The association between petrous apex cephalocele and empty sella.

PURPOSE: Petrous apex cephalocele (PAC) is a rare lesion that has been linked to empty sella in several case reports. The aim of this study is to document the incidence of empty sella and PAC in consecutive brain MRI studies and study the association between these two lesions to better understand the underlying etiology of PAC. METHODS: A total of 2410 brain MRI studies were performed in our institution in the period from January 2011 to December 2011. After eliminating duplicated studies, a total of 2093 studies met our inclusion criteria. Retrospective analysis of patients' head MRI was performed by two radiologists independently to identify the presence of empty sella and/or PAC. RESULTS: Empty sella was found in 322 (15.4 %) patients. PAC was found in 111 (5.3 %) patients (age range 6-81 years) of which 87 were females and 24 were males. Of all the patients with PAC, 77 (69.4 %) patients had associated empty sella. Bilateral PAC was more common and seen in 77 patients. CONCLUSION: PAC is associated with empty sella, and both lesions are probably related to the same cause.