Motion Compensation in PET Reconstruction

• US 20080287772A1
• Filed: 05/15/2008
• Published: 11/20/2008
• Est. Priority Date: 05/18/2007
• Status: Abandoned Application

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Declerck, Jerome, Hakl, Kevin Scott
• Application Number:
  US12/121,245
• Publication Number:
  US 20080287772A1
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/5247 combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
• CPC Class Codes: A61B 6/5264 due to motion
• CPC Class Codes: A61B 6/527 using data from a motion artifact sensor
• CPC Class Codes: G01R 33/481 MR combined with positron emission tomography [PET] or single photon emission computed tomography [SPECT]
• CPC Class Codes: G01R 33/56509 due to motion, displacement or flow, e.g. gradient moment nulling G01R33/567 takes precedence
• CPC Class Codes: G01R 33/5676 Gating or triggering based on an MR signal, e.g. involving one or more navigator echoes for motion monitoring and correction

Abstract

Method and apparatus motion compensation in Positron Emission Tomography (PET) imaging. PET and Magnetic Resonance Imaging (MRI) are performed simultaneously and the latter is used to determine motion of the subject during the acquisition process. The PET image data are then corrected according to the subject motion so determined.

Claims

1. A method of correcting a set of PET data for movement of a subject during PET data acquisition, said method comprising the steps of:

simultaneously performing a PET scan and an MRI scan;

processing the results of the MRI scan to generate an MRI image and to determine motion of the subject during the scans and

correcting the data acquired from the PET scan for subject motion so detected.

2. A method according to claim 1 comprising the steps of:

acquiring MRI image data over a sequence of discrete time periods, T₀-T_n, during acquisition of the PET data, to produce a sequence of corresponding MRI datasets, D₀-D_n;

selecting an MRI dataset D₀, acquired over one of the time periods T₀ as a reference;

for each dataset, D₁, calculating a geometric transformation matrix M_i representing the change in subject position between those represented by D_i and D₀ respectively;

applying each matrix M_i to the PET data acquired during T_i to produce a set of corrected PET data and

reconstructing the corrected PET data to produce a set of PET images, corrected for movement of the subject during data acquisition.

3. A method according to claim 2, where the Geometric Transformation matrices are used, during reconstruction, to modify the Geometric value assigned to the probability of each event, associated with a particular pair of detector bins, occurring in a particular voxel.

4. A method according to claim 2, wherein the Geometric transformation matrices are used to reassign each event to a particular detector bin pair prior to image reconstruction.

5. Apparatus for correcting a set of PET data for movement of a subject during PET data acquisition comprising means for simultaneously performing a PET scan and an MRI scan on a subject and a processor arranged to:

receive data resulting from the PET and MRI scans;

process the data resulting from the MRI scan to determine movement of the subject during the scan and

correct the data resulting from the PET scan according to the movement so determined.