More than 2500 patients were examined in our ultrasonographic laboratory. Out of them 324 were selected with the stenosis in the carotid bulbus. Unilateral and bilateral stenotic findings were revealed in 231 and 93 patients, respectively. The aim was to find out in which way these stenoses influenced the flow parameters in the cervical carotic blood vessels. Results: In carotid bulbus stenosis up to 50%, peak systolic velocity (PSV) increased on the average by 8 cm/s per every 10% of the stenosis, over 50% it was as much as 50 cm/s per every 10%. The increase is higher in patients with vystiboth carotid vessels narrowed if compared with those whose vascular system of the other side is healthy. Diastolic velocity was increasing in a lesser extent, quite minimal increase was seen in resistance index (RI) and pulsatility index (PI). In the common carotid artery (CCA), decrease of PSV with increasing extent of the bulbus stenosis was observed. The ratio of velocity in the stenosis towards velocity in the CCA was growing in dependence on the percentage of stenosis both for PSV and EDV. The number of findings of decreased or retrograde flow in the ophthalmic artery (AO) was higher in patients with higher levels of stenosis (more significantly from 60%). The patients with unilateral stenosis underwent the comparison with the vascular system of the other side. Againts our expectations, no increase in flow velocities in the internal carotid artery (ACI) of the other side as an expression of collateral blood supply was detected.

        Key words: systolic and diastolic velocity, stenosis, carotid arteries, ophthalmic arteries, collateral vascular system