Evaluation of eustachian tube function with ventilation scintigraphy by using 133Xe gas.

The aim of this study was to evaluate Eustachian tube function by ventilation scintigraphy. In 13 patients with normal tube function and 16 with one-sided tube dysfunction, 50 MBq 133Xe was applied into the nasopharyngeal space through a tube inserted into the nasal cavity. Immediately after the insufflation, the patients were asked to perform three Valsalva manoeuvres. The visualization of the middle ear was possible in 10 of the 13 patients (77 per cent) with normal tube function. Decreased uptake of the middle-ear region in the side of dysfunction was demonstrated in 11 of the 16 patients (68.7 per cent) with one-sided tube dysfunction. Quantitative evaluation by region of interest technique revealed that by using percentage retention of activity and uptake rates, there were significant differences between the sides of dysfunction and sides of normal tube function (p < 0.05) and also between sides of dysfunction and both sides of controls (p < 0.05). There was no significant differences between normal sides of patients and both sides of controls (p > 0.05). As a conclusion, this method is non-invasive, easy- to perform and has a low radiation burden in the evaluation of Eustachian tube function. Although the number of patients is limited, the test seems to be applicable with a success rate of about 74 per cent.