Validation a zero dimensional model for assessing the hemodynamics in the circle of Willis with TCD

We developed a zero-dimensional model to assess the hemodynamics in the circle of Willis. The simulation model has been compared with other published one-dimensional models and showed a good agreement. However, those numerical models have only validated with data from healthy volunteerrs at the level of ICA and MCA by MRA or TCD. We will collect data from a previously performed prospective study, that involved aneurysmal subarachnoid haemorrhage (aSAH) patients receiving TCD and brain CTA with in the same day. We assumed that the diameter of arteries in the circle of Wills remain the same within 24 hours even in patient during a progressive vasospasm. We will measure the diameter of each segment in the circle of Willis, and use it as input of our model to simulate the flow velocity of each segment. Then we compare those flow velocities with that measured by TCD, to check if our model can simulate the flow velocity in the circle of Willis for individual. This is a diagnostic accuracy study.

the zero-dimensional model is a reliable tool to predict the flow velocities in the circle of Willis .

finish case selection in two months, measure the diameter of each circle of Willis from CTA in 3 months, then analysis data and write the report.