Abstract #1290

Gereige J, Sun Y, Jacobson F, Mansour J, Butler J, Loring S, Ferrigno M, Albert M, Lindholm P

Pulmonary expansion at high lung volumes is believed to be homogeneous. However, there are no direct measurements in vivo of regional variations at high lung volumes. We studied regional lung ventilation differences using hyperpolarized 3He MRI. Images were obtained upon breath-hold after inhaling 1 liter of 3He at two different lung volumes: functional residual capacity (FRC) and total lung capacity (TLC). Our results show a sharp increase in ventilatory volume at TLC near the pericardial region of the lung. We believe this is caused by high regional compliance ratios, which may be due to this regions concave nature.