Method and system for X-ray image generation

Patent metadata

Field	Value
Publication number	US-9915864-B2
Application number	US-201715595527-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	Jul 23, 2013
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A method of creating an image including retrieving three-dimensional image data of an anatomy, retrieving a model of a portion of the anatomy, associating the model with the three-dimensional image data such that the model defines a bounded volume within the three-dimensional image data corresponding to the portion of the anatomy, and creating a virtual radiograph of the portion of the anatomy. Creating the virtual radiograph includes casting a plurality of rays from an origin point through the bounded volume, sampling, for each ray, the bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by a sampling distance, and calculating, for each ray, an accumulated attenuation value of the bounded volume along the ray based on the samples.

First claim

What is claimed is:

1. A method of creating an image, comprising:
retrieving three-dimensional image data of an anatomy;
retrieving a model of a portion of the anatomy;
associating the model with the three-dimensional image data such that the model defines a bounded volume within the three-dimensional image data corresponding to the portion of the anatomy; and
creating a virtual radiograph of the portion of the anatomy, wherein creating the virtual radiograph comprises:
casting a plurality of rays from an origin point through the bounded volume;
sampling, for each ray, the bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by a sampling distance; and
calculating, for each ray, an accumulated attenuation value of the bounded volume along the ray based on the samples.

2. The method of claim 1 , wherein the portion of the anatomy is a first portion of the anatomy, the model is a first model, and the bounded volume is a first bounded volume, the method further comprising:
retrieving a second model of a second portion of the anatomy, wherein the second portion of the anatomy is a subset of the first portion of the anatomy; and
associating the second model with the three-dimensional image data such that the second model defines a second bounded volume within the three-dimensional image data corresponding to the second portion of the anatomy, wherein the second bounded volume is a subset of the first bounded volume;
wherein creating the virtual radiograph further comprises:
casting a plurality of rays from the origin point through the second bounded volume;
sampling, for each ray, the second bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by the sampling distance;
calculating, for each ray, an accumulated attenuation value of the second bounded volume along the ray based on the samples; and
subtracting the accumulated attenuation values for the second bounded volume from the accumulated attenuation values for the first bounded volume.

3. The method of claim 2 , further comprising:
receiving a modification of the second model;
wherein creating the virtual radiograph further comprises:
modifying the accumulated attenuation values for the second bounded volume according to the modification of the second model; and
adding the modified accumulated attenuation values to the accumulated attenuation values for the first bounded volume.

4. The method of claim 3 , wherein the modification of the second model comprises at least one of a translation of the second model, a rotation of the second model, or a resection of the second model.

5. The method of claim 3 , wherein the modification of the second model is according to a preoperative plan.

6. The method of claim 1 , further comprising:
retrieving a model of an implant;
wherein creating the virtual radiograph further comprises:
selecting a view for the implant model;
determining a view-dependent thickness for the implant model;
calculating accumulated attenuation values for the implant model for the selected view, based on the view-dependent thickness; and
adding the accumulated attenuation values for the implant to the accumulated attenuation values for the bounded volume.

7. The method of claim 6 , wherein the implant is at least one component of a hip implant.

8. The method of claim 6 , wherein the accumulated attenuation values for the implant are added to the accumulated attenuation values for the bounded volume according to a preoperational plan.

9. The method of claim 1 , further comprising:
converting each accumulated attenuation value to a color; and
displaying an image of the virtual radiograph based the converted colors.

10. The method of claim 1 , wherein the model is a segmented bone model.

11. An image generation system, comprising:
an input/output interface;
a display coupled to the input/output interface; and
a processing circuit having a processor and a memory, the processing circuit configured to:
retrieve three-dimensional image data of an anatomy;
retrieve a model of a portion of the anatomy;
associate the model with the three-dimensional image data such that the model defines a bounded volume within the three-dimensional image data corresponding to the portion of the anatomy;
create a virtual radiograph of the portion of the anatomy, wherein creating the virtual radiograph comprises:
casting a plurality of rays from an origin point through the bounded volume;
sampling, for each ray, the bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by a sampling distance; and
calculating, for each ray, an accumulated attenuation value of the bounded volume along the ray based on the samples; and

display an image of the virtual radiograph on the display.

12. The system of claim 11 , wherein the portion of the anatomy is a first portion of the anatomy, the model is a first model, and the bounded volume is a first bounded volume, and wherein the processing circuit is further configured to:
retrieve a second model of a second portion of the anatomy, wherein the second portion of the anatomy is a subset of the first portion of the anatomy;
associate the second model with the three-dimensional image data such that the second model defines a second bounded volume within the three-dimensional image data corresponding to the second portion of the anatomy, wherein the second bounded volume is a subset of the first bounded volume; and
create the virtual radiograph of the first portion of the anatomy by:
casting a plurality of rays from the origin point through the second bounded volume;
sampling, for each ray, the second bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by the sampling distance;
calculating, for each ray, an accumulated attenuation value of the second bounded volume along the ray based on the samples; and
subtracting the accumulated attenuation values for the second bounded volume from the accumulated attenuation values for the first bounded volume.

13. The system of claim 12 , wherein the processing circuit is further configured to:
receive a modification of the second model; and
create the virtual radiograph by:
modifying the accumulated attenuation values for the second bounded volume according to the modification of the second model; and
adding the modified accumulation attenuation values to the accumulated attenuation values for the first bounded volume.

14. The system of claim 13 , wherein the modification of the second model comprises at least one of a translation of the second model, a rotation of the second model, or a resection of the second model.

15. The system of claim 11 , wherein the modification of the second model is according to a preoperative plan.

16. The system of claim 11 , wherein the processing circuit is further configured to:
retrieve a model of an implant; and
create the virtual radiograph by:
selecting a view for the implant model;
determining a view-dependent thickness for the implant model;
calculating accumulated attenuation values for the implant model for the selected view, based on the view-dependent thickness; and
adding the accumulated attenuation values for the implant to the accumulated attenuation values for the bounded volume.

17. The system of claim 16 , wherein the implant is at least one component of a hip implant.

18. The system of claim 16 , wherein the processing circuit is configured to add the accumul

Assignees

• Mako Surgical Corp

Inventors

• Ikits Milan

Classifications

• G09B23/286

  for scanning or photography techniques, e.g. X-rays, ultrasonics · CPC title

• G06T19/20

  Editing of three-dimensional [3D] images, e.g. changing shapes or colours, aligning objects or positioning parts · CPC title

• G06T2219/2016

  Rotation, translation, scaling · CPC title

• G03C2005/168

  X-ray material or process · CPC title

• G06T2210/41

  Medical · CPC title