Magnetic Resonance Imaging (MRI) has become a routine clinical procedure for the screening,
diagnosis and treatment monitoring of various clinical conditions. Although MRI has highly
desirable properties such as being completely non-ionizing and providing excellent soft tissue
contrast which has resulted in its widespread usage across the gamut of clinical applications,
it is limited by a slow data acquisition process. Several techniques have been developed over
the years that have considerably improved the speed of MRI but there is still a clinical need
to further accelerate MRI for many clinical applications. This thesis focuses on two recent
advances in MRI acceleration to reduce the overall patient scan time.
The first part of the thesis describes the development of a fast 3D neuroimaging methodology
that has been implemented in a clinical Magnetic Resonance (MR) sequence which was accelerated
using a combination of compressed sensing and sampling order optimization of acquired
measurements. This methodology reduced the overall scan time by more than 60% compared
to the normal scan time while also producing images of acceptable quality for clinical diagnosis.
The clinical utility of accelerated neuroimaging is demonstrated by conducting a healthy
volunteer study on eight subjects using this fast 3D MRI method. The results of the radiological
diagnostic quality assessments that were carried out on the accelerated human brain MR
images by four experienced neuroradiologists are presented. The results show that accelerated
MR neuroimaging retained sufficient clinical diagnostic value for certain clinical applications.
The second part of the thesis describes the development of an accelerated Cartesian sampling
scheme for a rapid quantitative MR method called Magnetic Resonance Fingerprinting (MRF).
This method was able to simultaneously generate quantitative multi-parametric maps such as
T1, T2 and proton density (PD) maps in a very short scan duration that is clinically acceptable.
The developed Cartesian sampling method using Echo Planar Imaging (EPI) is compared
with conventional spiral sampling that is generally used for MR fingerprinting. The ability of
novel iterative reconstruction techniques to improve the multi-parametric estimation accuracy
is also demonstrated. The results show that accelerated Cartesian MR fingerprinting can be an
alternative to conventional spiral MR fingerprinting
