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CEST, ASL, and magnetization transfer contrast : How similar pulse sequences detect different phenomena

Knutsson, Linda LU ; Xu, Jiadi ; Ahlgren, André LU and van Zijl, Peter C.M. (2018) In Magnetic Resonance in Medicine 80(4). p.1320-1340
Abstract

Chemical exchange saturation transfer (CEST), arterial spin labeling (ASL), and magnetization transfer contrast (MTC) methods generate different contrasts for MRI. However, they share many similarities in terms of pulse sequences and mechanistic principles. They all use RF pulse preparation schemes to label the longitudinal magnetization of certain proton pools and follow the delivery and transfer of this magnetic label to a water proton pool in a tissue region of interest, where it accumulates and can be detected using any imaging sequence. Due to the versatility of MRI, differences in spectral, spatial or motional selectivity of these schemes can be exploited to achieve pool specificity, such as for arterial water protons in ASL,... (More)

Chemical exchange saturation transfer (CEST), arterial spin labeling (ASL), and magnetization transfer contrast (MTC) methods generate different contrasts for MRI. However, they share many similarities in terms of pulse sequences and mechanistic principles. They all use RF pulse preparation schemes to label the longitudinal magnetization of certain proton pools and follow the delivery and transfer of this magnetic label to a water proton pool in a tissue region of interest, where it accumulates and can be detected using any imaging sequence. Due to the versatility of MRI, differences in spectral, spatial or motional selectivity of these schemes can be exploited to achieve pool specificity, such as for arterial water protons in ASL, protons on solute molecules in CEST, and protons on semi-solid cell structures in MTC. Timing of these sequences can be used to optimize for the rate of a particular delivery and/or exchange transfer process, for instance, between different tissue compartments (ASL) or between tissue molecules (CEST/MTC). In this review, magnetic labeling strategies for ASL and the corresponding CEST and MTC pulse sequences are compared, including continuous labeling, single-pulse labeling, and multi-pulse labeling. Insight into the similarities and differences among these techniques is important not only to comprehend the mechanisms and confounds of the contrasts they generate, but also to stimulate the development of new MRI techniques to improve these contrasts or to reduce their interference. This, in turn, should benefit many possible applications in the fields of physiological and molecular imaging and spectroscopy.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
arterial spin labeling, cerebral blood flow, CEST, chemical exchange, compartmental exchange, frequency selective, immobile proton pool, magnetization transfer contrast, mobile molecules, spatially selective
in
Magnetic Resonance in Medicine
volume
80
issue
4
pages
21 pages
publisher
Wiley Online Library
external identifiers
  • scopus:85051432204
  • pmid:29845640
ISSN
0740-3194
DOI
10.1002/mrm.27341https://doi.org/10.1002/mrm.27341
project
Natural sugar as an MRI contrast agent for cancer diagnosis
language
English
LU publication?
yes
id
d5a2de00-8047-4536-b1a5-f43d36817491
date added to LUP
2018-09-06 12:07:21
date last changed
2020-02-19 05:04:51
@article{d5a2de00-8047-4536-b1a5-f43d36817491,
  abstract     = {<p>Chemical exchange saturation transfer (CEST), arterial spin labeling (ASL), and magnetization transfer contrast (MTC) methods generate different contrasts for MRI. However, they share many similarities in terms of pulse sequences and mechanistic principles. They all use RF pulse preparation schemes to label the longitudinal magnetization of certain proton pools and follow the delivery and transfer of this magnetic label to a water proton pool in a tissue region of interest, where it accumulates and can be detected using any imaging sequence. Due to the versatility of MRI, differences in spectral, spatial or motional selectivity of these schemes can be exploited to achieve pool specificity, such as for arterial water protons in ASL, protons on solute molecules in CEST, and protons on semi-solid cell structures in MTC. Timing of these sequences can be used to optimize for the rate of a particular delivery and/or exchange transfer process, for instance, between different tissue compartments (ASL) or between tissue molecules (CEST/MTC). In this review, magnetic labeling strategies for ASL and the corresponding CEST and MTC pulse sequences are compared, including continuous labeling, single-pulse labeling, and multi-pulse labeling. Insight into the similarities and differences among these techniques is important not only to comprehend the mechanisms and confounds of the contrasts they generate, but also to stimulate the development of new MRI techniques to improve these contrasts or to reduce their interference. This, in turn, should benefit many possible applications in the fields of physiological and molecular imaging and spectroscopy.</p>},
  author       = {Knutsson, Linda and Xu, Jiadi and Ahlgren, André and van Zijl, Peter C.M.},
  issn         = {0740-3194},
  language     = {eng},
  number       = {4},
  pages        = {1320--1340},
  publisher    = {Wiley Online Library},
  series       = {Magnetic Resonance in Medicine},
  title        = {CEST, ASL, and magnetization transfer contrast : How similar pulse sequences detect different phenomena},
  url          = {http://dx.doi.org/10.1002/mrm.27341https://doi.org/10.1002/mrm.27341},
  doi          = {10.1002/mrm.27341https://doi.org/10.1002/mrm.27341},
  volume       = {80},
  year         = {2018},
}