Methods and systems for emission computed tomography image reconstruction

Patent metadata

Field	Value
Publication number	US-10360724-B2
Application number	US-201715618425-A
Country	US
Kind code	B2
Filing date	Jun 9, 2017
Priority date	Dec 21, 2016
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

The present disclosure relates to a method and system for reconstructing an Emission Computed Tomography (ECT) image based on locally adaptive gating. ECT projection data relating to a subject may be obtained. The ECT projection data may correspond to a plurality of voxels in a reconstructed image domain. The ECT projection data may be divided into a plurality of frames. A plurality of intermediate images may be reconstructed according to the plurality of frames. A plurality of motion amplitudes of the plurality of voxels may be obtained based on the plurality of intermediate images. A plurality of gate numbers may be determined for the plurality of voxels based on the plurality of motion amplitudes of the plurality of voxels. A plurality of ECT images may be reconstructed based on the ECT projection data and the plurality of gate numbers.

First claim

We claim:

1. A method for reconstructing an Emission Computed Tomography (ECT) image implemented on at least one machine each of which has at least one processor and storage, the method comprising:
obtaining ECT projection data relating to a subject, the ECT projection data corresponding to a plurality of voxels in a reconstructed image domain;
dividing the ECT projection data into a plurality of frames;
reconstructing a plurality of intermediate images according to the plurality of frames;
obtaining a plurality of motion amplitudes of the plurality of voxels based on the plurality of intermediate images; and
determining, based on the plurality of motion amplitudes of the plurality of voxels, a plurality of gate numbers for the plurality of voxels; and
reconstructing a plurality of ECT images based on the ECT projection data and the plurality of gate numbers.

2. The method of claim 1 , wherein the obtaining ECT projection data comprises:
acquiring the ECT projection data using a single-bed whole-body PET scanner.

3. The method of claim 1 , wherein the ECT projection data are acquired in a whole field of view (FOV).

4. The method of claim 3 , wherein the whole field of view comprises a plurality of local VOIs, the gate numbers corresponding to at least two of the local VOIs are different.

5. The method of claim 3 , further comprising:
determining a gating area in the whole field of view based on the plurality of motion amplitudes of the plurality of voxels.

6. The method of claim 1 , wherein the plurality of intermediate images comprise a first image frame and a second image frame, the method further comprising:
determining the plurality of motion amplitudes of the plurality of voxels based on the first image frame and the second image frame.

7. The method of claim 6 , wherein the determining the plurality of motion amplitudes of the plurality of voxels based on the first image frame and the second image frame comprises:
registering the first image frame and the second image frame to obtain a plurality of 3D motion vectors; and
determining the plurality of motion amplitudes of the plurality of voxels based on the plurality of motion vectors.

8. The method of claim 7 , wherein the registering the first image frame and the second image frame to obtain a plurality of 3D motion vectors includes:
performing 2D image registration of the first image frame and the second image frame;
determining, for each spatial point, a 2D motion vector in a coronal plane and a 2D motion vector in a sagittal plane based on the registration; and
determining the plurality of 3D motion vectors based on the 2D motion vectors in a coronal plane and the 2D motion vectors in a sagittal plane.

9. The method of claim 7 , wherein the registering the first image frame and the second image frame includes performing 3D image registration, the method further comprising:
estimating the plurality of 3D motion vectors based on the 3D image registration.

10. The method of claim 6 , wherein
the first image frame corresponds to a first involuntary motion phase of the subject,
the second image frame corresponds to a second involuntary motion phase of the subject, and
the first involuntary motion phase and the second involuntary motion phase correspond to an end-inspiration and an end-expiration of the subject, respectively, or the first involuntary motion phase and the second involuntary motion phase correspond to an end-diastolic phase and an end-systolic phase of the subject, respectively.

11. A system comprising:
at least one processor; and
storage for storing instructions, the instructions, when executed by the at least one processor, causing the system to perform a method including
obtaining ECT projection data relating to a subject, the ECT projection data corresponding to a plurality of voxels in a reconstructed image domain;
dividing the ECT projection data into a plurality of frames;
reconstructing a plurality of intermediate images according to the plurality of frames;
obtaining a plurality of motion amplitudes of the plurality of voxels based on the plurality of intermediate images; and
determining, based on the plurality of motion amplitudes of the plurality of voxels, a plurality of gate numbers for the plurality of voxels; and
reconstructing a plurality of ECT images based on the ECT projection data and the plurality of gate numbers.

12. The system of claim 11 , further comprising a total-body PET scanner.

13. The system of claim 11 , further comprising a display device configured to receive an input regarding a gating area of the subject.

14. The system of claim 11 , wherein the ECT projection data are acquired in a whole field of view (FOV).

15. The system of claim 14 , wherein the whole field of view comprises a plurality of local VOIs, the gate numbers corresponding to at least two of the local VOIs are different.

16. The system of claim 14 , wherein the system is caused to perform the method further including:
determining a gating area in the whole field of view based on the plurality of motion amplitudes of the plurality of voxels.

17. The system of claim 11 , wherein the plurality of intermediate images comprise a first image frame and a second image frame, and the system is caused to perform the method further including:
determining the plurality of motion amplitudes of the plurality of voxels based on the first image frame and the second image frame.

18. The system of claim 17 , wherein the determining the plurality of motion amplitudes of the plurality of voxels based on the first image frame and the second image frame includes:
registering the first image frame and the second image frame to obtain a plurality of 3D motion vectors; and
determining the plurality of motion amplitudes of the plurality of voxels based on the plurality of motion vectors.

19. The system of claim 17 , wherein
the first image frame corresponds to a first involuntary motion phase of the subject,
the second image frame corresponds to a second involuntary motion phase of the subject, and
the first involuntary motion phase and the second involuntary motion phase correspond to an end-inspiration and an end-expiration of the subject, respectively, or the first involuntary motion phase and the second involuntary motion phase correspond to an end-diastolic phase and an end-systolic phase of the subject, respectively.

Assignees

• Uih America Inc

Inventors

• Feng Tao
• Wang Jizhe
• Li Hongdi

Classifications

• G06T12/10

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• G06T2211/412

  Dynamic · CPC title

• G06T2210/41

  Medical · CPC title

• A61B6/5264

  due to motion · CPC title

• G06T17/20 Primary

  Finite element generation, e.g. wire-frame surface description, {tesselation} · CPC title