Feasibility of concurrent dual contrast enhancement using CEST contrast agents and superparamagnetic iron oxide particles.

TitleFeasibility of concurrent dual contrast enhancement using CEST contrast agents and superparamagnetic iron oxide particles.
Publication TypeJournal Article
Year of Publication2009
AuthorsGilad AA, van Laarhoven HWM, McMahon MT, Walczak P, Heerschap A, Neeman M, van Zijl PCM, Bulte JWM
JournalMagnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine
Volume61
Issue4
Pagination970-4
Date Published2009 Apr
Abstract

A major challenge for cellular and molecular MRI is to study interactions between two different cell populations or biological processes. We studied the possibility to simultaneously image contrast agents based on two different MRI contrast mechanisms: chemical exchange saturation transfer (CEST) and enhancement of T2 relaxation. Various amounts of superparamagnetic iron oxide (SPIO) nanoparticles were mixed with a fixed concentration (250 microM) of the CEST agent poly-L-lysine. T2 maps, CEST maps, and frequency-dependent saturation spectra were then measured. Color-coded overlay maps demonstrated the feasibility of concurrent dual contrast enhancement. We found that at concentrations lower than 5 microg(Fe)/mL both contrast agents can be imaged simultaneously. At higher concentrations, the iron-based agent can be used to "shut off" the signal arising from the CEST agent. These initial findings are a first step toward using dual CEST/T2 contrast imaging for studying multiple cellular or molecular targets simultaneously in vivo.

DOI10.1152/ajpcell.00277.2012
Alternate JournalMagn Reson Med