 Ultrasound as the potential to complement these functional imaging techniques at low cost. Ultrasound imaging can do real-time in-depth imaging of brain. However, its use to imaging of major vessels has been limited until now due to its poor sensitivity. To overcome this limitation functional ultrasound fUS was developed in Institut Langevin since 2011. This technique enables high spatio-temporal resolution imaging of whole-brain microvasculature dynamics in response to brain activation without the need of contrast agent. 