Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Transcription Attenuation in Prokaryotes02:42

Transcription Attenuation in Prokaryotes

18.5K
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure.  Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
18.5K
Design Consideration01:22

Design Consideration

582
Designing a structure involves a series of considerations, primarily the material's ultimate strength, calculated through tests that measure changes under increased force until the material reaches its breaking point or limit. The ultimate load, where the material breaks, is divided by its original cross-sectional area, resulting in the ultimate normal stress or strength. The ultimate shearing stress is another significant factor taken into account.
The factor of safety is another key...
582
Inertial Frames of Reference01:03

Inertial Frames of Reference

8.8K
Newton’s first law is usually considered to be a statement about reference frames. It provides a method for identifying a special type of reference frame: the inertial reference frame. In principle, we can make the net force on a body zero. If its velocity relative to a given frame is constant, then that frame is said to be inertial. So, by definition, an inertial reference frame is a reference frame where Newton's first law holds valid. Newton's first law applies to objects with...
8.8K
Non-inertial Frames of Reference01:27

Non-inertial Frames of Reference

7.2K
A reference frame accelerating or decelerating relative to an inertial frame is a non-inertial frame. To help understand this, consider what taking off in an airplane, turning a corner in a car, riding a merry-go-round, and the circular motion of a tropical cyclone all have in common. All these systems are accelerating, decelerating, or rotating relative to the Earth; hence, they all are non-inertial frames. All these systems exhibit inertial forces, which merely seem to arise from motion,...
7.2K
What are Estimates?01:06

What are Estimates?

8.8K
It isn't easy to measure a parameter such as the mean height or the mean weight of a population. So, we draw samples from the population and calculate the mean height or mean weight of the individuals in the sample. This sample data acts as a representative measure of the population parameter. These sample statistics are known as estimates. 
The estimate for the mean of a sample is denoted by ͞x, whereas the mean of the population is designated as μ. Further, parameters such...
8.8K
Tensile Strength Considerations of Concrete01:16

Tensile Strength Considerations of Concrete

558
Considering the tensile strength of concrete involves recognizing that the theoretical strength of cement paste can be up to a thousand times higher than what is observed in practical applications. This significant discrepancy is largely attributed to the presence of microscopic cracks within the concrete. These cracks tend to amplify stress at their tips when a load is applied, a phenomenon explained by Griffith's theory of brittle fracture.
The dimensions and shape of a concrete specimen...
558

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Lagrangian deformation tracking for strain imaging.

Progress in biomedical engineering (Bristol, England)·2026
Same author

Geometry aware neural radiance fields for freehand ultrasound reconstruction.

Biomedical physics & engineering express·2026
Same author

3D Freehand Ultrasound Reconstruction of the Carotid Artery.

Ultrasound in medicine & biology·2026
Same author

Introducing ARONG, A 3D Reconstruction Method for Highly Deformed Histology.

Journal of imaging informatics in medicine·2026
Same author

Comparison of 2D and 3D carotid plaque analysis and longitudinal <i>in vivo</i> ultrasound registration using 3D histology.

Journal of medical imaging (Bellingham, Wash.)·2026
Same author

Cerebrovascular Risk Factors for Body Mass Index, Diabetes, and Atherosclerosis in a Wisconsin Native American Population: A Cross-Sectional Observation Study.

Journal of the American Heart Association·2026
Same journal

Acoustic Characterization of a Modified IEC Agar-Based Tissue-Mimicking Material Across the 3.5-50 MHz Frequency Range.

Ultrasound in medicine & biology·2026
Same journal

Deep Learning-Based Standard Section Recognition and Multi-Organ Segmentation in Upper Abdominal Ultrasound.

Ultrasound in medicine & biology·2026
Same journal

Cardiac Natural Mechanical Wave Detection and Speed Estimation Using Deep Learning-Based 2-D Ultrasound Imaging: A Feasibility Study.

Ultrasound in medicine & biology·2026
Same journal

Region-Specific Evaluation of Plaque Segmentation in Cross-sectional Projections of Carotid Ultrasound Images Using Deep Learning Models in a Sub-clinical Atherosclerosis Cohort.

Ultrasound in medicine & biology·2026
Same journal

Simulating the Dedifferentiation Process of Thyroid Cancer: Insights from Mouse Models and Ultrasound Imaging.

Ultrasound in medicine & biology·2026
Same journal

A Nomogram Based on Ultrasound Features for Predicting Major Intra-Operative Hemorrhage in Patients With Placenta Accreta Spectrum (PAS).

Ultrasound in medicine & biology·2026
See all related articles

Related Experiment Video

Updated: Feb 8, 2026

P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation
06:09

P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation

Published on: September 8, 2023

958

Scatterer number density considerations in reference phantom-based attenuation estimation.

Nicholas Rubert1, Tomy Varghese1

  • 1Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.

Ultrasound in Medicine & Biology
|April 15, 2014
PubMed
Summary
This summary is machine-generated.

Attenuation estimation in liver tissue is crucial for thermal ablation monitoring. While reference phantoms assume Rayleigh scattering, biological tissues often deviate, increasing estimation variance in low scatterer number density (SND) conditions.

Keywords:
AttenuationEnvelope signal-to-noise ratioLiverMulti-taperReference phantomScatterer number densityThermal ablation

More Related Videos

Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy
09:25

Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy

Published on: August 22, 2018

13.2K
Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure
10:22

Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure

Published on: February 12, 2018

11.2K

Related Experiment Videos

Last Updated: Feb 8, 2026

P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation
06:09

P300-Based Brain-Computer Interface Speller Performance Estimation with Classifier-Based Latency Estimation

Published on: September 8, 2023

958
Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy
09:25

Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy

Published on: August 22, 2018

13.2K
Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure
10:22

Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure

Published on: February 12, 2018

11.2K

Area of Science:

  • Medical imaging
  • Ultrasound physics
  • Biomedical engineering

Background:

  • Attenuation estimation is vital for liver thermal ablation monitoring.
  • Current methods often use phantoms with high scatterer number density (SND), assuming Rayleigh scattering statistics.
  • Biological tissues frequently exhibit lower SND and deviate from Rayleigh statistics.

Purpose of the Study:

  • To investigate the impact of varying scatterer number density (SND) on ultrasound attenuation estimation accuracy.
  • To evaluate the robustness of attenuation estimation in biological tissues compared to phantoms.
  • To assess the effect of thermal coagulation on attenuation estimation in liver tissue.

Main Methods:

  • Attenuation estimation was performed using numerical and tissue-mimicking phantoms with variable SNDs.
  • Ex vivo bovine liver tissue, both before and after thermal coagulation, was analyzed.
  • Envelope signal-to-noise ratio (SNR) and attenuation slope were measured using specific ultrasound parameters and estimation kernel sizes.

Main Results:

  • Reference phantom-based attenuation estimation showed robustness to minor deviations from Rayleigh statistics.
  • Low SND in biological tissues led to significant increases in attenuation estimation variance as envelope SNR decreased.
  • Bias in attenuation slope estimates was negligible (<0.01 dB/cm-MHz) even with low SND.

Conclusions:

  • Attenuation estimation in low SND biological tissues is susceptible to increased variance, necessitating careful algorithm selection.
  • Standard phantom-based methods may require adjustments for accurate attenuation estimation in real biological tissues.
  • The study provides insights into the reliability of attenuation estimation for monitoring thermal ablation in liver.