by K. W. Wesselink-Schram, University of Twente

Schematic representation of the setup for both high-speed bright-field imaging (top left inset) and high-speed fluorescence imaging (top right inset). Credit: https://research.utwente.nl/en/publications/bubbles-and-waves-for-ultrasound-imaging-and-therapy

Charlotte Nawijn, Ph.D. candidate at the University of Twente, has developed a new technique to improve ultrasound images of blood flow. Using a smart ultrasound pulse train, she reduced noise in contrast ultrasound images. Nawijn obtained her Ph.D. on this subject on 24 October with the defense of her dissertation "Bubbles and Waves for Ultrasound Imaging and Therapy."

Microbubbles are tiny bubbles, smaller than red blood cells, that can be injected into the bloodstream as a contrast agent for ultrasound diagnostics. This helps doctors to visualize the blood flow (or lack thereof) to organs, such as the heart and large blood vessels.

Previous research has shown that emitting two pulse trains of ultrasound can greatly reduce the amount of noise in the ultrasound image, but this method did not work for contrast bubbles or rapid blood flow.

Charlotte Nawijn developed a technique to transmit and analyze this pulse train more effectively, enabling its use for contrast ultrasound of rapid blood flow. Thanks to her new technique, the contrast of the ultrasound images is increased and the amount of noise is reduced, which greatly improves the image quality. This technique opens up completely new possibilities in the diagnosis of cardiovascular diseases.

Calculated breaks

This clever approach takes advantage of the ability to time the pulses separately. Nawijn developed a method that calculates the optimal timing between pulses to get the best result. Instead of a regular series of pulses, the new method calculates the different pauses between the pulses, ensuring they work together optimally to produce a better ultrasound signal.

In addition, Nawijn was able to limit the emission pulse to a single pulse train, which now allows her to measure fast-moving flows, such as those in the aorta.

"Our technique allows for better images with higher precision and without slowing down the shooting speed," explains Nawijn. Tests showed this method reduced measurement errors by up to four times. This allows for a more precise image of blood flow, leading to better diagnoses for treating physicians.

More information: Dissertation: Bubbles and Waves for Ultrasound Imaging and Therapy

Provided by University of Twente