A cerebral blood flow measurement is an important part of studying various brain pathologies, particularly brain ischemia. The methods of measurement are still improving, although the physical substance of many of them, like Fick's or Doppler's principles, outlasts further. A change in quality in last several years came with the use of isotopes and a computer technique. New options in imaging of circulatory changes with the help of magnetic resonance technology seem to be particularly perspective. If there were no economical obstacles, this method, which is able to disclose non-invasively a brain perfusion disorder in the very beginning, would be certainly immediately applied in the broad clinical practice.