• Posterior communicating artery • Anterior communicating artery • Middle cerebral artery bifurcation. Sentinel, or "warning" leaks that produce minor blood leakage are reported to occur in 30-50% of ...

The arrowhead indicates absent anterior communicating artery and arrows indicate ... VA: vertebral artery; Acomm: anterior communicating artery; Pcomm: posterior communicating artery; A1 ...