Universal phantom for calibration and verification of optical and radiation systems

Patent metadata

Field	Value
Publication number	US-12144671-B2
Application number	US-202117560005-A
Country	US
Kind code	B2
Filing date	Dec 22, 2021
Priority date	Dec 22, 2021
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

A universal phantom includes a first phantom and a second phantom. The first phantom comprises a plurality of radiation markers. The second phantom comprises a plurality of optical markers. The second phantom is fixedly attachable to the first phantom in a predetermined position. A calibration method employs a universal phantom to consolidate the tasks of determining the isocenter of a radiation machine, calibrating optical devices, and registering the optical devices in a radiation coordinate system with origin at the isocenter.

First claim

What is claimed is:

1. An apparatus, comprising:
a first phantom including a plurality of radiation markers; and
a second phantom including a plurality of optical markers, the second phantom being fixedly attachable to the first phantom in a position, the plurality of optical markers including a first optical marker and a second optical marker, and the first phantom being between the first optical marker and the second optical marker.

2. The apparatus of claim 1 , wherein the first phantom comprises a three-dimensional (3D) body, and the plurality of radiation markers are distributed in the 3D body.

3. The apparatus of claim 1 , wherein the second phantom comprises a board member having a planar surface, and the plurality of optical markers are in a two-dimensional (2D) pattern on the planar surface.

4. The apparatus of claim 3 , wherein the second phantom further comprises a plurality of radiation markers.

5. The apparatus of claim 3 , wherein a portion of the board member of the second phantom is radiation-transparent.

6. The apparatus of claim 1 , wherein
the second phantom comprises a modular unit; and
the second phantom is fixedly attachable to the first phantom, via the modular unit, in a first orientation and a second orientation, the second orientation being different from the first orientation.

7. The apparatus of claim 1 , wherein
the first phantom comprises a three-dimensional (3D) body, the plurality of radiation markers being distributed in the 3D body;
the second phantom comprises a board member having a planar surface, the plurality of optical markers being in a two-dimensional (2D) pattern on the planar surface; and
the second phantom is fixedly attachable to the 3D body of the first phantom, via the board member, in a first orientation and a second orientation, the second orientation being different from the first orientation.

8. The apparatus of claim 7 , wherein
a shape of the 3D body of the first phantom is at least one of a cylinder, a partial cylinder, or a cube;
the board member of the second phantom has a cut-out; and
a portion of the 3D body of the first phantom is in the cut-out of the board member.

9. The apparatus of claim 8 , wherein the second phantom further comprises a plurality of radiation markers.

10. The apparatus of claim 1 , further comprising:
a radiation machine comprising a source operable to produce radiation, the radiation including at least one of x-rays, protons, heavy ions, or electrons.

11. The apparatus of claim 10 , further comprising:
one or more optical devices.

12. The apparatus of claim 11 , further comprising:
a positioning device configured to
support the first phantom and the second phantom, and
move relative to the source such that a view of at least one of the one or more optical devices includes at least a portion of the first phantom or the second phantom.

13. The apparatus of claim 10 , wherein the radiation machine is configured to operate at a megavoltage energy level, and the source is configured to produce radiation for at least one of treatment or imaging.

14. The apparatus of claim 10 , wherein the radiation machine is operable at a kilovoltage energy level, and the source is configured to produce radiation for at least one of imaging or treatment.

15. A method of calibrating a system, the system including a radiation machine and one or more cameras, and the method comprising:
positioning a phantom device at an approximate isocenter of the radiation machine, the phantom device including a first phantom and a second phantom, the first phantom including a plurality of radiation markers, the second phantom including a plurality of optical markers, and the second phantom being fixedly attachable to the first phantom;
acquiring first images containing the plurality of radiation markers of the first phantom using radiation from the radiation machine;
determining a verified isocenter of the radiation machine using the first images;
defining a position of the first phantom in a first coordinate system, the first coordinate system having an origin at the verified isocenter;
defining a position of the second phantom in the first coordinate system based on a position of the second phantom relative to the first phantom;
calibrating the one or more cameras in a second coordinate system relative to the second phantom using second images containing the plurality of optical markers acquired with the one or more cameras; and
mapping a position of the one or more cameras to the first coordinate system.

16. The method of claim 15 , wherein the plurality of optical markers are in a two-dimensional (2D) pattern, and the second images contain the plurality of optical markers in the 2D pattern.

17. The method of claim 16 , wherein
the second phantom further comprises a plurality of radiation markers; and
the defining of the position of the second phantom in the first coordinate system includes verifying the position of the second phantom relative to the first phantom using the first images, the first images containing the plurality of radiation markers of the second phantom.

18. The method of claim 16 , wherein the calibrating of the one or more cameras comprises verifying intrinsic parameters of the one or more cameras using the second images.

19. The method of claim 15 , wherein
the radiation machine includes
a source operable at a megavoltage (MV) energy level, and
an image detector operable to acquire the first images using radiation from the source; and

the method further comprises:
determining an imaging isocenter between the source and the image detector using the first images, and
adjusting a position of the image detector in response to determining that the imaging isocenter is misaligned with the verified isocenter.

20. The method of claim 15 , wherein
the radiation machine includes
a source operable at a kilovoltage (kV) energy level, and
an image detector operable to acquire the first images using radiation from the source; and

the method further comprises:
determining an imaging isocenter between the source and the image detector using the first images, and
adjusting a position of the image detector in response to determining that the imaging isocenter is misaligned with the verified isocenter.

21. A non-transitory computer-readable medium storing executable instructions for calibrating a system, the system including a radiation machine and one or more cameras, the instructions, when executed by one or more processors, configuring the one or more processors to cause the system to:
position a phantom device at an approximate isocenter of the radiation machine, the phantom device including a first phantom and a second phantom, the first phantom including a plurality of radiation markers, the second phantom including a plurality of optical markers, and the second phantom being fixedly attached to the first phantom;
acquire first images containing the plurality of radiation markers of the first phantom using radiation from the radiation machine;
determining a verified isocenter of the radiation machine using the first images;
determine a position of the first phantom in a first coordinate system, the first coordinate system having an origin at the verified isocenter; and
define a position of the second phantom in the first coordinate system based on a position of the second phantom relative to the first phantom;
calibrate the one or more cameras in a second coordinate system

Assignees

• Varian Medical Systems Int Ag
• Siemens Healthineers Int Ag

Inventors

• Stamm Christian
• Scheib Stefan
• Kisrákói Andrea
• Meier Roland

Classifications

• A61N2005/1091

  Kilovoltage or orthovoltage range photons · CPC title

• A61N2005/1089

  Electrons · CPC title

• A61N2005/1087

  Ions; Protons · CPC title

• A61N2005/1076

  using a dummy object placed in the radiation field, e.g. phantom · CPC title

• A61N5/1075

  for testing, calibrating, or quality assurance of the radiation treatment apparatus · CPC title