Abstract:

        Objective    To explore anatomic relationship between normal eustachian tube and that of otitis media, through multi-plane reformation of the multi-slice helical CT (MSCT), and provide anatomic basis for clinical application. Methods   The Otitis media group consisted of 85 ears of 61 patients with otitis media. The control group consisted of 30 ears of 15 volunteers without symptoms of otitis media or abnormal findings in ET function tests. Both groups were scanned under MSCT, and then imaging data were reconstructed adopting multi-plane reformation. The bony part distance, the opening tubal distance, the closing tubal distance and the utility closing tubal distance were measured and compared in both groups.  Results   For control and otitis media groups, the diameters of pre-tympanic segment, of junctional portion of cartilaginous and bony, and the length of bony portion were (9.95±1.29) mm and (9.85±0.83) mm, (3.89±0.50)mm and (3.92±0.37) mm, (20.89±1.81)mm and (20.51±2.13) mm respectively. For static CT images, the length of open zone and occlusive zone were (10.99±0.87) mm and (8.50±0.55) mm, (36.90±6.73) mm and (42.26±7.19) mm respectively, however, the length of occlusive zone were (10.20±3.96) mm and (33.32±9.44) mm respectively for dynamic CT images. Conclusions  There are no significant differences of the length of bony portion between otitis media and the control groups. The occlusive zone is longer in otitis media group than that in control group (P<0.05) under the static CT, however, which is significantly longer in otitis media group than that in control under the dynamic CT.

Key words: Multi-slice helical computed tomography (MSCT), Multi-plane reformation (MPR), eustachian tube (ET), Otitis media