A 9-year-old boy presents with impaired vision, headaches and has been recently diagnosed with diabetes insipidus. He has been complaining of trouble with his eyes and headaches for a few weeks but his mum thought he was trying to avoid his homework and going to school as he has problems with bullying. The development of insensible thirst really alarmed his mum and led to further investigations. You are awaiting for the cranial MRI and you are thinking of possible causes for these symptoms.What would you most likely expect to see on the MRI?