Validation of a Doppler method for peak blood velocity detection in a CFD-simulated carotid model

The peak velocity of the blood flowing in carotid is a parameter of high impact in the diagnosis of cardiovascular diseases. Current measurement methods are based on heuristic thresholds applied to the Doppler spectrum. Unfortunately, they often produce inaccurate assessments due to their sensitivity to noise and to the spectral broadening effect. Recently, a new vector technique has been proposed that solves these shortcomings thanks to a threshold calculated through an accurate mathematical model of the Doppler spectrum. However, the evaluation of its accuracy in real-life conditions is hampered by the difficulty of obtaining a reliable gold standard. Computational fluid dynamics (CFD) simulations, based on real carotid geometries, can help in filling this gap. In this work the proposed peak measurement method is tested on a realistic CFD model of the carotid bifurcation with an eccentric plaque in the internal branch. Common (CCA) and internal (ICA) arteries were separately investigated for a whole cardiac cycle, and the measurements from the method under test were compared to the CFD velocity reference. The obtained errors are +4.3% and +5.2% for the whole heart cycle in CCA and ICA, respectively, and +4.6% and +3.1% for the systolic peak.

[1]  R Eugene Zierler,et al.  Carotid artery stenosis: gray-scale and Doppler US diagnosis--Society of Radiologists in Ultrasound Consensus Conference. , 2003, Radiology.

[2]  D. Holdsworth,et al.  Flow Patterns at the Stenosed Carotid Bifurcation: Effect of Concentric versus Eccentric Stenosis , 2000, Annals of Biomedical Engineering.

[3]  H. Torp,et al.  Ultrasound simulation of complex flow velocity fields based on computational fluid dynamics , 2009, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  Piero Tortoli,et al.  Finding the peak velocity in a flow from its doppler spectrum , 2013, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.

[5]  K. Boone,et al.  Effect of skin impedance on image quality and variability in electrical impedance tomography: a model study , 1996, Medical and Biological Engineering and Computing.

[6]  Piero Tortoli,et al.  An improved Doppler model for obtaining accurate maximum blood velocities. , 2014, Ultrasonics.

[7]  A. Nowicki,et al.  Comparison of the performance of three maximum Doppler frequency estimators coupled with different spectral estimation methods. , 1994, Ultrasound in medicine & biology.

[8]  J. Arendt Paper presented at the 10th Nordic-Baltic Conference on Biomedical Imaging: Field: A Program for Simulating Ultrasound Systems , 1996 .

[9]  L. William Varner,et al.  Geometrical Spectrum Broadening in Ultrasonic Doppler Systems , 1977, IEEE Transactions on Biomedical Engineering.

[10]  Piero Tortoli,et al.  Accurate blood peak velocity estimation using spectral models and vector doppler , 2015, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.

[11]  J. Jensen,et al.  Calculation of pressure fields from arbitrarily shaped, apodized, and excited ultrasound transducers , 1992, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[12]  Lucia Francesca Lucca,et al.  Wall shear stress is lower in the carotid artery responsible for a unilateral ischemic stroke. , 2006, Atherosclerosis.

[13]  Piero Tortoli,et al.  Comparison of carotid artery blood velocity measurements by vector and standard Doppler approaches. , 2015, Ultrasound in medicine & biology.

[14]  R. Matera,et al.  Validation of a novel vector method for blood peak velocity detection in an anthropomorphic phantom , 2015, 2015 IEEE International Ultrasonics Symposium (IUS).

[15]  M. Fox Multiple crossed-beam ultrasound Doppler velocimetry , 1978 .

[16]  Piero Tortoli,et al.  Accuracy and reproducibility of a novel dynamic volume flow measurement method. , 2013, Ultrasound in medicine & biology.

[17]  Richard S C Cobbold,et al.  Human factors as a source of error in peak Doppler velocity measurement. , 2005, Journal of vascular surgery.