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Ultrasound phantom

Billy Y S Yiu, Alfred C H Yu
As new ultrasound flow imaging methods are being developed, there is a growing need to devise appropriate flow phantoms that can holistically assess the accuracy of the derived flow estimates. In this paper, we present a novel spiral flow phantom design whose Archimedean spiral lumen naturally gives rise to multi-directional flow over all possible angles (i.e. from 0° to 360°). Developed using lost-core casting principles, the phantom geometry comprised a three-loop spiral (4 mm diameter, 5 mm pitch), and it was set to operate in steady flow mode (3 mL/s flow rate)...
October 13, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Ahnryul Choi, David D McPherson, Hyunggun Kim
Intravascular ultrasound (IVUS) imaging provides an excellent tool for evaluation of the type, morphology, extent, and severity of an atheromatous plaque. 3 D IVUS imaging offers additive information pertaining to morphology of the arterial structures and volumetric plaque distributions. A new 3 D IVUS visualization technique was developed to provide 3 D structural information of a curved artery. A virtual 3 D curved arterial phantom consisting of varying cross-sectional shapes, wall thicknesses, and acoustic intensity information was utilized to validate the nonlinear interpolation technique to create intermediary 2 D IVUS images...
October 16, 2017: Computer Assisted Surgery (Abingdon, England)
Maëva Vallet, François Varray, Jérôme Boutet, Jean-Marc Dinten, Giosuè Caliano, Alessandro Stuart Savoia, Didier Vray
Photoacoustic (PA) signals are short ultrasound (US) pulses typically characterized by a single-cycle shape, often referred to as N-shape. The spectral content of such wideband signals ranges from a few hundred kilohertz to several tens of megahertz. Typical reception frequency responses of classical piezoelectric US imaging transducers, based on PZT technology, are not sufficiently broadband to fully preserve the entire information contained in PA signals, which are then filtered, thus limiting PA imaging performance...
December 2017: Photoacoustics
Mawia Khairalseed, Fangyuan Xiong, Jung-Whan Kim, Robert F Mattrey, Kevin J Parker, Kenneth Hoyt
H-Scan is a new ultrasound imaging technique that relies on matching a model of pulse-echo formation to the mathematics of a class of Gaussian-weighted Hermite polynomials. This technique may be beneficial in the measurement of relative scatterer sizes and in cancer therapy, particularly for early response to drug treatment. Because current H-scan techniques use focused ultrasound data acquisitions, spatial resolution degrades away from the focal region and inherently affects relative scatterer size estimation...
October 11, 2017: Ultrasound in Medicine & Biology
Elisabeth Brusseau, Adeline Bernard, Cyril Meynier, Philippe Chaudet, Valérie Detti, Guillaume Férin, Olivier Basset, An Nguyen-Dinh
Ultrasound applications such as elastography can benefit from 3-D data acquisition and processing. In this article, we describe a specific ultrasound probe, designed to acquire series of three adjacent imaging planes over time. This data acquisition makes it possible to consider the out-of-plane motion that can occur at the central plane during medium scanning, and is proposed with the aim of improving the results of strain imaging. In this first study, experiments were conducted on phantoms, and controlled axial and elevational displacements were applied to the probe using a motorized system...
October 11, 2017: Ultrasound in Medicine & Biology
Pierre D Mourad, Janna L Friedly, Abbi M McClintic, Tessa A Olmstead, John D Loeser
Objective: Identifying pain generators in tissue deep in the skin can require uncomfortable, complicated, and invasive tests. We describe pilot studies testing the hypothesis that ultrasound image-guided, intense focused ultrasound (ig-iFU) can noninvasively and differentially stimulate the end of transected nerves in the residual limbs of amputee patients. Design: We applied iFU to the transected nerve ending as individual pulses with a length of 0.1 seconds using a carrier frequency of 2...
September 7, 2017: Pain Medicine: the Official Journal of the American Academy of Pain Medicine
Libertario Demi, Wim van Hoeve, Ruud J G van Sloun, Gino Soldati, Marcello Demi
B-lines are ultrasound-imaging artifacts, which correlate with several lung-pathologies. However, their understanding and characterization is still largely incomplete. To further study B-lines, lung-phantoms were developed by trapping a layer of microbubbles in tissue-mimicking gel. To simulate the alveolar size reduction typical of various pathologies, 170 and 80 µm bubbles were used for phantom-type 1 and 2, respectively. A normal alveolar diameter is approximately 280 µm. A LA332 linear-array connected to the ULA-OP platform was used for imaging...
October 6, 2017: Scientific Reports
Roozbeh Shams, Yiming Xiao, Francois Hebert, Matthew Abramowitz, Rupert Brooks, Hassan Rivaz
Image guidance has become the standard of care for patient positioning in radiotherapy, where image registration is often a critical step to help manage patient motion. However, in practice, verification of registration quality is often adversely affected by difficulty in manual inspection of 3D images and time constraint, thus affecting the therapeutic outcome. Therefore, we proposed to employ both bootstrapping and the supervised learning methods of linear discriminant analysis and random forest to help robustly assess registration quality in ultrasound-guided radiotherapy...
September 28, 2017: IEEE Transactions on Medical Imaging
Guenther Paltauf, Petra Hartmair, Georgi Kovachev, Robert Nuster
Photoacoustic tomography relies on a dense coverage of the surface surrounding the imaged object with ultrasound sensors in order to enable an accurate reconstruction. A curved arrangement of integrating line sensors is proposed that is able to acquire data for a linear projection image of the absorbed energy density distribution in the object. Upon rotation of the object relative to the array, three-dimensional (3D) images can be obtained. The proposed design is based on the cost-effective piezoelectric polymer film technology with 64 line shaped sensors arranged on a half-cylindrical surface...
December 2017: Photoacoustics
Ki Joo Pahk, Pierre Gélat, David Sinden, Dipok Kumar Dhar, Nader Saffari
The aim of boiling histotripsy is to mechanically fractionate tissue as an alternative to thermal ablation for therapeutic applications. In general, the shape of a lesion produced by boiling histotripsy is tadpole like, consisting of a head and a tail. Although many studies have demonstrated the efficacy of boiling histotripsy for fractionating solid tumors, the exact mechanisms underpinning this phenomenon are not yet well understood, particularly the interaction of a boiling vapor bubble with incoming incident shockwaves...
September 28, 2017: Ultrasound in Medicine & Biology
Ece Ozkan, Valeriy Vishnevsky, Orcun Goksel
Ultrasound (US) beamforming is the process of reconstructing an image from acquired echo traces on several transducer elements. Typical beamforming approaches, such as Delay-And-Sum, perform simple projection operations, while techniques using statistical information also exist, e.g. adaptive, phase-coherence, Delay-Multiply-And-Sum, and sparse coding approaches. Inspired by the feasibility and success of inverse problem formulations in several image reconstruction problems, such as computed tomography, we herein devise an inverse problem approach for US beamforming...
September 28, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Jonathan Poree, Boris Chayer, Gilles Soulez, Jacques Ohayon, Guy Cloutier
Mechanical and morphological characterization of atherosclerotic lesions in carotid arteries remains an essential step for the evaluation of rupture prone plaques and the preven-tion of strokes. In this study, we propose a non-invasive imaging modulography method (NIV-iMod), which is able of reconstruct-ing a heterogeneous Young's modulus distribution of a carotid plaque from the Von Mises strain elastogram. Elastograms were computed with non-invasive ultrasound images using the La-grangian speckle model estimator (LSME) and a dynamic seg-mentation-optimization procedure to highlight mechanical heter-ogeneities...
September 28, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Viksit Kumar, Richard Liu, Randall R Kinnick, Adriana Gregory, Azra Alizd, Marek Belohlavek, Mostafa Fatemi
OBJECTIVE: Ultrasound-guided biopsies and minimally invasive procedures have been used in numerous medical applications, including catheter guidance. The biggest challenge for catheter guidance by ultrasound lies in distinguishing the catheter from neighboring tissue, as well as the ability to differentiate the catheter body from its tip. METHODS: In our previous work, we introduced a functional prototype of an acoustically active catheter, in which a miniature piezoelectric crystal allowed accurate localization of the catheter tip by pulsed wave (PW) Doppler imaging and Doppler spectrogram...
September 25, 2017: IEEE Transactions on Bio-medical Engineering
Stephanie Wössner, Kirsten Weber, Anna C Steinbeck, Markus Oberhauser, Matthias Feuerecker
BACKGROUND AND PURPOSE: The purpose of this case report is to describe a multimodal pain therapeutic concept including the adjunct use of pregabalin in a 4.5 year-old child after forefoot amputation. Phantom limb pain and sensation is a complex pain syndrome that is difficult to treat and prevent. 70-75% of all children develop such a pain syndrome after amputation. We describe here a paediatric patient who underwent forefoot amputation following traumatic foot injury and received multimodal pain therapy including pregabalin...
September 22, 2017: Scandinavian Journal of Pain
Chih-Yen Chien, Jeng-Wen Chen, Chun-Hsiang Chang, Chih-Chung Huang
Obstructive sleep apnea (OSA), a breathing disorder characterized by repetitive collapse of the pharyngeal airway during sleep, can cause intermittent hypoxemia and frequent arousal. The evaluation of dynamic tongue motion not only provides the biomechanics and pathophysiology for OSA diagnosis, but also helps doctors to determine treatment strategies for these patients with OSA. The purpose of this study was to develop and verify a dedicated tracking algorithm, called the modified optical flow (OF)-based method, for monitoring the dynamic motion of the tongue base in ultrasound image sequences derived from controls and patients with OSA...
September 20, 2017: Ultrasound in Medicine & Biology
Jonathan E Lundt, Steven P Allen, Jiaqi Shi, Timothy L Hall, Charles A Cain, Zhen Xu
Histotripsy is a non-invasive, non-thermal ablation technique that uses high-amplitude, focused ultrasound pulses to fractionate tissue via acoustic cavitation. The goal of this study was to illustrate the potential of histotripsy with electronic focal steering to achieve rapid ablation of a tissue volume at a rate matching or exceeding those of current clinical techniques (∼1-2 mL/min). Treatment parameters were established in tissue-mimicking phantoms and applied to ex vivo tissue. Six-microsecond pulses were delivered by a 250-kHz array...
September 19, 2017: Ultrasound in Medicine & Biology
Kassem Harris, Emily Oakley, David Bellnier, Gal Shafirstein
Recent advances in interventional pulmonology led to a significant expansion of the diagnostic and therapeutic role of endobronchial ultrasound. In this paper, we describe a new concept for using endobronchial ultrasound to guide interstitial photodynamic therapy (PDT). For this purpose, we conducted in vitro and in vivo experiments using a phantom and animal models, respectively. A new 0.5 mm optical fiber, with cylindrical diffuser end, was used to deliver the therapeutic light through the 21-gauge endobronchial ultrasound needle...
August 2017: Journal of Thoracic Disease
Anna Rethy, Jørn Ove Sæternes, Jostein Halgunset, Ronald Mårvik, Erlend F Hofstad, Juan A Sánchez-Margallo, Thomas Langø
PURPOSE: The objective of this study was to develop a multimodal, permanent liver phantom displaying functional vasculature and common pathologies, for teaching, training and equipment development in laparoscopic ultrasound and navigation. METHODS: Molten wax was injected simultaneously into the portal and hepatic veins of a human liver. Upon solidification of the wax, the surrounding liver tissue was dissolved, leaving a cast of the vessels. A connection was established between the two vascular trees by manually manipulating the wax...
September 19, 2017: International Journal of Computer Assisted Radiology and Surgery
Chawan Manaspon, Christopher Hernandez, Pinunta Nittayacharn, Selva Jeganathan, Norased Nasongkla, Agata A Exner
One of the challenges in developing sustained-release local drug delivery systems is the limited treatment volume that can be achieved. In this work, we examine the effectiveness of using low frequency, high intensity ultrasound to promote the spatial penetration of drug molecules away from the implant/injection site boundary upon release from injectable, phase inverting poly(lactic acid-co-glycolic acid) (PLGA) implants. Fluorescein-loaded PLGA solutions were injected into poly(acrylamide) phantoms, and the constructs were treated daily for 14 days with ultrasound at 2...
September 19, 2017: Annals of Biomedical Engineering
Muhammad Arif, Adriaan Moelker, Theo van Walsum
AIM: Needle visibility is crucial for effective and safe ultrasound-guided interventional procedures. Several studies have investigated needle visibility in 2D ultrasound imaging, but less information is available for 3D ultrasound imaging, a modality that has great potential for image guidance interventions. We performed a prospective study, to quantitatively compare the echogenicity of various commercially available needles in 3D ultrasound images used in clinical practice under freehand needle introduction...
September 19, 2017: Cardiovascular and Interventional Radiology
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