Measurement of paranasal sinus ventilation by xenon-enhanced dynamic computed tomography.

Ventilation of the paranasal sinuses plays an important role in the etiology of acute and chronic sinusitis. We present a new method to determine sinus ventilation. Two to three liters of pure stable xenon are insufflated into the sinus system, and the xenon washout is measured subsequently by dynamic CT. Gas exchange parameters for the different sinuses are obtained from the washout curves by an exponential fit. We report our preliminary clinical results. The method proved to be reliable and easy to apply. Compared with existing procedures it is the only noninvasive quantitative method for the determination of the ventilation of all paranasal sinuses.