Presentation
Left chronic otitis media for HRCT temporal bone evaluation to rule out underlying cholesteatoma.
Patient Data
Lateral projection of the sigmoid sinus posterior the mastoid air cells resulting in rarefaction of the right occipital calvarium, a finding incidentally detected in this plain HRCT of temporal bones.
Case Discussion
Sigmoid sinus wall dehiscence and diverticuli are a common etiology for pulsatile tinnitus especially when the wall dehiscence is seen anteriorly in relation to the mastoid temporal bone. One must keep in mind this anatomic variance as a differential when dealing with chronic inflammation of ear and mastoid that results in skull bone rarefaction.