Kathryn Radabaugh Nightingale

Journal article The Journal of the Acoustical Society of America · November 2025 Elastic properties of materials can be measured by observing shear wave propagation following localized, impulsive excitations and comparing the spatiotemporal signals with signals calculated using a mechanical model of the material. These calculations are ... Full text Cite

3D rotational shear wave elasticity imaging (3D-RSWEI) in anisotropic lattice phantoms.

Journal article Journal of the mechanical behavior of biomedical materials · October 2025 We present ultrasonic 3D rotational shear wave elasticity imaging (3D-RSWEI) characterization of anisotropic 3D-printed hydrogel lattice phantoms that were originally developed for magnetic resonance elastography (MRE) applications. Shear wave speeds versu ... Full text Cite

Evaluation of 3D ARFI imaging of prostate cancer: diagnostic reliability and concordance with MpMRI.

Journal article Cancer imaging : the official publication of the International Cancer Imaging Society · April 2025 PurposeThe prevalence of prostate cancer (PCa) necessitates advanced diagnostic approaches for detection and lesion characterization. Utilizing two patient cohorts (n = 85), this study analyzes a custom-designed 3D ultrasonic acoustic radiation fo ... Full text Cite

Clinical Feasibility of 3-D Acoustic Radiation Force Impulse (ARFI) Imaging for Targeted Prostate Biopsy Guidance.

Journal article Ultrason Imaging · March 2025 We have developed a 3-D acoustic radiation force impulse (ARFI) prostate imaging system to identify regions suspicious for cancer and guide a targeted prostate biopsy in a single visit. The system uses a side-fire transrectal probe and an automated rotatio ... Full text Link to item Cite

Parameterization of the stress-strain relation for modeling wave propagation in nearly incompressible transversely isotropic materials.

Journal article The Journal of the Acoustical Society of America · December 2024 The stress-strain relation in a transversely isotropic (TI) material is described by five independent parameters. In the incompressible limit, only three parameters are required to describe shear wave propagation. Existing material parameterization models ... Full text Cite

Multiparametric Ultrasound Imaging of Prostate Cancer Using Deep Neural Networks.

Journal article Ultrasound Med Biol · November 2024 OBJECTIVE: A deep neural network (DNN) was trained to generate a multiparametric ultrasound (mpUS) volume from four input ultrasound-based modalities (acoustic radiation force impulse [ARFI] imaging, shear wave elasticity imaging [SWEI], quantitative ultra ... Full text Link to item Cite

Ultrasound Shear Wave Elastography in Cardiology.

Journal article JACC. Cardiovascular imaging · March 2024 The advent of high-frame rate imaging in ultrasound allowed the development of shear wave elastography as a noninvasive alternative for myocardial stiffness assessment. It measures mechanical waves propagating along the cardiac wall with speeds that are re ... Full text Cite

Rotational 3D shear wave elasticity imaging: Effect of knee flexion on 3D shear wave propagation in in vivo vastus lateralis.

Journal article J Mech Behav Biomed Mater · February 2024 Skeletal muscle is a complex tissue, exhibiting not only direction-dependent material properties (commonly modeled as a transversely isotropic material), but also changes in observed material properties due to factors such as contraction and passive stretc ... Full text Link to item Cite

Combined ARFI and Shear Wave Imaging of Prostate Cancer: Optimizing Beam Sequences and Parameter Reconstruction Approaches.

Journal article Ultrason Imaging · July 2023 This study demonstrates the implementation of a shear wave reconstruction algorithm that enables concurrent acoustic radiation force impulse (ARFI) imaging and shear wave elasticity imaging (SWEI) of prostate cancer and zonal anatomy. The combined ARFI/SWE ... Full text Link to item Cite

Repeatability of Rotational 3-D Shear Wave Elasticity Imaging Measurements in Skeletal Muscle.

Journal article Ultrasound Med Biol · March 2023 Shear wave elasticity imaging (SWEI) usually assumes an isotropic material; however, skeletal muscle is typically modeled as a transversely isotropic material with independent shear wave speeds in the directions along and across the muscle fibers. To captu ... Full text Link to item Cite

Quantifying the Impact of Imaging Through Body Walls on Shear Wave Elasticity Measurements.

Journal article Ultrasound in medicine & biology · March 2023 In the context of ultrasonic hepatic shear wave elasticity imaging (SWEI), measurement success has been determined to increase when using elevated acoustic output pressures. As SWEI sequences consist of two distinct operations (pushing and tracking), acqui ... Full text Cite

Parametric Analysis of SV Mode Shear Waves in Transversely Isotropic Materials Using Ultrasonic Rotational 3-D SWEI.

Journal article IEEE Trans Ultrason Ferroelectr Freq Control · November 2022 Ultrasonic rotational 3-D shear wave elasticity imaging (SWEI) has been used to induce and evaluate multiple shear wave modes, including both the shear horizontal (SH) and shear vertical (SV) modes in in vivo muscle. Observations of both the SH and SV mode ... Full text Link to item Cite

Perspective on ultrasound bioeffects and possible implications for continuous post-dive monitoring safety.

Journal article Diving and hyperbaric medicine · June 2022 Ultrasound monitoring, both in the form of Doppler and 2D echocardiography, has been used post-dive to detect decompression bubbles circulating in the bloodstream. With large variability in both bubble time course and loads, it has been hypothesised that s ... Full text Cite

Phase and group velocities for shear wave propagation in an incompressible, hyperelastic material with uniaxial stretch.

Journal article Physics in medicine and biology · April 2022 Objective.Determining elastic properties of materials from observations of shear wave propagation is difficult in anisotropic materials because of the complex relations among the propagation direction, shear wave polarizations, and material symmetri ... Full text Cite

Methods of monitoring thermal ablation of soft tissue tumors - A comprehensive review.

Journal article Medical physics · February 2022 Thermal ablation is a form of hyperthermia in which oncologic control can be achieved by briefly inducing elevated temperatures, typically in the range 50-80°C, within a target tissue. Ablation modalities include high intensity focused ultrasound, radiofre ... Full text Cite

Full Characterization of in vivo Muscle as an Elastic, Incompressible, Transversely Isotropic Material Using Ultrasonic Rotational 3D Shear Wave Elasticity Imaging.

Journal article IEEE Trans Med Imaging · January 2022 Using a 3D rotational shear wave elasticity imaging (SWEI) setup, 3D shear wave data were acquired in the vastus lateralis of a healthy volunteer. The innate tilt between the transducer face and the muscle fibers results in the excitation of multiple shear ... Full text Link to item Cite

Assessing cardiac stiffness using ultrasound shear wave elastography.

Journal article Physics in medicine and biology · January 2022 Shear wave elastography offers a new dimension to echocardiography: it measures myocardial stiffness. Therefore, it could provide additional insights into the pathophysiology of cardiac diseases affecting myocardial stiffness and potentially improve diagno ... Full text Cite

Uniqueness of shear wave modeling in an incompressible, transversely isotropic (ITI) material.

Journal article Physics in medicine and biology · October 2021 Five material parameters are required to describe a transversely isotropic (TI) material including two Poisson's ratios that characterize the compressibility of the material. Both Poisson's ratios must be specified to model an incompressible, TI (ITI) mate ... Full text Cite

On the Relationship between Spatial Coherence and In Situ Pressure for Abdominal Imaging.

Journal article Ultrasound in medicine & biology · August 2021 Tissue harmonic signal quality has been shown to improve with elevated acoustic pressure. The peak rarefaction pressure (PRP) for a given transmit, however, is limited by the Food and Drug Administration guidelines for mechanical index. We have previously ... Full text Cite

Prostate Cancer Detection Using 3-D Shear Wave Elasticity Imaging.

Journal article Ultrasound Med Biol · July 2021 Transrectal ultrasound (TRUS) B-mode imaging provides insufficient sensitivity and specificity for prostate cancer (PCa) targeting when used for biopsy guidance. Shear wave elasticity imaging (SWEI) is an elasticity imaging technique that has been commerci ... Full text Link to item Cite

Deep Convolutional Neural Networks for Displacement Estimation in ARFI Imaging.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · July 2021 Ultrasound elasticity imaging in soft tissue with acoustic radiation force requires the estimation of displacements, typically on the order of several microns, from serially acquired raw data A-lines. In this work, we implement a fully convolutional neural ... Full text Cite

Semi-automated weak annotation for deep neural network skin thickness measurement.

Journal article Ultrason Imaging · July 2021 Correctly calculating skin stiffness with ultrasound shear wave elastography techniques requires an accurate measurement of skin thickness. We developed and compared two algorithms, a thresholding method and a deep learning method, to measure skin thicknes ... Full text Link to item Cite

Quantifying the Effect of Abdominal Body Wall on In Situ Peak Rarefaction Pressure During Diagnostic Ultrasound Imaging.

Journal article Ultrasound in medicine & biology · June 2021 In this study, 3-D non-linear ultrasound simulations and experimental measurements were used to estimate the range of in situ pressures that can occur during transcutaneous abdominal imaging and to identify the sources of error when estimating in situ peak ... Full text Cite

Radiological Society of North America/Quantitative Imaging Biomarker Alliance Shear Wave Speed Bias Quantification in Elastic and Viscoelastic Phantoms.

Journal article J Ultrasound Med · March 2021 OBJECTIVES: To quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms. METHODS: Two elastic phantoms, ... Full text Link to item Cite

Multiparametric Ultrasound for Targeting Prostate Cancer: Combining ARFI, SWEI, QUS and B-Mode.

Journal article Ultrasound Med Biol · December 2020 Diagnosing prostate cancer through standard transrectal ultrasound (TRUS)-guided biopsy is challenging because of the sensitivity and specificity limitations of B-mode imaging. We used a linear support vector machine (SVM) to combine standard TRUS imaging ... Full text Link to item Cite

Analysis of multiple shear wave modes in a nonlinear soft solid: Experiments and finite element simulations with a tilted acoustic radiation force.

Journal article Journal of the mechanical behavior of biomedical materials · July 2020 Tissue nonlinearity is conventionally measured in shear wave elastography by studying the change in wave speed caused by the tissue deformation, generally known as the acoustoelastic effect. However, these measurements have mainly focused on the excitation ... Full text Cite

On the Challenges Associated with Obtaining Reproducible Measurements Using SWEI in the Median Nerve.

Journal article Ultrasound Med Biol · May 2020 This work discusses challenges we have encountered in acquiring reproducible measurements of shear wave speed (SWS) in the median nerve and suggests methods for improving reproducibility. First, procedural acquisition challenges are described, including ne ... Full text Link to item Cite

Measurement of Viscoelastic Material Model Parameters Using Fractional Derivative Group Shear Wave Speeds in Simulation and Phantom Data.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · February 2020 While ultrasound shear wave elastography originally focused on tissue stiffness under the assumption of elasticity, recent work has investigated the higher order, viscoelastic properties of the tissue. This article presents a method to use group shear wave ... Full text Cite

Tractable calculation of the Green's tensor for shear wave propagation in an incompressible, transversely isotropic material.

Journal article Physics in medicine and biology · January 2020 Assessing material properties from observations of shear wave propagation following an acoustic radiation force impulse (ARFI) excitation is difficult in anisotropic materials because of the complex relations among the propagation direction, shear wave pol ... Full text Cite

Characterization of Viscoelastic Materials Using Group Shear Wave Speeds.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · May 2018 Recent investigations of viscoelastic properties of materials have been performed by observing shear wave propagation following localized, impulsive excitations, and Fourier decomposing the shear wave signal to parameterize the frequency-dependent phase ve ... Full text Cite

Impact of Acoustic Radiation Force Excitation Geometry on Shear Wave Dispersion and Attenuation Estimates.

Journal article Ultrasound in medicine & biology · April 2018 Shear wave elasticity imaging (SWEI) characterizes the mechanical properties of human tissues to differentiate healthy from diseased tissue. Commercial scanners tend to reconstruct shear wave speeds for a region of interest using time-of-flight methods rep ... Full text Cite

Evaluating the Benefit of Elevated Acoustic Output in Harmonic Motion Estimation in Ultrasonic Shear Wave Elasticity Imaging.

Journal article Ultrasound Med Biol · February 2018 Harmonic imaging techniques have been applied in ultrasonic elasticity imaging to obtain higher-quality tissue motion tracking data. However, harmonic tracking can be signal-to-noise ratio and penetration depth limited during clinical imaging, resulting in ... Full text Link to item Cite

Accounting for the Spatial Observation Window in the 2-D Fourier Transform Analysis of Shear Wave Attenuation.

Journal article Ultrasound in medicine & biology · October 2017 Recent measurements of shear wave propagation in viscoelastic materials have been analyzed by constructing the 2-D Fourier transform (2DFT) of the shear wave signal and measuring the phase velocity c(ω) and attenuation α(ω) from the peak location and full ... Full text Cite

Quantifying Image Quality Improvement Using Elevated Acoustic Output in B-Mode Harmonic Imaging.

Journal article Ultrasound Med Biol · October 2017 Tissue harmonic imaging has been widely used in abdominal imaging because of its significant reduction in acoustic noise compared with fundamental imaging. However, tissue harmonic imaging can be limited by both signal-to-noise ratio and penetration depth ... Full text Link to item Cite

Ultrasonic Shear Wave Elasticity Imaging Sequencing and Data Processing Using a Verasonics Research Scanner.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · January 2017 Ultrasound elasticity imaging has been developed over the last decade to estimate tissue stiffness. Shear wave elasticity imaging (SWEI) quantifies tissue stiffness by measuring the speed of propagating shear waves following acoustic radiation force excita ... Full text Cite

Evaluating the Improvement in Shear Wave Speed Image Quality Using Multidimensional Directional Filters in the Presence of Reflection Artifacts.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · August 2016 Shear waves propagating through interfaces where there is a change in stiffness cause reflected waves that can lead to artifacts in shear wave speed (SWS) reconstructions. Two-dimensional (2-D) directional filters are commonly used to reduce in-plane refle ... Full text Cite

Identifying Clinically Significant Prostate Cancers using 3-D In Vivo Acoustic Radiation Force Impulse Imaging with Whole-Mount Histology Validation.

Journal article Ultrasound Med Biol · June 2016 Overly aggressive prostate cancer (PCa) treatment adversely affects patients and places an unnecessary burden on our health care system. The inability to identify and grade clinically significant PCa lesions is a factor contributing to excessively aggressi ... Full text Link to item Cite

On System-Dependent Sources of Uncertainty and Bias in Ultrasonic Quantitative Shear-Wave Imaging.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · March 2016 Ultrasonic quantitative shear-wave imaging methods have been developed over the last decade to estimate tissue elasticity by measuring the speed of propagating shear waves following acoustic radiation force excitation. This work discusses eight sources of ... Full text Cite

Preliminary Results on the Feasibility of Using ARFI/SWEI to Assess Cutaneous Sclerotic Diseases.

Journal article Ultrasound Med Biol · November 2015 In this study, acoustic radiation force impulse (ARFI) and shear wave elasticity imaging (SWEI) were applied to the skin to investigate the feasibility of their use in assessing sclerotic skin diseases. Our motivation was to develop a non-invasive imaging ... Full text Link to item Cite

An analytic, Fourier domain description of shear wave propagation in a viscoelastic medium using asymmetric Gaussian sources.

Journal article The Journal of the Acoustical Society of America · August 2015 Recent measurements of shear wave propagation in viscoelastic materials have been analyzed by constructing the two-dimensional Fourier transform (2D-FT) of the spatial-temporal shear wave signal and using an analysis procedure derived under the assumption ... Full text Cite

Analyzing the Impact of Increasing Mechanical Index and Energy Deposition on Shear Wave Speed Reconstruction in Human Liver.

Journal article Ultrasound in medicine & biology · July 2015 Shear wave elasticity imaging (SWEI) has found success in liver fibrosis staging. This work evaluates hepatic SWEI measurement success as a function of push pulse energy using two mechanical index (MI) values (1.6 and 2.2) over a range of pulse durations. ... Full text Cite

Conditionally Increased Acoustic Pressures in Nonfetal Diagnostic Ultrasound Examinations Without Contrast Agents: A Preliminary Assessment.

Journal article Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine · July 2015 The mechanical index (MI) has been used by the US Food and Drug Administration (FDA) since 1992 for regulatory decisions regarding the acoustic output of diagnostic ultrasound equipment. Its formula is based on predictions of acoustic cavitation under spec ... Full text Cite

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver.

Journal article Ultrasound in medicine & biology · May 2015 The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced these guidelines for the use of elastography techniques in liver disease. For each available technique, the reproducibility, results, and limitations are analyzed, and recomme ... Full text Cite

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 1: basic principles and terminology.

Journal article Ultrasound in medicine & biology · May 2015 Conventional diagnostic ultrasound images of the anatomy (as opposed to blood flow) reveal differences in the acoustic properties of soft tissues (mainly echogenicity but also, to some extent, attenuation), whereas ultrasound-based elasticity images are ab ... Full text Cite

WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 2: breast.

Journal article Ultrasound in medicine & biology · May 2015 The breast section of these Guidelines and Recommendations for Elastography produced under the auspices of the World Federation of Ultrasound in Medicine and Biology (WFUMB) assesses the clinically used applications of all forms of elastography used in bre ... Full text Cite

Single- and multiple-track-location shear wave and acoustic radiation force impulse imaging: matched comparison of contrast, contrast-to-noise ratio and resolution.

Journal article Ultrasound in medicine & biology · April 2015 Acoustic radiation force impulse imaging and shear wave elasticity imaging (SWEI) use the dynamic response of tissue to impulsive mechanical stimulus to characterize local elasticity. A variant of conventional, multiple-track-location SWEI, denoted single- ... Full text Cite

A theoretical study of inertial cavitation from acoustic radiation force impulse imaging and implications for the mechanical index.

Journal article Ultrasound in medicine & biology · February 2015 The mechanical index (MI) attempts to quantify the likelihood that exposure to diagnostic ultrasound will produce an adverse biological effect by a non-thermal mechanism. The current formulation of the MI implicitly assumes that the acoustic field is gener ... Full text Cite

Analysis of rapid multi-focal-zone ARFI imaging.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · February 2015 Acoustic radiation force impulse (ARFI) imaging has shown promise for visualizing structure and pathology within multiple organs; however, because the contrast depends on the push beam excitation width, image quality suffers outside of the region of excita ... Full text Cite

B-mode and acoustic radiation force impulse (ARFI) imaging of prostate zonal anatomy: comparison with 3T T2-weighted MR imaging.

Journal article Ultrason Imaging · January 2015 Prostate cancer (PCa) is the most common non-cutaneous malignancy among men in the United States and the second leading cause of cancer-related death. Multi-parametric magnetic resonance imaging (mpMRI) has gained recent popularity to characterize PCa. Aco ... Full text Link to item Cite

Derivation and analysis of viscoelastic properties in human liver: impact of frequency on fibrosis and steatosis staging.

Journal article IEEE Trans Ultrason Ferroelectr Freq Control · January 2015 Commercially-available shear wave imaging systems measure group shear wave speed (SWS) and often report stiffness parameters applying purely elastic material models. Soft tissues, however, are viscoelastic, and higher-order material models are necessary to ... Full text Link to item Cite

Finite element modeling of impulsive excitation and shear wave propagation in an incompressible, transversely isotropic medium.

Journal article Journal of biomechanics · November 2013 Elastic properties of materials can be measured by observing shear wave propagation following localized, impulsive excitations and relating the propagation velocity to a model of the material. However, characterization of anisotropic materials is difficult ... Full text Cite

Imaging transverse isotropic properties of muscle by monitoring acoustic radiation force induced shear waves using a 2-D matrix ultrasound array.

Journal article IEEE transactions on medical imaging · September 2013 A 2-D matrix ultrasound array is used to monitor acoustic radiation force impulse (ARFI) induced shear wave propagation in 3-D in excised canine muscle. From a single acquisition, both the shear wave phase and group velocity can be calculated to estimate t ... Full text Cite

Acoustic radiation force elasticity imaging in diagnostic ultrasound.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · April 2013 The development of ultrasound-based elasticity imaging methods has been the focus of intense research activity since the mid-1990s. In characterizing the mechanical properties of soft tissues, these techniques image an entirely new subset of tissue propert ... Full text Cite

On the precision of time-of-flight shear wave speed estimation in homogeneous soft solids: initial results using a matrix array transducer.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · April 2013 A system capable of tracking radiation-force-induced shear wave propagation in a 3-D volume using ultrasound is presented. In contrast to existing systems, which use 1-D array transducers, a 2-D matrix array is used for tracking shear wave displacements. A ... Full text Cite

Should the mechanical index be revised for ARFI imaging?

Journal article IEEE International Ultrasonics Symposium : [proceedings]. IEEE International Ultrasonics Symposium · October 2012 The mechanical index (MI) quantifies the likelihood that exposure to diagnostic ultrasound will produce an adverse biological effect by a nonthermal mechanism. The current formulation of the MI is based on inertial cavitation thresholds in two liquids, wat ... Full text Cite

Parameters affecting the resolution and accuracy of 2-D quantitative shear wave images.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · August 2012 Time-of-flight methods allow quantitative measurement of shear wave speed (SWS) from ultrasonically tracked displacements following impulsive acoustic radiation force excitation in tissue. In heterogeneous materials, reflections at boundaries can distort t ... Full text Cite

Functional neuroimaging using ultrasonic blood-brain barrier disruption and manganese-enhanced MRI.

Journal article J Vis Exp · July 12, 2012 Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been u ... Full text Link to item Cite

Reply to: The use of acoustic radiation force-based shear stiffness in non-alcoholic fatty liver disease

Journal article Journal of Hepatology · April 1, 2012 Full text Cite

Acoustic radiation force impulse imaging of human prostates: initial in vivo demonstration.

Journal article Ultrasound Med Biol · January 2012 Reliably detecting prostate cancer (PCa) has been a challenge for current imaging modalities. Acoustic radiation force impulse (ARFI) imaging is an elasticity imaging method that uses remotely generated, focused acoustic beams to probe tissue stiffness. A ... Full text Link to item Cite

The impact of hepatic pressurization on liver shear wave speed estimates in constrained versus unconstrained conditions.

Journal article Physics in medicine and biology · January 2012 Increased hepatic venous pressure can be observed in patients with advanced liver disease and congestive heart failure. This elevated portal pressure also leads to variation in acoustic radiation-force-derived shear wave-based liver stiffness estimates. Th ... Full text Cite

Comparison between Acoustic Radiation Force Impulse (ARFI)-based hepatic stiffness quantification in deformed and undeformed pressurized canine livers

Journal article IEEE International Ultrasonics Symposium Ius · December 1, 2011 Increased hepatic interstitial pressure can be observed in patients with advanced liver disease and is associated with worsened clinical outcomes. Elevated hepatic stiffness has been reported clinically with increases in hepatic venous pressure gradient (H ... Full text Cite

Improving shear wave speed estimation precision in homogeneous media by tracking shear wave propagation in 3D using a real-time volumetric imaging transducer

Journal article IEEE International Ultrasonics Symposium Ius · December 1, 2011 A system capable of tracking radiation force induced shear wave propagation in 3D using ultrasound is presented. In contrast to existing systems, which use 1D array transducers, a 2D matrix array is used for tracking shear wave displacements. A HIFU piston ... Full text Cite

Acoustic Radiation Force Impulse (ARFI) Imaging: a Review.

Journal article Current medical imaging reviews · November 2011 Acoustic radiation force based elasticity imaging methods are under investigation by many groups. These methods differ from traditional ultrasonic elasticity imaging methods in that they do not require compression of the transducer, and are thus expected t ... Full text Cite

Combined ultrasonic thermal ablation with interleaved ARFI image monitoring using a single diagnostic curvilinear array: a feasibility study.

Journal article Ultrasonic imaging · October 2011 The goal of this work is to demonstrate the feasibility of using a diagnostic ultrasound system (Siemens Antares and CH6-2 curvilinear array) to ablate ex vivo liver with a custom M-mode sequence and monitor the resulting tissue stiffening with 2-D Acousti ... Full text Cite

Noninvasive evaluation of hepatic fibrosis using acoustic radiation force-based shear stiffness in patients with nonalcoholic fatty liver disease.

Journal article J Hepatol · September 2011 BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD), the most common form of chronic liver disease in developed countries, may progress to nonalcoholic steatohepatitis (NASH) in a minority of people. Those with NASH are at increased risk for cirrho ... Full text Link to item Cite

Acoustic radiation force-based elasticity imaging methods.

Journal article Interface focus · August 2011 Conventional diagnostic ultrasound images portray differences in the acoustic properties of soft tissues, whereas ultrasound-based elasticity images portray differences in the elastic properties of soft tissues (i.e. stiffness, viscosity). The benefit of e ... Full text Cite

What challenges must be overcome before ultrasound elasticity imaging is ready for the clinic?

Journal article Imaging in medicine · August 2011 Ultrasound elasticity imaging has been a research interest for the past 20 years with the goal of generating novel images of soft tissues based on their material properties (i.e., stiffness and viscosity). The motivation for such an imaging modality lies i ... Full text Cite

Acoustic radiation force-driven assessment of myocardial elasticity using the displacement ratio rate (DRR) method.

Journal article Ultrasound in medicine & biology · July 2011 A noninvasive method of characterizing myocardial stiffness could have significant implications in diagnosing cardiac disease. Acoustic radiation force (ARF)-driven techniques have demonstrated their ability to discern elastic properties of soft tissue. Fo ... Full text Cite

GPU-based real-time small displacement estimation with ultrasound.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · February 2011 General purpose computing on graphics processing units (GPUs) has been previously shown to speed up computationally intensive data processing and image reconstruction algorithms for computed tomography (CT), magnetic resonance (MR), and ultrasound images. ... Full text Cite

Acoustic Radiation Force Impulse (ARFI) imaging-based needle visualization.

Journal article Ultrason Imaging · January 2011 Ultrasound-guided needle placement is widely used in the clinical setting, particularly for central venous catheter placement, tissue biopsy and regional anesthesia. Difficulties with ultrasound guidance in these areas often result from steep needle insert ... Full text Link to item Cite

Robust estimation of time-of-flight shear wave speed using a radon sum transformation.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · December 2010 Time-of-flight methods allow quantitative measurement of shear wave speed (SWS) from ultrasonically tracked displacements following impulsive excitation in tissue. However, application of these methods to in vivo data are challenging because of the presenc ... Full text Cite

Robust estimation of time-of-flight shear wave speed using a Radon sum transformation

Journal article Proceedings IEEE Ultrasonics Symposium · December 1, 2010 Time-of-flight methods allow quantitative measurement of shear wave speed (SWS) from ultrasonically tracked displacements following impulsive excitation in tissue. However, application of these methods to in vivo data is challenging due to the presence of ... Full text Cite

Contrast-enhanced in vivo magnetic resonance microscopy of the mouse brain enabled by noninvasive opening of the blood-brain barrier with ultrasound.

Journal article Magn Reson Med · October 2010 The use of contrast agents for neuroimaging is limited by the blood-brain barrier (BBB), which restricts entry into the brain. To administer imaging agents to the brain of rats, intracarotid infusions of hypertonic mannitol have been used to open the BBB. ... Full text Link to item Cite

Characterizing stiffness of human prostates using acoustic radiation force.

Journal article Ultrason Imaging · October 2010 Acoustic Radiation Force Impulse (ARFI) imaging has been previously reported to portray normal anatomic structures and pathologies in ex vivo human prostates with good contrast and resolution. These findings were based on comparison with histological slide ... Full text Link to item Cite

Imaging arrays with improved transmit power capability.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · September 2010 Bonded multilayer ceramics and composites incorporating low-loss piezoceramics have been applied to arrays for ultrasound imaging to improve acoustic transmit power levels and to reduce internal heating. Commercially available hard PZT from multiple vendor ... Full text Cite

Improving the robustness of time-of-flight based shear wave speed reconstruction methods using RANSAC in human liver in vivo.

Journal article Ultrasound in medicine & biology · May 2010 The stiffness of tissue can be quantified by measuring the shear wave speed (SWS) within the medium. Ultrasound is a real-time imaging modality capable of tracking the propagation of shear waves in soft tissue. Time-of-flight (TOF) methods have previously ... Full text Cite

Acoustic radiation force impulse imaging of human prostates ex vivo.

Journal article Ultrasound Med Biol · April 2010 It has been challenging for clinicians using current imaging modalities to visualize internal structures and detect lesions inside human prostates. Lack of contrast among prostatic tissues and high false positive or negative detection rates of prostate les ... Full text Link to item Cite

Quantitative images of elastic modulus using tissue dynamics in the region of impulsive acoustic radiation force excitation

Journal article ASME International Mechanical Engineering Congress and Exposition Proceedings · January 1, 2010 Focused, impulsive, acoustic radiation force excitations can generate shear waves with microns of displacement in tissue. The speed of shear wave propagation is directly related to the tissue's shear modulus, which can be correlated with tissue pathology t ... Full text Cite

In vivo quantification of liver stiffness in a rat model of hepatic fibrosis with acoustic radiation force.

Journal article Ultrasound Med Biol · October 2009 Liver fibrosis is currently staged using needle biopsy, a highly invasive procedure with a number of disadvantages. Measurement of liver stiffness changes that accompany progression of the disease may provide a quantitative and noninvasive method to assess ... Full text Link to item Cite

Blood-brain barrier (BBB) disruption using a diagnostic ultrasound scanner and Definity in Mice.

Journal article Ultrasound in medicine & biology · August 2009 The objective of this work was to determine whether diagnostic ultrasound and contrast agent could be used to transcranially and nondestructively disrupt the blood-brain barrier (BBB) in mice under ultrasound image guidance and to quantify that disruption ... Full text Cite

On the feasibility of imaging peripheral nerves using acoustic radiation force impulse imaging.

Journal article Ultrason Imaging · July 2009 Regional anesthesia is preferred over general anesthesia for many surgical procedures; however, challenges associated with poor image guidance limit its widespread acceptance as a viable alternative. In B-mode ultrasound images, the current standard for gu ... Full text Link to item Cite

An integrated indenter-ARFI imaging system for tissue stiffness quantification.

Journal article Ultrasonic imaging · April 2008 The goal of this work is to develop and characterize an integrated indenter-ARFI (acoustic radiation force impulse) imaging system. This system is capable of acquiring matched datasets of ARFI images and stiffness profiles from ex vivo tissue samples, whic ... Full text Cite

Quantifying hepatic shear modulus in vivo using acoustic radiation force.

Journal article Ultrasound in medicine & biology · April 2008 The speed at which shear waves propagate in tissue can be used to quantify the shear modulus of the tissue. As many groups have shown, shear waves can be generated within tissues using focused, impulsive, acoustic radiation force excitations, and the resul ... Full text Cite

Dependence of in vivo, radiation force derived hepatic shear modulus estimates on imaging approach: Intercostal vs. subcostal

Journal article Proceedings IEEE Ultrasonics Symposium · December 1, 2007 The speed at which shear waves propagate can be used to quantify the shear modulus of tissue. Focused, impulsive, acoustic radiation force excitations can be used to generate transient displacement fields in soft tissue that create shear waves that propaga ... Full text Cite

In-vivo staging of liver fibrosis in a rat model using acoustic radiation force

Journal article Proceedings IEEE Ultrasonics Symposium · December 1, 2007 Liver fibrosis is currently staged using needle biopsy, a highly invasive procedure with a number of disadvantages. Measurement of liver stiffness changes which accompany progression of the disease may provide a quantitative and noninvasive method to asses ... Full text Cite

A parallel tracking method for acoustic radiation force impulse imaging

Journal article IEEE Trans. Ultrason. Ferroelectr. Freq. Control (USA) · 2007 Radiation force-based techniques have been developed by several groups for imaging the mechanical properties of tissue. Acoustic radiation force impulse (ARFI) imaging is one such method that uses commercially available scanners to generate localized radia ... Cite

On the potential for guidance of ablation therapy using acoustic radiation force impulse imaging

Journal article 2007 4th IEEE International Symposium on Biomedical Imaging from Nano to Macro Proceedings · January 1, 2007 Acoustic radiation force imaging methods utilize acoustic radiation force to mechanically excite tissue, and the tissue response is monitored with conventional imaging methods. Radiation force based methods comprise a subset of elasticity imaging, in which ... Full text Cite

Shear wave velocity estimation using acoustic radiation force impulsive excitation in liver In Vivo

Journal article Proceedings IEEE Ultrasonics Symposium · December 1, 2006 Acoustic radiation force can be used to mechanically excite tissue in remote, focused locations, and the tissue response can be monitored using ultrasonic correlation based methods. The speed with which the resulting shear waves propagate away from the foc ... Full text Cite

Dynamic mechanical response of elastic spherical inclusions to impulsive acoustic radiation force excitation.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · November 2006 Acoustic radiation force impulse imaging has been used clinically to study the dynamic response of lesions relative to their background material to focused, impulsive acoustic radiation force excitations through the generation of dynamic displacement field ... Full text Cite

Ultrasonic tracking of acoustic radiation force-induced displacements in homogeneous media.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · July 2006 The use of ultrasonic methods to track the tissue deformation generated by acoustic radiation force is subject to jitter and displacement underestimation errors, with displacement underestimation being primarily caused by lateral and elevation shearing wit ... Full text Cite

Streaming detection for evaluation of indeterminate sonographic breast masses: a pilot study.

Journal article AJR Am J Roentgenol · May 2006 OBJECTIVE: Streaming detection is a novel sonography technique that uses ultrasonic energy to induce movement in cyst fluid that is detected on Doppler sonography. This pilot study evaluates the utility of streaming detection for differentiating cysts from ... Full text Link to item Cite

Characterizing acoustic attenuation of homogeneous media using focused impulsive acoustic radiation force.

Journal article Ultrasonic imaging · April 2006 A new method to characterize a material's attenuation using acoustic radiation force is proposed. Comparison of displacement magnitudes generated in a homogeneous material by acoustic radiation force excitations can be used to estimate the material's atten ... Full text Cite

Undergraduate biomedical imaging education.

Journal article Annals of biomedical engineering · February 2006 Full text Cite

Analysis of contrast in images generated with transient acoustic radiation force.

Journal article Ultrasound in medicine & biology · January 2006 Several mechanical imaging methods are under investigation that use focused ultrasound (US) as a source of mechanical excitation. Images are then generated of the tissue response to this localized excitation. One such method, acoustic radiation force impul ... Full text Cite

A combined indenter/ARFI imaging system

Journal article Proceedings IEEE Ultrasonics Symposium · December 1, 2005 The goal of this project is to develop an integrated indenter-ARFI (acoustic radiation force impulse imaging) system. The system is capable of acquiring matched datasets from ex vivo tissue samples, which will be used to evaluate excised colorectal tumors ... Full text Cite

A finite-element method model of soft tissue response to impulsive acoustic radiation force.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · October 2005 Several groups are studying acoustic radiation force and its ability to image the mechanical properties of tissue. Acoustic radiation force impulse (ARFI) imaging is one modality using standard diagnostic ultrasound scanners to generate localized, impulsiv ... Full text Cite

Acoustic radiation force impulse imaging of the abdomen: demonstration of feasibility and utility.

Journal article Ultrasound Med Biol · September 2005 The feasibility of utilizing acoustic radiation force impulse (ARFI) imaging to assess the mechanical properties of abdominal tissues was investigated. The thermal safety of the technique was also evaluated through the use of finite element method models. ... Full text Link to item Cite

Acoustic radiation force impulse imaging of myocardial radiofrequency ablation: initial in vivo results.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · April 2005 Acoustic radiation force impulse (ARFI) imaging techniques were used to monitor radiofrequency (RF) ablation of ovine cardiac tissue in vivo. Additionally, ARFI M-mode imaging methods were used to interrogate both healthy and ablated regions of myocardial ... Full text Cite

Acoustic radiation force impulse (ARFI) imaging of the gastrointestinal tract.

Journal article Ultrason Imaging · April 2005 The evaluation of lesions in the gastrointestinal (GI) tract using ultrasound can suffer from poor contrast between healthy and diseased tissue. Acoustic Radiation Force Impulse (ARFI) imaging provides information about the mechanical properties of tissue ... Full text Link to item Cite

Acoustic radiation force impulse imaging of the mechanical properties of arteries: in vivo and ex vivo results.

Journal article Ultrasound Med Biol · September 2004 We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified commercial sca ... Full text Link to item Cite

On the thermal effects associated with radiation force imaging of soft tissue.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · May 2004 Several laboratories are investigating the use of acoustic radiation force to image the mechanical properties of tissue. Acoustic Radiation Force Impulse (ARFI) imaging is one approach that uses brief, high-intensity, focused ultrasound pulses to generate ... Full text Cite

On the thermal effects associated with radiation force imaging of soft tissue.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · May 1, 2004 Several laboratories are investigating the use of acoustic radiation force to image the mechanical properties of tissue. Acoustic Radiation Force Impulse (ARFI) imaging is one approach that uses brief, high-intensity, focused ultrasound pulses to generate ... Full text Cite

Experimental studies of the thermal effects associated with radiation force imaging of soft tissue.

Journal article Ultrasonic imaging · April 2004 Many groups are studying acoustic radiation force-based imaging modalities to determine the mechanical properties of tissue. Acoustic Radiation Force Impulse (ARFI) imaging is one of these modalities that uses standard diagnostic ultrasound scanners to gen ... Full text Cite

Acoustic radiation force impulse imaging of thermally- and chemically-induced lesions in soft tissues: preliminary ex vivo results.

Journal article Ultrasound in medicine & biology · March 2004 The ability of acoustic radiation force impulse (ARFI) imaging to visualize thermally- and chemically-induced lesions in soft tissues was investigated. Lesions were induced in freshly excised bovine liver samples. Chemical lesions were induced via the inje ... Full text Cite

Imaging tissue mechanical properties using impulsive acoustic radiation force

Journal article 2004 2nd IEEE International Symposium on Biomedical Imaging Macro to Nano · January 1, 2004 Acoustic Radiation Force Impulse (ARFI) imaging utilizes brief, high energy, focused acoustic pulses to generate radiation force in tissue, and conventional diagnostic ultrasound methods to detect the resulting tissue displacements in order to image the re ... Full text Cite

Shear-wave generation using acoustic radiation force: in vivo and ex vivo results.

Journal article Ultrasound in medicine & biology · December 2003 Acoustic radiation force impulse (ARFI) imaging involves the mechanical excitation of tissue using localized, impulsive radiation force. This results in shear-wave propagation away from the region of excitation. Using a single diagnostic transducer on a mo ... Full text Cite

Acoustic radiation force impulse imaging: A parametric analysis of factors affecting image quality

Journal article Proceedings of the IEEE Ultrasonics Symposium · December 1, 2003 Acoustic Radiation Force Impulse (ARFI) imaging utilizes brief, high energy, focused acoustic pulses to generate radiation force in tissue, and conventional diagnostic ultrasound methods to detect the resulting tissue displacements in order to image the me ... Cite

ARFI imaging of the cardiovascular system

Journal article Proceedings of the IEEE Ultrasonics Symposium · December 1, 2003 We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the medial and adventitial layers in the carotid, and popliteal arteries. The data was obt ... Cite

BSS-based filtering of physiological and ARFI-induced tissue and blood motion.

Journal article Ultrasound in medicine & biology · November 2003 Blind source separation (BSS) for adaptive filtering is presented in application to imaging both physiological and acoustic radiation force impulse (ARFI)-induced tissue and blood motion in the common carotid artery. The collected raw radiofrequency (RF) d ... Full text Cite

Estimates of echo correlation and measurement bias in acoustic radiation force impulse imaging.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · June 2003 Acoustic radiation force impulse (ARFI) imaging is a novel imaging modality in which pulses from a diagnostic ultrasound scanner are used to displace tissue and track its motion. The region displaced has lateral and elevational dimensions of similar scale ... Full text Cite

Observations of tissue response to acoustic radiation force: opportunities for imaging.

Journal article Ultrason Imaging · July 2002 Acoustic Radiation Force Impulse (ARFI) imaging is a method for characterizing local variations in tissue mechanical properties. In this method, a single ultrasonic transducer array is used to both apply temporally short localized radiation forces within t ... Full text Link to item Cite

Acoustic radiation force impulse imaging of in vivo vastus medialis muscle under varying isometric load.

Journal article Ultrasonic imaging · April 2002 Acoustic Radiation Force Impulse (ARFI) imaging is a method for characterizing local variations in tissue mechanical properties. In this method, a single ultrasonic transducer array is used to both apply temporally short localized radiation forces within t ... Full text Cite

Acoustic radiation force impulse imaging: in vivo demonstration of clinical feasibility.

Journal article Ultrasound Med Biol · February 2002 The clinical viability of a method of acoustic remote palpation, capable of imaging local variations in the mechanical properties of soft tissue using acoustic radiation force impulse (ARFI) imaging, is investigated in vivo. In this method, focused ultraso ... Full text Link to item Cite

Acoustic radiation force impulse imaging: Remote palpation of the mechanical properties of tissue

Journal article Proceedings of the IEEE Ultrasonics Symposium · 2002 An overview is given of the Acoustic Radiation Force Impulse (ARFI) imaging. It discusses the derivation of radiation force, the response of tissue to radiation force, and the potential for this imaging method to evaluate the mechanical properties of tissu ... Cite

Evaluation of the mechanical properties of active skeletal muscle using acoustic radiation force impulse imaging

Journal article Proceedings of the IEEE Ultrasonics Symposium · December 1, 2001 Acoustic Radiation Force Impulse (ARFI) imaging is a method for characterizing local variations in tissue mechanical response. In this method, a single ultrasonic transducer array is used to both apply temporally short localized radiation forces within tis ... Cite

On the feasibility of remote palpation using acoustic radiation force.

Journal article The Journal of the Acoustical Society of America · July 2001 A method of acoustic remote palpation, capable of imaging local variations in the mechanical properties of tissue, is under investigation. In this method, focused ultrasound is used to apply localized (on the order of 2 mm3) radiation force within tissue. ... Full text Cite

Investigation of real-time remote palpation imaging

Journal article Proceedings of SPIE the International Society for Optical Engineering · January 1, 2001 We are investigating a novel ultrasonic method for remote palpation, which provides images of local variations in tissue stiffness. Acoustic radiation force is applied to small volumes of tissue, and the resulting displacement patterns are imaged using ult ... Full text Cite

In vivo demonstration of acoustic radiation force impulse (ARFI) imaging in the thyroid, abdomen, and breast

Journal article Proceedings of the IEEE Ultrasonics Symposium · 2001 Acoustic Radiation Force Impulse (ARFI) imaging is proposed as a method for characterizing local variations in tissue mechanical response. In this method, a single ultrasonic transducer array is used to both apply localized radiation forces within tissue a ... Cite

A finite element model for simulating acoustic streaming in cystic breast lesions with experimental validation.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · January 2000 Streaming detection is an ultrasonic technique that can be used to distinguish fluid-filled lesions, or cysts, from solid lesions. With this technique, high intensity ultrasound pulses are used to induce acoustic streaming in cyst fluid, and this motion is ... Full text Cite

A finite element model of remote palpation of breast lesions using radiation force: factors affecting tissue displacement.

Journal article Ultrasonic imaging · January 2000 The early detection of breast cancer reduces patient mortality. The most common method of breast cancer detection is palpation. However, lesions that lie deep within the breast are difficult to palpate when they are small. Thus, a method of remote palpatio ... Full text Cite

The use of acoustic streaming in breast lesion diagnosis: a clinical study.

Journal article Ultrasound in medicine & biology · January 1999 Results from a clinical study are presented, in which ultrasonically-induced acoustic streaming was successfully used to differentiate fluid-filled lesions (cysts) from solid lesions in the breast. In this study, high-intensity ultrasound pulses from a mod ... Full text Cite

Speckle decorrelation due to two-dimensional flow gradients.

Journal article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · January 1998 The performance of ultrasonic velocity estimation methods is degraded by speckle decorrelation, the change in received echoes over time. Because ultrasonic speckle is formed by the complex sum of echoes from subresolution scatterers, it is sensitive to the ... Full text Cite

A preliminary evaluation of the effects of primary and secondary radiation forces on acoustic contrast agents

Journal article IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control · December 1, 1997 Primary and secondary radiation forces result from pressure gradients in the incident and scattered ultrasonic fields. These forces and their dependence on experimental parameters are described, and the theory for primary radiation force is extended to con ... Full text Cite

Ensemble tracking: a new method for 2D vector velocity measurement

Journal article Proceedings of the IEEE Ultrasonics Symposium · December 1, 1995 We described a new method, called ensemble tracking, for quantifying two dimensional velocities. Compared to previous two-dimensional speckle tracking techniques, ensemble tracking measures motion over smaller translations, thereby reducing errors due to s ... Cite

A novel ultrasonic technique for differentiating cysts from solid lesions: preliminary results in the breast.

Journal article Ultrasound in medicine & biology · January 1995 The feasibility of a new ultrasonic technique to distinguish cysts from solid lesions is explored. High intensity pulses are used to induce acoustic streaming in cyst fluid, and this motion is detected using Doppler techniques. Acoustic streaming cannot be ... Full text Cite

Three-dimensional flow images by reconstruction from two-dimensional vector velocity maps.

Journal article J Am Soc Echocardiogr · 1995 A method for constructing three-dimensional images of flow is described. The technique involves the acquisition of numerous closely spaced planes, each comprised of a map of the two-dimensional velocities measured in that plane. Each such vector velocity m ... Full text Link to item Cite

Generation and detection of acoustic streaming to differentiate between solid and cystic breast lesions

Journal article Proceedings of the IEEE Ultrasonics Symposium · January 1, 1994 Results from both a pilot clinical study and phantom studies performed to evaluate a new ultrasonic technique to distinguish cysts from solid lesions are presented. High intensity pulses are used to induce acoustic streaming in cyst fluid, and this motion ... Full text Cite

Three-dimensional flow visualization via reconstruction from successive two-dimensional vector velocity maps

Journal article Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society Full text Cite