Figure 2
(a) Ultrafast Doppler pipeline acquisition: four ultrasonic images are obtained by sending tilted ultrasound plane waves in the medium. Those images are coherently compounded to increase contrast and resolution. This process is repeated 1000 times at a framerate of 2000 Hz. Each stack of 1000 images is filtered to retrieve blood signal. (b) Cerebral autoregulation in normal rabbits (Sham group, N = 6) assessed via the acquisition of relative UfD as a function of mean arterial pressure. Arterial blood pressure was increased by progressive compression of the abdominal aorta. When the mean arterial blood pressure is modified by an external event, individuals tend to regulate their cerebral blood flow to a constant value. On N = 6 rabbits (each one being depicted by different symbols) undergoing rather important modifications of their mean arterial blood pressure (up to 140 mmHg), the relative UfD signal show a moderate increase (lower than 60%).
