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

Assaf A. Gilad, Hanneke W.M. Van Laarhoven, Michael T. Mcmahon, Piotr Walczak, Arend Heerschap, Michal Neeman, Peter C.M. Van Zijl, Jeff W.M. Bulte

Research output: Contribution to journalArticle


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 μM) 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 μg(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. Magn Reson Med 61:970-974, 2009.

Original languageEnglish (US)
Pages (from-to)970-974
Number of pages5
JournalMagnetic resonance in medicine
Issue number4
StatePublished - Apr 1 2009



  • CEST agent
  • Molecular imaging
  • Superparamagnetic iron oxide

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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