Automatic Initialization for 2D/3D Registration

• US 20130051647A1
• Filed: 08/22/2012
• Published: 02/28/2013
• Est. Priority Date: 08/23/2011
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens Corp. (Siemens AG)
• Inventors: Miao, Shun, Chefd'hotel, Christophe, Liao, Rui
• Granted Patent: US 8,879,815 B2
• Time in Patent Office: Days
• US Class Current: 382/132
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/10121 Fluoroscopy
• CPC Class Codes: G06T 7/344 involving models

Abstract

A method for automatic initialization of 2D to 3D image registration includes acquiring a 3D model. A plurality of shape descriptor features is calculated from the acquired 3D model representing a plurality of poses of the 3D model. A 2D image is acquired. The plurality of shape descriptors is matched to the acquired 2D model. An optimum pose of the 3D model is determined based on the matching of the plurality of shape descriptors to the acquired 2D model. An initial registration is generated, in an image processing system, between the 3D model and the 2D image based on the determined optimum pose.

Claims

1. A method for automatic initialization of 2D to 3D image registration, comprising:

acquiring a 3D model;

calculating a plurality of shape descriptor features from the acquired 3D model representing a plurality of poses of the 3D model;

acquiring a 2D image;

matching the plurality of shape descriptors to the acquired 2D model;

determining an optimum pose of the 3D model based on the matching of the plurality of shape descriptors to the acquired 2D model; and

generating an initial registration, in an image processing system, between the 3D model and the 2D image based on the determined optimum pose.

2. The method of claim 1, wherein the 3D model is a computer aided design (CAD) model.

3. The method of claim 1, wherein the 3D model is acquired from a medical imaging study.

4. The method of claim 1 wherein the plurality of shape descriptor features include a set of statistical characterizations of the 3D model at respective poses of he plurality of poses.

5. The method of claim 4, wherein the set of statistical characterizations includes a measure of distances between an outer contour of a silhouette of a 2D rendering of the 3D model at the corresponding pose and a point of reference.

6. The method of claim 5 wherein the point of reference is a center of mass of the silhouette.

7. The method of claim 5 wherein the point of reference is a point on the contour and the measure of distance is an arc length along the contour.

8. The method of claim 1, wherein determining the optimum pose of the 3D model based on the matching of the plurality of shape descriptors to the acquired 2D model includes determining which shape descriptor of the plurality of shape descriptors is a best match to the acquired 2D image and determining the pose of the plurality of posses associated with the best match shape descriptor.

9. The method of claim 1, wherein the plurality of shape descriptor features are calculated from the 3D model and stored in a library of shape descriptor features prior to the acquisition of the 2D image and the plurality of shape descriptor features are retrieved from the library at about the time of the 2D image acquisition.

10. The method of claim 1, wherein the 2D image is an X-ray image.

11. The method of claim 10, wherein the X-ray image is part of a fluoroscopic image sequence.

12. The method of claim 1, wherein the initial registration is used to perform automatic registration between the 3D model and the 2D image.

13. The method of claim 12, wherein the 2D image is a frame within a sequence of 2D images and the automatic registration is used to combine the 3D model with the sequence of 2D images.

14. The method of claim 13, wherein the combined sequence is displayed in real-time.

15. The method of claim 1, wherein the acquired 2D image is preprocessed prior to the matching to determine a set of features analogous to the shape descriptor features.

16. A system for providing intervention guidance, comprising:

a feature generating device for receiving a 3D model and calculating a plurality of shape descriptor features from the acquired 3D model representing a plurality of poses of the 3D model;

a database for storing the plurality of shape descriptor features;

a feature matching device for retrieving the plurality of shape descriptor features from the database, matching the plurality of shape descriptors to an acquired 2D model, and determining an optimum pose of the 3D model based on the matching of the plurality of shape descriptors to the acquired 2D model;

an image processing device for generating an initial registration, in an image processing system, between the 3D model and the 2D image based on the determined optimum pose, performing automatic registration between the 3D model and the 2D image based on the initial registration, and combining the 3D model with a sequence of 2D image frames that includes the 2D image; and

a display device for displaying the combined image sequence in real-time.

17. The system of claim 16, wherein the 3D model is a computer aided design (CAD) model or a medical imaging study.

18. The system of claim 16, wherein the plurality of shape descriptor features includes a set of statistical characterizations of the 3D model at respective poses of the plurality of poses, and the set of statistical characterizations includes a measure of distances between an outer contour of a silhouette of a 2D rendering of the 3D model at the corresponding pose and a point of reference.

19. The system of claim 16, wherein the 2D image is an X-ray image that is part of a fluoroscopic image sequence.

20. A computer system comprising:

a processor; and

a non-transitory, tangible, program storage medium, readable by the computer system, embodying a program of instructions executable by the processor to perform method steps for automatic initialization of 2D to 3D image registration, the method comprising;

matching a plurality of shape descriptor features from an acquired 3D model representing a plurality of poses of the 3D model to an acquired 2D model;

determining an optimum pose of the 3D model based on the matching of the plurality of shape descriptors to the acquired 2D model; and

generating an initial registration, in an image processing system, between the 3D model and the 2D image based on the determined optimum pose.