Unilateral MRI using a rastered projection

Bray, Christina L.; Hornak, Joseph P.

doi:10.1016/j.jmr.2007.06.010

Cited by 8 publications

(5 citation statements)

References 30 publications

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“…The latter movement is obtained by a transmission belt driven by a dc motor that allows positioning of the magnet with an angular accuracy of 0.1 • . Such angular precision is necessary for the acquisition and reconstruction of 2D images from a set of 1D radial images of the sample [10]. We plan to extend the prototype capabilities with another mechanical support that allows 90 • magnet rotation to image surfaces perpendicular to the aluminium base.…”

Section: Magnet Construction and Testingmentioning

confidence: 99%

Design of an elliptical permanent magnet for surface magnetic resonance imaging

Ciarrocchi

Miccoli²,

Alecci

et al. 2008

Meas. Sci. Technol.

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Our aim is the construction of a general purpose portable device with possible applications in materials science, biology, environmental science and medicine. In this note, we present a new design of a hand-size elliptical permanent magnet suitable for unilateral NMR spectroscopy and one-dimensional (1D) MRI. We optimized the magnet configuration to get a penetration depth of up to 1 cm and 1D imaging capabilities.

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Section: Magnet Construction and Testingmentioning

confidence: 99%

Design of an elliptical permanent magnet for surface magnetic resonance imaging

Ciarrocchi

Miccoli²,

Alecci

et al. 2008

Meas. Sci. Technol.

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“…A structure constituted by two FCs placed antiparallel side by side forming a BC, which provided bigger sensitive volume for thin samples, was designed for the same portable scanner [8]. Bray et al [9] described the use of a 12.4 MHz-tuned multi-turn BC in a unilateral magnetic resonance imaging system, where both magnet and RF coil are on one side of the sample. Their approach utilized the stray field from a disk magnet and RF excitation from the BC for exciting and detecting a signal from spins located within a volume centred on a curved line through the sample.…”

Section: Introductionmentioning

confidence: 99%

“…A 15 MHz-tuned 7 cm diameter BC was used in a standalone surface MRI system for skin imaging, specifically designed for dermatologic investigation to depths of 1 cm. Phantom tomographic images were obtained by using the so-called "rastered backprojection" technique [14]. The same system was employed for MRI of materials used in organic light-emitting diodes (OLEDs) and liquid crystal displays (LCDs), in order to investigate their performance loss due to moisture egress [15].…”

Section: Introductionmentioning

confidence: 99%

Biot–Savart-Based Design and Workbench Validation at 100 MHz of Transverse Field Surface RF Coils

2023

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Radiofrequency (RF) surface coils are extensively used as receivers in magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) systems thanks to their high signal-to-noise ratio (SNR). For specific magnetic resonance applications, the design of dedicated RF surface coils with a transverse (to the coil’s plane) RF magnetic field pattern can be necessary. Such transverse-field RF coils are constituted by several central linear (parallel or crossing) conductor elements connected by return current paths. Typically, the outer shape of such RF coils is circular or squared, although other geometries can be used. This paper describes the implementation and validation of a transverse-field RF surface coil simulator based on magnetostatic analysis, which permits the design and optimization of square butterfly and figure-of-eight RF coils with adjustable size and mutual distance between the central linear current elements. The simulation results, compared with the ones provided by a standard square loop RF coil, were validated with 100 MHz workbench measurements performed on three home-built prototypes. Finally, two novel quadrature RF coil structures designed by overlapping two orthogonal square butterfly and figure-of-eight RF coils were simulated and theoretically characterized. The RF coils described here should be suitable for a wide range of MRI/MRS preclinical/clinical applications, mainly at fields below 3 T.

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“…Magnetic resonance sounding [7] is useful for finding aquifers and the R 1 value is often used to infer pore size. Near-surface magnetic resonance imaging [8,9] of hydrated soil may one day allow imaging of buried utilities. The signal from this technique is strongly dependent on the R 1 value of the hydrated soil.…”

Section: Introductionmentioning

confidence: 99%

A Possible Difference in the Surface Relaxivity of Costal and Inland Sands

Hornak¹

2010

TOMRJ

Self Cite

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The 1 H nuclear magnetic resonance (NMR) spin-lattice relaxation rate of hydrated sands is related to the surface-to-volume ratio of the voids or pores between the hydrated sand grains and the surface relaxivity of the grains. The electron spin resonance (ESR) signal is often used to predict the relative surface relaxivity as the surface relaxivity is thought to be proportional to the concentration of paramagnetic species in the sand grains. We have identified a discrepancy in the surface relaxivity and ESR signal of an ocean beach sand compared to two sands of similar diameter from inland deposits. This difference can either be due to more surface weathering of the inland sand or more paramagnetic material from seawater adhering to the ocean sand.

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Unilateral MRI using a rastered projection

Cited by 8 publications

References 30 publications

Design of an elliptical permanent magnet for surface magnetic resonance imaging

Design of an elliptical permanent magnet for surface magnetic resonance imaging

Biot–Savart-Based Design and Workbench Validation at 100 MHz of Transverse Field Surface RF Coils

A Possible Difference in the Surface Relaxivity of Costal and Inland Sands

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