Development and validation of a quantitative measurement of the biomechanical marker of arterial disease, wall shear stress, using contrast enhanced high-frame rate plane-wave Doppler ultrasound

Abstract

The development of arterial disease in the renal arteries is of clinical interest as it is associated with increased risk of conditions such as heart failure, hypertension, diabetes mellitus and cerebrovascular disease (Ganz and Hsue, 2013) [1] . A biomechanical marker of this damage is Wall Shear Stress (WSS), which plays a significant role in maintaining proper arterial functioning, and is linked to arterial wall stiffening and the formation of atherosclerotic plaques, and also contributes to the initiation and possibly the progression of atherosclerotic disease (Ganz and Hsue, 2013) [1] , (Zalunardo and Tuttle, 2004) [2] and (Chien et al., 1998) [3] . The effect of WSS on haemodynamic flow, is hence of considerable scientific and clinical interest. This poster will firstly, present an overview of wall shear stress and then critically review the different attempts which have been made to measure WSS, namely, magnetic resonance imaging and conventional pulsed-wave Doppler ultrasound techniques. The main limitations associated with both of these techniques are their inability to detect low blood velocity and also their poor velocity resolution, both of which are critical for accurate WSS measurements (Katritsis et al., 2007) [4] and (Torii et al., 2009) [5] . One approach which can be potentially implemented to improve the SNR and velocity resolution of pulsed-wave Doppler ultrasound is ultrasound microbubble contrast agents. However, ultrasound contrast agents have been used with limited success to improve the quality of the velocity information from blood and the main results from these studies will be discussed in this poster. Finally, the concluding aspect of this review will be a discussion of whether the determination of wall shear stress can be achieved using commercially available ultrasound systems.