Low-flow infarctions, also called borderzone infarctions, are considered the result of critically reduced cerebral perfusion pressure (CPP) in far-downstream brain arteries that causes critically compromised cerebral blood flow and insufficient oxygen supply in certain vulnerable brain areas. Transhemispheric and interterritorial collateral blood flow via the anterior and posterior communicating arteries and their individual distributions must be considered with respect to the site and size of borderzone infarctions. Cardiac arrest and hypotension can also cause low-flow infarcts that are usually bilateral. Although hypoxic-ischemic cerebellar damage is often found at necropsy, clinical signs of cerebellar dysfunction are rare and are usually overshadowed by cerebral abnormalities. The general medical prognosis of patients with low-flow infarcts is poor. Deaths as a result of cardiovascular complications are frequent and account for about 10% of deaths per year. An important diagnostic improvement in identifying low-flow infarcts was the use of rCBF techniques.