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Updated: Jun 10, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Edited MRS is sensitive to changes in lactate concentration during inspiratory hypoxia
Richard A E Edden1, Ashley D Harris, Kevin Murphy
1Russell H Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland, USA. raee2@jhu.edu
Purpose:
To demonstrate the application of Mescher-Garwood (MEGA) point-resolved spectroscopy sequence (PRESS) editing to the detection of lactate in the brain at 3T and to investigate changes in lactate concentration associated with inspiratory gas challenges.
Materials And Methods:
Edited lactate measurements were made in six healthy volunteers while the subjects breathed normoxic (21% O(2)), hypoxic (12% O(2)), and hyperoxic (40% O(2)) gas mixtures. Lactate concentration was quantified relative to the unsuppressed water signal from the same volume.
Results:
Lactate concentration was elevated in all subjects during hypoxia in a highly significant fashion (mean increase = 39%; P = 0.0003). There was no significant change seen in hyperoxia.
Conclusion:
MEGA-PRESS editing at 3T is sufficiently sensitive to detect lactate in the healthy brain with good signal-to-noise ratio (SNR), and can be used to investigate changes in cerebral metabolism arising during inspiratory gas challenges.
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