Format

Send to:

Choose Destination
See comment in PubMed Commons below
Magn Reson Med. 2014 Dec;72(6):1746-54. doi: 10.1002/mrm.25064. Epub 2013 Dec 19.

Human whole-blood (1)H2O longitudinal relaxation with normal and high-relaxivity contrast reagents: influence of trans-cell-membrane water exchange.

Author information

  • 1Radiology, University of Washington, Seattle, Washington, USA.

Abstract

PURPOSE:

Accurate characterization of contrast reagent (CR) longitudinal relaxivity in whole blood is required to predict arterial signal intensity in contrast-enhanced MR angiography (CE-MRA). This study measured the longitudinal relaxation rate constants (R1 ) over a concentration range for non-protein-binding and protein-binding CRs in ex vivo whole blood and plasma at 1.5 and 3.0 Tesla (T) under physiologic arterial conditions.

METHODS:

Relaxivities of gadoteridol, gadobutrol, gadobenate, and gadofosveset were measured for [CR] from 0 to 18 mM [mmol(CR)/L(blood)]: the latter being the upper limit of what may be expected in CE-MRA.

RESULTS:

In plasma, the (1) H2 O R1 [CR]-dependence was nonlinear for gadobenate and gadofosveset secondary to CR interactions with the serum macromolecule albumin, and was well described by an analytical expression for effective 1:1 binding stoichiometry. In whole blood, the (1) H2 O R1 [CR]-dependence was markedly non-linear for all CRs, and was well-predicted by an expression for equilibrium exchange of water molecules between plasma and intracellular spaces using a priori parameter values only.

CONCLUSION:

In whole blood, (1) H2 O R1 exhibits a nonlinear relationship with [CR] over 0 to 18 mM CR. The nonlinearity is well described by exchange of water between erythrocyte and plasma compartments, and is particularly evident for high relaxivity CRs.

© 2013 Wiley Periodicals, Inc.

KEYWORDS:

MR angiography; MRI; contrast agents; relaxation rate constant; relaxation time constant

PMID:
24357240
[PubMed - indexed for MEDLINE]
PMCID:
PMC4470616
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Write to the Help Desk