[Tumors of the craniocervical junction. I. Strategies of radiological examinations depending on the clinical syndrome].

Tumors of craniocervical junction (ccjct) may cause a variety of non specific signs and symptoms. Before the advent of computed tomography (CT) diagnosis was sometimes possible only by surgical exploration, as the available radiologic methods--plain film radiography, angiography, and myelocisternography--essentially provided only indirect information about the neural structures. Because of its beam hardening artifacts, CT remained unsatisfactory as well. These diagnostic problems have practically disappeared with the availability of magnetic resonance imaging (MRI), which is now considered the method of choice if a space-occupying lesion is suspected at the ccjct. In some cases invasive angiography may still be necessary for surgical planning, and angiography may also be needed, whenever CT or MRI suggest the presence of an aneurysm. In the first part of this overview we present strategies for the radiological examination of the ccjct.