The skull base: tumoral lesions.

Many lesions occur in the anterior, central and posterior skull base. In order to detect and characterise them, one has to apply the best imaging technique. Today MR is the preferred technique, and the use of CT is more and more restricted to evaluate the presence of calcifications and involvement of thin bony walls, foramina and fissures. However, MR is only superior when the right sequences and imaging planes are used. Many lesions can be characterised by their specific signal intensity on different sequences and by their location. Nevertheless some lesions can only be characterised after biopsy. The purpose of imaging in skull base tumours remains in the first place the evaluation of the exact tumour extent, and this is again best achieved with MR. In this paper the imaging technique and the most frequent skull base tumours are discussed.