QUESPOWR MRI: QUantification of Exchange as a function of Saturation Power On the Water Resonance

Edward A. Randtke, Mark "Marty" Pagel, Julio Cárdenas-Rodríguez

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

QUantification of Exchange as a function of Saturation Power On the Water Resonance (QUESPOWR) MRI is a new method that can estimate chemical exchange rates. This method acquires a series of OPARACHEE MRI acquisitions with a range of RF powers for the WALTZ16 pulse train, which are applied on the water resonance. A QUESPOWR plot can be generated from the power dependence of the % water signal, which is similar to a QUESP plot that is generated from CEST MRI acquisition methods with RF saturation applied off-resonance from water. A QUESPOWR plot can be quantitatively analyzed using linear fitting methods to provide estimates of average chemical exchange rates. Analyses of the shapes of QUESPOWR plots can also be used to estimate relative differences in average chemical exchange rates and concentrations of biomolecules. The performance of QUESPOWR MRI was assessed via simulations, an in vitro study with iopamidol, and an in vivo study with a mouse model of mammary carcinoma. The results showed that QUESPOWR MRI is especially sensitive to chemical exchange between water and biomolecules that have intermediate to fast chemical exchange rates and chemical shifts that are close to water, which are notoriously difficult to assess with other CEST MRI methods. In addition, in vivo QUESPOWR MRI detected acidic tumor tissues relative to normal tissues that are pH-neutral, and therefore may be a new paradigm for tumor detection with MRI.

Original languageEnglish (US)
Pages (from-to)56-70
Number of pages15
JournalJournal of Magnetic Resonance
Volume270
DOIs
StatePublished - Sep 1 2016

Fingerprint

Magnetic resonance imaging
saturation
Water
water
plots
Biomolecules
Tumors
acquisition
tumors
estimates
Iopamidol
Tissue
Chemical shift
mice
chemical equilibrium
Neoplasms
cancer
Breast Neoplasms
shift

Keywords

  • CEST MRI
  • OPARACHEE
  • QUESP
  • QUESPOWR
  • Tumor pH

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

QUESPOWR MRI : QUantification of Exchange as a function of Saturation Power On the Water Resonance. / Randtke, Edward A.; Pagel, Mark "Marty"; Cárdenas-Rodríguez, Julio.

In: Journal of Magnetic Resonance, Vol. 270, 01.09.2016, p. 56-70.

Research output: Contribution to journalArticle

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