Posttreatment imaging of the skull base.

Imaging the skull base after surgery can be challenging because anatomic structures may have been destroyed by an underlying process or removed at surgery. Foreign substances may be introduced to fill a void left by tumor resection, for hemostasis, and to repair dural defects. Previous imaging studies must be available for comparison to understand the characteristics of an underlying lesion. By following the progression of a lesion on subsequent imaging studies, the nature of treatment-related changes and residual or recurrent pathology is best realized.