FIG 1. Case 1: 46-year-old woman with a growth hormone–secreting adenoma.

A, Coronal T1-weighted MR image after administration of contrast material shows a large sellar tumor compressing the right cavernous sinus. The left cavernous sinus is enhanced and normal in shape.

B, T1-weighted MR image shows clearly enhanced tentorium on the right side.

C and D, Sagittal T1-weighted images show linear enhancement of the tentorium from the posterior portion of the cavernous sinus on the right side (C). Note asymmetric tentorial enhancement sign.

E, Postoperative T1-weighted MR image after administration of contrast material shows enlarged posterior part of the cavernous sinus; however, no tentorial enhancement was seen preoperatively (C).