Richard Lopata, associate professor at the Department of Biomedical Engineering, wants to avoid early rupture and unnecessary surgery in people with an aneurysm – a dilated blood vessel – in the abdominal artery. A ruptured aorta can be fatal. The current treatment relies on the diameter of the aorta. If it is more than 5.5 cm, or if it is growing rapidly, then it is current clinical standard to perform surgery. However, in some patients the aneurysm will rupture at a smaller diameter, while in others the aneurysm remains stable despite a much larger diameter. Therefore, vascular surgeons want to be able to predict who is at risk of rupture, or, which patient is safe for the time being despite the dilated aorta.
An aneurysm does not rupture because of its size, but because the stresses or strains in the vascular wall increases too much, just like a balloon that is overinflated. The stiffness indicates the extent to which a material can still move elastically. Changes in stiffness can be an indicator for growth or even rupture of the aneurysm. In order to be able to measure this stiffness inexpensively and without radiation, Lopata and his PhD students previously developed a 3D ultrasound technique. Now Lopata wants to improve that technique by extending the field of view of the measurement and increasing the quality of the images drastically.
The variation in heart rate and blood pressure makes it difficult to combine separate 3D images. That’s why Lopata wants to use multiple ultrasound transducers to achieve high contrast, high resolution and high temporal resolution. Lopata is going to develop the hardware to obtain raw and functional ultrasound images with multiple probes, partially in collaboration with the company Philips. Next, Lopata will develop new techniques to merge the data into improved 3D images. He will test various methods in the laboratory on different tissues.
Ultimately he would like to develop a model-based analysis method to differentiate between different types of aneurysms based on biomechanical properties. Lopata will use both laboratory studies and patient studies to test the system, the latter in close collaboration with the Catharina Hospital in Eindhoven.