Measurement of xenon diffusing capacity in the rat lung by hyperpolarized 129Xe MRI and dynamic spectroscopy in a single breath-hold

✍ Scribed by Nishard Abdeen; Albert Cross; Gregory Cron; Steven White; Thomas Rand; David Miller; Giles Santyr

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 460 KB
• Volume: 56
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.20943

✦ Synopsis

Abstract

We used the dual capability of hyperpolarized ^129^Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or D~LCO~) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath‐hold, the volume is measured by hyperpolarized ^129^Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma (D~LXeLP~)), xenon diffusing capacity in RBCs (D~LXeRBC~), and total lung xenon diffusing capacity (D~LXe~)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. D~LXeLP~, D~LXeRBC~, and D~LXe~ were 56 ± 10 ml/min/mmHg, 64 ± 35 ml/min/mmHg, and 29 ± 9 ml/min/mmHg, respectively, for normal rats, and 27 ± 9 ml/min/mmHg, 42 ± 27 ml/min/mmHg, and 16 ± 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP (T~trLP~) were 16 ± 2 ml and 22 ± 3 ms, respectively, for normal rats and 12 ± 2 ml and 35 ± 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.