Radiotherapy method, computer program and computer system

• US 9,786,093 B2
• Filed: 12/16/2016
• Issued: 10/10/2017
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: RaySearch Laboratories AB (RaySearch Laboratories)
• Original Assignee: RaySearch Laboratories AB (RaySearch Laboratories)
• Inventors: Svensson, Stina
• Primary Examiner(s): ZALALEE, SULTANA MARCIA
• Application Number:
  US15/381,382
• Publication Number:
  US 20170178391A1
• Time in Patent Office: 298 Days
• Field of Search: None
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61N 5/103 Treatment planning systems
• CPC Class Codes: A61N 5/1039 using functional images, e.g. PET or MRI
• CPC Class Codes: G06T 11/003 Reconstruction from projections, e.g. tomography
• CPC Class Codes: G06T 15/20 Perspective computation
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics
• CPC Class Codes: G06T 19/20 Editing of 3D images, e.g. changing shapes or colours, aligning objects or positioning parts
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/10088 Magnetic resonance imaging [MRI]
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 2210/41 Medical
• CPC Class Codes: G06T 3/14 Transformations for image registration, e.g. adjusting or mapping for alignment of images
• CPC Class Codes: G06T 7/344 involving models
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A method of obtaining a 3D image of a part of a patient'"'"'s body is disclosed, based on a fraction image having a limited field-of-view and complementing this with information from a planning image having a greater field-of-view. In the area outside of the fraction image field-of-view, contour and anatomical data from the planning image are used to complement the fraction image, by means of a contour-guided deformable registration between the planning image and the fraction image.

Claims

1. A method of obtaining a 3D composite image of at least a first portion of a patient'"'"'s body, comprising the steps of:

obtaining a 3D planning image corresponding to the first portion of the patient'"'"'s body and having a first field-of-view,

obtaining a 3D fraction image of the first portion of the patient'"'"'s body, the fraction image having a second field-of-view which is limited in at least one dimension compared to the first field-of-view,

creating a model outline including at least one area of the patient'"'"'s body included in the first field-of-view but not in the second field-of-view,

appending the model outline to the fraction image, to include at least one outlined portion in the fraction image which is outside the second field-of-view to obtain an intermediate image,

performing a deformable registration between the outline of the planning image and the outline of the fraction image,

using the result of the deformable registration to include material information from the area in the planning image inside of the outlined portion in the intermediate image, to obtain a composite image.

2. A method according to claim 1, wherein a statistical shape model outline based on the planning image is used as the model outline, the method comprising the step of adapting the model outline to the fraction image.

3. A method according to claim 1, wherein a cost function based on a distance transform is used for adapting the model outline to the fraction image.

4. A method according to claim 1, comprising the step of performing a rigid registration between the planning image and the fraction image to determine an initial overlap between the model outline and the fraction image, before adapting the model outline to the fraction image.

5. A method according to claim 1, wherein the outlined portion is selected in such a way that the field-of-view of the composite image corresponds to the first field-of-view.

6. A method according to claim 1, wherein the planning image is an image of the patient, taken at an earlier point in time than the fraction image.

7. A method according to claim 1, wherein the 3D planning image is a CT image and the fraction image is a CT or CBCT image.

8. A method according to claim 1, wherein the planning image is an MRI image and the fraction image is an MRI image.

9. A method according to claim 1, wherein the material information includes density information, atomic composition and/or anatomical information.

10. A computer program product encoded in a non-transitory computer-readable medium for controlling a computer, said computer program product comprising computer-readable code arranged to cause the computer to perform the method according to claim 1.

11. A computer system comprising a processor, a data memory and a program memory, said data memory being arranged to hold at least one planning image and/or at least one fraction image and said program memory being arranged to hold a computer program product comprising computer-readable code that causes the computer to perform the method according to claim 1 when executed, in such a way that the computer program product can be used to control the processor.