Method and apparatus to detect and correct motion in list-mode PET data with a gated signal

Patent metadata

Field	Value
Publication number	US-9305377-B2
Application number	US-201113977030-A
Country	US
Kind code	B2
Filing date	Dec 22, 2011
Priority date	Jan 5, 2011
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A PET scanner ( 20, 22, 24, 26 ) generates a plurality of time stamped lines of response (LORs). A motion detector ( 30 ) detects a motion state, such as motion phase or motion amplitude, of the subject during acquisition of each of the LORs. A sorting module ( 32 ) sorts the LORs by motion state and a reconstruction processor ( 36 ) reconstructs the LORs into high spatial, low temporal resolution images in the corresponding motion states. A motion estimator module ( 40 ) determines a motion transform which transforms the LORs into a common motion state. A reconstruction module ( 50 ) reconstructs the motion corrected LORs into a static image or dynamic images, a series of high temporal resolution, high spatial resolution images.

First claim

The invention claimed is:

1. An imaging system comprising:
a list-mode memory which stores nuclear image data generated of a subject moving through a plurality of motion states in a list-mode;
a clock configured to mark the list-mode data with time stamps;
a motion sensor configured to sense motion states of the subject as the data is generated;
at least one processor programmed to perform the steps of:
sorting the stored list-mode data based on the motion state,
reconstructing the list-mode data sorted into each of the motion states into a high spatial resolution, low temporal resolution image, each high spatial resolution, low temporal resolution image being in a different one of the plurality of the motion states,
deriving from the high spatial resolution, low temporal resolution images transforms which transforms the list-mode data into one or more selected motion states, and
reconstructing the stored list-mode data transformed to the one or more selected motion state into a static image with a high temporal resolution and a high spatial resolution or reconstructing the list-mode data transformed into each of a plurality of motion states into a dynamic series of images with high temporal resolution and high spatial resolution.

2. The system according to claim 1 , wherein motion state includes at least one of motion phase and motion amplitude.

3. The system according to claim 1 , further including:
a positron emission scanner configured to generate PET nuclear image data;
a coincidence detector configured to find coincident detection data pairs to define lines of response (LORs), the lines of response and the time stamps being stored in the list-mode data memory.

4. The system according to claim 3 , further including:
a time-of-flight processor configured to analyze differences in arrival times of the two coincident events in the PET image data to localize a radiation decay event along each LOR.

5. The system according to claim 1 , further including:
an anatomical scanner configured to scan the subject to generate anatomical image data; and
wherein the at least one processor is further programmed to:
reconstruct the anatomical data into one or more anatomical images in the one or more selected motion states; and
generate an attenuation map in the one or more selected motion states; and
correct the list-mode data transformed into one of the selected motion states with the attenuation map in the one selected motion state during the reconstructing.

6. The system according to claim 1 , wherein:
the motion states of the subject sensed by the motion sensor as the data is generated is recorded with the concurrently generated nuclear data in the list-mode memory.

7. The system according to claim 3 , wherein the list-mode
memory is configured to store list-mode data for each LOR, the list-mode data for each LOR including the time stamp and a detected motion state.

8. The system according to claim 1 , wherein the monitored motion states of the subject sensed during generating of the nuclear image data are combined with the nuclear image data; and
wherein the list-mode memory is configured to store the combined nuclear image data with the sensed motion states.

9. An imaging method comprising:
time stamping generated functional nuclear data lines of response (LORs) generated as a subject moves through a plurality of motion states;
monitoring the motion states of the subject during generating of the functional nuclear data LORs;
storing the functional nuclear data LORs in a list-mode based on the time stamping, the stored functional data LORs including a corresponding motion state indicator;
generating a plurality of low temporal resolution motion phase images from the stored list-mode data, each of the plurality of motion phase images corresponding to one of the plurality of motion states;
from the plurality of motion phase images determining a motion model which models the plurality of motion states;
transforming the stored list-mode functional nuclear data LORs to a first selected motion state using the motion model;
reconstructing the list-mode functional nuclear data LORs transformed into the first selected motion state into a first high temporal and spatial resolution image.

10. The method according to claim 9 , further including:
selecting a second motion state;
transforming the stored list-mode functional nuclear data LOR into the second selected motion state;
reconstructing the list-mode functional nuclear data LORs transformed into the second motion state into a second high temporal and spatial resolution image, the second high temporal and spatial resolution image depicting the subject in the second selected motion state.

11. The method according to claim 9 , further including prior to generating the motion phase images, sorting the list-mode functional nuclear data LORs according to motion state:
identifying an amplitude and slope of a waveform corresponding to each motion state;
mapping the amplitude and slope to the waveform of the corresponding motion state; and
sorting the list-mode functional nuclear data LORs by motion state based on at least one of amplitude and slope.

12. The method according to claim 9 , further including:
generating an attenuation map of the subject in the first selected motion state; and
using the first selected state attenuation map to perform attenuation correction during the reconstructing of the list-mode functional nuclear data LORs into the first high temporal and spatial resolution image.

13. The method according to claim 9 , further including:
after determining the motion model, grouping the stored nuclear image data LORs into temporally contiguous LOR groups;
transforming each of the LOR groups into the first selected motion state;
reconstructing the transformed LOR groups into a series of temporally displaced high temporal and spatial resolution images in the first selected motion state.

14. A non-transitory computer-readable medium carrying software which controls one or more processors to perform the method according to claim 9 .

15. An imaging system comprising:
a functional scanner which generates the functional data; and
one or more processors programmed to perform the method according to claim 9 .

16. An imaging system comprising:
a PET scanner system configured to generate a plurality of time stamped lines of response (LORs) of a subject undergoing cyclic motion;
a motion detector configured to detect a motion state of the subject during acquisition of each of the LORs;
a list-mode memory configured to store each LOR in a list-mode including a time stamp and the detected motion state;
a sorting module configured to sort the stored LORs by motion state;
one or more reconstruction processors configured to reconstruct the LORs in each motion state into a high spatial, low temporal resolution image of the subject in the corresponding motion state;
a motion estimation module configured to determine a motion model from the high spatial, low temporal resolution images;
a motion correction module configured to transform the LORs into a common motion state;
a reconstruction module configured to reconstruct temporally contiguous LOR groups the LORs in the common motion state into a temporally spaced series of high temporal resolution, high spatial resolution images.

Assignees

• Olivier Patrick
• Perkins Amy
• Zhang Bin
• Tung Chi-Hua
• Koninkl Philips Nv

Inventors

• Olivier Patrick
• Perkins Amy
• Zhang Bin
• Tung Chi-Hua

Classifications

• G06T12/10 Primary

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

• G06T12/00 Primary

  Tomographic reconstruction from projections · CPC title

• G06T11/005

  Physics · mapped topic

• G06T2211/412

  Dynamic · CPC title

• G06T11/003 Primary

  Physics · mapped topic