Magnetic resonance angiography using non-Cartesian trajectories
Abstract/Contents
- Abstract
- Magnetic resonance imaging (MRI) is a versatile medical imaging modality that provides excellent soft-tissue contrast without ionizing radiation. Magnetic resonance angiography (MRA) is a type of MRI that is specifically aimed to image blood vessels, and is a powerful clinical tool for the diagnosis and management of arterial diseases. Various techniques can be used for MRA to produce bright blood signals while suppressing background signals such as muscle and fat. This dissertation describes two MRA methods that use non-Cartesian k-space trajectories to improve the contrast between the arterial signals and the background signals while achieving shorter scan times than conventional approaches. The ultimate goal of this work is to make MRA more clinically practical and reliable in terms of scan time and diagnostic image quality. The first method is a non-contrast-enhanced peripheral MRA sequence using a 3D concentric cylinders trajectory. The concentric cylinders are acquired in a sliding interleaved manner over a series of thin slabs. Concentric cylinders enable improved scan time efficiency while providing less noticeable artifacts from k-space amplitude modulation compared to a conventional Cartesian sequence. The thin-slab-scan nature of the proposed sequence and the centric-ordered sampling geometry of concentric cylinders are exploited to implement efficient fluid-suppression and parallel imaging approaches. In vivo experiments in healthy subjects and a patient with arterial stenosis demonstrate that the proposed method can provide improved artery-vein contrast even with slow arterial flow. The second method is a first-pass contrast-enhanced coronary MRA sequence using a 2D spiral-ring trajectory. In addition to the speed inherited from a regular spiral trajectory, the spiral-ring trajectory is capable of effectively capturing transient contrast generated by the first-pass contrast agent. The centric-ordered structure of the spiral-ring trajectory is exploited to efficiently generate time-resolved datasets, which makes the sequence more robust to the variation of the timing of contrast bolus and more flexible to capture different contrast fillings in different coronary branches. In vivo experiments in healthy subjects and patients demonstrate that the proposed method can provide improved blood-muscle contrast within a single breath-hold.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2015 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Kwon, Kie Tae |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Nishimura, Dwight George |
| Thesis advisor | Nishimura, Dwight George |
| Thesis advisor | Hu, Bob |
| Thesis advisor | Pauly, John (John M.) |
| Advisor | Hu, Bob |
| Advisor | Pauly, John (John M.) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Kie Tae Kwon. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by Kie Tae Kwon
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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