Case courtesy Dr. Erez Nossek.

What you don’t see leads to when patient can’t see.

Another example of the Network principle.  There is a spectrum of meningeal-ophthalmic connections we cover extensively in MMA and ophthalmic artery pages.  The point is that these connections are many, and their visualization is dependent on hemodynamic and technical factors — injection pressure, catheter position, vessel size, etc.  Good angiographic technique and knowing anatomy is how you stay safe

Subdural hematoma

usual-appearing ophthalmic origin

Usual-appearing frontal ECA

Usual-appearing lateral ECA

Proximal MMA injection.  Catheter – black arrows, sphenoid ridge branch (40) — white arrow.  The sphenoid ridge branch is the usual connection between the MMA and proximal ophthalmic artery (via superior orbital fissure anastomosis [41])

A detailed look at the preceeding ECA injection shows subtle unopacified inflow at the junction with the sphenoid ridge branch

A more distal position in the MMA.  Reflux into proximal sphenoid ridge branch — white arrow

Post embo with PVA and coils — avoiding reflux

Schematic of how this happens