1. Unilateral MRI using a rastered projection
- Author
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Bray, Christina L. and Hornak, Joseph P.
- Subjects
- *
MEDICAL imaging systems , *ATOMS , *FIELD theory (Physics) , *GEOMAGNETISM , *MAGNETICS - Abstract
Abstract: Unilateral magnetic resonance techniques, where magnet and radio frequency (RF) coil are placed on one side of the sample, can provide valuable information about a sample which otherwise cannot be accommodated in conventional high spectral resolution magnetic resonance systems. A unilateral magnetic resonance imaging approach utilizing the stray field from a disc magnet and a butterfly geometry RF coil is described. The coil excites spins in a volume centered around an arc through the sample. Translating the RF coil relative to the magnet and recording the signal at each translational location creates a projection of the signal in a tomographic slice through the sample. Rotating the RF coil relative to the sample and repeating the translation creates projections through the sample at different angles. Backprojecting this information yields an image. A proof of concept device operating on this principle at 12.4MHz was constructed and characterized. Projections through three phantoms are presented with a 1.2–4cm field of view, thickness of 102μm, and at a distance of 3mm from the RF coil and 14mm from the magnet. The edge spread function (ESF) was measured resulting in a 4mm full width at half maximum (FWHM) line spread function (LSF) estimation using a Gaussian model. An example of one reconstructed image is presented. [Copyright &y& Elsevier]
- Published
- 2007
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