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

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