What features may be visible on T1 non-enhanced images?
Some often subtle morphology changes include bulkiness of the gland on the side of the microadenoma, subtle remodelling of the floor of the sella, deviation of the pituitary infundibulum.
How are 'dynamic contrast enhanced' images obtained?
Contrast in injected into a vein with a pump and the pituitary gland is imaged at multiple times (e.g. t = 0, 15, 30, 60, 90, 120 seconds) at a number of locations (e.g. 6 contiguous silices, in the coronal plane). The images are then viewed at the same location, scrolling through the different times so that contrast can be seen flowing into the pituitary, first from the stalk than then out to the more peripheral parts of the gland.
Centred within the right aspect of the pituitary gland is a rounded hypo-enhancing lesion measuring 8 x 6 x 6.5 mm. Pituitary tissue is elevated upwards only 1mm, away from of the right side of the optic chiasm, which is not yet contacted or compressed. The infundibulum remains deviated towards the left. There is no evidence of invasion of the cavernous sinuses.