What are the radiological features and clinical implications of superior ophthalmic vein pathology, particularly in the context of cavernous sinus thrombosis and carotid-cavernous fistulas?

Superior ophthalmic vein thrombosis is often associated with cavernous sinus thrombosis, presenting as a loss of the normal flow void on MRI and potential enlargement on CT or MRI. In cases of carotid-cavernous fistulas, the vein may be dilated due to increased venous pressure. Key diagnostic features include proptosis, chemosis, and ocular motor nerve palsies. Clinically, it is crucial to differentiate from other causes of proptosis, such as orbital cellulitis, to guide appropriate management.