What we do
About our project
Approximately 120,000 people, mostly women, suffer from heart failure with preserved ejection fraction (HFpEF). In this condition, the heart does not relax properly and cannot fill with blood effectively. Early diagnosis is crucial for management of the disease but standard echocardiography is not sensitive or specific enough its early stages.
Part of the limitation of current echocardiography is the reliance on ultrasound Doppler for haemodynamic measurements, which is limited to only estimating the 1-dimensional blood flow components towards or away from the probe, providing a limited view of intracardiac haemodynamics.
In this project we will develop 4D-flow echocardiography to measure the haemodynamics in the left ventricle with unparalleled temporal resolution. This technique is capable of quantifying blood flow in 4-dimensions (3- spatial dimensions + time), and also the pressure gradients within the left ventricle. This technique has potential for improved understanding of the haemodynamic mechanisms of left ventricular diastolic dysfunction as well as a tool for early stage identification of individuals at risk of developing HFpEF.
Our research focus
Realization of 4D-flow echocardiography can be broken-up into the three different sections listed below:
High Frame Rate Contrast Enhanced Echocardiography
Recent advances in ultrasound technology have enabled imaging frame rates to increase from less than 100 to more than 1000 frames per second. One downside of high frame rate imaging is the loss of signal/image quality. To recover some image/signal quality we use ultrasound contrast agents (UCA = tiny microbubbles).
Echo-Particle Image/Tracking Velocimetry
Echo-particle image velocimetry (echoPIV), is a method which tracks the motion of intravenously injected UCA to quantify blood flow. We will combine echoPIV with another method called echo-particle tracking velocimetry (echoPTV) which tracks individual bubbles over time. The combination of both techniques is expected to provide more accurate results than each on their own.
Physics-Informed RegularisationTo make the velocity estimates from echoPIV/echoPTV more robust, we will use physics-informed regularisation. This compares the velocity estimates measured with our fundamental understanding of fluid mechanics to remove estimates that are physically impossible. A benifit of using this approach is that the relative pressure fields within the heart are also computed, thus we obtain an estimate of the suction forces generated within the ventricle.
Funds & Grants
- Ultrasound Research Group, Department of Circulation and Medical Imaging, Norwegien University of Science and Technology.