Table 1.

MRI Features Analyzed and Grading Scheme Used

MRI Feature	Grading
Sellar configuration	1 – normal (unflattened pituitary); 2 – <50% flattened; 3 – >50% flattened; 4 – completely flattened pituitary
Optic nerve diameter (OND)	Measured in mm
Optic nerve sheath diameter (ONSD)	Measured in mm
OND/ONSD ratio	Ratio of ON diameter to ON sheath diameter
CSF space	ONSD-OND (mm)
Globe configuration	1 – normal outwards convexity of sclera at attachment to ON; 2 – flattening of sclera; 3 – protrusion of ON head into globe (concave towards globe)
Optic nerve head enhancement	0 – none; 1 – subtle; 2 – obvious but < muscle; 3 – equal to or > muscle
Ventricular size	0 – normal; 1 – slit-like; 2 – dilated
Sulci prominence	0 – normal; 1 – obliterated; 2 – prominent