Research

our research activities include:

  • development of MRI sequences
  • construction of mechanical devices for elastography
  • signal processing and numerical methods for the solution of inverse problems
  • viscoelastic modeling
  • pressure and elasticity in porous media
  • time-harmonic ultrasound elastography
  • micro MRE of tissue samples and animal models
  • abdominal MRE
  • cardiac MRE
  • cerebral MRE
  • MRE of skeletal muscle
  • MRE of the lung
  • elastography for the diagnosis of:
    • cardiac relaxation abnormalities
    • liver fibrosis
    • neurodegenerative processes
    • tumors

Selected Projects

Structure sensitive elastography

Structure sensitive elastography   Background: Clinical diagnosis often relies on imaging modalities. However, in many cases the palpating hand is more sensitive to suspicious lesions than million-dollar expensive hardware. This is due to the incredible wide range of the shear modulus in the body: From fluids to bone – the shear modulus spans over more…

New methods for elastography

New methods for elastography Nonmagnetic vibration generation and 3DMMRE with MDEV inversion   Background: Elastography can be considered as a technique for imaging-based palpation. Since ages long before the advent of diagnostic modalities, palpation has been fundamental for the assessment of tissue’s health. The high sensitivity of the palpating hand is related to the scaling…

Time-harmonic ultrasound elastography

Time-harmonic ultrasound elastography   Background: Elastography in ultrasound and MRI relies on the mechanical stimulation of soft biological tissue and measures the elastic response as a biomarker sensitive to many diseases. In MR elastography (MRE) time harmonic waves are used for mechanical tissue stimulation. Time-harmonic waves in the low audible range can penetrate the whole…

Real-time signal processing for time-harmonic ultrasound elastography

Real-time signal processing for time-harmonic ultrasound elastography   Background: The measurement of tissue stiffness by elastography is increasingly used as a noninvasive biomarker for hepatic fibrosis. Various elastography methods have been developed for MRI or ultrasound, which rely on the mechanical stimulation of soft tissue by static deformation or dynamic waves. To date MRI elastography…

3DMMRE: Combining spatial resolution with viscosity-sensitive MRE

3DMMRE: Combining spatial resolution with viscosity-sensitive MRE   Background: The acquisition of wave fields is a central point in MRE. High sensitivity to motion is required along with robust image quality and sufficient SNR. Moreover, MRE should be fast since the mechanical stimulation may be inconvenient for patients when exceeding certain time limits. Problem: Currently,…

Compression sensitive elastography

Compression sensitive elastography   Background: Many diseases are associated with imbalanced fluid pressure regulation mechanisms. For example, normal pressure hydrocephalus or hepatic hypertension impose permanent or transient parenchymal pressure alterations which are hard to detect by conventional imaging methods. MRE, sensitive to mechanical constants of living tissue, may offer a way for the early and…

Towards high-resolution MRE

Towards high-resolution MRE   Background: Viscoelastic constants have been reported sensitive to various pathological processes and provide a new diagnostic marker for the assessment of tissue health. MRE is capable to measure tissue mechanical constants in vivo and non-invasively [1]. Problem: MRE still suffers from uncertainty regions in elastograms, which have to be masked in…

Solving the inverse problem for time-harmonic elastography

Solving the inverse problem for time-harmonic elastography   Background: MRE is capable to measure the full 3D displacement field of externally induced waves inside living organs and tissues. Viscoelastic constants are then reconstructed in order to detect pathological alterations. Problems and perspectives: In classical MRE, spatial maps of viscoelastic parameters lack consistency. These so-called elastograms…