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Ultrasound phantom

Azad Mashari, Mario Montealegre-Gallegos, Jelliffe Jeganathan, Lu Yeh, Joshua Qua Hiansen, Massimiliano Meineri, Feroze Mahmood, Robina Matyal
METHODS: Anonymized CT DICOM data was segmented to create a 3D model of the lumbar spine. The 3D model was modified, placed inside a digitally designed housing unit and fabricated on a desktop 3D printer using polylactic acid (PLA) filament. The model was filled with an echogenic solution of gelatin with psyllium fiber. Twenty-two staff anesthesiologists performed a spinal and epidural on the 3D printed simulator and a commercially available Simulab phantom. Participants evaluated the tactile and ultrasound imaging fidelity of both phantoms via Likert-scale questionnaire...
2018: PloS One
Anthony S Podkowa, Michael L Oelze, Jeffrey A Ketterling
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 in an effective downsampling of the slow-time signal, thereby artificially reducing the frame rate. To alleviate this effect, a new transmit sequence is introduced where each transmit angle is repeated in succession...
2018: Applied Sciences
Kevin J Haworth, Bryan H Goldstein, Karla P Mercado-Shekhar, Rohan Srivastava, P Arunkumar, Haili Su, Ellena M Privitera, Christy K Holland, Andrew N Redington
Modification of dissolved gas content by acoustic droplet vaporization (ADV) has been proposed for several therapeutic applications. Reducing dissolved oxygen (DO) during reperfusion of ischemic tissue during coronary interventions could inhibit reactive oxygen species production and rescue myocardium. The objective of this study was to determine whether intravascular ultrasound (IVUS) can trigger ADV and reduce DO. Perfluoropentane emulsions were created using high-speed shaking and microfluidic manufacturing...
September 2017: IEEE International Ultrasonics Symposium: [proceedings]
Boran Zhou, Xiaoming Zhang
The purpose of this study is to compare five viscoelastic models (Voigt, Maxwell, standard linear solid, spring-pot, and fractional Voigt models) for estimating viscoelastic properties based on ultrasound shear wave elastography measurements. We performed the forward problem analysis, the inverse problem analysis, and experiments. In the forward problem analysis, the shear wave speeds at different frequencies were calculated using the Voigt model for given shear elasticity and varying shear viscosity. In the inverse problem analysis, the viscoelastic parameters were estimated from the given wave speeds for the five viscoelastic models using the least-square regression...
May 30, 2018: Journal of the Mechanical Behavior of Biomedical Materials
Ferga C Gleeson, Erik J Tryggestad, Nicholas B Remmes, Chris J Beltran, Jon J Kruse, Michael G Haddock, Christopher L Hallemeier, Andrew C Storm, Michael J Levy
Background and study aims : Little consideration has been given to selection of endoscopic ultrasound-guided fiducials for proton radiotherapy and the resulting perturbations in the therapy dose and pattern. Our aim was to assess the impact of perturbations caused by six fiducials of different composition and dimensions in a phantom gel model. Materials and methods:  The phantom was submerged in a water bath and irradiated with a uniform 10 cm × 10 cm field of 119...
June 2018: Endoscopy International Open
Jiawen Yan, Bo Pan, Yunfeng Qi, Jin Ben, Yili Fu
BACKGROUND: Applying transrectal ultrasound to robot-assisted laparoscopic radical prostatectomy has attracted attention in recent years, and it is considered as a proper method to provide real-time subsurface anatomic features. A precise registration between the ultrasound equipment and robotic surgical system is necessary, which usually requires a fast and accurate recognition of the registration tool in the ultrasound image. METHODS: Tissue forceps are chosen as the registration tool...
June 6, 2018: International Journal of Medical Robotics + Computer Assisted Surgery: MRCAS
Vincent Groenhuis, Francesco Visentin, Françoise J Siepel, Bogdan M Maris, Diego Dall'alba, Paolo Fiorini, Stefano Stramigioli
PURPOSE: Patient-specific biomedical modeling of the breast is of interest for medical applications such as image registration, image guided procedures and the alignment for biopsy or surgery purposes. The computation of elastic properties is essential to simulate deformations in a realistic way. This study presents an innovative analytical method to compute the elastic modulus and evaluate the elasticity of a breast using magnetic resonance (MRI) images of breast phantoms. METHODS: An analytical method for elasticity computation was developed and subsequently validated on a series of geometric shapes, and on four physical breast phantoms that are supported by a planar frame...
June 4, 2018: International Journal of Computer Assisted Radiology and Surgery
Aiguo Han, Yassin Labyed, Ethan Z Sy, Andrew S Boehringer, Michael P Andre, John W Erdman, Rohit Loomba, Claude B Sirlin, William D O'Brien
OBJECTIVES: To assess inter-sonographer reproducibility of ultrasound attenuation coefficient (AC), backscatter coefficient (BSC) and shear wave speed (SWS) in adults with known/suspected non-alcoholic fatty liver disease (NAFLD). METHODS: The institutional review board approved this HIPAA-compliant prospective study; informed consent was obtained. Participants with known/suspected NAFLD were recruited and underwent same-day liver examinations with a clinical scanner...
June 4, 2018: European Radiology
N S Buch, E Qerama, N B Finnerup, L Nikolajsen
Background and aims Injury to peripheral nerves associated with trauma, amputation, or surgery may lead to the formation of neuromas that can cause severe pain. Unfortunately, neuromas are frequently refractory to medical and surgical treatment. This ongoing study examines whether neuromas are more frequent in patients experiencing pain after peripheral nerve injury or amputation than in patients without pain. Methods In this observational cohort study, 80 patients with peripheral nerve injury or amputation will be recruited...
December 29, 2017: Scandinavian Journal of Pain
Boran Zhou, Xiaoming Zhang
Lung mass density is directly associated with lung pathology. Computed Tomography (CT) evaluates lung pathology using the Hounsfield unit (HU) but not lung density directly. We have developed a lung ultrasound surface wave elastography (LUSWE) technique to measure the surface wave speed of superficial lung tissue. The objective of this study was to develop a method for analyzing lung mass density of superficial lung tissue using a deep neural network (DNN) and synthetic data of wave speed measurements with LUSWE...
May 23, 2018: Ultrasonics
Paul Mignon, Philippe Poignet, Jocelyne Troccaz
Robotic control of needle bending aims at increasing the precision of percutaneous procedures. Ultrasound feedback is preferable for its clinical ease of use, cost and compactness but raises needle detection issues. In this paper, we propose a complete system dedicated to robotized guidance of a flexible needle under 3D ultrasound imaging. This system includes a medical robot dedicated to transperineal needle positioning and insertion, a rapid path planning for needle steering using bevel-tip needle natural curvature in tissue, and an ultrasound-based automatic needle detection algorithm...
May 29, 2018: Annals of Biomedical Engineering
Prashant Pandey, Pierre Guy, Antony J Hodgson, Rafeef Abugharbieh
PURPOSE: Ultrasound (US) is a safer alternative to X-rays for bone imaging, and its popularity for orthopedic surgical navigation is growing. Routine use of intraoperative US for navigation requires fast, accurate and automatic alignment of tracked US to preoperative computed tomography (CT) patient models. Our group previously investigated image segmentation and registration to align untracked US to CT of only the partial pelvic anatomy. In this paper, we extend this to study the performance of these previously published techniques over the full pelvis in a tracked framework, to characterize their suitability in more realistic scenarios, along with an additional simplified segmentation method and similarity metric for registration...
May 26, 2018: International Journal of Computer Assisted Radiology and Surgery
Sphoorti Shellikeri, Susan J Back, Laura Poznick, Kassa Darge
Contrast-enhanced voiding urosonography (ceVUS) is a radiation-free and highly sensitive examination for detecting vesicoureteral reflux and imaging the urethra in children. This examination is performed with ultrasound and intravesical administration of a gas-filled microbubble US contrast agent. The U.S. Food and Drug Administration recently approved the use of a US contrast agent for ceVUS in children. Because of the growing interest among physicians and US technologists in using ceVUS in children, a urinary bladder phantom was developed to teach intravesical ultrasound contrast administration to perform ceVUS procedures...
May 22, 2018: Ultrasound in Medicine & Biology
Basavarajappa Lokesh, Anne M Ten Dam, Chris L de Korte, Arun K Thittai
Ultrasound elastography has been found to be useful in different clinical applications. For example, in breast imaging, axial strain elastography provides information related to tissue stiffness, which is used to characterize breast lesions as either benign or malignant. In addition, these lesions also differ in their bonding properties. Benign breast lesions are loosely bonded and malignant breast lesions are firmly bonded to the surrounding tissues. Therefore, only benign breast lesions will rotate/slip on the application of deformation...
May 22, 2018: Ultrasound in Medicine & Biology
Joseph Nathaniel Stember
Ultrasound is notoriously plagued by high user dependence. There is a steep drop-off in information in going from what the sonographer sees during image acquisition and what the interpreting radiologist is able to view at the reading station. One countermeasure is probe localization and tracking. Current implementations are too difficult and expensive to use and/or do not provide adequate detail and perspective. The aim of this work was to demonstrate that a protocol combining surface three-dimensional photographic imaging with traditional ultrasound images may be a solution to the problem of probe localization, this approach being termed surface point cloud ultrasound (SPC-US)...
May 23, 2018: Journal of Digital Imaging: the Official Journal of the Society for Computer Applications in Radiology
Justin Michael, Daniel Morton, Deidre Batchelar, Michelle Hilts, Juanita Crook, Aaron Fenster
PURPOSE: Permanent breast seed implantation (PBSI) is a promising radiotherapy technique for early-stage breast cancer, completed in a single visit by permanently implanting 103 Pd seeds using needles inserted through a template and guided by 2D ultrasound (US). However, operator dependence has been highlighted as a limitation of this procedure. Consequently, we propose and have developed an intraoperative guidance system using 3D US and an instrumented mechanical arm to provide intraoperative 3D imaging and needle template tracking...
May 23, 2018: Medical Physics
Christopher P Favazza, Krzysztof R Gorny, Matthew R Callstrom, Anil N Kurup, Michael Washburn, Pamela S Trester, Charles L Fowler, Nicholas J Hangiandreou
We present the development of a two-component magnetic resonance (MR) fiducial system, that is, a fiducial marker device combined with an auto-segmentation algorithm, designed to be paired with existing ultrasound probe tracking and image fusion technology to automatically fuse MR and ultrasound (US) images. The fiducial device consisted of four ~6.4 mL cylindrical wells filled with 1 g/L copper sulfate solution. The algorithm was designed to automatically segment the device in clinical abdominal MR images...
May 21, 2018: Journal of Applied Clinical Medical Physics
Yuqi Wang, Jingfeng Jiang, Timothy J Hall
A 3-D region-growing motion-tracking (RGMT) method for ultrasound elasticity imaging is described. This 3-D RGMT method first estimates the displacements at a sparse subset of points, called seeds; uses an objective measure to determine, among those seeds, which displacement estimates to trust; and then performs RGMT in three dimensions to estimate displacements for the remaining points in the field. During the growing process in three dimensions, the displacement estimate at one grid point is employed to guide the displacement estimation of its neighboring points using a 3-D small search region...
May 18, 2018: Ultrasound in Medicine & Biology
Hugo Luis Manterola, Lucas Lo Vercio, Alejandro Díaz, Mariana Del Fresno, Ignacio Larrabide
In low- and middle-income regions, a relatively large number of deaths occur from cardiovascular disease or stroke. Carotid intima-media thickness (cIMT) and carotid lumen diameter (cLD) are strong indicators of cardiovascular event risk and stenosis severity, respectively. The interactive open-source software described here, Cimtool, is based on active contours for measuring these indicators in clinical practice and thus helping in preventive diagnosis and treatment. Cimtool was validated using carotid phantoms and real images obtained using ultrasound...
May 14, 2018: Ultrasound in Medicine & Biology
Nicholas J Freeman, Henrik Odéen, Dennis L Parker
PURPOSE: Evaluate a numerical inverse Green's function method of deriving specific absorption rates (SARs) from high intensity focused ultrasound (HIFU) sonications given tissue parameters (thermal conductivity, specific heat capacity, and mass density) and 3-D magnetic resonance imaging (MRI) temperature measurements. METHODS: SAR estimates were evaluated using simulations and MR temperature measurements from HIFU sonications. For simulations, a "true" SAR was calculated using the hybrid angular spectrum method for ultrasound simulations...
May 17, 2018: Medical Physics
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