Method of mosaicing ultrasonic volumes for visual simulation

• US 5,956,418 A
• Filed: 12/10/1996
• Issued: 09/21/1999
• Est. Priority Date: 12/10/1996
• Status: Expired due to Term

• Current Assignee: TomTec Imaging Systems GmbH (Koninklijke Philips N.V.)
• Original Assignee: Medisim Limited
• Inventors: Cohen-Or, Daniel, Aiger, Dror
• Primary Examiner(s): Au, Amelia
• Assistant Examiner(s): Prikockis, Larry J.
• Application Number:
  US08/763,577
• Time in Patent Office: 1,015 Days
• Field of Search: 382/294, 382/293, 382/291, 382/284, 382/215, 382/216, 382/209, 382/154, 358/450, 395/136
• US Class Current: 382/154
• CPC Class Codes: G06T 3/147 using affine transformations
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images

Abstract

A method for mosaicing medical images, particularly volumes acquired by a 3D ultrasound device. The method relies on an image-based technique that transforms a target volume to align with a reference volume. The transformation is composed of a coarse rigid transformation and a fine elastic warp. The fine transformation assumes that the two volumes are close enough for the mapping between them to be expressed in terms of their gradient values.

Claims

1. A method for blending a three-dimensional target image with a three-dimensional reference image, the target image including a plurality of points, the method comprising the steps of:

(a) determining at least one seam plane shared by the target image and the reference image;

(b) for each of said at least one seam plane;

(i) extracting an input target slice from the target image along said seam plane,

(ii) extracting an input reference slice from the reference image along said seam plane,

(iii) subdividing the input target slice into a plurality of target subslices,

(iv) subdividing the input reference slice into a plurality of reference subslices, there being a one-to-one correspondence between said reference subslices and said target subslices,

(v) for each of said target subslices, determining a local transformation that warps said target subimage to match said corresponding reference subimage,

(vi) recursively performing both said subdividing and said determining of said local transformation at a plurality of levels of localization, said recuring further including the steps of;

(A) for each of said target subslices, composing said local transformation with a prior transformation, thereby obtaining a local composed transformation, and

(B) forming a weighted sum of said local composed transformations, thereby obtaining a global transformation;

(c) applying a weight sum of said at least one global transformation to at least one of the points.

2. A method for mosaicing a three-dimensional target image with a three-dimensional reference image, comprising the steps of:

(a) registering the target image with the reference image by steps including;

(i) rigidly transforming the target image to match the reference image, thereby providing a rigidly transformed target image, and

(ii) warping said rigidly transformed target image to match the reference image by steps including;

(A) subdividing the rigidly transformed target image into a plurality of target subimages,

(B) subdividing the reference image into a plurality of reference subimages, there being a one-to-one correspondence between said reference subimages and said target subimages, and

(C) for each of said target subimages, determining a local transformation that warps said target subimage to match said corresponding reference subimage, thereby providing a registered target image;

(b) determining at least one seam plane shared by the registered target image and the reference image; and

(c) blending the registered target image and the reference image along said at least one seam plane, by steps including, for each of said at least one seam plane;

(i) extracting a target slice from said registered target image along said each seam plane,

(ii) extracting a reference slice from said reference image alone said each seam plane, and

(iii) registering said target slice with said reference slice.

3. A method for mosaicing a three-dimensional target image with a three-dimensional reference image, comprising the steps of:

(a) registering the target image with the reference image, thereby providing a registered target image;

(b) determining at least one seam plane shared by the registered target image and the reference image; and

(c) blending the registered target image and the reference image along said at least one seam plane by steps including;

(i) for each of said seam planes;

(A) extracting a target slice from said registered target image along said each seam plane,

(B) extracting a reference slice from said reference image along said each seam plane, and

(C) determining a two-dimensional transformation that registers said target slice with said reference slice, and

(ii) applying a weighted sum of said two-dimensional transformations to said registered target image.