MR imaging of the skull base.

Fifty-four patients with abnormalities primarily involving the base of the skull were evaluated by magnetic resonance (MR) imaging. The results were compared with information obtained by other radiologic studies, primarily X-ray CT. On MR imaging, better anatomic definition of soft tissues in the deep compartments of the nasopharynx was achieved through the high level of tissue contrast discrimination and lack of bone artifacts. The parapharyngeal fat plane, separating pterygoid from pharyngeal musculatures, was consistently demonstrated. However, the inability of MR to image compact bone proved to be a major drawback where bony detail was required. In general, MR imaging demonstrated 100% sensitivity to abnormalities involving the posterior compartment (clivus and craniovertebral junction) and was least valuable in the evaluation of the anterior compartment (orbits, cribiform plate, and sinuses.