What findings support this diagnosis?
Enlarged empty sella, prominent optic nerve sheaths, stenosis of dural venous sinuses.
How do you know that the left transverse sinus / sigmoid sinus are hypoplastic rather than thrombosed?
In addition to not seeing a thrombosed sinus, the groove in the skull is an excellent guide to the expected size of the sinus. On the right the groove for the proximal sigmoid sinus is large, whereas on the left it is tiny.
Normal enhancement and flow within the dural venous sinuses, without evidence of thrombosis. Hypoplasia of the proximal left transverse sinus is noted, with 2 prominent arachnoid granulations within the mid portion.
A largely empty sella, increased tortuosity of the optic nerves, with prominence of their CSF envelopes, and flattening of the posterior globe contour at the level of the optic discs.
No intra or extra axial mass lesion or parenchymal signal abnormality. No areas of diffusion restriction. No abnormal contrast enhancement identified.