CT lecture anatomy:
http://www.radiologytutorials.com/tutorial/show.cgi?sessionid=sessionid&Kd8LIo8=Kd8LIo8&s0sdfJg6d=s0sdfJg6d&tutorial=Petrous_bone_-_coronal&lang=en
Epitympanum, mesotympanum, hypotympanum, tymp sinus.