Study of diffusion in erythrocyte suspension using internal magnetic field inhomogeneity

Lisitza, Natalia; Warren, W. S.; Song, Yi‐Qiao

doi:10.1016/j.jmr.2007.04.010

Cited by 8 publications

(7 citation statements)

References 59 publications

(108 reference statements)

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“…Natural magnetized particles were also examined (red blood cell suspensions [196,197] and samples of liver or ferritin [198]) to demonstrate and expand the different relaxation models mentioned above. Different environments, particle sizes, coating types, etc.…”

Section: Applications Of Magnetic Nanoparticlesmentioning

confidence: 99%

Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

Issa

Kim

Albiss

et al. 2013

IJMS

1,009

455

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Due to finite size effects, such as the high surface-to-volume ratio and different crystal structures, magnetic nanoparticles are found to exhibit interesting and considerably different magnetic properties than those found in their corresponding bulk materials. These nanoparticles can be synthesized in several ways (e.g., chemical and physical) with controllable sizes enabling their comparison to biological organisms from cells (10–100 μm), viruses, genes, down to proteins (3–50 nm). The optimization of the nanoparticles’ size, size distribution, agglomeration, coating, and shapes along with their unique magnetic properties prompted the application of nanoparticles of this type in diverse fields. Biomedicine is one of these fields where intensive research is currently being conducted. In this review, we will discuss the magnetic properties of nanoparticles which are directly related to their applications in biomedicine. We will focus mainly on surface effects and ferrite nanoparticles, and on one diagnostic application of magnetic nanoparticles as magnetic resonance imaging contrast agents.

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Section: Applications Of Magnetic Nanoparticlesmentioning

confidence: 99%

Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

Issa

Kim

Albiss

et al. 2013

IJMS

1,009

455

View full text Add to dashboard Cite

show abstract

“…The exchange rate in red blood cells has been determined using various independent methods such as diffusion NMR and the Kärger model [117, 122, 123], the Mn 2+ doping 1 H NMR method [124], and studies of diffusion using internal magnetic field inhomogeneity [125]. The different methods have provided similar results.…”

Section: Model Validation In Cell Suspensions and Excised Tissuementioning

confidence: 99%

The role of tissue microstructure and water exchange in biophysical modelling of diffusion in white matter

Nilsson

Westen

Ståhlberg

et al. 2013

Magn Reson Mater Phy

133

139

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Biophysical models that describe the outcome of white matter diffusion MRI experiments have various degrees of complexity. While the simplest models assume equal-sized and parallel axons, more elaborate ones may include distributions of axon diameters and axonal orientation dispersions. These microstructural features can be inferred from diffusion-weighted signal attenuation curves by solving an inverse problem, validated in several Monte Carlo simulation studies. Model development has been paralleled by microscopy studies of the microstructure of excised and fixed nerves, confirming that axon diameter estimates from diffusion measurements agree with those from microscopy. However, results obtained in vivo are less conclusive. For example, the amount of slowly diffusing water is lower than expected, and the diffusion-encoded signal is apparently insensitive to diffusion time variations, contrary to what may be expected. Recent understandings of the resolution limit in diffusion MRI, the rate of water exchange, and the presence of microscopic axonal undulation and axonal orientation dispersions may, however, explain such apparent contradictions. Knowledge of the effects of biophysical mechanisms on water diffusion in tissue can be used to predict the outcome of diffusion tensor imaging (DTI) and of diffusion kurtosis imaging (DKI) studies. Alterations of DTI or DKI parameters found in studies of pathologies such as ischemic stroke can thus be compared with those predicted by modelling. Observations in agreement with the predictions strengthen the credibility of biophysical models; those in disagreement could provide clues of how to improve them. DKI is particularly suited for this purpose; it is performed using higher b-values than DTI, and thus carries more information about the tissue microstructure. The purpose of this review is to provide an update on the current understanding of how various properties of the tissue microstructure and the rate of water exchange between microenvironments are reflected in diffusion MRI measurements. We focus on the use of biophysical models for extracting tissue-specific parameters from data obtained with single PGSE sequences on clinical MRI scanners, but results obtained with animal MRI scanners are also considered. While modelling of white matter is the central theme, experiments on model systems that highlight important aspects of the biophysical models are also reviewed.

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“…Some of these challenges can be resolved by modifying the surface of the particle by coating with organic or inorganic materials such as starch, dextran or polyethylene glycol (PEG) [23,24]. In addition to particles synthesized out of iron oxides, natural magnetized particles were also examined (red blood cell suspensions [25] and samples of liver or ferritin) to examine the different relaxation models mentioned below.…”

Section: Magnetic Nanoparticles (Mnp)mentioning

confidence: 99%

Magnetic Nanoparticles as MRI Contrast Agents

Issa¹,

Obaidat²

2019

Magnetic Resonance Imaging

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Magnetic Resonance Imaging (MRI) is a non-invasive imaging modality that offers both anatomical and functional information. Intrinsic longitudinal and transverse relaxation times (T 1 and T 2 , respectively) provide tools to manipulate image contrast. Additional control is yielded when paramagnetic and magnetic particulate materials are used as contrast materials. Superparamagnetic particles are mostly synthesized from iron oxide and are usually coated with polymers and functional particles to offer multifunctional biomedical applications. The latter include not only MRI but also cancer treatment through drug delivery and hyperthermia. This Chapter reviews the fundamental dipole-dipole diamagnetic proton relaxation mechanism dominant in water followed by a brief description of the use of gadolinium complexes as MRI contrast agent. Finally, a description of the important chemical and physical properties of magnetic nanoparticle (MNP) that define their use as MRI relaxation enhancing agents especially for T 2. The main governing models are described for the different motional regimes with few simulation results demonstrating the applicability of the given equations.

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Study of diffusion in erythrocyte suspension using internal magnetic field inhomogeneity

Cited by 8 publications

References 59 publications

Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

Magnetic Nanoparticles: Surface Effects and Properties Related to Biomedicine Applications

The role of tissue microstructure and water exchange in biophysical modelling of diffusion in white matter

Magnetic Nanoparticles as MRI Contrast Agents

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