An in vitro system for Doppler ultrasound flow studies in the stenosed carotid artery bifurcation

Poepping, Tamie L.; Nikolov, N.; Rankin, N.; Lee, Mark; Holdsworth, David W.

« Previous Next »Ultrasound in Medicine and Biology
Volume 28, Issue 4 , Pages 495-506, April 2002

An in vitro system for Doppler ultrasound flow studies in the stenosed carotid artery bifurcation

Tamie L. Poepping
- The John P. Robarts Research Institute, London, ON, Canada
- Department of Medical Biophysics The University of Western Ontario, London, ON, Canada
N. Nikolov
- The John P. Robarts Research Institute, London, ON, Canada
N. Rankin
- Department of Diagnostic Radiology and Nuclear Medicine, The University of Western Ontario, London, ON, Canada
Mark Lee
- The John P. Robarts Research Institute, London, ON, Canada
David W. Holdsworth
- Address correspondence to: D. W. Holdsworth, Imaging Research Laboratories, The John P. Robarts Research Institute, P.O. Box 5015, 100 Perth Drive, London, Ontario N6A 5K8 Canada
- The John P. Robarts Research Institute, London, ON, Canada
- Department of Medical Biophysics The University of Western Ontario, London, ON, Canada
- Department of Diagnostic Radiology and Nuclear Medicine, The University of Western Ontario, London, ON, Canada

Received 28 August 2001; accepted 9 January 2002.

Abstract

To investigate the correlation between disease severity and Doppler spectral measurements in the carotid artery bifurcation, a unique in vitro system has been developed that mimics the human vasculature with respect to both anatomy and flow perfusion. Agar-based carotid phantoms are perfused with a blood-mimicking fluid using a computer-controlled pump and realistic pulsatile flow waveform. A three-axis translational stage allows the lumen to be interrogated with a 0.6-μL Doppler sample volume at the desired spatial intervals using a semiautomated acquisition system, to collect 10 cardiac cycles of gated quadrature data at each site. Off-line analysis, including a 1024-point FFT, produces a 4-D (i.e., time-varying 3-D) Doppler velocity data set with 1.3-cm/s velocity resolution and 12-ms temporal resolution. Using this system, in vitro flow in bifurcations with both normal and stenosed lumen geometry (from 30% to 80% stenosis by NASCET criteria) can be studied, along with the effect of factors, such as stenosis geometry (concentric vs. eccentric) and flow rate, on the observed Doppler ultrasound (US) spectra and haemodynamic patterns. (E-mail: dholdswo@irus.rri.ca)

Keywords: Carotid artery bifurcation, In vitro, Blood flow velocity, Stenosis, Duplex ultrasound, Doppler sample volume power response, Spectral analysis, Turbulence intensity, Spectral broadening index