Abstract
Forty patients with tumors involving the skull base were selected on the basis of findings at high resolution computed tomography (CT). The reliability of demonstrating bony lesions with magnetic resonance imaging (MRI) and CT were compared. CT showed osseous lesions of the skull base better than MRI but was less sensitive in evaluating an associated inflammatory reaction or in defining intracerebral infiltration. Small cortical lesions were only demonstrable with CT. MRI was superior in defining the full extent of soft tissue infiltration. Arterial encasement was observed at MRI. The special advantage of Gd-DTPA lies in the additional possibility to differentiate vessels from tumor-like lesions and in en plaque tumors.