RESUMO
Objective To observe the opening movement of eustachian tube pharyngeal orifice in patients with secretory otitis media(SOM) by cine CT to mearsure the thickness of the lateral ET wall ,and to evaluate the roles played by those peri-tube structure in the pathogenesis of ET obstruction .Methods Twenty -seven SOM patients as experiment group underwent low -radiation dose cine CT scans of the ET ,the image were reconstructed into a cine image to see the opening movement of the eustachian tube pharyngeal orifice .The CT scan of sixty-four non-SOM patient as control group was performed .The images were reconstructed to show the relationship among the in‐ferior turbinate ,the nasopharyngeal soft tissue and the eustachian tube .These serial images were analyzed to meas‐uring the thickness of the lateral wall of ET cartilage segment and to find out whether the gas exist in the pharyngeal recess .Results The opening movement of the pharyngeal orifice was observed in 23 SOM patients ,the mean thick‐ness of the lateral wall of ET cartilage segment in ithe ears studied and healthy ears of SOM patients are 8 .93 ± 1 .6 mm and 8 .89 ± 1 .2 mm ,respectively ,much larger than those of in non-SOM patients ,but with no static signifi‐cance .The pharyngeal recess in 69 .0% (29/42) affected ears of som patients and 58 .3% (7/12) in healthy ears were gas free .This rate in som patients was significantly higher than that in the non-SOM patient group .Conclusion The etiologies of dysfunction of eustachian tube may include hypertrophic inferior turbinate ,chronic inflammation of eustachian tube mucosa ,compression of the nasal pharyngeal soft tissue .The compression of the nasal pharyngeal soft tissue may play an important role in the obstruction of the specific cartilage segment of the ET .