FIG 1. Images from the case of a 59-year-old man with a giant pituitary adenoma.

A, Midsagittal contrast-enhanced T1-weighted MR image obtained before treatment. A huge tumor (arrowhead) is visible in and on the sella turcica.

B, Axial heavily T2-weighted MR image obtained one section above the level of the optic tract before treatment. Tumor (arrowhead) is visible in the third ventricle. Edema-like changes are visible bilaterally and are more prominent on the left side of the brain (right side of the figure) (large arrows). Large Virchow-Robin spaces related to anterior perforated substance are also visible (small arrows).

C, Coronal heavily T2-weighted MR image obtained before treatment. Large Virchow-Robin space (large arrow) is located on the right optic tract (small arrow). Medium sized arrow and arrowhead indicate the edema-like change on the left side and the tumor, respectively.