# US 8,542,892 B2 · Method and apparatus for compensating for motion in an imaged object

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- Number: US 8,542,892 B2
- Document ID: US8542892B2
- Status: Granted
- Kind: B2
- Application number: 12/613,384
- Filed: 2009-11-05
- Published: 2011-05-05
- Granted: 2013-09-24
- Earliest claimed: 2009-11-05
- Assignees: General Electric Company
- Applicants: Gil Kovalski
- Inventors: Gil Kovalski
- Web page: https://patentgrep.com/patent/US8542892B2

## CPC

- G06T 7/33: using feature-based methods
- G06T 2207/10108: Single photon emission computed tomography [SPECT]
- G06T 2207/30004: Biomedical image processing
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL

## Abstract

A method and apparatus for compensating for motion in an imaged object are provided. The method includes obtaining nuclear medicine (NM) image data for an object acquired from an NM imaging system, wherein the NM image data includes single photon emission computed tomography (SPECT) image data. The method further includes performing resolution recovery on the NM image data. The method also includes reconstructing the resolution recovered NM image data into a plurality of subsets and morphing the reconstructed NM image data in at least one of the plurality of subsets. The method additionally includes normalizing the NM image data based on a magnitude of the morphing and summing the NM image data to generate an NM image compensated for motion of the object.

## Claims

### Claim 1

A method for compensating for motion in an imaged object, the method comprising:
obtaining nuclear medicine (NM) image data for an object acquired from an NM imaging system, the NM image data including single photon emission computed tomography (SPECT) image data;
performing resolution recovery on the NM image data;
reconstructing the resolution recovered NM image data into a plurality of subsets;
morphing the reconstructed NM image data in at least one of the plurality of subsets, wherein the plurality of subsets of reconstructed NM image data correspond to NM images of gated phases of a cardiac cycle and the morphing comprises registering the NM images in different subsets to a selected gated NM image in one of the subsets by modifying a portion of the NM images to match a portion of the selected gated NM image to provide a similar geometry and registration;
normalizing the NM image data based on a magnitude of the morphing; and
summing the NM image data to generate an NM image compensated for motion of the object.

### Claim 2 (depends on 1)

A method in accordance with claim 1 wherein the gating information corresponds to cardiac gates determined from electrocardiogram (ECG) information.

### Claim 3 (depends on 1)

A method in accordance with claim 1 wherein performing resolution recovery comprises extrapolating the NM data into a higher resolution image space.

### Claim 4 (depends on 1)

A method in accordance with claim 1 wherein the reconstruction comprises compensating for a detector response of the NM imaging system.

### Claim 5 (depends on 1)

A method in accordance with claim 1 further comprising reformatting the reconstructed NM images in each of the plurality of subsets to a common axis.

### Claim 6 (depends on 1)

A method in accordance with claim 1 further comprising defining image boundary control points based on the segmentation for use in the morphing.

### Claim 7 (depends on 1)

A method in accordance with claim 1 wherein the morphing comprises selecting a subset of NM image data as a reference subset and stretching the NM image data in the other subsets to match the reference subset.

### Claim 8 (depends on 7)

A method in accordance with claim 7 wherein the reference subset is an end diastole gated subset.

### Claim 9 (depends on 1)

A method in accordance with claim 1 wherein the normalizing comprises adjusting a photon count based on the magnitude of the morphing.

### Claim 10 (depends on 1)

A method in accordance with claim 1 further comprising reducing a resolution of the summed NM images to a resolution prior to performing the resolution recovery.

### Claim 11 (depends on 1)

A method in accordance with claim 1 wherein performing resolution recovering comprises increasing a voxel size of the NM image data.

### Claim 12 (depends on 1)

A method in accordance with claim 1 wherein the object comprises a heart and the morphing comprises matching myocardium shapes of the heart in different cardiac phases.

### Claim 13 (depends on 1)

A method in accordance with claim 1 wherein the object comprises a heart and the normalizing comprises applying a normalization factor that compensates for volume contraction of a myocardium of the heart, and wherein the normalization factor is applied prior to the summing.

### Claim 14 (depends on 1)

A method in accordance with claim 1 further comprising displaying the summed NM image concurrently with an NM image generated from the obtained NM image data.

### Claim 15 (depends on 1)

A method in accordance with claim 1, wherein the morphing comprises using a plurality of control points in the NM images to register the NM images in different subsets to the selected gated NM image in one of the subsets.

### Claim 16 (depends on 1)

A method in accordance with claim 1, wherein the NM images comprises images of a myocardium and the modifying comprises resizing the NM images of the myocardium to match the selected gated NM image of the myocardium.

### Claim 17 (depends on 1)

A method in accordance with claim 1, wherein the modifying comprises expanding a border of the NM images of the myocardium to match a border of the selected gated NM image of the myocardium.

### Claim 18 (depends on 1)

A method in accordance with claim 1, wherein the modifying comprises one of image resizing or image geometry matching.

### Claim 19 (depends on 1)

A method in accordance with claim 1, wherein the modifying comprises one of inflating or stretching.

### Claim 20 (depends on 1)

A method in accordance with claim 1, wherein the NM images comprise three-dimensional (3D) image slices and the normalizing comprises normalizing to a magnitude of the inflating or stretching.

### Claim 21 (depends on 1)

A method in accordance with claim 1, wherein the normalizing comprises compensating for counts in each of the morphed NM images based on a magnitude of the morphing by multiplying each of the NM images by a factor corresponding to an amount of the modifying.

### Claim 22

A method for reducing blurring in nuclear medicine (NM) cardiac images, the method comprising:
obtaining gated NM cardiac images including photon count information, the NM cardiac images including cardiac single photon emission computed tomography (SPECT) data;
morphing a count distribution of a plurality of phases of the gated NM cardiac images into a location of a selected one of the plurality of phases;
applying a normalization factor to the morphed gated NM cardiac images, the normalization factor based on an amount of heart contraction; and
summing the normalized gated NM cardiac images to generate an image of a heart having reduced blurring.

### Claim 23 (depends on 22)

A method in accordance with claim 22 wherein the selected one of the plurality of phases comprises an end diastole phase of the heart.

### Claim 24 (depends on 22)

A method in accordance with claim 22 wherein the morphing comprises matching myocardium shapes of the heart in each of the plurality if phases.

### Claim 25 (depends on 22)

A method in accordance with claim 22 further comprising extrapolating the gated NM cardiac images to generated resolution recovered NM images prior to morphing.

### Claim 26

An imaging system comprising:
a gantry having at least one imaging detector configured to acquire nuclear medicine (NM) image data of a patient including single photon emission computed tomography (SPECT) image data;
an electrocardiogram (ECG) processor module configured to acquired ECG gating information corresponding to the acquired NM image data of the patient; and
an image motion compensation module configured to morph the NM image data for each of a plurality of gates using resolution recovered image data, wherein the resolution recovered image data is reconstructed into a plurality of subsets, the plurality of subsets corresponding to NM images of gated phases of a cardiac cycle, and the image motion compensation module is further configured to normalize the NM image data based on a magnitude of the morphing and register the NM image data in different subsets to a selected gated NM image in one of the subsets by modifying a portion of the NM images to match a portion of the selected gated NM image to provide a similar geometry and registration.