Diffusion-Weighted Imaging of Bacteria Colonies in the STRAFI Plane

Carlton, K.J.; Halse, M.R.; Strange, John H.

doi:10.1006/jmre.1999.1959

Cited by 12 publications

(13 citation statements)

References 11 publications

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“…In 1996 Köpf, et al, realized this capability on biological tissue, performing diffusion measurements using a 50 T/m static gradient in the stray field of a superconducting 9.4 T magnet (58). Another stray field study by Carlton, et al, used an 18 T/m static gradient to measure bacteria concentrations (46). Bacteria are roughly a micron in diameter, similar to sub-cellular structures in tissue.…”

Section: Discussionmentioning

confidence: 99%

“…Signal at τ ≥ 1.8 ms is fit with the model for water restricted in spherical compartments in the limit of long τ (Eq. S5, solid black line) (17) incorporating the AXR=110 s −1 (46), estimating a radius R = 900 nm. The dotted black line extrapolates back to I/I0 = 0.2.…”

Section: Restricted Diffusion Measures Sub-micron Structuresmentioning

confidence: 99%

“…Surprisingly, an experiment dating back to the origins of MR (8,9), performed in a large static gradient field, can break this microstructural resolution limit (44). Low-cost, portable, bench-top, single-sided NMR devices with greater than 10 T/m static gradients (45) can probe submicron structures (46) that ordinarily cannot be resolved from larger microscale structures using state-of-the-art pulsed gradient MR systems with lower maximum gradient strengths (47). Displacement encoding within a static gradient field occurs by using radiofrequency (RF) pulses (8,9) to switch the "effective gradient" (11), allowing for diffusion encoding times as short as 100 µs (48).…”

Section: Introductionmentioning

confidence: 99%

“…Displacement encoding within a static gradient field occurs by using radiofrequency (RF) pulses (8,9) to switch the "effective gradient" (11), allowing for diffusion encoding times as short as 100 µs (48). This permits resolution of submicron structures that can contain rapidly exchanging water pools (46). The static gradient 1-D diffusion (49) and 2-D DEXSY (50) experiments can then be used to probe cellular and sub-cellular components and water exchange between them.…”

Section: Introductionmentioning

confidence: 99%

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Magnetic resonance measurements of cellular and sub-cellular membrane structures in live and fixed neural tissue

Williamson

Ravin

Benjamini

et al. 2019

Preprint

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We develop magnetic resonance (MR) methods for measuring real-time changes of tissue microstructure and membrane permeability of live and fixed neural tissue. Diffusion and exchange MR measurements are performed using the large static gradient produced by a single-sided permanent magnet. Using tissue delipidation methods, we show that water diffusion is restricted solely by lipid membranes. Most of the diffusion signal can be assigned to water in tissue which is far from membranes. The remaining 25% can be assigned to water restricted on length scales of roughly a micron or less, near or within membrane structures at the cellular, organelle, and vesicle levels. Diffusion exchange spectroscopy measures water exchanging between membrane structures and free environments at 100 s −1 . tissue microstructure|diffusion exchange spectroscopy | porous media | membrane permeability| NMR-MOUSE Correspondence: basserp@mail.nih.gov

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Section: Discussionmentioning

confidence: 99%

Section: Restricted Diffusion Measures Sub-micron Structuresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Magnetic resonance measurements of cellular and sub-cellular membrane structures in live and fixed neural tissue

Williamson

Ravin

Benjamini

et al. 2019

Preprint

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“…In particular, this method has been used to study protons in solid matter such as ice [8], resins [6] and polyacrylates [9] as well as in the interstitial phase of porous materials like cements [10,11] or ceramics [12]. Moreover, as in MRI, the gradient can be also used to encode the displacement of spins and measure diffusion coefficients [13,14].…”

Section: Introductionmentioning

confidence: 99%

Micrometer scale resolution of materials by stray-field Magnetic Resonance Imaging

Landeghem

Bresson

Blümich

et al. 2011

Journal of Magnetic Resonance

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As Magnetic Resonance Imaging devices are becoming more and more powerful, resolutions as small as 10 μm can now be obtained. But, this is only possible when systems with slow transverse relaxation rates, like living tissues, are investigated. In this case, the time available for gradients space-encoding is long, and high k values can be reached in the Fourier domain. However, numerous materials have fast relaxation rates, thus limiting the spatial resolution to a few hundreds of microns. The Stray Field Imaging technique has solved this problem by using a very high (typically 5000 G/cm) static gradient. Consequently, the trajectory in k space is accelerated and it is possible, in principle, to reach a micrometer resolution in a few hundreds of microseconds. Most of the time, however, only resolutions in the millimeter range can be achieved due to mispositioning of the sample within the static magnetic field. Here, we show that by finely mapping the magnetic field and precisely positioning the sample, it is possible with a standard spectrometer to reach a micrometer resolution even on very fast relaxing materials.

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The Diffusion Exchange Ratio (DEXR): A minimal sampling of diffusion exchange spectroscopy to probe exchange, restriction, and time-dependence

Cai,

Williamson,

Ravin

et al. 2024

Journal of Magnetic Resonance

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Diffusion-Weighted Imaging of Bacteria Colonies in the STRAFI Plane

Cited by 12 publications

References 11 publications

Magnetic resonance measurements of cellular and sub-cellular membrane structures in live and fixed neural tissue

Magnetic resonance measurements of cellular and sub-cellular membrane structures in live and fixed neural tissue

Micrometer scale resolution of materials by stray-field Magnetic Resonance Imaging

The Diffusion Exchange Ratio (DEXR): A minimal sampling of diffusion exchange spectroscopy to probe exchange, restriction, and time-dependence

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