Intralobar bronchopulmonary sequestration: evidence of air trapping shown by dynamic xenon-133 SPECT.

Dynamic single photon emission computed tomography with xenon-133 gas in a 29-year-old male patient showed xenon-133 retention within an intralobar bronchopulmonary sequestration (BPS) with a focal hyperlucent lung area on CT. Left lower lobectomy showed no fistulous connection between the anomalous and normal bronchial trees, but non-contiguous, incompletely developed visceral pleura between the sequestration and the adjacent normally ventilated lung. These features strongly support the role of intralobar collateral air drift and air trapping in producing secondary changes of a focal hyperlucent lung area in BPS.