Blood flow is pulsatile and and the pulsatility is essential to maintain vessel wall function. Pulsatility Index is measures of vascular resistance. Phase contrast technique is used to determine blood flow quantification in cerebrovascular and cardiovascular pathologies. In this research, using blood flow velocity values obtained phase contrast technique over the one cardiac cycle from 4 control subjects and 4 cerebral aneurysm patiens, Pulsatility Index value was calculated for internal carotid and vertebral arteries that supporting the brain. Aneurysms were unilateral and unruptured.