Method for creating a motion correction for PET data, a method for creating PET images as well as a correspondingly embodied MR system and PET system

Patent metadata

Field	Value
Publication number	US-10267884-B2
Application number	US-201414225824-A
Country	US
Kind code	B2
Filing date	Mar 26, 2014
Priority date	Mar 28, 2013
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A method is disclosed for creating a motion correction for PET data acquired by a PET system from a volume segment of an examination object. The method includes acquisition of MR data within the volume segment by the magnetic resonance system; and determination of a motion model of a motion within the volume segment as a function of the MR data. The motion model, as a function of a respective motion state of the motion, provides a correction specification for PET data which is acquired during this motion state. During acquisition of the MR data, specific MR data is acquired in the center of the k-space or of a straight-line segment which passes through the center of the k-space. The MR data determined is converted by a mathematical function into one value, as a function of which the respective motion state is determined.

First claim

What is claimed is:

1. A method for generating at least one positron emission tomography (PET) image based on a motion correction for PET data acquired by a PET system from a volume segment of an examination object, the method comprising:
acquiring magnetic resonance (MR) data within the volume segment via a magnetic resonance system, the acquiring including,
acquiring particular MR data along straight-line segments that pass through a center of a k-space and are disposed in layers parallel to one another, an angle between a first straight-line segment and a subsequent straight-line segment corresponding to a golden angle, each of the straight-line segments intersects with an axis which is at a right angle to each layer and passes through the center of the k-space, the acquiring the particular MR data acquires the particular MR data in each respective layer along straight-line segments having a same position in the layers, respectively, before acquiring the particular MR data along the subsequent straight-line segment;

obtaining the PET data;
determining a motion model of a motion within the volume segment as a function of the MR data, the motion model providing a correction specification for PET data acquired during a respective motion state as a function of the respective motion state of the motion, the determining the motion model including converting only the particular MR data by a mathematical function into one value and the respective motion state is determined as a function of the one value, only the particular MR data passing through the center of the k-space;
correcting the PET data using the motion model to generate the at least one PET image; and
generating the at least one PET image using the corrected PET data.

2. The method of claim 1 , wherein the mathematical function corresponds to an averaging of the particular MR data such that the value corresponds to an average value of the particular MR data.

3. A non-transitory computer readable medium including program code segments, when executed by a control device of a PET system, an MR system or a combined MR/PET device, cause the control device to perform the method of claim 2 .

4. The method of claim 1 , wherein the correcting includes,
generating an individual attenuation map as a function of the MR data for each respective motion state, the correcting of the PET data includes correcting the PET data acquired during the respective motion state with the individual attenuation map corresponding to the respective motion state; and
transforming the corrected PET data with the motion model into a same selected motion state.

5. The method of claim 1 , wherein the correcting includes,
reconstructing the PET data by integrating the motion correction by way of the motion model and an attenuation correction.

6. The method of claim 1 , further comprising:
acquiring a physiological signal of the examination object, and the correcting includes,
identifying a current motion state as a function of the physiological signal and performing the motion correction as a function of the current motion state.

7. The method of claim 1 , wherein the acquiring the MR data and the obtaining the PET data are performed simultaneously, and the correcting includes,
identifying a current motion state as a function of the MR data and performing motion correction of the PET data as a function of the current motion state.

8. A combined magnetic resonance (MR)/positron emission tomography (PET) system for creating PET images in a volume segment of an examination object, the combined MR/PET system comprising:
a control unit configured to activate a positron emission detector of the combined MR/PET system and receive measurement signals accepted by at least one receive coil element of the combined MR/PET system; and
an image processing unit configured to receive PET data of a volume segment acquired by the positron emission detector, configured to create the PET images from the PET data, and combine the PET images with MR images from MR data based on the measurement signals, wherein the combined MR/PET system is configured to perform the method of claim 1 .

9. A non-transitory computer readable medium storing computer readable instructions that, when executed by a control device of a PET system, an MR system or a combined MR/PET device, cause the control device to perform the method of claim 1 .

10. A magnetic resonance (MR) system for creating a motion correction for positron emission tomography (PET) data acquired by a PET system from a volume segment of an examination object, the magnetic resonance system comprising:
a basic field magnet;
a gradient field system;
at least one radio frequency (RF) antenna;
at least one receive coil element; and
a control device configured to activate the gradient field system and the at least one RF antenna, configured to receive measurement signals accepted by the at least one receive coil element and configured to evaluate the measurement signals and create MR data of the volume segment, wherein
the control device is configured to determine a motion model of a motion within the volume segment as a function of the MR data, wherein the motion model provides a correction specification for PET data acquired during a respective motion state as a function of the respective motion state of the motion, wherein the control device is configured to acquire particular MR data of the created MR data along straight-line segments which pass through a center of a k-space and are disposed in layers parallel to one another in order to convert only the particular MR data by a mathematical function into one value and to determine the respective motion state as a function of the one value, only the particular MR data passing through the center of the k-space, an angle between a first straight-line segment and a subsequent straight-line segment corresponding to a golden angle, each of the straight-line segments intersects with an axis which is at a right angle to each layer and passes through the center of the k-space, and the control device is configured to acquire the particular MR data by acquiring the particular MR data in each respective layer along straight-line segments having a same position in the layers, respectively, before acquiring the particular MR data along the subsequent straight-line segment.

11. A combined positron emission tomography (PET) and magnetic resonance (MR) system for creating at least one PET image in a volume segment of an examination object, the combined PET and MR system comprising:
a positron emission detector;
a control unit configured to activate the positron emission detector of the PET system; and
an image processing unit configured to receive PET data of a volume segment acquired by the positron emission detector and configured to create the PET images from the PET data, wherein the combined PET and MR system is configured to correct a motion within the volume segment with motion correction, created by,
acquiring MR data within the volume segment, the acquiring including, acquiring particular MR data along straight-line segments that pass through a center of a k-space and are disposed in lavers parallel to one another, an angle between a first straight-line segment and a subsequent straight-line segment corresponding to a golden angle, each of the straight-line segments intersects with an axis which is at a right angle to each layer and passes through the center of the k-space, the acquiring the particular MR data in each acquires the particular MR data in each respective layer along straight-line segments having a same position in the lavers, respectively, before acquiring the particular MR data

Assignees

• Siemens Ag
• Siemens Aktiengesellchaft

Inventors

• Bauer Simon
• Dregely Isabel
• Fürst Sebastian
• GRIMM Robert
• Kiefer Berthold
• Nickel Marcel Dominik

Classifications

• A61B5/0035

  adapted for acquisition of images from more than one imaging mode, e.g. combining MRI and optical tomography · CPC title

• A61B6/5247

  combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title

• A61B6/037

  Emission tomography · CPC title

• A61B2576/00

  Medical imaging apparatus involving image processing or analysis (A61B1/00009, A61B6/52 and A61B8/52 take precedence) · CPC title