Unraveling diffusion constants in biological tissue by combining Carr‐Purcell‐Meiboom‐Gill imaging and pulsed field gradient NMR

Dusschoten, Dagmar van; Moonen, Chrit; Jager, P.A. de; As, Henk Van

doi:10.1002/mrm.1910360613

Cited by 83 publications

(89 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To obtain images of the H 2 O diffusion constants in mat samples, i.e., D s , we used either a so-called pulsed field gradient Carr-Purcell-Meiboom-Gill (PFG CPMG) sequence (van Dusschoten et al 1996) or a pulsed field gradient turbo spin echo (PFG TSE) sequence (Scheenen et al 1998). The PFG CPMG sequence enables the simultaneous determination of A 0 , T 2 , and diffusion at a set of echo times (van Dusschoten et al 1996), but one NMR imaging experiment in microbial mats takes about 2-3 h (usually consisting of 128 imaging steps ϫ 8 pulsed field gradients steps ϫ 2-8 averaging steps at a repetition time TR).…”

Section: Methodsmentioning

confidence: 99%

“…The PFG CPMG sequence enables the simultaneous determination of A 0 , T 2 , and diffusion at a set of echo times (van Dusschoten et al 1996), but one NMR imaging experiment in microbial mats takes about 2-3 h (usually consisting of 128 imaging steps ϫ 8 pulsed field gradients steps ϫ 2-8 averaging steps at a repetition time TR). The use of the PFG TSE sequence reduced the measuring time to 0.5-1 h in microbial mats.…”

Section: Methodsmentioning

confidence: 99%

“…Using this twodimensional fitting routine, the data were fitted to Eq. 3, assuming that molecules within one pixel element experienced a similar physical environment (see van Dusschoten et al 1996). The set of images obtained from the PFG TSE experiment was analyzed by fitting the data (in each pixel) to an equation describing the decay of the signal amplitude (as a function of diffusion, see second part of Eq.…”

Section: Methodsmentioning

confidence: 99%

“…An image consists of N ϫ N (here 128 ϫ 128) picture elements, so-called pixels. Single parameter images of, e.g., the nucleus density (amount of nuclei per pixel of defined volume) and diffusion coefficient can be obtained on a pixel by pixel basis (van Dusschoten et al 1996;Van As and van Dusschoten 1997;Edzes et al 1998).…”

Section: Acknowledgmentsmentioning

confidence: 99%

See 3 more Smart Citations

Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

Wieland¹,

Beer²,

Damgaard³

et al. 2001

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

Noninvasive 1 H-nuclear magnetic resonance (NMR) imaging was used to investigate the diffusive properties of microbial mats in two dimensions. Pulsed field gradient NMR was used to acquire images of the H 2 O diffusion coefficient, D s , and multiecho imaging NMR was used to obtain images of the water density in two structurally different microbial mats sampled from Solar Lake (Egypt). We found a pronounced lateral and vertical variability of both water density and water diffusion coefficient, correlated with the laminated and heterogeneous distribution of microbial cells and exopolymers within the mats. The average water density varied from 0.5 to 0.9, whereas the average water diffusion coefficient ranged from 0.4 to 0.9 relative to the values obtained in the stagnant water above the mat samples. The apparent water diffusivities estimated from NMR imaging compared well to apparent O 2 diffusivities measured with a diffusivity microsensor. Analysis of measured O 2 concentration profiles with a diffusion-reaction model showed that both the magnitude of calculated rates and the depth distribution of calculated O 2 consumption/production zones changed when the observed variations of diffusivity were taken into account. With NMR imaging, diffusivity can be determined at high spatial resolution, which can resolve inherent lateral and vertical heterogeneities found in most natural benthic systems.Diffusion is the predominant mode of solute mass transfer between bacteria and their surroundings and is also the major mechanism of solute transport in impermeable sediments,

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Acknowledgmentsmentioning

confidence: 99%

See 2 more Smart Citations

Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

Wieland¹,

Beer²,

Damgaard³

et al. 2001

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

show abstract

“…25 steps of the inversion recovery time between 750 s and 15 s were used to sample a T 1 relaxation decay curve. In the T 2 -D correlation measurement a diffusion-weighted multi-spin-echo pulse sequence [41] was used to determine the correlation between T 2 and the selfdiffusion coefficient of water in the peat samples. 25 gradient steps with a maximal gradient strength of 1.2 T m -1 were used.…”

Section: Swelling Kinetics At 5°c 19°c and 30°c By 1 H Nmr Measurementsmentioning

confidence: 99%

Proton NMR Relaxometry as a Useful Tool to Evaluate Swelling Processes in Peat Soils~!2009-07-26~!2009-12-04~!2010-06-15~!

Jaeger¹,

Shchegolikhina²,

As³

et al. 2010

TOMRJ

View full text Add to dashboard Cite

Dramatic physical and physico-chemical changes in soil properties may arise due to temperature and moisture variations as well as swelling of soil organic matter (SOM) under constant conditions. Soil property variations may influence sorption/desorption and transport processes of environmental contaminants and nutrients in natural-organic-matterrich soils. Notwithstanding the studies reported in literature, a mechanistic model for SOM swelling is unavailable yet. The objective of the present study was the evaluation of the swelling of peat soils, considered as SOM models, by 1 H NMR relaxometry and differential scanning calorimetry (DSC). Namely, information on the processes governing physical and physicochemical changes of peat during re-hydration were collected. The basic hypothesis of the present study was that the changes are slow and may affect water state as well as amounts of different water types into the peats. For this reason, such changes can be evidenced through the variations of mobility and thermal behaviour of the involved H 2 O molecules by using 1 H NMR relaxometry and DSC. According to the experimental results, a mechanistic model, describing the fundamental processes of peat swelling, was obtained. Two different peats re-wetted at three temperatures were used. The swelling process was monitored by measuring spin-spin relaxation time (T2) over a hydration time of several months. Moreover, DSC, T1 -T2 and T2 -D correlation measurements were done at the beginning and at the end of the hydration. Supplementary investigations were also done in order to discriminate between the swelling effects and the contributions from soil solution, internal magnetic field gradients and/or soil microorganisms to proton relaxation. All the results revealed peat swelling. It was evidenced by pore size distribution changes, volumetric expansion and redistribution of water, increasing amounts of nonfreezable and loosely bound water, as well as formation of gel phases and reduction of the translational and rotational mobility of H 2 O molecules. All the findings implied that changes of the physical and physicochemical properties of peats were obtained. In particular, three different processes having activation energies comprised in the interval 5 -50 kJ mol -1 were revealed. The mechanistic model which was, then, developed included water reorientation in bound water phases, water diffusion into the peat matrix and reorientation of SOM chains as fundamental processes governing SOM swelling. This study is of environmental significance in terms of re-naturation and re-watering of commercially applied peatlands and of sorption/desorption and transport processes of pollutants and nutrients in natural organic matter rich soils.

show abstract

1H-NMR study of water dynamics in hydrated collagen: Transverse relaxation-time and diffusion analysis

Traoré¹,

Foucat²,

Renou³

2000

Biopolymers

View full text Add to dashboard Cite

Water proton transverse relaxation times (T2) and self‐diffusion coefficients (D) were measured in randomly oriented hydrated collagen fibers. Three T2 relaxation times were discerned indicating the presence of at least three water fractions in the collagen sample. The D values associated with each water fraction were determined. The diffusion time dependence of D suggests water motion is restricted by macromolecular structure. The experimental results are discussed with reference to the structural properties of hydrated collagen fibers. © 2000 John Wiley & Sons, Inc. Biopoly 53: 476–483, 2000

show abstract

Unraveling diffusion constants in biological tissue by combining Carr‐Purcell‐Meiboom‐Gill imaging and pulsed field gradient NMR

Cited by 83 publications

References 27 publications

Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

Proton NMR Relaxometry as a Useful Tool to Evaluate Swelling Processes in Peat Soils~!2009-07-26~!2009-12-04~!2010-06-15~!

1H-NMR study of water dynamics in hydrated collagen: Transverse relaxation-time and diffusion analysis

Contact Info

Product

Resources

About