Chemical shift of 129 Xe dissolved in red blood cells: Application to a rat model of bronchopulmonary dysplasia

• Published in: Magnetic resonance in medicine Vol. 84; no. 1; pp. 52 - 60
• Main Authors: Friedlander, Yonni, Zanette, Brandon, Lindenmaier, Andras, Sadanand, Siddharth, Li, Daniel, Stirrat, Elaine, Couch, Marcus, Kassner, Andrea, Jankov, Robert P, Santyr, Giles
• Format: Journal Article
• Language: English
• Published: United States 01.07.2020
• Subjects: Animals; Bronchopulmonary Dysplasia; Erythrocytes; Humans; Hyperoxia; Infant, Newborn; Lung; Rats; Rats, Sprague-Dawley; Xenon; dissolved xenon; rat model; chemical shift; bronchopulmonary dysplasia; 129Xe
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.28121

To measure the chemical shift of hyperpolarized Xe dissolved in the red blood cells(δ ) of a cohort of rats exposed to hyperoxia and intermittent hypoxia (IH) to mimic human bronchopulmonary dysplasia, and to investigate the effect of xenon-blood distribution time on δ . δ was measured from spectra acquired using a chemical shift saturation recovery sequence from 15 Sprague-Dawley rats exposed to hyperoxia-IH and 10 age-matched control rats. Sensitization to the xenon-blood distribution time was achieved by varying the time between saturation pulses, τ. δ was compared with blood fraction measured by histology of the cohort and blood oxygenation measured directly using pulse oximetry following a hypoxic challenge in an identically exposed cohort. The mean δ in the hyperoxia-IH exposed rats was 0.55 ± 0.04 ppm lower than that of the healthy cohort (P = .0038), and this difference did not depend on τ (P = .996). The blood fraction of the exposed cohort was lower than that of the healthy cohort (P = .0397). Oximetry measurements showed that the baseline arterial oxygen saturation (S O ) of each cohort was not different (P = .72), but after a hypoxic challenge, the S O of the exposed cohort was lower than that of the healthy cohort (P = .003). δ is reduced in rats exposed to hyperoxia-IH compared with control rats. The change in δ is consistent with enhanced blood oxygen desaturation of the exposed cohort measured by pulse oximetry during a hypoxic challenge. This suggests that the observed change in δ reflects enhanced desaturation in the hyperoxia-IH exposed cohort compared with the healthy cohort.