Projects in ultrasound image reconstruction and elastography

Our research group tackles several interesting research problems in medical ultrasound image reconstruction and elastography. In image reconstruction, we use pulse-echo recordings to map out an image of the reflections from the human body. In elastography, we use an external vibrator that generates a shear wave. The propagation of this shear wave is mapped using pulse-echo ultrasound, and this way we can discern the stiffness of the medium. This stiffness has great diagnostic value in the clinic.

Please come see us for further dialogue if you're interested in working on these interesting research directions.

Examples of such research directions are:

1) Elastography

We have several interesting topics to tackle in the domain of mapping tissue stiffness using Time harmonic elastography.

Bildet kan inneholde: diagram, tomt.

Image from: Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.
Walker HK, Hall WD, Hurst JW

2) Ultrasound localization microscopy (ULM)

In ULM, microbubble contrast agents are injected in to the bloodstream. By tracking the path of individual bubble, an extremely detailed view of the microvascular structure can be achieved. This has several important applications in, for example, imaging the brain.

Bildet kan inneholde: blå, rød, oransje, symmetri.
Image from the MSc thesis of Simon Andreas Bjørn (2025).

3) Spectral Doppler for blood flow characterization

Ultrasound spectral Doppler is used to assess how blood flow at a specific location changes through time. This information is used for instance for detection of stenotic arteries as well as the degree of stenosis.

Karabiyik Y, Avdal J, Ekroll IK, Fiorentini S, Torp H, Lovstakken L. Data-Adaptive 2-D Tracking Doppler for High-Resolution Spectral Estimation. IEEE Trans Ultrason Ferroelectr Freq Control. 2020

4) Image reconstruction and grating lobe suppression

There are several reasons why ultrasound imaging systems often feature sensors that are distributed at a distance which is greater than half the wavelength of the ultrasound pulse. This spatial undersampling generates artifacts called grating lobes, where non-physical "copies" of true structures appear in the image. We will look into methods to bot identify and to reduce such artifacts in the final ultrasound image.

Necessary experience

  • To have taken or later take the course in Ultrasound imaging (IN3015/IN4015)
  • To have taken or later take the course in Signal processing (IN3190/IN4190)
  • To take the course in Array signal processing (IN5450)
  • Strong scientific programming skills

Additional beneficial experience

  • Wave physics
  • Interest in medical technology
Published Sep. 22, 2025 11:32 AM - Last modified Oct. 5, 2026 3:49 PM

Supervisor(s)

Scope (credits)

60