Mastering Doppler Principles and Hemodynamics- AllAboutUltrasound (HTML)

In the world of ultrasound, it’s easy to get caught up in the day-to-day tasks and forget about the basics of physics. However, image optimization begins with understanding the fundamentals. This is where Doppler principles and hemodynamics come into play. While some may cringe at the thought of studying for the Ultrasound Physics registry, there’s no need to fear Doppler. It’s simple once you break it down. The Doppler Effect is relative to the observer and creates either a positive shift (a compression in wavelength or higher frequency) or a negative shift (an elongated wavelength or lower frequency). In Doppler ultrasound, frequency shifts come from moving red blood cells and give us the spectral display seen in Continuous Wave and Pulse Wave Doppler. Velocities obtained from these frequency shifts can also be displayed in Color Doppler, superimposed on top of the 2D ultrasound image. To ensure accurate velocity results, it’s important to maintain the Doppler sample volume and angle of insonation, since changes in position can result in different velocities observed. The Society for Vascular Ultrasound recommends maintaining a scanning angle between 45-60 degrees to ensure consistency in the lab.