Xenon diffusing capacity, a novel noninvasive technique of measuring gas exchange analogous to carbon monoxide diffusion capacity, was evaluated in a rat model of pnemonitis caused by intratracheal instillation of Stachybotrys chartarum spores.
The xenon diffusing capacity was defined analogously to the carbon monoxide diffusing capacity as the product of a gas transfer time or time constant of uptake into lung parenchyma (determined by hyperpolarized 129 Xenon dynamic spectroscopy) and alveolar volume(determined by hyperpolarized 129 Xenon magnetic resonance imaging). The xenon diffusing capacity was compared in a group of normal and diseased rats with histologically proven pneumonitis caused by intratracheal instillation of Stachybotrys chartarum spores.
The xenon diffusing capacity for lung parenchyma was significantly reduced in a group of 6 rats with pneumonitis caused by intratracheal instillation of Stachybotrys chartarum spores relative to a group of 6 normal rats(29+/-11 mL/min/mmHg and 66+/-10 mL/min/mmHg, p<0.05). Gas transfer times and lung volumes were significantly reduced for the diseased rats (22+/-3 ms and 11+/-2mL respectively)relative to normal rats (35+/-8 ms and 16 +/-2 mL respectively).
Xenon diffusing capacity is an effective at detecting gas exchange abnormalities on a millisecond time scale in a rat model of pneumonitits.These results support further evaluation of xenon diffusing capacity in characterization of experimental lung disease.
Xenon diffusing capacity quantifies gas exchange abnormalities on a much shorter (millisecond) time scale than the carbon monoxide diffusing capacity. The method may prove to be a useful adjunct to the carbon monoxide diffusing capacity in lung diseases charcaterized by a gas diffusion abnormalitities.
Nishard Abdeen, Product/procedure/technique that is considered research and is NOT yet approved for any purpose. Hyperpolarized 129 xenon spectroscopy and MR imaging.