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Detecting pulmonary capillary blood pulsations using hyperpolarized xenon‐129 chemical shift saturation recovery (CSSR) MR spectroscopy
Author(s) -
Ruppert Kai,
Altes Talissa A.,
Mata Jaime F.,
Ruset Iulian C.,
Hersman F. William,
Mugler John P.
Publication year - 2016
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25794
Subject(s) - xenon , chemistry , nuclear magnetic resonance , saturation (graph theory) , lung , hyperpolarization (physics) , arterial blood , nuclear magnetic resonance spectroscopy , medicine , physics , mathematics , organic chemistry , combinatorics
Purpose To investigate whether chemical shift saturation recovery (CSSR) MR spectroscopy with hyperpolarized xenon‐129 is sensitive to the pulsatile nature of pulmonary blood flow during the cardiac cycle. Methods A CSSR pulse sequence typically uses radiofrequency (RF) pulses to saturate the magnetization of xenon‐129 dissolved in lung tissue followed, after a variable delay time, by an RF excitation and subsequent acquisition of a free‐induction decay. Thereby it is possible to monitor the uptake of xenon‐129 by lung tissue and extract physiological parameters of pulmonary gas exchange. In the current studies, the delay time was instead held at a constant value, which permitted observation of xenon‐129 gas uptake as a function of breath‐hold time. CSSR studies were performed in 13 subjects (10 healthy, 2 chronic obstructive pulmonary disease [COPD], 1 second‐hand smoke exposure), holding their breath at total lung capacity. Results The areas of the tissue/plasma and the red‐blood‐cell peaks in healthy subjects varied by an average of 1.7 ± 0.7 % and 15.1 ± 3.8 % , respectively, during the cardiac cycle. In 2 subjects with COPD these peak pulsations were not detectable during at least part of the measurement period. Conclusion: CSSR spectroscopy is sufficiently sensitive to detect oscillations in the xenon‐129 gas‐uptake rate associated with the cardiac cycle. Magn Reson Med 75:1771–1780, 2016. © 2015 Wiley Periodicals, Inc.