Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Carotid-cavernous fistula:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

"

This is based on MRI scan, magnetic resonance angiography and CT scan. A cerebral digital subtraction angiography (DSA) enhances visualization of the fistula.[citation needed]