Development of whole-heart myocardial perfusion magnetic resonance imaging
File(s)
Author(s)
Fair, Merlin John Casper
Type
Thesis or dissertation
Abstract
Myocardial perfusion imaging is of huge importance for the detection of
coronary artery disease (CAD), one of the leading causes of morbidity
and mortality worldwide, as it can provide non-invasive detection at the
early stages of the disease. Magnetic resonance imaging (MRI) can assess
myocardial perfusion by capturing the rst-pass perfusion (FPP) of a
gadolinium-based contrast agent (GBCA), which is now a well-established
technique and compares well with other modalities. However, current MRI
methods are restricted by their limited coverage of the left ventricle. Interest
has therefore grown in 3D volumetric \whole-heart" FPP by MRI, although
many challenges currently limit this. For this thesis, myocardial perfusion
assessment in general, and 3D whole-heart FPP in particular, were reviewed
in depth, alongside MRI techniques important for achieving 3D FPP. From
this, a 3D `stack-of-stars' (SOS) FPP sequence was developed with the aim
of addressing some current limitations. These included the breath-hold
requirement during GBCA rst-pass, long 3D shot durations corrupted by
cardiac motion, and a propensity for artefacts in FPP. Parallel imaging and
compressed sensing were investigated for accelerating whole-heart FPP, with
modi cations presented to potentially improve robustness to free-breathing.
Novel sequences were developed that were capable of individually improving
some current sequence limits, including spatial resolution and signal-to-noise
ratio, although with some sacri ces. A nal 3D SOS FPP technique was
developed and tested at stress during free-breathing examinations of CAD
patients and healthy volunteers. This enabled the rst known detection of an
inducible perfusion defect with a free-breathing, compressed sensing, 3D FPP
sequence; however, further investigation into the diagnostic performance is
required. Simulations were performed to analyse potential artefacts in 3D
FPP, as well as to examine ways towards further optimisation of 3D SOS
FPP. The nal chapter discusses some limitations of the work and proposes
opportunities for further investigation.
coronary artery disease (CAD), one of the leading causes of morbidity
and mortality worldwide, as it can provide non-invasive detection at the
early stages of the disease. Magnetic resonance imaging (MRI) can assess
myocardial perfusion by capturing the rst-pass perfusion (FPP) of a
gadolinium-based contrast agent (GBCA), which is now a well-established
technique and compares well with other modalities. However, current MRI
methods are restricted by their limited coverage of the left ventricle. Interest
has therefore grown in 3D volumetric \whole-heart" FPP by MRI, although
many challenges currently limit this. For this thesis, myocardial perfusion
assessment in general, and 3D whole-heart FPP in particular, were reviewed
in depth, alongside MRI techniques important for achieving 3D FPP. From
this, a 3D `stack-of-stars' (SOS) FPP sequence was developed with the aim
of addressing some current limitations. These included the breath-hold
requirement during GBCA rst-pass, long 3D shot durations corrupted by
cardiac motion, and a propensity for artefacts in FPP. Parallel imaging and
compressed sensing were investigated for accelerating whole-heart FPP, with
modi cations presented to potentially improve robustness to free-breathing.
Novel sequences were developed that were capable of individually improving
some current sequence limits, including spatial resolution and signal-to-noise
ratio, although with some sacri ces. A nal 3D SOS FPP technique was
developed and tested at stress during free-breathing examinations of CAD
patients and healthy volunteers. This enabled the rst known detection of an
inducible perfusion defect with a free-breathing, compressed sensing, 3D FPP
sequence; however, further investigation into the diagnostic performance is
required. Simulations were performed to analyse potential artefacts in 3D
FPP, as well as to examine ways towards further optimisation of 3D SOS
FPP. The nal chapter discusses some limitations of the work and proposes
opportunities for further investigation.
Version
Open Access
Date Issued
2017-09
Date Awarded
2017-12
Advisor
Gatehouse, Peter
Firmin, David
Sponsor
British Heart Foundation
Grant Number
FS/13/21/30143
Publisher Department
National Heart and Lung Institute
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)