Circle of Willis CT angiogram  
 

This image of the Circle of Willis is a computer-generated three-dimensional reconstruction of the original source images. The view is as though the brain has been removed and you are looking at the arterial circle from a superior perspective. The anterior cranial fossa is at the top of the image, and the foramen magnum is the black area at the bottom of the image.

 
 

Identify the following:

1. basilar artery

2. posterior cerebral artery

3. internal carotid artery

4. middle cerebral artery

5. anterior cerebral artery

6. anterior communicating artery

 
[Remove labels]