A5068173854- Ultrasound Imaging and Elastography
- Ultrasonics and Acoustic Wave Propagation
- Seismic Imaging and Inversion Techniques
- Hydraulic Fracturing and Reservoir Analysis
- Photoacoustic and Ultrasonic Imaging
- Seismic Waves and Analysis
- Drilling and Well Engineering
- Advanced MRI Techniques and Applications
- Medical Imaging Techniques and Applications
- Ultrasound and Hyperthermia Applications
ETH Zurich
2021-2024
Czech Academy of Sciences, Institute of Geophysics
2024
Computational models of acoustic wave propagation are frequently used in transcranial ultrasound therapy, for example, to calculate the intracranial pressure field or phase delays correct skull distortions. To allow intercomparison between different modeling tools and techniques by community, an international working group was convened formulate a set numerical benchmarks. Here, these benchmarks presented, along with results. Nine increasing geometric complexity defined. These include...
Full-waveform inversion applied to ultrasound computed tomography is a promising technique provide highresolution quantitative images of soft human tissues, which are otherwise difficult illuminate by conventional imaging. A particular challenge arises within transcranial the imprint solid skull on measured wavefield. We present an acoustoelastic approach full-waveform for that accurately accounts solid-fluid interactions along skull-tissue interfaces. Using spectral-element method cubical...
Full-waveform inversion (FWI) for ultrasound computed tomography is an advanced method to provide quantitative and high-resolution images of tissue properties. Two main reasons hindering the widespread adoption FWI in clinical practice are (1) its high computational cost (2) requirement a good initial model mitigate non-convexity inverse problem. The latter commonly referred as "cycle-skipping", which occurs phase differences between synthetic observed signals usually traps local minimum....
Using waveform-based inversion methods within transcranial ultrasound computed tomography is an attractive emerging reconstruction technique for imaging the human brain. However, such approaches generally rely on possessing accurate model of skull in order to account complex interactions which occur when waves propagate between soft tissue and bone. In recover shape context full-waveform inversion, adjoint-based optimization performed this study. The gradients with respect acoustic...
This work explores the use of an optimal transport misfit function combined with coupled acoustic-elastic wave equation for transcranial ultrasound computed tomography. approach utilizes full-waveform inversion together a starting model derived from reverse time migration. Source encoding is additionally used to reduce overall computational cost reconstruction process. The cycle skipping effects which are accentuated due inexact knowledge skull geometry can be effectively mitigated using...
Full-waveform modelling serves as the basis for many emerging inversion techniques within ultrasound computed tomography. Being able to accurately depict strong material interfaces, such between soft tissue and bone, is particularly important ensuring that these numerical methods produce physically correct results. We present a procedure constructing digital twins of various parts human body through use conforming hexahedral meshes, which are used together with spectral-element method model...
We present a full-waveform inversion (FWI) of an in-vivo data set acquired with transmission-reflection optoacoustic ultrasound imaging platform containing cross-sectional slice through mouse. FWI is high-resolution reconstruction method that provides quantitative images tissue properties such as the speed sound. As iterative data-fitting procedure, relies on ability to accurately predict physics wave propagation in heterogeneous media account for non-linear relationship between ultrasonic...
Constructing a physics-augmented digital twin of the skull is imperative for wide range transcranial ultrasound applications including computed tomography and focused therapy. The high impedance contrast as well acoustic-elastic coupling observed between soft tissue bone increase complexity wavefield considerably, thus emphasizing need waveform-based inversion approaches. This work applies reverse time migration in conjunction with spectral-element method to an vitro human obtain starting...
This work explores techniques for accurately modeling the propagation of ultrasound waves in lossy fluid-solid media, such as within transcranial ultrasound, using spectral-element method. The objectives this are twofold, namely, (1) to present a formulation coupled viscoacoustic-viscoelastic wave equation method order incorporate attenuation both fluid and solid regions (2) provide an end-to-end workflow performing simulations ultrasound. matrix-free implementation high-order finite-element...