IEEE Ultrasonics Symposium, Rome, September 20-23, 2009

Short Course 6A: Estimation and Imaging of Blood Flow Velocity

Hans Torp and Lasse Løvstakken
Department of Circulation and Medical Imaging
Norwegian University of Science and Technology
Trondheim, Norway

E-mail:  Hans.Torp(at)ntnu.no, Lasse.Lovstakken(at)ntnu.no

Course summary:  

This course provides a basic understanding of the physical principles and signal processing methods for estimation of blood flow velocity. The course begins with an overview of currently used techniques for velocity estimation using pulsed- and continuous-wave Doppler, and color flow imaging. Fundamental challenges related to data acquisition will be presented. Further, statistical models for the received signal as well as commonly used velocity estimators will be developed. The suppression of clutter from slowly moving targets is central to all processing schemes and will be given special attention. Finally, and introduction to advanced topics such as adaptive clutter filtering and 2-D / 3-D vector velocity estimation techniques will be given. Principles and practical limitations will be discussed, and potential clinical applications will be shown.

Hans Torp received the MS degree in mathematics in 1978, and the Dr. Techn. Degree in electrical engineering in 1992; both from the University of Trondheim, Norway. Since 1980 he has been working with ultrasound technology applied to blood flow measurements and imaging at the University of Trondheim, in cooperation with GE-Vingmed Ultrasound. He is currently professor of medical technology at the Norwegian Univesity of Science and Technology, and has since 1987 given courses on ultrasound imaging and blood flow measurements for students in electrical engineering and biophysics. His research interests include statistical signal- and image processing with application in medical ultrasound imaging.

Lasse Løvstakken received the Masters degree in Engineering Cybernetics in 2002 and a PhD in Medical Technology in 2007, both at the Norwegian University of Science and Technology, in Trondheim, Norway. He is currently working as a Research Fellow at the Department of Circulation and Medical Imaging at the Norwegian University of science and Technology. His research interests include signal and image processing with applications in ultrasound imaging, with a special focus on imaging of blood and tissue movement

Slides from the short course:

Doppler Short Course 2009 slides (pdf format) (Lectures 1-4)

Relevant litterature:

1. H. Torp: Signal processing in ultrasound Doppler and Color Flow Imaging. NTNU 2002  (pdf)

2. L. Løvstakken: Signal processing in diagnostic ultrasound – algorithms for real-time estimation and visualization of blood flow velocity, chapter 2 – Background, NTNU 2007 (pdf)

Matlab demonstrations

1. Continuous wave signal from moving scatterer (cwdoppler.m)

2. Pulsed wave signal from moving reflector  (pwdoppler.m)

3. Complex Gaussian process demonstration (Csignaldemo.m)

4. Doppler spectrum estimation  (Dopplerspectrum.m)

5. Doppler signal examples (dopplersignal1.mat dopplersignal2.mat)

6. Autocorrelation method applied to simulated signal (AcorrEst.m)

7. Autocorrelation method, effect of averaging (AcorrAverage.m)

Download all Matlab demonstration files: matlabdemo.zip

Last update: Sept 7, 2009