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Jeffrey Ketterling

Jeffrey Ketterling
Weill Cornell Medicine · Radiology

PhD

About

228
Publications
10,562
Reads
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1,856
Citations
Additional affiliations
April 2022 - present
Weill Cornell Medicine
Position
  • Assistant Professor of Biomedical Engineering in Radiology (Interim)
November 1999 - March 2022
Riverside Research
Position
  • Research Director
September 1992 - May 1994
University of Washington Seattle
Position
  • Student

Publications

Publications (228)
Article
Ultrasound localization microscopy (ULM) is an emerging, super-resolution imaging technique for detailed mapping of the microvascular structure and flow velocity via subwavelength localization and tracking of microbubbles. Because microbubbles rely on blood flow for movement throughout the vascular space, acquisition times can be long in the smalle...
Article
Elevated intraocular pressure is the most prevalent risk factor for initiation and progression of neurodegeneration in glaucoma. Ocular hypertension results from increased resistance to aqueous fluid outflow caused by reduced porosity and increased stiffness of tissues of the outflow pathway. Acoustic activation and resulting bioeffects of the perf...
Article
In a previous study, an annular-array transducer was employed to characterize homogeneous scattering phantoms and excised rat livers using backscatter envelope statistics and frequency domain analysis. A sound field correction method was also applied to take into account the average attenuation of the entire scattering medium. Here, we further gene...
Article
No PDF available ABSTRACT We examined both eyes of 58 post-partum subjects within 72 hours of delivery with plane-wave ultrasound and optical coherence tomography angiography (OCTA). 8 had preeclampsia (PE), 21 severe PE (sPE). 9 chronic or gestational hypertension and 21 were controls. We performed plane-wave ultrasound with a Verasonics Vantage-1...
Article
No PDF available ABSTRACT Ultrasound localization microscopy (ULM) is a promising super-resolutionimaging technique based on the build-up of subwavelength localizations of gas-filled ultrasound contrast agents (UCAs) within the microvascular space. Slow flow regions can reduce localization rates and diminish the isolation of microbubble signals fro...
Article
Most studies of the effect of acute elevation of intraocular pressure (IOP) on ocular blood-flow have utilized optical coherence tomography (OCT) to characterize retinal and choroidal flow and vascular density. This study investigates the effect of acute IOP elevation on blood flow velocity in the retrobulbar arteries and veins supplying and draini...
Article
Full-text available
Segmentation and mutant classification of high-frequency ultrasound (HFU) mouse embryo brain ventricle (BV) and body images can provide valuable information for developmental biologists. However, manual segmentation and identification of BV and body requires substantial time and expertise. This paper proposes an accurate, efficient and explainable...
Article
The rodent heart is frequently used to study human cardiovascular disease (CVD). Although advanced cardiovascular ultrasound imaging methods are available for human clinical practice, application of these techniques to small animals remains limited due to the temporal and spatial-resolution demands. Here, an ultrasound vector-flow workflow is demon...
Article
Clinical ultrasound is widely used for quantitative diagnosis. To clarify the relationship between anatomical and acoustic properties, high resolution imaging using high-frequency ultrasound (HFU) is required. However, when tissue properties are evaluated using HFU, the depth of field (DOF) is limited. To overcome this problem, an annular array tra...
Conference Paper
The segmentation of the brain ventricle (BV) and body in embryonic mice high-frequency ultrasound (HFU) volumes can provide useful information for biological researchers. However, manual segmentation of the BV and body requires substantial time and expertise. This work proposes a novel deep learning based end-to-end auto-context refinement framewor...
Article
Full-text available
Preclinical imaging, especially of rodent models, plays a major role in experimental ophthalmology. Our aim was to determine if ultrasound can be used to visualize and measure flow dynamics in the retrobulbar vessels supplying and draining the eye and the potential of contrast microbubbles to provide image and measurement enhancement. To accomplish...
Article
Multi-pulse (MP) ultrasound contrast agent (UCA) imaging is a method to increase the contrast-to-background (CBR) ratio in regions of blood flow. Plane-wave imaging allows high frame rates, and with high-frequency ultrasound, fine-spatial and temporal resolution. MP and plane-wave imaging have not been applied to high-frequency ultrasound. Here, an...
Preprint
Full-text available
High-frequency ultrasound (HFU) is well suited for imaging embryonic mice due to its noninvasive and real-time characteristics. However, manual segmentation of the brain ventricles (BVs) and body requires substantial time and expertise. This work proposes a novel deep learning based end-to-end auto-context refinement framework, consisting of two st...
Article
No PDF available ABSTRACT Blood-flow plays an important role in pathogenesis and progression of many ocular diseases. While optical coherence tomography angiography (OCT-A) has revolutionized depiction of the retinal vasculature, it provides little information regarding flow velocities and cannot visualize the arteries and veins supplying and drain...
Article
No PDF available ABSTRACT Plane-wave imaging allows high-frame rates, and with high-frequency (HF) ultrasound, fine-spatial and temporal resolution. HF, plane-wave multi-pulse (MP) imaging methods of acoustic contrast agents (UCAs) are still an unexplored area for small-animal and small-parts imaging. The MP methods of pulse inversion (PI, + 1 and...
Preprint
Full-text available
High-frequency ultrasound (HFU) is well suited for imaging embryonic mice in vivo because it is non-invasive and real-time. Manual segmentation of the brain ventricles (BVs) and whole body from 3D HFU images is time-consuming and requires specialized training. This paper presents a deep-learning-based segmentation pipeline which automates several t...
Article
High-frequency ultrasound (HFU, >20 MHz) and quantitative ultrasound (QUS) methods permit a means to understand the relationship between anatomical and acoustic characteristics. In our previous research, we showed that analyzing the acoustic scattering with HFU was an effective method for noninvasive diagnosis. However, the depth of field (DOF) of...
Article
Full-text available
Purpose: Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser treatment is performed on vitreous floaters, but studies of structural and functional effects with objective outcome measures are lacking. This study evaluated Nd:YAG laser effects by comparing participants with vitreous floaters who previously underwent laser treatment with untreated contr...
Article
No PDF available ABSTRACT Sophisticated methods of visualizing and analyzing the complex blood flow patterns in humans have been available for a number of years on ultrasound machines. To date, these methods have not been applied to healthy mouse models or mice with cardiac defects. Here, a high-speed plane-wave imaging approach was used to study l...
Conference Paper
Full-text available
Volumetric analysis of brain ventricle (BV) structure is a key tool in the study of central nervous system development in embryonic mice. High-frequency ultrasound (HFU) is the only non-invasive, real-time modality available for rapid volumetric imaging of embryos in utero. However, manual segmentation of the BV from HFU volumes is tedious, time-co...
Preprint
Full-text available
Volumetric analysis of brain ventricle (BV) structure is a key tool in the study of central nervous system development in embryonic mice. High-frequency ultrasound (HFU) is the only non-invasive, real-time modality available for rapid volumetric imaging of embryos in utero. However, manual segmentation of the BV from HFU volumes is tedious, time-co...
Article
Full-text available
Purpose The choroid is a vascular network providing the bulk of the oxygen and nutrient supply to the retina and may play a pivotal role in retinal disease pathogenesis. While optical coherence tomography angiography provides an en face depiction of the choroidal vasculature, it does not reveal flow dynamics. In this report, we describe the use of...
Article
Perfluorocarbon (PF) nanodrops (NDs) undergo a phase change from liquid to vapor with an acoustic stimulation. Activation thresholds are established with relatively high-concentrations of NDs. Activating single NDs with high-frequency plane waves without the need to switch between transmit waveforms would allow uninterrupted high-speed imaging stud...
Conference Paper
Full-text available
This paper presents a fully automatic segmentation system for whole-body high-frequency ultrasound (HFU) images of mouse embryos that can simultaneously segment the body contour and the brain ventricles (BVs). Our system first locates a region of interest (ROI), which covers the interior of the uterus, by sub-surface analysis. Then, it segments the...
Article
High-frequency ultrasound Doppler modes have been used extensively for murine cardiovascular (CV) studies, but traditional linear-array imaging modes are limited in terms of spatial and temporal resolution. Plane-wave imaging methods allow for high-speed vector-flow information to be obtained throughout a full image frame. Plane-wave imaging has be...
Article
Full-text available
The maximum detectable velocity of high-frame-rate color flow Doppler ultrasound is limited by the imaging frame rate when using coherent compounding techniques. Traditionally, high quality ultrasonic images are produced at a high frame rate via coherent compounding of steered plane wave reconstructions. However, this compounding operation results...
Article
Full-text available
Real-time imaging of the embryonic murine cardiovascular system is challenging due to the small size of the mouse embryo and rapid heart rate. High-frequency, linear-array ultrasound systems designed for small-animal imaging provide high-frame-rate and Doppler modes but are limited in regards to the field of view that can be imaged at fine-temporal...
Article
Full-text available
The subharmonic threshold for ultrasound contrast agent has been defined as a 20-25 dB difference between fundamental and subharmonic (2/1) spectral components of the backscatter signal. However, this Fourier-based criteria assumes a linear, time-invariant signal. A more appropriate criterion for short cycle and frequency modulated waveforms is pro...
Article
Ophthalmic ultrasonography is currently performed virtually exclusively with mechanically scanned, focused single-element transducers. This technology provides B-scan images at approximately 10 frames/s and does not offer any capacity for imaging or measurement of blood-flow. Conventional linear array systems often exceed FDA guidelines for ophthal...
Article
Plane-wave imaging methods allow for high-speed image capture at a time interval equal to round trip acoustic propagation. Plane-wave imaging is ideally suited for cardiovascular imaging where fine-temporal resolution can reveal important information about cardiac mechanics and blood flow patterns. While plane-wave imaging has been demonstrated in...
Article
Full-text available
Clinical ophthalmic ultrasound is currently performed with mechanically scanned, single-element probes, but these are unable to provide useful information about blood flow with Doppler techniques. Linear arrays are well-suited for the detection of blood flow, but commercial systems generally exceed FDA ophthalmic safety limits. A high-speed plane-w...
Article
Full-text available
Purpose: Ophthalmic ultrasound imaging is currently performed with mechanically scanned single-element probes. These probes have limited capabilities overall and lack the ability to image blood flow. Linear-array systems are able to detect blood flow, but these systems exceed ophthalmic acoustic intensity safety guidelines. Our aim was to implemen...
Conference Paper
Full-text available
Ophthalmic ultrasound is almost exclusively performed using single-element, handheld transducers. Linear-array systems are not feasible for ophthalmology for the foreseeable future. Annular arrays permit linear-array image quality but without the system complexity and cost. Here, an annular-array transducer previously demonstrated using a cumbersom...
Article
Full-text available
We propose a fully automatic segmentation method called nested graph cut (NGC) to segment images (2D or 3D) that contain multiple objects with a nested structure. Compared to other graph-cut-based methods developed for multiple regions, our method can work well for nested objects without requiring manual selection of initial seeds, even if differen...
Article
Full-text available
This paper presents an adaptive synthetic-focusing scheme that, when applied to photoacoustic (PA) data acquired using an annular array, improves focusing across a greater imaging depth and enhances spatial resolution. The imaging system was based on a 40-MHz, 5-element, annular-array transducer with a focal length of 12 mm and an 800-µm diameter h...
Article
The measurement and prediction of the subharmonic threshold of ultrasound contrast agents is of significant interest, particularly for high frequency applications. Theoretical analytical predictions typically follow from a weakly nonlinear analysis assuming continuous, single frequency forcing. Furthermore, numerical simulation and experimental def...
Article
Patients with myopic vitreopathy (MV) and posterior vitreous detachment (PVD) see floaters, which often can degrade contrast sensitivity to a significant extent. The floaters are associated with irregularly shaped vitreous opacities. In contrast, asteroid hyalosis (AH), which is characterized by microscopic, spherical, white asteroid bodies (ABs) t...
Article
Full-text available
Polymer-shelled ultrasound contrast agents (UCAs) may expel their encapsulated gas subject to ultrasound- induced shell buckling or rupture. Nonlinear oscillations of this gas bubble can produce a subharmonic component in the ultrasound backscatter. This study investigated the relationship between this gas-release mechanism and shell-thickness??? t...
Article
Full-text available
Purpose: Clinical evaluation of floaters lacks quantitative assessment of vitreous structure. This study used quantitative ultrasound (QUS) to measure vitreous opacities. Since floaters reduce contrast sensitivity (CS) and quality of life (Visual Function Questionnaire, VFQ), it is hypothesized that QUS will correlate with CS and VFQ in patients wi...
Conference Paper
This paper describes a non-contact optical technique to characterize surface-displacement fields of high-frequency transducers. We have developed an ultra-broadband (1 GHz), fine-resolution (0.5 microns), optical interferometer to map the displacement and pressure fields of high-frequency transducers beyond the limits of conventional hydrophones an...
Article
Acoustic behaviors of five different polymer (polylactide) encapsulated microbubbles-PB127 (Point Biomedical), PH37, PH43, PH44, PH45 (Phillips Healthcare) with different shell-thickness-to-radius ratios (STRR) of 3.5, 30, 40, 65, and 100 nm/μm have been characterized. In vitro attenuation data were used to determine the interfacial rheological pro...
Article
Polymer shelled ultrasound contrast agents have been used in ultrasound imaging and tissue perfusion studies. The destruction of the agent produced by the rupture of the shell often through complicated buckling has been quantified with overpressure experiments and optical visualization. Approximate material parameters have been correspondingly esti...
Article
Analytical expressions for subharmonic threshold previously developed for free gas bubbles often been generalized and used for ultrasound contrast agents. However, many of those formulations were developed under the assumptions of mono-frequency steady state, continuous acoustic forcing which are typically not applicable to diagnostic and therapeut...
Article
Bob Apfel passed away in 2002 after having taught at Yale University for over thirty years. During his tenure at Yale, Bob graduated 28 Ph.D. students, trained 12 post-doctoral students and influenced countless masters and undergraduate students. Bob devoted considerable time and effort to the Acoustical Society of America (his honors include the G...
Article
Full-text available
With the emergence of the mouse as the predominant model system for studying mammalian brain development, in utero imaging methods are urgently required to analyze the dynamics of brain growth and patterning in mouse embryos. To address this need, we combined synthetic focusing with a high-frequency (38-MHz) annular-array ultrasound imaging system...
Conference Paper
Volumetric analysis of brain ventricles is important to the study of normal and abnormal development of the central nervous system of mouse embryos. High-frequency ultrasound (HFU) is frequently used to image embryos because HFU is real-time, non-invasive, and provides fine-resolution images. However, manual segmentation of ventricles from 3D HFU v...
Conference Paper
Full-text available
This paper presents an adaptive synthetic-focusing scheme for improving the quality of high-frequency ultrasound (HFU) and photoacoustic (PA) images acquired using a 40-MHz, 5-element, annular-array transducer. A 532-nm laser beam was coaxially delivered through an 800-μm hole in the central element of the array. The assembly was raster-scanned to...
Conference Paper
Full-text available
High-throughput, fine-resolution, in utero imaging methods are urgently required to analyze the dynamics of brain growth and patterning in mouse embryos. To address this need, a 5-ring, 38-MHz, annular-array ultrasound imaging system was developed to obtain three-dimensional (3D) data from individual, in utero embryos. Data were collected with the...
Article
Full-text available
Piezopolymer-based hydrophone arrays consisting of 20 elements were fabricated and tested for use in measuring the acoustic field from a shock-wave lithotripter. The arrays were fabricated from piezopolymer films and were mounted in a housing to allow submersion into water. The motivation was to use the array to determine how the shot-to-shot varia...
Article
A high-frequency (HF) imaging system based on a custom 5-element, 40 MHz annular array has been used to study the cardiovascular development of mouse embryos. High-frame-rate imaging of the heart dynamics was achieved using a retrospective reconstruction method based on Doppler-derived electrocardiogram (ECG) waveforms and respiratory gating was us...
Article
Full-text available
This paper presents a combined ultrasound and photoacoustic (PA) imaging (PAI) system used to obtain high-quality, co-registered images of mouse-embryo anatomy and vasculature. High-frequency ultrasound (HFU, >20 MHz) is utilized to obtain high-resolution anatomical images of small animals while PAI provides high-contrast images of the vascular net...
Article
This two-part study investigated shell rupture of ultrasound contrast agents (UCAs) under static overpressure conditions and the subharmonic component from UCAs subjected to 20-MHz tonebursts. Five different polylactide-shelled UCAs with shell-thickness-to-radius ratios (STRRs) of 7.5, 30, 40, 65, and 100 nm/¿m were subjected to static overpressure...