[The clinical application of spiral CT virtual endoscopy of middle ear]

To explore the clinical application of CT virtual endoscopy (CTVE) of ossicular chain in middle ear, and to establish the accurate method of observing ossicular chain and middle ear anatomy.

Volume scanning with spiral CT unit was performed in forty normal cases without illness of ear. Endoscopic 3D processing was carried out on a separate workstation equipped with a flying through program. From three isolated points(A, B and C), ear drum and ossicles were observed with CTVE method. The status of auditory ossicles connection were focused.

In CTVE via A, B and C points, the indication rates of the malleus, the indus, the drum cape, the canalis facialis horizontal section, and the prominence of horizontal semicircular canals were prosperously 100%. The indication rates of round window and the fenestra ovalis were 90%, 93%, 98% via A, B and C points respectively. And the indication rates of complete demonstration of ear ossicles were 100%, 95%, 93%, respectively.

With appropriate approach, CTVE has advantage of showing ear ossicles and their connections, which is a good supplement of routine CT.