There is a heterogeneous 30 x 23 x 28mm mass centred in the sella extending to the suprasellar cistern. This demonstrates small foci of T1 hyperintensity with central low density on T2 imaging. There is mild peripheral rim enhancement post contrast.
The mass contacts and superiorly displaces the optic chiasm superiorly and displaces the cavernous carotid arteries laterally with mild attenuation of the cavernous carotid flow signal. No phase artifact to suggest this is a pulsatile mass. There is opacification of the sphenoid sinus.
Moderate size area of T2 FLAIR hyperintensity in the right posterior frontal lobe cortex has convex margins, with FLAIR signal extending to cortex. It does not enhance nor diffusion restrict, but note only limited sequences performed as part of this pituitary protocol.
Posterior fossa structures unremarkable. Normal cervicomedullary junction.
MRA (not shown) demonstrates normal opacification of the intracranial ICA, vertebrobasilar system and circle of willis. No aneurysms identified.
Conclusion:
The appearances are more in keeping with pituitary macroadenoma with superimposed haemorrhage/ pituitary apoplexy than a thrombosed large midline aneurysm centred in the sella.