Signal processing techniques for operator independent Doppler ultrasound : potential for use in transcranial Doppler ultrasound

2D Doppler ultrasound can be used for continuous monitoring of vasospasm. However, the use of Doppler ultrasound suffers from operator dependence requiring a skilled ultrasonographer to make Doppler angle corrections. The aim of the research is to minimize the need of dedicated ultrasonographers for Doppler ultrasound monitoring of cerebral vasospasms. In this thesis, three studies including a steady flow phantom, pulsatile flow phantom and in vivo human internal carotid artery (ICA) were completed with the use of 3D Doppler ultrasound. The 3D vascular structure of the phantom and ICA were obtained using binary skeletonization from 3D power Doppler images. The vascular structure was used in combination with angle independent pulsed-wave Doppler to reconstruct the temporal blood velocity profiles at various parts of the vasculature. The results indicate that Doppler angle corrections can be minimized with the use of 3D Doppler ultrasound, and operator independent monitoring of blood flow is possible.