Comparison of three reference methods for the measurement of intracellular pH using 31P MRS in healthy volunteers and patients with lymphoma.
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Date
2014-02-01Author
Rata, M
Giles, SL
deSouza, NM
Leach, MO
Payne, GS
Type
Journal Article
Metadata
Show full item recordAbstract
31P magnetic resonance spectroscopy (31P MRS) can measure intracellular pH (pHi) using the chemical shift difference between pH-dependent inorganic phosphate (Pi) and a pH-independent reference peak. This study compared three different frequency reference peaks [phosphocreatine (PCr), α resonance of adenosine triphosphate (αATP) and water (using 1H MRS)] in a cohort of 10 volunteers and eight patients with non-Hodgkin's lymphoma (NHL). Well-resolved chemical shift imaging (CSI) spectra were acquired on a 1.5T scanner for muscle, liver and tumour. The pH was calculated for all volunteers and patients using the available methods. The consistency of the resulting pH was evaluated. The direct Pi–PCr method was best for those spectra with a very well-defined PCr, such as muscle (pH=7.05 ± 0.02). In liver, the Pi–αATP method gave more consistent results (pH=7.30 ± 0.06) than the calibrated water-based method (pH=7.27 ± 0.11). In NHL nodes, the measured pH using the Pi–αATP method was 7.25 ± 0.12. Given that the measured range includes some biological variation in individual patients, treatment-related changes of the order of 0.1 pH units should be detectable.
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Subject
Humans
Lymphoma, Non-Hodgkin
Phosphates
Phosphorus Isotopes
Magnetic Resonance Spectroscopy
Sensitivity and Specificity
Reproducibility of Results
Hydrogen-Ion Concentration
Algorithms
Reference Values
Adult
Aged
Middle Aged
Female
Male
Research team
Magnetic Resonance
Language
eng
License start date
2014-02
Citation
NMR in biomedicine, 2014, 27 (2), pp. 158 - 162
Publisher
WILEY-BLACKWELL