Creatine mapping of the brain at 3T by CEST MRI

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

11 Scopus Citations
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Author(s)

  • Kexin Wang
  • Licheng Ju
  • Su Xu
  • Rao P. Gullapalli
  • Yajie Liang
  • Joshua Rogers
  • Yuguo Li
  • Peter C. M. van Zijl
  • Robert G. Weiss
  • Jiadi Xu

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)51-60
Journal / PublicationMagnetic Resonance in Medicine
Volume91
Issue number1
Online published9 Oct 2023
Publication statusPublished - Jan 2024

Abstract

Purpose: To assess the feasibility of CEST-based creatine (Cr) mapping in brain at 3T using the guanidino (Guan) proton resonance.
Methods: Wild type and knockout mice with guanidinoacetate N-methyltransferase deficiency and low Cr and phosphocreatine (PCr) concentrations in the brain were used to assign the Cr and protein-based arginine contributions to the GuanCEST signal at 2.0 ppm. To quantify the Cr proton exchange rate, two-step Bloch–McConnell fitting was used to fit the extracted CrCEST line-shape and multi-B1 Z-spectral data. The pH response of GuanCEST was simulated to demonstrate its potential for pH mapping.
Results: Brain Z-spectra of wild type and guanidinoacetate N-methyltransferase deficiency mice show a clear Guan proton peak at 2.0 ppm at 3T. The CrCEST signal contributes ∼23% to the GuanCEST signal at B1 = 0.8 μT, where a maximum CrCEST effect of 0.007 was detected. An exchange rate range of 200–300 s−1 was estimated for the Cr Guan protons. As revealed by the simulation, an elevated GuanCEST in the brain is observed when B1 is less than 0.4 μT at 3T, when intracellular pH reduces by 0.2. Conversely, the GuanCEST decreases when B1 is greater than 0.4 μT with the same pH drop.
Conclusions: CrCEST mapping is possible at 3T, which has potential for detecting intracellular pH and Cr concentration in brain.

© 2023 International Society for Magnetic Resonance in Medicine.

Research Area(s)

  • amideCEST, arginine CEST (ArgCEST), chemical exchange saturation transfer (CEST), concentration, creatine CEST (CrCEST), exchange rate, guanidino or guanidinium CEST (GuanCEST), high spectral resolution (HSR) CEST, pH mapping, polynomial Lorentzian line-shape fitting (PLOF), two-step Bloch–McConnell (BM) fitting

Citation Format(s)

Creatine mapping of the brain at 3T by CEST MRI. / Wang, Kexin; Huang, Jianpan; Ju, Licheng et al.
In: Magnetic Resonance in Medicine, Vol. 91, No. 1, 01.2024, p. 51-60.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review