MOTION CORRECTION OF SPECT IMAGES

• US 20120326034A1
• Filed: 06/21/2011
• Published: 12/27/2012
• Est. Priority Date: 06/21/2011
• Status: Active Grant

• Current Assignee: GE Medical Systems Israel, Ltd
• Original Assignee: General Electric Company
• Inventors: Sachs, Jonathan, Volokh, Lana, Hefetz, Yaron
• Granted Patent: US 8,421,021 B2
• Time in Patent Office: Days
• US Class Current: 250/336.1
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 2211/412 Dynamic
• CPC Class Codes: G06T 2211/424 Iterative

Abstract

The present disclosure relates approaches for removing or reducing the effects of motion in parallel and non-parallel data acquisitions using a nuclear medicine imaging system. In certain embodiments, translation vectors are derived based on a registration performed on transaxial slices generated from the acquired projection data. The translation vectors may be employed to update a system matrix such that images generated using the updated system matrix are free or motion artifacts or have reduced motion artifacts.

Claims

1. An image reconstruction method, comprising the acts of:

acquiring a set of projection data at a plurality of views and time intervals with respect to an imaging volume;

reconstructing a plurality of slices based on the set of projection data and a system matrix associated with the acquisition of the set of projection data;

registering the slices to generate a plurality of transformation vectors describing the translation in three-dimensional space for each time interval during the acquisition of the set of projection data;

determining one or more transformation vectors based on the act of registering the slices;

generating an updated system matrix based on the one or more transformation vectors and the associated time intervals; and

reconstructing a motion-corrected image using the updated system matrix.

2. The image reconstruction method of claim 1, wherein the set of projection data comprises a set of single photon emission computed tomography (SPECT) projection data.

3. The image reconstruction method of claim 1, wherein the set of projection data is acquired at a variety of view angles and time intervals with respect to the imaging volume.

4. The image reconstruction method of claim 1, wherein the system matrix describes one or both of a system geometry or time intervals at different imaging positions associated with the acquisition of the set of projection data.

5. The image reconstruction method of claim 1, wherein the slices comprise transaxial slices.

6. The image reconstruction method of claim 1, wherein registering the slices comprises registering the slices against a baseline or reference slice.

7. The image reconstruction method of claim 1, comprising combining elements where a translational offset is not determined to be present based on the act of registering the slices.

8. The image reconstruction method of claim 1, wherein the registration uses a translation of vector transformation.

9. The image reconstruction method of claim 1, wherein the updated system matrix corresponds to a two or more virtual detectors, each characterized by a position and an exposure time.

10. The image reconstruction method of claim 1, wherein the set of projection data is acquired using a non-parallel detector geometry.

11. The image reconstruction method of claim 10, wherein the non-parallel detector geometry is associated with one or more of a pin-hole camera, a convergently collimated detector, or a divergently collimated detector.

12. One or more machine readable media encoding routines that, when executed by a processor, cause acts to be performed comprising:

reconstructing a plurality of slices based on a set of projection data acquired at a plurality of views and time intervals and a system matrix associated with the acquisition of the set of projection data;

generating a plurality of transformation vectors describing the translation in three-dimensional space for each time interval during the acquisition of the set of projection data;

determining one or more translational offsets based on the plurality of transformation vectors; and

generating an updated system matrix that apply the translational offsets to one or more virtual detectors that correspond to different exposure times during the acquisition of the set of projection data.

13. The one or more machine readable media of claim 12, wherein the plurality of transformation vectors are generated based upon a registration operation performed on the plurality of slices.

14. The one or more machine readable media of claim 12, wherein the system matrix describes one or both of a system geometry or time intervals at different imaging positions associated with the acquisition of the set of projection data.

15. The one or more machine readable media of claim 12, wherein the one or more machine readable media encode routines that, when executed by a processor, cause acts to be performed comprising combining elements where a translational offset is not determined to be present.

16. An image analysis system, comprising:

one or more processing components configured to receive measured projections of an imaging volume acquired at different views and time intervals with respect to the imaging volume, and to execute one or more executable routines stored in a memory;

the memory storing the one or more executable routines, wherein the stored routines, when executed, reconstruct a plurality of slices based on the set of projection data and a system matrix associated with the acquisition of the set of projection data, register the slices to generate a plurality of transformation vectors describing the translation in three-dimensional space for each time interval during the acquisition of the set of projection data, and generate an updated system matrix based on the plurality of transformation vectors and corresponding time intervals; and

interface circuitry configured to allow user interaction with the image analysis system.

17. The image analysis system of claim 16, comprising:

one or more detector assemblies suitable for detecting radiation emitted from a patient, wherein the one or more detector assemblies detect non-parallel radiation emissions;

data acquisition circuitry configured to acquire signals from the one or more detector assemblies, wherein the measured projections are or are derived from the acquired signals.

18. The image analysis system of claim 17, wherein the one or more detector assemblies comprise pin-hole gamma cameras, convergently collimated detector assemblies, or divergently collimated detector assemblies.

19. The image analysis system of claim 17, comprising a positioner capable of moving the one or more detector assemblies with respect to the imaging volume.

20. The image analysis system of claim 16, wherein the registration uses a translation or vector transformation.