The ultrasound technology research at the Department of Circulation and Medical Imaging is focused on the following general fields:
Ultrasound images are impaired by multiple reflections (reverberations) and heterogeneities in tissue sound velocity (abberations). Correcting or removing these artifacts yields improved image quality.
With transducers which consist of a high number of elements it is possible to form the radiated acoustic field (the beam). Adjusting the beam shape is crucial for optimal imaging performance.
Ultrasound contrast agents are tiny gas bubbles encapsulated in a lipid shell. The bubbles are small enough to pass the capillaries but they are too big to leak from the vessel into the tissue. This makes these microbubbles a bloodpool agent which can be used to detect and image vasculature which has not enough flow to be detected by other modalities as f.ex. doppler.
The doppler effect gives rise to frequency shifts of waves in case of a moving source or receiver - in every day life f.ex. experienced when an ambulance with a horn passes. In ultrasound imaging this effect is utilized to visualize blood flow, tissue in motion or extract other parameters as tissue strain.
Cardiac ultrasound, also known as echocardiography, concerns the ultrasound imaging of a very fast moving complex organ positioned deep within the body - the heart. The main technological challenge in the actual imaging is to achieve the frame rate/temporal resolution and spatial resolution needed in the final video loops to resolve all cardiac details.
Sound speed and scattering properties in tissue and in contrast agents are generally pressure dependent. This is used in SURF imaging where the propagation and scattering properties are modified by a manipulation pulse and observed with an imaging pulse. This can be used to suppress reverberations, enhance resolution for contrast imaging or characterize tissue.
Akutten og Hjerte-lunge-senteret
Prinsesse Kristinas gt. 3.
Det Medisinske Fakultet
Institutt for sirkulasjon og bildediagnostikk
Medisinsk teknisk forskningssenter