High-resolution computed tomographic bronchiolography using perfluoroctylbromide (PFOB): an experimental model.

The use of perfluoroctylbromide (PFOB), a liquid ventilatory agent, was evaluated as a computed tomographic contrast agent to visualize small airway anatomy to the level of the centrilobular bronchiole, normally not visible on high-resolution computed tomography (HRCT). A freshly excised neonatal lamb heart-lung preparation was tracheally intubated, suspended in a saline bath, and mechanically ventilated with gas. After obtaining HRCT control images with suspended respiration using continuous positive airway pressure, 30 ml of perfluorocytlbromide was instilled into the trachea and repeat scans were obtained. These images demonstrated PFOB filling and distending the airways to the level of the centrilobular bronchioles and their first order branches. There was only minimal spillage into air spaces, allowing excellent anatomic detail of the bronchiolar structures. A liquid ventilatory agent, PFOB is a superb candidate as a bronchographic contrast agent due to its promotion of gas exchange, low toxicity, low surface tension, radiopacity, and vaporized excretion via the lung. It has great potential to evaluate small airway disease when used in conjunction with HRCT.