Clinically-directed CT in occult disease of the skull base involving foramen ovale.

Occult disease of the skull base may present as an isolated neurogenic symptom in the absence of physical signs or radiologic findings. It therefore often remains undiagnosed until advanced. Computed tomography (CT) provides the potential for diagnostic imaging far beyond conventional radiology. Not only do current generation scanners provide exquisite bone detail, they also provide the capability of soft tissue imaging. In the past year, we have matched the diagnostic problem of occult disease of the middle fossa skull base and its foramina with the potential diagnostic imaging solution of CT. Five patients were referred with possible occult middle fossa skull base disease--all had persistent unilateral facial paraesthesia in the distribution of one of the lower two trigeminal nerve divisions (V2 V3) as their only complaint; all had previously been extensively investigated (including axial CT); all remained undiagnosed. Utilizing clinically-directed CT (based on acoustic neuroma diagnostic index of suspicion and imaging experience), 2 of the 5 patients were found to have small mass lesions involving foramen ovale. This presentation will demonstrate our experience based on image-manipulated CT, actively monitored by both radiologist and otolaryngologist.