Normal variants: Occipital artery origin from internal carotid

The occipital artery can rarely originate from the posterior aspect of the proximal internal carotid artery. The normal origin is the external carotid artery. The patient shown below has this anomalous origin bilaterally.

Case #1

Case #1a

Lateral right common carotid angiogram

The occipital artery is seen to originate from the posterior aspect of the internal carotid artery.

Case #1b

Lateral left common carotid angiogram

The anomalous origin is also seen on the left.

Case #1c

Oblique left common carotid angiogram

An oblique view better demonstrates the left occipital artery origin.
 
Back to Normal Variants