Study on stability of carotid blood flow measurement based on blood flow vector

Objective To explore different methods of measuring carotid blood flow based on blood flow vector and their stability.

Methods A total of 15 healthy volunteers and 40 patients were selected as study objects. The blood flow of common carotid artery was measured by five critical care physicians through ultrasound examination with seven methods: trigonometric function double section measurement, trigonometricfunction single section measurement, cross section fixed angle measurement, longitudinal section measurement, maximum flow velocity approximation, average flow velocity approximation and improved circular approximation.Then the stability of the results was analyzed to find a stable blood flow measurement method.

Results The stability of trigonometric function single section measurement was significantly better than that of trigonometric function double section measurement, cross section fixed angle measurement and longitudinal section measurement (P < 0.05). The stability of the maximum blood flow velocity measurement method showed no significant difference compared with that of the mean flow velocity approximation method(P>0.05). There was no significant difference between the modified circular approximation method and the maximum blood flow velocity approximation method(P>0.05), but the analysis showed that the former method was significantly better than the latter method (P < 0.05).

Conclusion Trigonometric function single section measurement method can measure stable blood flow velocity; for patients with carotid plaque, the improved circular approximation method can obtain more stable blood flow, but the stability of evaluation still needs to be further improved.