Motion Detection and Correction in Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a non-invasive technique used to produce high-quality images of the interior of the human body. Compared to other imaging modalities, however, MRI requires a relatively long data acquisition time to form an image. Patients often have difficulty staying still durin...

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Bibliographic Details
Main Author: Maclaren, Julian Roscoe
Language:en
Published: University of Canterbury. Electrical and Computer Engineering 2008
Subjects:
MRI
FSE
Online Access:http://hdl.handle.net/10092/1220
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spelling ndltd-canterbury.ac.nz-oai-ir.canterbury.ac.nz-10092-12202015-03-30T15:28:56ZMotion Detection and Correction in Magnetic Resonance ImagingMaclaren, Julian RoscoeMRIFSETRELLISmotion correctionimage processingMagnetic resonance imaging (MRI) is a non-invasive technique used to produce high-quality images of the interior of the human body. Compared to other imaging modalities, however, MRI requires a relatively long data acquisition time to form an image. Patients often have difficulty staying still during this period. This is problematic as motion produces artifacts in the image. This thesis explores the methods of imaging a moving object using MRI. Testing is performed using simulations, a moving phantom, and human subjects. Several strategies developed to avoid motion artifact problems are presented. Emphasis is placed on techniques that provide motion correction without penalty in terms of acquisition time. The most significant contribution presented is the development and assessment of the 'TRELLIS' pulse sequence and reconstruction algorithm. TRELLIS is a unique approach to motion correction in MRI. Orthogonal overlapping strips fill k-space and phase-encode and frequency-encode directions are alternated such that the frequency-encode direction always runs lengthwise along each strip. The overlap between pairs of orthogonal strips is used for signal averaging and to produce a system of equations that, when solved, quantifies the rotational and translational motion of the object. Acquired data is then corrected using this motion estimation. The advantage of TRELLIS over existing techniques is that k-space is sampled uniformly and all collected data is used for both motion detection and image reconstruction. This thesis presents a number of other contributions: a proposed means of motion correction using parallel imaging; an extension to the phase-correlation method for determining displacement between two objects; a metric to quantify the level of motion artifacts; a moving phantom; a physical version of the ubiquitous Shepp-Logan head phantom; a motion resistant data acquisition technique; and a means of correcting for T2 blurring artifacts.University of Canterbury. Electrical and Computer Engineering2008-09-07T23:03:07Z2008-09-07T23:03:07Z2007Electronic thesis or dissertationTexthttp://hdl.handle.net/10092/1220enNZCUCopyright Julian Roscoe Maclarenhttp://library.canterbury.ac.nz/thesis/etheses_copyright.shtml
collection NDLTD
language en
sources NDLTD
topic MRI
FSE
TRELLIS
motion correction
image processing
spellingShingle MRI
FSE
TRELLIS
motion correction
image processing
Maclaren, Julian Roscoe
Motion Detection and Correction in Magnetic Resonance Imaging
description Magnetic resonance imaging (MRI) is a non-invasive technique used to produce high-quality images of the interior of the human body. Compared to other imaging modalities, however, MRI requires a relatively long data acquisition time to form an image. Patients often have difficulty staying still during this period. This is problematic as motion produces artifacts in the image. This thesis explores the methods of imaging a moving object using MRI. Testing is performed using simulations, a moving phantom, and human subjects. Several strategies developed to avoid motion artifact problems are presented. Emphasis is placed on techniques that provide motion correction without penalty in terms of acquisition time. The most significant contribution presented is the development and assessment of the 'TRELLIS' pulse sequence and reconstruction algorithm. TRELLIS is a unique approach to motion correction in MRI. Orthogonal overlapping strips fill k-space and phase-encode and frequency-encode directions are alternated such that the frequency-encode direction always runs lengthwise along each strip. The overlap between pairs of orthogonal strips is used for signal averaging and to produce a system of equations that, when solved, quantifies the rotational and translational motion of the object. Acquired data is then corrected using this motion estimation. The advantage of TRELLIS over existing techniques is that k-space is sampled uniformly and all collected data is used for both motion detection and image reconstruction. This thesis presents a number of other contributions: a proposed means of motion correction using parallel imaging; an extension to the phase-correlation method for determining displacement between two objects; a metric to quantify the level of motion artifacts; a moving phantom; a physical version of the ubiquitous Shepp-Logan head phantom; a motion resistant data acquisition technique; and a means of correcting for T2 blurring artifacts.
author Maclaren, Julian Roscoe
author_facet Maclaren, Julian Roscoe
author_sort Maclaren, Julian Roscoe
title Motion Detection and Correction in Magnetic Resonance Imaging
title_short Motion Detection and Correction in Magnetic Resonance Imaging
title_full Motion Detection and Correction in Magnetic Resonance Imaging
title_fullStr Motion Detection and Correction in Magnetic Resonance Imaging
title_full_unstemmed Motion Detection and Correction in Magnetic Resonance Imaging
title_sort motion detection and correction in magnetic resonance imaging
publisher University of Canterbury. Electrical and Computer Engineering
publishDate 2008
url http://hdl.handle.net/10092/1220
work_keys_str_mv AT maclarenjulianroscoe motiondetectionandcorrectioninmagneticresonanceimaging
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