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Electrostatic interactions are important for the distribution of Gd(DTPA) 2− in articular cartilage
Author(s) -
Algotsson Jenny,
Forsman Jan,
Topgaard Daniel,
Söderman Olle
Publication year - 2016
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25889
Subject(s) - monte carlo method , gadolinium , charge density , magnetic resonance imaging , fixed charge , ionic bonding , chemistry , articular cartilage , charge (physics) , ion , statistical physics , physics , molecular physics , mathematics , statistics , radiology , medicine , pathology , osteoarthritis , alternative medicine , organic chemistry , quantum mechanics
Purpose The delayed gadolinium‐enhanced magnetic resonance imaging of cartilage (dGEMRIC) method can be used to assess the content of glycosaminoglycan in cartilage. In in vitro and model studies, the content of glycosaminoglycan is often expressed in terms of a fixed charge density (FCD). Values of the fixed charge density obtained using the dGEMRIC method differs from values obtained using other methods. The purpose of this work was to further clarify the origin of this discrepancy. Methods dGEMRIC experiments were performed in a μMRI setup on a custom‐designed, well‐defined model system capturing the relevant ionic features of cartilage. The model system allows for good control over and systematic variation of relevant parameters. The experimental data was compared with results from Monte Carlo simulations on a coarse‐grained model. Results Application of ideal Donnan theory on data obtained from experiments as well as simulations lead to underestimation of the fixed charge density, in agreement with previous studies. Conclusion To obtain more accurate estimates of the fixed charge density using the dGEMRIC method, interionic interactions need to be taken into account in the Donnan analysis. Furthermore, the results suggest that the combination of μMRI dGEMRIC experiments and Monte Carlo simulations are useful tools for an improved understanding of these effects. Magn Reson Med 76:500–509, 2016. © 2015 Wiley Periodicals, Inc.