Imaging of skull-base cephalocoeles and cerebrospinal fluid leaks.

Skull-base cephalocoeles and cerebrospinal fluid (CSF) leaks may be congenital, spontaneous, or secondary. A classification of congenital lesions is formulated and the imaging features are illustrated. The concept of spontaneous skull-base CSF leaks and the significance of aberrant arachnoid granulations in imaging these patients are explored. The majority of secondary lesions relate to trauma; however, other potential causes of secondary skull-base cephalocoeles and CSF leaks are discussed. Imaging evaluation in these clinical scenarios may be complex and the role of each imaging method is reviewed.