明显双侧对称的黑的褪色区域，表示在大脑动脉环的前部和中部之间的区域最近出现的梗死。相对或绝对的脑低灌注都可能造成这种梗死。
The bilaterally symmetric dark discolored areas seen superiorly and just lateral to the midline represent recent infarction in the watershed zone between anterior and middle cerebral arterial circulations. Such watershed infarctions can occur with relative or absolute hypoperfusion of the brain.