Advances in Magnetic Resonance Phase‐Contrast Velocity Mapping

Phase-contrast MRI is used to assess functional flow parameters of the cardiovascular system. Long scan times of three-dimensional flow encoded MRI in particular have, however, hampered the acceptance of the method in a clinical routine setting. Furthermore, concerns have recently been raised about the limited accuracy of the technique. The present work focuses on these two limitations. Phase unsteadiness in fast phase-contrast sequences and its effect on flow quantitation is analysed and a modification to the sequence design is proposed. In a next step, system imperfections resulting from uncompensated eddy currents are studied using dynamic magnetic field monitoring demonstrating that mechanical vibrations can have a large impact on flow quantification. Approaches for background phase offset correction based on field monitoring data are discussed. To address the long scan times, dual slice excitation and spatiotemporally constrained image reconstruction are implemented to enable highly undersampled phase-contrast measurements. The successful application of these methods to three-dimensional phase-contrast MRI of congenital heart disease demonstrates clinical feasibility and robustness with great potential for future adaptation of the method in a routine setting.

Name dc:type.qualificationname

Doctor of Philosophy

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

King's College London

Year dc:date.issued

2012

Author dc:creator

• Giese, Daniel

Advisors dc:contributor.advisor

• Kozerke, Sebastian
• Schaeffter, Tobias Richard

Language dc:language

eng

Identifier

oai:kclpure.kcl.ac.uk:studenttheses/4c30f886-7860-4d4f-b0b4-02fdeb5136c1

OAI identifier oai:identifier

oai:kclpure.kcl.ac.uk:studenttheses/4c30f886-7860-4d4f-b0b4-02fdeb5136c1