The incidence of petrous apex opacification on CT and MRI in the asymptomatic population

E. T. Gross, H. A. Brodie, W. R. Nemzek

Research output: Contribution to journalArticlepeer-review


Petrositis is an inflammatory process of the petrous apex that may occur in isolation but is primarily seen associated with acute or chronic otitis media Due to the advent of antibiotics, petrositis is now considered rare. Pneurnatization of the petrous pyramid may contribute to the development of petrositis. Symptoms include the triad of otorrhea, deep facial or retroorbital pain, and diplopia secondary to ipsi lateral abducens nerve paralysis (Gradenigo's syndrome), and may be accompanied by mild vertigo, transient facial nerve paralysis, and low grade intermittent fever. The diagnosis is confirmed by computed tomography (CT) or magnetic resonance imaging (MRI). We hypothesize that a significant number of asymptomatic individuals exist in the general population that exhibit similar petrous opacification on CT and MRI as those people afflicted with petrositis. By assessing a percentage of these individuals, we may be able to better diagnose patients referred for evaluation of petrositis. Out of 199 cases reviewed randomly, males and females of all ages, we found 48% of these displayed some form of pneumatization. Nine percent were mildly pneumatized bilaterally, 4.5% were moderate bilaterally, and 7.5% were extensive bilaterally. The remaining 27% ranged from mild to extensive and were variant between the left and right apices. Although our research revealed significant aeration of the petrous pyramid in almost half of the cases reviewed, only 0.5% (1 case) exhibited imaging consistent with that seen in patients with petrositis. These results contradict our hypotheses. It is difficult to determine the significance of the incidental CT or MRI finding of opacification of a large petrous apex air cell. This study demonstrates a low incidence of opacification in the general population. In the asymptomatic patient with an Incidental finding of an opacified petrous apex we continue to recommend observation and monitoring radiologically as opposed to surgical intervention.

Original languageEnglish (US)
JournalJournal of Investigative Medicine
Issue number2
StatePublished - Feb 1999

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


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