Type
Text
Type
Dissertation
Advisor
Button, Terry | Mujica-Parodi, Lilianne | Vaska, Paul | Caparelli, Elisabeth.
Date
2013-12-01
Keywords
Biomedical engineering | BOLD, fcMRI, functional connectivity, resting state, Simultaneous Multislice Acquisition, Social Anxiety Disorder
Department
Department of Biomedical Engineering.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76985
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Deciphering signal from noise is a pre-requisite for making any scientific observation. Regardless of the imaging modality, any successful attempt in improving the Signal-to-Noise Ratio (SNR) brings about a wave of applications. The use of multichannel array coils in functional and structural magnetic resonance imaging (MRI) provides increased SNR, higher sensitivity, and parallel imaging capabilities. However, their benefits remain to be systematically explored in the context of resting-state functional connectivity MRI (fcMRI). In this work, signal detectability within and between commercially available multichannel brain coils, a 32-Channel (32Ch), and a 12-Channel (12Ch) were compared at 3 Tesla, in a high-resolution regime (2 mm-isotropic) to accurately map resting-state networks. The findings demonstrate that although the 12Ch coil can be used to reveal resting-state connectivity maps, the 32Ch coil provides increased detailed functional connectivity maps in a number of widely reported resting-state networks. The exploration of subcortical networks, which are scarcely reported due to limitations in spatial-resolution and coil sensitivity, also proved beneficial with the 32Ch coil. This was extended to the clinical realm by collecting resting-state fcMRI data from medication naïve patients with Social Anxiety Disorder and healthy control participants. Subcortical resting state networks from mid-brain and cerebellum seeds were compared between the two groups. Significant hyper-connectivity was observed in the patient group as compared to controls in all the subcortical networks that were explored. In addition, comparisons regarding the data acquisition time required to successfully map resting state networks indicated that scan time can be significantly reduced by 50% when a coil with increased number of channels (i.e. | 32Ch) is used. Finally, the advantages of multichannel coils were explored with simultaneous multi-slice (SMS) acquisition scheme employing a range of repetition times (TR). Specifically, comparisons between 32Ch and 12Ch array coils revealed significant improvements in detecting functional connectivity maps at high temporal (TR=800 ms, SMS factor=7) and spatial resolutions. Switching to multichannel arrays in resting-state fcMRI could, therefore, provide both detailed functional connectivity maps and acquisition time reductions, which could further benefit imaging special subject populations, such as patients or pediatrics who have less tolerance in lengthy imaging sessions. | Deciphering signal from noise is a pre-requisite for making any scientific observation. Regardless of the imaging modality, any successful attempt in improving the Signal-to-Noise Ratio (SNR) brings about a wave of applications. The use of multichannel array coils in functional and structural magnetic resonance imaging (MRI) provides increased SNR, higher sensitivity, and parallel imaging capabilities. However, their benefits remain to be systematically explored in the context of resting-state functional connectivity MRI (fcMRI). In this work, signal detectability within and between commercially available multichannel brain coils, a 32-Channel (32Ch), and a 12-Channel (12Ch) were compared at 3 Tesla, in a high-resolution regime (2 mm-isotropic) to accurately map resting-state networks. The findings demonstrate that although the 12Ch coil can be used to reveal resting-state connectivity maps, the 32Ch coil provides increased detailed functional connectivity maps in a number of widely reported resting-state networks. The exploration of subcortical networks, which are scarcely reported due to limitations in spatial-resolution and coil sensitivity, also proved beneficial with the 32Ch coil. This was extended to the clinical realm by collecting resting-state fcMRI data from medication naïve patients with Social Anxiety Disorder and healthy control participants. Subcortical resting state networks from mid-brain and cerebellum seeds were compared between the two groups. Significant hyper-connectivity was observed in the patient group as compared to controls in all the subcortical networks that were explored. In addition, comparisons regarding the data acquisition time required to successfully map resting state networks indicated that scan time can be significantly reduced by 50% when a coil with increased number of channels (i.e. | 32Ch) is used. Finally, the advantages of multichannel coils were explored with simultaneous multi-slice (SMS) acquisition scheme employing a range of repetition times (TR). Specifically, comparisons between 32Ch and 12Ch array coils revealed significant improvements in detecting functional connectivity maps at high temporal (TR=800 ms, SMS factor=7) and spatial resolutions. Switching to multichannel arrays in resting-state fcMRI could, therefore, provide both detailed functional connectivity maps and acquisition time reductions, which could further benefit imaging special subject populations, such as patients or pediatrics who have less tolerance in lengthy imaging sessions. | 81 pages
Recommended Citation
Arnold Anteraper, Sheeba Rani, "Applications of Multichannel Brain Array Coils in Functional Neuroimaging" (2013). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2850.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2850