IMAGE PROVISION FOR REGISTRATION

• US 20110235890A1
• Filed: 11/19/2009
• Published: 09/29/2011
• Est. Priority Date: 11/25/2008
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ruijters, Daniel Simon Anna
• Granted Patent: US 8,488,910 B2
• Time in Patent Office: Days
• US Class Current: 382/132
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/10121 Fluoroscopy
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 3/14 Transformations for image registration, e.g. adjusting or mapping for alignment of images
• CPC Class Codes: G06T 7/38 Registration of image sequences

Abstract

The invention relates to a device and a method for providing a basis for registering a three-dimensional model of an anatomical region with two-dimensional projection images, by deriving a three-dimensional model of an anatomical region at a phase of a periodic signal; deriving two-dimensional projection images of a region which overlaps with the anatomical region re-constructed as the three-dimensional model; pre-5 selecting a subset of projection images out of the derived two-dimensional projection images, which are closest to the phase; and selecting a reference image for the registration from the subset of pre-selected projection images by choosing the projection image with the most contrast.

Claims

1. A device for providing a basis for registering a three-dimensional model of an anatomical region with two-dimensional projection images, comprising:

a 3D imaging system (10) for deriving a three-dimensional model of an anatomical region at a phase of a periodic signal;

a 2D imaging system (11) for deriving two-dimensional projection images of a region which overlaps with the anatomical region reconstructed by the 3D imaging system;

a pre-selector (15) for selecting a subset of projection images out of the derived two-dimensional projection images, which are closest to the phase; and

a selector (16) for selecting a reference image for the registration from the subset of pre-selected projection images by choosing the projection image with the most contrast.

2. The device according to claim 1, further comprising

a signal monitoring system (12) for detecting the periodic signal;

and

a time allocator (14) for assigning a time position of the periodic signal to the respective phase of the three-dimensional model.

3. The device according to claim 1, further comprising

a signal monitoring system (12) for detecting the periodic signal, wherein the 2D imaging system (11) is prospectively gated based on the periodic signal for obtaining the two-dimensional projection images within a certain time period which includes the phase of the three-dimensional model.

4. The device according to claim 1, wherein the selector (16) is a darkness evaluator for choosing the projection image with the most contrast by choosing the darkest projection image.

5. The device according to claim 1, wherein the selector (16) is a middle locator for choosing the projection image with the most contrast by choosing the projection image which is closest to the middle with respect to a time period from the first projection image to the last projection image of the derived two-dimensional projection images.

13. An x-ray system comprising a device according to claim 1.

6. A method of providing a basis for registering a three-dimensional model of an anatomical region with two-dimensional projection images, comprising the steps:

deriving a three-dimensional model (S100) of an anatomical region at a phase of a periodic signal;

deriving two-dimensional projection images (S101) of a region which overlaps with the anatomical region reconstructed as the three-dimensional model;

pre-selecting (S103) a subset of projection images out of the derived two-dimensional projection images, which are closest to the phase; and

selecting (S104) a reference image for the registration from the subset of pre-selected projection images by choosing the projection image with the most contrast.

7. The method according to claim 6, further comprising the steps:

detecting (S101) the periodic signal; and

assigning (S102) a time position of the periodic signal to the respective phase of the three-dimensional model.

8. The method according to claim 6, further comprising the steps:

detecting (S101) the periodic signal; and

prospectively gating the 2D imaging system (11) based on the periodic signal for obtaining the two-dimensional projection images within a certain time period which includes the phase of the three-dimensional model.

9. The method according to claim 6, wherein in the step of selecting (S104), the darkest projection image is chosen.

10. The method according to claim 6, wherein in the step of selecting (S104), the projection image is chosen which is closest to the middle with respect to a time period from the first projection image to the last projection image of the derived two-dimensional projection images.

11. The method according to claim 6, wherein the closest frames are derived by multiplying the individual time positions by the frame rate, and rounding to the nearest integer.

12. A device arranged to perform the method according to claim 6.