The role of the coupling term in transient elastography.

J Acoust Soc Am

Echosens, Research & Development Department, 42 rue Monge, 75005 Paris, France.

Published: January 2004

The transient radiation of low-frequency elastic waves through isotropic and homogeneous soft media is investigated using the Green's function approach. A careful analysis of the coupling term is performed and yields the introduction of a very near field region in which its amplitude behaves as 1/r. To address the calculation of impulse responses, a simplified Green's function is proposed for semi-infinite media and compared to exact solutions. Impulse response calculations are successfully compared with experimental measurements obtained for circular radiators of different diameters using transient elastography. Results presented in this paper provide a better understanding of the role of the coupling term in elastography and should be used to compensate diffraction and coupling effects observed in transient elastography.

Download full-text PDF

Source
http://dx.doi.org/10.1121/1.1635412DOI Listing

Publication Analysis

Top Keywords

coupling term
12
transient elastography
12
role coupling
8
green's function
8
transient
4
term transient
4
elastography
4
elastography transient
4
transient radiation
4
radiation low-frequency
4

Similar Publications

Background: Married or long-term partnered patients with chronic diseases generally have better outcomes than unmarried patients, likely due to the potential for multifaceted support. However, the impact of marital status on multiple sclerosis (MS) radiographic disease burden is currently unknown.

Objective: To compare total white matter hyperintensity lesion volumes, periventricular lesion volumes, and whole brain and grey matter volumes in married and unmarried people with MS (PwMS).

View Article and Find Full Text PDF

Hydrogels are flexible materials characterized by a 3D network structure, which possess high water content and adjustable physicochemical properties. They have found widespread applications in tissue engineering, electronic skin, drug delivery, flexible sensors, and photothermal therapy. However, hydrogel networks often exhibit swelling behavior in aqueous environments, which can result in structural degradation and a loss of gel performance.

View Article and Find Full Text PDF

Background: Acute hepatic porphyria (AHP) is characterized by debilitating and potentially life-threatening neurovisceral attacks, possible chronic symptoms, and long-term complications. In a phase 1/2 open-label extension (OLE) study and the phase 3 ENVISION study, givosiran led to sustained improvement in annualized attack rate and quality of life (QOL) measures. To capture the patient experience of symptoms and impacts of AHP, and any changes experienced during treatment with givosiran, qualitative interviews were conducted with study participants.

View Article and Find Full Text PDF

Cardiac Cine Magnetic Resonance Imaging (MRI) provides an accurate assessment of heart morphology and function in clinical practice. However, MRI requires long acquisition times, with recent deep learning-based methods showing great promise to accelerate imaging and enhance reconstruction quality. Existing networks exhibit some common limitations that constrain further acceleration possibilities, including single-domain learning, reliance on a single regularization term, and equal feature contribution.

View Article and Find Full Text PDF

BACKGROUND: Patients with brain tumors continue to exhibit a lower quality of life than the general population, even after an extended period after surgery. Therefore, this study aimed to assess the postoperative quality of life of patients with brain tumors in South Korea and explore its determinants. METHODS: This study used a descriptive correlational design and collected data using questionnaires and electronic medical records.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!