FIG 3. MR images through the skull base.

A, Axial T1-weighted (600/12/2 [TR/TE/excitations]) MR image, obtained from an outside institution and performed 10 weeks prior to CN VI palsy onset, reveals foci of signal hypointensity in the clivus and bilateral petrous apexes (arrowheads).

B, Axial T1-weighted (600/9/2) MR image, obtained at our institution 10 weeks after A, shows progressive heterogeneity of the marrow fat in the central skull base.

C, Contrast enhanced fat-suppressed coronal T1-weighted (600/9/2) MR image shows bilateral, thick, smooth enhancement of the dura of the medial wall and floor of the middle cranial fossae (arrowheads) and abnormal marrow enhancement in the clivus (asterisk).

FIG 4.  A 3-mm-thick CT image obtained using a high-resolution bone algorithm postoperatively more clearly shows the extensive erosive changes in the central skull base (brackets)