Ultrasound Cerebral Vasculature Velocimetry: A Comparative Study between Ultrafast Vector Doppler and Ultrasound Localization Microscropy

Ultrasound Doppler is an effective tool for blood flow velocity measurement. Recently, ultrafast plane-wave-based color Doppler imaging (CDI) has been well established for the velocity estimation of vasculature with high spatiotemporal resolution. Nevertheless, conventional CDI can only be used to determine the velocity component along the ultrasound beam direction with angle-dependent limitation. As an angle-independent approach, vector Doppler imaging has been validated in the carotid artery, jugular vein, intracardiac chamber, etc. However, its applicability for small vessels remains to be verified. In the present study, the VDI-based velocimetry technique was applied for cerebral vasculature imaging of a rat brain and was compared with ultrasound localization microscopy velocimetry (vULM) for accuracy evaluation.