Abstract
Magnetic resonance imaging (MRI) is a versatile tool to image the human body. Among many of the advances achieved with MRI, one was the ability to work on the human brain and discover its functioning, as well as helping to improve diagnostic capabilities. However, clinical MR systems in today's hospital services have a limited image quality. Therefore, researchers have been working on increasing image quality.
One way to achieve better images in MRI is to increase the static magnetic field intensity, i.e., the magnet strength. Although the clinical standard MRI scanners have a magnet strength of 1.5 Tesla, researchers enabled human MR scanners up to 10.5 Tesla. However, a stronger magnetic field drives new challenges in the MR sensor design. One of the most commercially available sensor systems for head imaging at 7 Tesla MRI suffers from signal loss down to the neck. On the other hand, a new sensor, shielded-coaxial-cable coils (SCCs), has recently been given attention among MR researchers due to their flexibility in the placement on the human body. Although SCCs would be good candidates with their initial promise of flexible placement to extend the coverage of the head imaging at 7 Tesla MRI, researchers reported conflicting results on the working mechanism of SCCs.
In this thesis, we first clarified the ambiguity in the literature and explained the working mechanism of SCCs. Then, we explored the alternative configuration setups to improve the signal quality with SCCs. Finally, we extended the coverage of a commercially available sensor system with SCCs and achieved whole head and neck imaging at 7 Tesla MRI. The new sensor is easily adaptable to research systems worldwide, and we believe it has strong potential to widen the horizon of brain research.
One way to achieve better images in MRI is to increase the static magnetic field intensity, i.e., the magnet strength. Although the clinical standard MRI scanners have a magnet strength of 1.5 Tesla, researchers enabled human MR scanners up to 10.5 Tesla. However, a stronger magnetic field drives new challenges in the MR sensor design. One of the most commercially available sensor systems for head imaging at 7 Tesla MRI suffers from signal loss down to the neck. On the other hand, a new sensor, shielded-coaxial-cable coils (SCCs), has recently been given attention among MR researchers due to their flexibility in the placement on the human body. Although SCCs would be good candidates with their initial promise of flexible placement to extend the coverage of the head imaging at 7 Tesla MRI, researchers reported conflicting results on the working mechanism of SCCs.
In this thesis, we first clarified the ambiguity in the literature and explained the working mechanism of SCCs. Then, we explored the alternative configuration setups to improve the signal quality with SCCs. Finally, we extended the coverage of a commercially available sensor system with SCCs and achieved whole head and neck imaging at 7 Tesla MRI. The new sensor is easily adaptable to research systems worldwide, and we believe it has strong potential to widen the horizon of brain research.
Originalsprog | Engelsk |
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Forlag | DTU Health Technology |
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Status | Udgivet - 29 aug. 2024 |