Abstract:

Objective　To understand occurrence of frontal sinus inflammation by investigating the imaging of 64 slice spiral CT on the frontal drainage type and anatomy of frontal recess of the distribution channel.　Methods　The CT images of 1355 cases of nasal sinus were anatomically observed and diagnosed of frontal sinusitis. All of them underwent thin-layer scanning and multi-planar reconstruction. The gasification frontal sinus were classified according to uncinate attachment site: attachment to the orbital wall, sieve plate and skull base were frontal sinus drainage type I, II and III. The anatomical characteristics and variation of the frontal recess air chamber were observed. The frontal recess gas room was classified according to the international frontal sinus anatomy classification ( IFAC ).   Results    A total of 1355 patients, 2582 sides of frontal sinus were gasified. There were 456 cases of frontal sinusitis of them. The incidence of inflammation in type II and III frontal sinus drainage channels was higher. Type I was different with type II and III with statistical significance (P<0.05). There was no significant difference between type II and III（P＞0.05）. The agger nasi cell (ANC) and supra bulla cell (SBC) were “permanent air chambers”. The incidence of inflammation was similar to the average incidence of frontal sinus inflammation. The rest of the types of frontal crypt air chamber had statistical significance for the incidence of frontal sinus inflammation（P<0.05）.   Conclusion  Both the variation of frontal sinus drainage channel and the gasification of frontal sinus recess gas room have important impact on the frontal sinus inflammation. High resolution CT scan and multi-planar reconstruction can clearly reflect the frontal sinus drainage around the channel variation and different type of gas room real anatomy.

Key words: Computer Tomography;　 Frontal sinus, 　Uncinate process, 　Inflammation