The use of pulmonary scintigraphy for endobronchial foreign bodies.

Pulmonary scintigraphy using 99mTc-MAA clearly demonstrated a perfusion defect in the entire left lung of an 11-month-old girl with endobronchial foreign body. Other initial examinations, including a chest roentgenogram, showed only minimal changes. Repeated pulmonary scintigraphy 24 hr after endoscopic removal of a peanut fragment from the left main stem bronchus demonstrated almost normal blood flow in the left lung. The well-known physiological explanation for diminished pulmonary blood flow due to endobronchial foreign bodies is as follows; alveolar hypoxia caused by hypoventilation due to bronchial check-valve obstruction leads to a pulmonary vasoconstriction with resultant diminution of the regional perfusion. Furthermore, the increase in alveolar pressure caused by bronchial check-valve obstruction may play a significant role in decreased pulmonary blood flow.