Registration for tracked medical tools and X-ray systems

Patent metadata

Field	Value
Publication number	US-9949701-B2
Application number	US-201414181600-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 14, 2013
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

In order to increase the accuracy of registration between a world coordinate system and an image coordinate system such that a tracked medical tool may be moved forward in the body of a patient without any additional or with limited live imaging, a method for registration of the tracked medical tool with an X-ray system is provided. The method includes receiving image data from the X-ray system at a plurality of time points, receiving tracking data from a tracking device of the tracked medical tool at the plurality of time points, and registering the world coordinate system and the image coordinate system based on the received image data and the received tracking data at the plurality of time points.

First claim

The invention claimed is:

1. A method for registration of an endovascular device with an X-ray system, the endovascular device comprising a tracking device, the method comprising:
receiving image data from the X-ray system at a plurality of time points, the image data comprising image data representing at least a portion of the endovascular device in a first coordinate system as the endovascular device moves within or through the first coordinate system;
receiving tracking data generated by the tracking device at the plurality of time points, the tracking data representing a global position of the endovascular device in a second coordinate system, the second coordinate system being a global coordinate system;
registering, by a processor, the second coordinate system with the first coordinate system based on the received image data and the received tracking data at the plurality of time points,
wherein the tracking device comprises tracking coils configured to generate an electromagnetic (EM) signal comprising the tracking data representing the global position of the endovascular device in the second coordinate system.

2. The method of claim 1 , further comprising:
generating, by the processor, a plurality of projection images based on the received image data from the X-ray system; and
calculating, by the processor, positions of one or more markers of the tracking device within the first coordinate system, the first coordinate system being a three-dimensional (3D) image coordinate system,
wherein the registering comprises performing point based registration between the calculated positions of the one or more markers of the tracking device and the received tracking data from the tracking device.

3. The method of claim 2 , wherein the calculating comprises:
generating a three-dimensional (3D) image based on the plurality of generated projection images and segmenting the one or more markers from the 3D image; or
segmenting the one or more markers of the tracking device from the plurality of projection images and reconstructing a 3D image of the one or more markers.

4. The method of claim 1 , further comprising:
generating, by the processor, a plurality of projection images based on the received image data from the X-ray system;
generating a three-dimensional (3D) image based on the plurality of generated projection images, the generated 3D image representing at least the portion of the endovascular device; and
segmenting at least the portion of the endovascular device from the 3D image,
wherein receiving the tracking data comprises receiving data representing positions of one or more tracking markers of the tracking device in the second coordinate system from the tracking device, and
wherein the registering comprises matching the segmented portion of the endovascular device from the 3D image to the received data representing the positions of the one or more tracking markers of the tracking device.

5. The method of claim 4 , further comprising filtering the plurality of projection images, the filtering isolating the endovascular device within the plurality of projection images.

6. The method of claim 1 , wherein the received image data is received first image data, and
wherein the method further comprises:
receiving second image data from the X-ray system or another X-ray system, the second image data representing an object in which the endovascular device is disposable, the received second image data comprising image data representing the object with a contrast agent injected and image data representing the object with no contrast agent injected; and
generating a three dimensional (3D) digital subtraction angiography (DSA) image of the object based on the received second image data.

7. The method of claim 6 , further comprising:
generating one or more fluoroscopic image pairs of at least the portion of the endovascular device based on the received first image data, fluoroscopic images of each of the one or more generated fluoroscopic image pairs being in different planes;
triangulating a 3D position of one or more markers of the tracking device within the 3D DSA image based on the one or more generated fluoroscopic image pairs,
wherein the registering comprises performing point based registration between the triangulated 3D position of the one or more markers of the tracking device and the received tracking data from the tracking device.

8. The method of claim 6 , further comprising:
generating, by the processor, a plurality of fluoroscopic images based on the received first image data; and
segmenting a representation of an electromagnetic (EM) trackable marker of the tracking device or a representation of the endovascular device from each fluoroscopic image of the plurality of fluoroscopic images.

9. The method of claim 8 , wherein receiving the second image data comprises receiving second image data that represents the object and at least the portion of the endovascular device, at least a portion of the second image data representing the EM trackable marker, the received tracking data comprising tracking data representing a position of the EM trackable marker in the second coordinate system at the plurality of time points and another time point, and
wherein the generating of the 3D DSA image comprises generating a 3D DSA image of the object and at least the portion of the endovascular device based on the received second image data.

10. The method of claim 9 , further comprising:
generating a 3D mask image of the object and at least the portion of the endovascular device based on the received second image data;
segmenting a representation of the EM trackable marker and a representation of the endovascular device from the 3D mask image;
matching the representation of the EM trackable marker segmented from the 3D mask image with the tracking data representing the position of the EM trackable marker in the second coordinate system at the other time point;
altering the representation of the endovascular device segmented from the 3D mask image, the altering comprising increasing a diameter of the representation of the endovascular device segmented from the 3D mask image;
backprojecting the representation of the EM trackable marker or the representation of the endovascular device segmented from each fluoroscopic image of the plurality of fluoroscopic images into the altered segmented representation of the endovascular device; and
determining a position of at least the portion of the endovascular device in the first coordinate system, the determining comprising identifying one or more intersection points of the backprojected representation of the EM trackable marker or the backprojected representation of the endovascular device with the altered segmented representation of the endovascular device,
wherein the registering comprises performing point based registration between the one or more intersection points and a portion of the received tracking data from the tracking device.

11. The method of claim 1 , wherein receiving the image data comprises receiving image data representing an object in which the endovascular device is disposable, the received image data comprising image data representing the object with a contrast agent injected and image data representing the object with no contrast agent injected,
wherein the method further comprises:
generating a plurality of projection images based on the received image data from the X-ray system;
generating a 3D mask image of the object and at least the portion of the endovascular device based on the plurality of generated projection images, the generated 3D mask image including a reconstruction of the endovascular devic

Assignees

• Meyer Andreas
• Schafer Sebastian
• Siemens Ag

Inventors

• Meyer Andreas
• Schafer Sebastian

Classifications

• A61B6/481

  involving the use of contrast agents · CPC title

• A61B6/12 Primary

  Arrangements for detecting or locating foreign bodies · CPC title

• A61B6/466

  adapted to display 3D data · CPC title

• A61B6/485

  involving fluorescence X-ray imaging · CPC title

• A61B6/5235

  combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT · CPC title