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EP0602730A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Registration of Volumetric images which are relatively elastically deformed by matching surfaces

Assignee: Koninklijke Philips NV
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Filing: 1993-12-10
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Granted: —
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Expires: 2013-12-10
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Abstract

Abstract An 3D imaging method registers relatively deformed first and second volumetric images of an object which may be obtained from different imaging modalities, and/or at different times by performing an elastic geometric transformation on one of the volumetric images. The method includes extracting first and second corresponding surfaces from the respective first and second images, which surfaces delineate the same feature, such as a bone/tissue interface. This is done by extracting a stack of contours for each surface. The first surface is iteratively warped toward alignment with the second surface to arrive at a global translation vector and a set of residual surface distortion vectors. Volume distortion vectors, determined by applying a weighting function to the residual surface distortion vectors, are used to indicate the locations in the second volumetric image of voxel centers whose interpolated intensities are to be moved to lattice points. The weighting function includes a constant indicative of elastic stiffness of the second volume. The extraction of the first surface, surface warping, and volume distortion vector determination steps are repeated in successive iterations until a measure of mis-registration between the volumetric images is less than a predetermined value, with the elastic stiffness constant being decreased each time.

Inventors

  • 👤 Mehran Moshfeghi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 21:57
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/14; G06T3/153; G06T7/00; G06T7/30; G06T7/33; G06T7/344; G06V; G06V10/00; G06V10/70; G06V10/74; G06V10/75; G06V10/755; H; H04; H04N; H04N19/00; H04N19/50; H04N19/503; H04N19/51; H04N19/537; H04N19/54; H04N19/577; H04N19/20

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 223 words
An 3D imaging method comprising: a) obtaining scanning information from at least a region of an object scanned with an imaging modality to obtain one of first and second relatively geometrically deformed three dimensional images containing voxels at a three dimensional grid of lattice points, the other of said first and second images being available; b) extracting a first surface from the first image by identifying spaced apart surface sample points lying on the first surface, said first surface delineating a feature of said object in said first image; c) extracting a second surface from the second image by identifying spaced apart surface sample points lying on the second surface, said second surface delineating in said second image the same feature of said object as delineated by said first surface in said first image; d) determining a set of 3D surface point deformation vectors applicable to the respective sample points of one of the first and second surfaces for warping said one surface toward the other of said first and second surfaces; e) determining a set of 3D lattice point deformation vectors applicable to said grid of lattice points as a weighting function of the set of 3D surface point deformation vectors; and f) applying said set of 3D lattice point deformation vectors to elastically transform said second image into a compensated image.
Claim 2
Dependent Claim 38 words
The imaging method as claimed in Claim 1, wherein said set of 3D surface point deformation vectors determined is applicable to the respective sample points of the first surface for warping the first surface toward the second surface.
Claim 3
Dependent Claim 146 words
The imaging method as claimed in Claim 1 or 2, wherein: the spaced apart surface sample points lying on the first surface are vertex points of polygonal patches which tile the first surface, the spaced apart surface sample points lying on the second surface are vertex points of polygonal patches which tile the second surface, and said determining a set of 3D surface point deformation vectors is in response to a 3D force field and comprises the steps of: g) for each vertex point on the first and second surfaces, determining a 3D displacement vector directed to a nearest patch of the other surface, so as to produce first and second sets of displacement vectors applicable to the vertex points of the first and second surfaces, respectively; and h) determining said 3D force field as a function of said first and second sets of displacement vectors.
Claim 4
Dependent Claim 55 words
The imaging method as claimed in Claim 1 or 2, further comprising: g) forming a measure of the degree of mis-registration between the compensated image and the first image; and h) repeating steps d) through f), by substituting a last compensated image for said second image, until said measure does not exceed a predetermined maximum.
Claim 5
Dependent Claim 30 words
The imaging method as claimed in Claim 1, 2, 3 or 4, further comprising the step of simultaneously displaying at least image portions from said first and said compensated images.
Claim 6
Dependent Claim 37 words
The method of Claim 1, 2, 3 or 4, further comprising the step of displaying an image whose voxels are determined as a function of the intensities of corresponding voxels of said first and said compensated images.

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