claim 8
Dependent Claim
91 words
Apparatus for extracting a surface within a plurality of two-dimensional tomographic slices, each slice including a plurality of voxels, said apparatus comprising: data means for storing voxel densities of said slices arranged according to location within substantially parallel slices which are spaced along a z-axis; and identifying means coupled to said data means for identifying at least portions of each voxel containing said surface according to an identification criterion, the criterion applied to each respective voxel being dependent on the location along said z-axis of the respective slice containing said voxel.
Claim 9
Dependent Claim
43 words
The apparatus of claim 6 wherein said identifying means comprises: selective weighting means coupled to said data means for selectively weighting said voxel densities; and comparison means coupled to said selective weighting means for comparing selectively weighted voxel densities to a predetermined threshold.
Claim 10
Dependent Claim
43 words
The apparatus of claim 6 wherein said identifying means includes comparison means coupled to said data means for comparing said voxel densities to a variable threshold, said variable threshold having a value dependent on the location of the respective slice containing each voxel.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-02 | 1993-10-02 | 1994-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-02 | 1997-10-02 | 1998-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-02 | 2001-10-02 | 2002-04-03 | $7700.00 | Window Closed / Lapsed |