1999 年 12 巻 3 号 p. 125-128
We evaluated the relationship between the grade of internal carotid artery (ICA) stenosis and the pulsatility index (PI) of the middle cerebral artery (MCA) . [Methods] PI and MCA mean velocity (Vm) values were obtained for 27 patients with ICA stenosis using transcranial Doppler sonography. The PI values were also obtained for 16 healthy volunteers (0.77±0.12) . The patients were divided into 3 groups (Group A (n=8) : PI<0.65; Group B (n=12) : 0.65≤PI<0.89; Group C (n=7) : 0.89≤PI) and the grades of ICA stenosis and the Vm values were compared among the three groups. [Results] There was a significant correlation between the grade of ICA stenosis and the PI (stenosis=112.5-39.3×PI, R=0.644, p=0.0003) . The grades of ICA stenosis in groups A (91.1±6.2%) and B (80.6±12.6%) were significantly greater than those in group C (67.9±9.1%) (p<0.05) . There was no significant correlation between Vm and PI. [Conclusions] There was a linear correlation between the grade of ICA stenosis and PI, suggesting that the grade of stenosis is greater in cases with lower PI.