The vertebral arteries are not normally considered part of the circle of Willis, but are important to the intracranial arterial supply. view more Credit: Penn Medicine/Brett Cucchiara, MD and John ...

The arterial supply of blood to the brain is protected by a series of connections between the major arteries, termed the "circle of Willis" after the English physician who first described it in ...

Figure 1. Magnetic resonance imaging (MRI), MR angiography (MRA), and 3D-CTA. A, MRI demonstrates a small high-signal area in the right cerebellar hemisphere (white arrowheads) on both T2-weighted ...