Can computed tomography and magnetic resonance imaging differentiate between malignant pathology and osteomyelitis in the central skull base?

BACKGROUND: Central skull base osteomyelitis is clinically difficult to distinguish from malignancy.

METHOD: The computed tomography and magnetic resonance imaging scans of six patients with central skull base osteomyelitis were compared with scans from patients with a range of skull base conditions.

RESULTS AND CONCLUSION: Computed tomography scans of central skull base osteomyelitis show much less bony destruction relative to the magnetic resonance imaging changes, whereas malignancy cases were associated with similar bony destruction on computed tomography and magnetic resonance imaging. In magnetic resonance imaging scans, it was possible to confirm previous findings of clival hypointensity on T1-weighted images relative to normal fatty marrow. In addition, there were signs of pre- and para-clival soft tissue infiltration, with the obliteration of normal fat planes and frank soft tissue masses in all six central skull base osteomyelitis patients. Signal intensity on T2-weighted images of the clivus was high in five central skull base osteomyelitis patients. With intravenous contrast, fascial plane anatomy appeared restored in central skull base osteomyelitis cases, almost in keeping with that of non-involved areas. This was not a feature in any of the malignant conditions.