The pulsed ultrasound method adapted for examination of paranasal sinuses.

Three different ultrasonic display systems for examination of paranasal sinuses (oscilloscope; light emitting diodes; gas discharge display) have been evaluated in model experiments, on healthy subjects and in clinical materials. With the three different ultrasonic display systems air could be separated from other types of sinusal contents in model experiments. The detectable amount of saline solution in normal sinuses was 1-5 ml with all display units. The different display units showed the same screening capacity as radiography. The oscilloscope display system was significantly more efficient than the other display systems in separating different pathological conditions. Also regarding radiography the oscilloscope display was significantly more efficient in detecting secretion, but no difference was found in the capacity of predicting intrasinusal cysts. Thus, the oscilloscope display seems to be the most useful for both clinical and scientific purposes.