| 1. | Subtle changes , such as polyps in the early stages , can easily be identified . purulent secretions are seen streaming here from the maxillary sinus ostium posteriorally towards the nasopharynx . posteriorally , medial to the tail of the middle turbinate , the ostium of the sphenoid sinus may be identified 能很容易的发现类似早期息肉等微小的病变,还可以显示脓性分泌物从上颌窦口向后流向鼻咽部和后方的中鼻甲的后段和蝶窦的开口。 |