Magnetization transfer prepared gradient echo MRI for CEST imaging

Zhuozhi Dai, Jim Ji, Gang Xiao, Gen Yan, Shengkai Li, Guishan Zhang, Yan Lin, Zhiwei Shen, Renhua Wu

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Chemical exchange saturation transfer (CEST) is an emerging MRI contrast mechanism that is capable of noninvasively imaging dilute CEST agents and local properties such as pH and temperature, augmenting the routine MRI methods. However, the routine CEST MRI includes a long RF saturation pulse followed by fast image readout, which is associated with high specific absorption rate and limited spatial resolution. In addition, echo planar imaging (EPI)-based fast image readout is prone to image distortion, particularly severe at high field. To address these limitations, we evaluated magnetization transfer (MT) prepared gradient echo (GRE) MRI for CEST imaging. We proved the feasibility using numerical simulations and experiments in vitro and in vivo. Then we optimized the sequence by serially evaluating the effects of the number of saturation steps, MT saturation power (B1), GRE readout flip angle (FA), and repetition time (TR) upon the CEST MRI, and further demonstrated the endogenous amide proton CEST imaging in rats brains (n = 5) that underwent permanent middle cerebral artery occlusion. The CEST images can identify ischemic lesions in the first 3 hours after occlusion. In summary, our study demonstrated that the readily available MT-prepared GRE MRI, if optimized, is CEST-sensitive and remains promising for translational CEST imaging.

Original languageEnglish
Article numbere112219
JournalPloS one
Volume9
Issue number11
DOIs
Publication statusPublished - 10 Nov 2014

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ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Cite this

Dai, Z., Ji, J., Xiao, G., Yan, G., Li, S., Zhang, G., Lin, Y., Shen, Z., & Wu, R. (2014). Magnetization transfer prepared gradient echo MRI for CEST imaging. PloS one, 9(11), [e112219]. https://doi.org/10.1371/journal.pone.0112219