Image artifact reduction for fast magnetic resonance imaging
Abstract/Contents
- Abstract
- Magnetic resonance imaging (MRI) is a rich source for diagnostic information. It has the ability to obtain excellent soft-tissue contrast at a very high spatial resolution. The imaging process of this modality can be conveniently described as a linear system with Fourier encoding. However, to increase flexibility and robustness, imaging techniques are used that cause basic assumptions of this model to fall apart. As a result, image artifacts arise, decreasing the clinical quality of the scans. More sophisticated methods that take these effects into account must be considered. Many of the errors reside in both the spatial and frequency domain, so simple linear solutions do not suffice. Two sources of image artifacts are investigated: (1) concomitant gradient field and field inhomogeneity and (2) nonrigid motion in free-breathing acquisitions. Each image-artifact source has specific effects which are dependent on the application. For real-time cardiac imaging with spiral k-space trajectories, concomitant gradient field and field inhomogeneity errors result in image blurring. Two fast and practical solutions are developed and applied to real-time cardiac studies and high-resolution cardiac studies. MRI is also a compelling choice for imaging pediatric patients as they are highly susceptible to risks of ionizing radiation of computed tomography and nuclear scintigraphy studies. However, this imaging modality is highly sensitive to motion. The motion can result in destructive image artifacts. To enable free-breathing volumetric exams, novel data acquisition strategies and image reconstruction techniques are developed to compensate for nonrigid respiratory motion. These methods are demonstrated in select pediatric patient studies. Image artifacts fromrespiratory motion are reduced from the free-breathing abdominal scans.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Cheng, Joseph Yitan |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Pauly, John (John M.) |
| Thesis advisor | Pauly, John (John M.) |
| Thesis advisor | Nishimura, Dwight George |
| Thesis advisor | Vasanawala, Shreyas |
| Advisor | Nishimura, Dwight George |
| Advisor | Vasanawala, Shreyas |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Joseph Yitan Cheng. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Joseph Yitan Cheng
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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