Image-Capture Devices Extend Medicine's Reach

NASA Technical Reports Server (NTRS)

2009-01-01

Johnson Space Center, Henry Ford Hospital in Detroit, and Houston-based Wyle Laboratories collaborated on NASA's Advanced Diagnostic Ultrasound in Microgravity (ADUM) experiment, which developed revolutionary medical ultrasound diagnostic techniques for long-distance use. Mediphan, a Canadian company with U.S. operations in Springfield, New Jersey drew on NASA expertise to create frame-grabber and data archiving technology that enables ultrasound users with minimal training to send diagnostic-quality ultrasound images and video to medical professionals via the Internet in near real time allowing patients as varied as professional athletes, Olympians, and mountain climbers to receive medical attention as soon as it is needed.

WE-AB-206-02: ACR Ultrasound Accreditation: Requirements and Pitfalls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, J.

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less

Medical revolution in Argentina.

PubMed

Ballarin, V L; Isoardi, R A

2010-01-01

The paper discusses the major Argentineans contributors, medical physicists and scientists, in medical imaging and the development of medical imaging in Argentina. The following are presented: history of medical imaging in Argentina: the pioneers; medical imaging and medical revolution; nuclear medicine imaging; ultrasound imaging; and mathematics, physics, and electronics in medical image research: a multidisciplinary endeavor.

WE-AB-206-00: Diagnostic QA/QC Hands-On Workshop

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environmentmore » with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.« less

Adding New Tools to the Black Bag—Introduction of Ultrasound into the Physical Diagnosis Course

PubMed Central

Amponsah, David; Yang, James; Mendez, Jennifer; Bridge, Patrick; Hays, Gregory; Baliga, Sudhir; Crist, Karen; Brennan, Simone; Jackson, Matt; Dulchavsky, Scott

2010-01-01

INTRODUCTION Ultrasound, a versatile diagnostic modality that permits real-time visualization at the patient’s bedside, can be used as an adjunct in teaching physical diagnosis (PD). Aims: (1) to study the feasibility of incorporating ultrasound into PD courses and (2) determine whether learners can demonstrate image recognition and acquisition skills. PROGRAM DESCRIPTION Three hundred seven second-year medical students were introduced to cardiovascular and abdominal ultrasound scanning after training in the physical examination. This consisted of a demonstration of the ultrasound examination, followed by practice on standardized patients (SPs). Pre-post tests were administered to evaluate students’ knowledge and understanding of ultrasound. Students performed an ultrasound examination during the PD final examination. PROGRAM EVALUATION Pre-post test data revealed significant improvements in image recognition. On the final exam, the highest scores (98.4%) were obtained for the internal jugular vein and lowest scores (74.6%) on the Focused Assessment with Sonography for Trauma images. Eighty-nine percent of students’ surveyed felt ultrasound was a valuable tool for physicians. DISCUSSION An introductory ultrasound course is effective in improving medical students' acquisition and recognition of basic cardiovascular and abdominal ultrasound images. This innovative program demonstrates the feasibility of incorporating portable ultrasound as a learning tool during medical school. Electronic supplementary material The online version of this article (doi:10.1007/s11606-010-1451-5) contains supplementary material, which is available to authorized users. PMID:20697974

Thyroid gland visualization with 3D/4D ultrasound: integrated hands-on imaging in anatomical dissection laboratory.

PubMed

Carter, John L; Patel, Ankura; Hocum, Gabriel; Benninger, Brion

2017-05-01

In teaching anatomy, clinical imaging has been utilized to supplement the traditional dissection laboratory promoting education through visualization of spatial relationships of anatomical structures. Viewing the thyroid gland using 3D/4D ultrasound can be valuable to physicians as well as students learning anatomy. The objective of this study was to investigate the perceptions of first-year medical students regarding the integration of 3D/4D ultrasound visualization of spatial anatomy during anatomical education. 108 first-year medical students were introduced to 3D/4D ultrasound imaging of the thyroid gland through a detailed 20-min tutorial taught in small group format. Students then practiced 3D/4D ultrasound imaging on volunteers and donor cadavers before assessment through acquisition and identification of thyroid gland on at least three instructor-verified images. A post-training survey was administered assessing student impression. All students visualized the thyroid gland using 3D/4D ultrasound. Students revealed 88.0% strongly agreed or agreed 3D/4D ultrasound is useful revealing the thyroid gland and surrounding structures and 87.0% rated the experience "Very Easy" or "Easy", demonstrating benefits and ease of use including 3D/4D ultrasound in anatomy courses. When asked, students felt 3D/4D ultrasound is useful in teaching the structure and surrounding anatomy of the thyroid gland, they overwhelmingly responded "Strongly Agree" or "Agree" (90.2%). This study revealed that 3D/4D ultrasound was successfully used and preferred over 2D ultrasound by medical students during anatomy dissection courses to accurately identify the thyroid gland. In addition, 3D/4D ultrasound may nurture and further reinforce stereostructural spatial relationships of the thyroid gland taught during anatomy dissection.

Ultrasound image edge detection based on a novel multiplicative gradient and Canny operator.

PubMed

Zheng, Yinfei; Zhou, Yali; Zhou, Hao; Gong, Xiaohong

2015-07-01

To achieve the fast and accurate segmentation of ultrasound image, a novel edge detection method for speckle noised ultrasound images was proposed, which was based on the traditional Canny and a novel multiplicative gradient operator. The proposed technique combines a new multiplicative gradient operator of non-Newtonian type with the traditional Canny operator to generate the initial edge map, which is subsequently optimized by the following edge tracing step. To verify the proposed method, we compared it with several other edge detection methods that had good robustness to noise, with experiments on the simulated and in vivo medical ultrasound image. Experimental results showed that the proposed algorithm has higher speed for real-time processing, and the edge detection accuracy could be 75% or more. Thus, the proposed method is very suitable for fast and accurate edge detection of medical ultrasound images. © The Author(s) 2014.

Evaluation of Chest Ultrasound Integrated Teaching of Respiratory System Physiology to Medical Students

ERIC Educational Resources Information Center

Paganini, Matteo; Bondì, Michela; Rubini, Alessandro

2017-01-01

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term…

Evaluation of a Novel Wireless Transmission System for Trauma Ultrasound Examinations From Moving Ambulances.

PubMed

Morchel, Herman; Ogedegbe, Chinwe; Chaplin, William; Cheney, Brianna; Zakharchenko, Svetlana; Misch, David; Schwartz, Matthew; Feldman, Joseph; Kaul, Sanjeev

2018-03-01

To determine if physicians trained in ultrasound interpretation perceive a difference in image quality and usefulness between Extended Focused Assessment with Sonography ultrasound examinations performed at bedside in a hospital vs. by emergency medical technicians minimally trained in medical ultrasound on a moving ambulance and transmitted to the hospital via a novel wireless system. In particular, we sought to demonstrate that useful images could be obtained from patients in less than optimal imaging conditions; that is, while they were in transport. Emergency medical technicians performed the examinations during transport of blunt trauma patients. Upon patient arrival at the hospital, a bedside Extended Focused Assessment with Sonography examination was performed by a physician. Both examinations were recorded and later reviewed by physicians trained in ultrasound interpretation. Data were collected on 20 blunt trauma patients over a period of 13 mo. Twenty ultrasound-trained physicians blindly compared transmitted vs. bedside images using 11 Questionnaire for User Interaction Satisfaction scales. Four paired samples t-tests were conducted to assess mean differences between ratings for ambulatory and base images. Although there is a slight tendency for the average rating across all subjects and raters to be slightly higher in the base than in the ambulatory condition, none of these differences are statistically significant. These results suggest that the quality of the ambulatory images was viewed as essentially as good as the quality of the base images.

Ultrasound in Radiology: from Anatomic, Functional, Molecular Imaging to Drug Delivery and Image-Guided Therapy

PubMed Central

Klibanov, Alexander L.; Hossack, John A.

2015-01-01

During the past decade, ultrasound has expanded medical imaging well beyond the “traditional” radiology setting - a combination of portability, low cost and ease of use makes ultrasound imaging an indispensable tool for radiologists as well as for other medical professionals who need to obtain imaging diagnosis or guide a therapeutic intervention quickly and efficiently. Ultrasound combines excellent ability for deep penetration into soft tissues with very good spatial resolution, with only a few exceptions (i.e. those involving overlying bone or gas). Real-time imaging (up to hundreds and thousands frames per second) enables guidance of therapeutic procedures and biopsies; characterization of the mechanical properties of the tissues greatly aids with the accuracy of the procedures. The ability of ultrasound to deposit energy locally brings about the potential for localized intervention encompassing: tissue ablation, enhancing penetration through the natural barriers to drug delivery in the body and triggering drug release from carrier micro- and nanoparticles. The use of microbubble contrast agents brings the ability to monitor and quantify tissue perfusion, and microbubble targeting with ligand-decorated microbubbles brings the ability to obtain molecular biomarker information, i.e., ultrasound molecular imaging. Overall, ultrasound has become the most widely used imaging modality in modern medicine; it will continue to grow and expand. PMID:26200224

Simulation Study of Effects of the Blind Deconvolution on Ultrasound Image

NASA Astrophysics Data System (ADS)

He, Xingwu; You, Junchen

2018-03-01

Ultrasonic image restoration is an essential subject in Medical Ultrasound Imaging. However, without enough and precise system knowledge, some traditional image restoration methods based on the system prior knowledge often fail to improve the image quality. In this paper, we use the simulated ultrasound image to find the effectiveness of the blind deconvolution method for ultrasound image restoration. Experimental results demonstrate that the blind deconvolution method can be applied to the ultrasound image restoration and achieve the satisfactory restoration results without the precise prior knowledge, compared with the traditional image restoration method. And with the inaccurate small initial PSF, the results shows blind deconvolution could improve the overall image quality of ultrasound images, like much better SNR and image resolution, and also show the time consumption of these methods. it has no significant increasing on GPU platform.

Virtual Guidance Ultrasound: A Tool to Obtain Diagnostic Ultrasound for Remote Environments

NASA Technical Reports Server (NTRS)

Caine,Timothy L.; Martin David S.; Matz, Timothy; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.

2012-01-01

Astronauts currently acquire ultrasound images on the International Space Station with the assistance of real-time remote guidance from an ultrasound expert in Mission Control. Remote guidance will not be feasible when significant communication delays exist during exploration missions beyond low-Earth orbit. For example, there may be as much as a 20- minute delay in communications between the Earth and Mars. Virtual-guidance, a pre-recorded audio-visual tutorial viewed in real-time, is a viable modality for minimally trained scanners to obtain diagnostically-adequate images of clinically relevant anatomical structures in an autonomous manner. METHODS: Inexperienced ultrasound operators were recruited to perform carotid artery (n = 10) and ophthalmic (n = 9) ultrasound examinations using virtual guidance as their only instructional tool. In the carotid group, each each untrained operator acquired two-dimensional, pulsed, and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. RESULTS: Eight of the 10 carotid studies were judged to be diagnostically adequate. With one exception the quality of all the ophthalmic images were adequate to excellent. CONCLUSION: Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by untrained operators with instruction only from an audio/video tutorial viewed in real time while scanning. This form of quick-response-guidance, can be developed for other ultrasound examinations, represents an opportunity to acquire important medical and scientific information for NASA flight surgeons and researchers when trained medical personnel are not present. Further, virtual guidance will allow untrained personnel to autonomously obtain important medical information in remote locations on Earth where communication is difficult or absent.

Space Technology - Game Changing Development NASA Facts: Autonomous Medical Operations

NASA Technical Reports Server (NTRS)

Thompson, David E.

2018-01-01

The AMO (Autonomous Medical Operations) Project is working extensively to train medical models on the reliability and confidence of computer-aided interpretation of ultrasound images in various clinical settings, and of various anatomical structures. AI (Artificial Intelligence) algorithms recognize and classify features in the ultrasound images, and these are compared to those features that clinicians use to diagnose diseases. The acquisition of clinically validated image assessment and the use of the AI algorithms constitutes fundamental baseline for a Medical Decision Support System that will advise crew on long-duration, remote missions.

Image dissemination and archiving.

PubMed

Robertson, Ian

2007-08-01

Images generated as part of the sonographic examination are an integral part of the medical record and must be retained according to local regulations. The standard medical image format, known as DICOM (Digital Imaging and COmmunications in Medicine) makes it possible for images from many different imaging modalities, including ultrasound, to be distributed via a standard internet network to distant viewing workstations and a central archive in an almost seamless fashion. The DICOM standard is a truly universal standard for the dissemination of medical images. When purchasing an ultrasound unit, the consumer should research the unit's capacity to generate images in a DICOM format, especially if one wishes interconnectivity with viewing workstations and an image archive that stores other medical images. PACS, an acronym for Picture Archive and Communication System refers to the infrastructure that links modalities, workstations, the image archive, and the medical record information system into an integrated system, allowing for efficient electronic distribution and storage of medical images and access to medical record data.

Medical Ultrasound Technology Research and Development at the University of Washington Center for Industrial and Medical Ultrasound

DTIC Science & Technology

2003-10-02

provide a world-class, advanced research center for bioengineering development and graduate education in high-intensity, focused ultrasound ( HIFU ). This...convenient, and robust. These technological enhancements have enabled the development of HIFU arrays and image-guided ultrasound systems for greater... Ultrasound (CIMU). The many disparate facilities and technical capabilities available to CIMU staff and students were integrated and enhanced to

WE-A-210-00: Educational: Diagnostic Ultrasound QA

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This presentation will focus on the present role of ultrasound medical physics in clinical practices. The first part of the presentation will provide an overview of ultrasound QC methodologies and testing procedures. A brief review of ultrasound phantoms utilized in these testing procedures will be presented. The second part of the presentation will summarize ultrasound imaging technical standards and professional guidelines by American College of Radiology (ACR), American Institute of Ultrasound in Medicine (AIUM), American Association of Physicists in Medicine (AAPM) and International Electrotechnical Commission (IEC). The current accreditation requirements by ACR and AIUM for ultrasound practices will be describedmore » and the practical aspects of implementing QC programs to be compliant with these requirements will be discussed. Learning Objectives: Achieve familiarity with common ultrasound QC test methods and ultrasound phantoms. Understand the coverage of the existing testing standards and professional guidelines on diagnostic ultrasound imaging. Learn what a medical physicist needs to know about ultrasound program accreditation and be able to implement ultrasound QC programs accordingly.« less

WE-B-210-01: Introduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, M.

In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafastmore » doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented spatial and temporal resolution compared to fMRI. Combined with contrast agents, our group demonstrated that Ultrafast Ultrasound Localization could provide a first in vivo and non invasive imaging modality at microscopic scales deep into organs. Many of these ultrafast modes should lead to major improvements in ultrasound screening, diagnosis, and therapeutic monitoring. Learning Objectives: Achieve familiarity with recent advances in ultrafast ultrasound imaging technology. Develop an understanding of potential applications of ultrafast ultrasound imaging for diagnosis and therapeutic monitoring. Dr. Tanter is a co-founder of Supersonic Imagine,a French company positioned in the field of medical ultrasound imaging and therapy.« less

WE-B-210-00: Carson/Zagzebski Distinguished Lectureship

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafastmore » doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented spatial and temporal resolution compared to fMRI. Combined with contrast agents, our group demonstrated that Ultrafast Ultrasound Localization could provide a first in vivo and non invasive imaging modality at microscopic scales deep into organs. Many of these ultrafast modes should lead to major improvements in ultrasound screening, diagnosis, and therapeutic monitoring. Learning Objectives: Achieve familiarity with recent advances in ultrafast ultrasound imaging technology. Develop an understanding of potential applications of ultrafast ultrasound imaging for diagnosis and therapeutic monitoring. Dr. Tanter is a co-founder of Supersonic Imagine,a French company positioned in the field of medical ultrasound imaging and therapy.« less

WE-B-210-03: Closing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, M.

In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafastmore » doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented spatial and temporal resolution compared to fMRI. Combined with contrast agents, our group demonstrated that Ultrafast Ultrasound Localization could provide a first in vivo and non invasive imaging modality at microscopic scales deep into organs. Many of these ultrafast modes should lead to major improvements in ultrasound screening, diagnosis, and therapeutic monitoring. Learning Objectives: Achieve familiarity with recent advances in ultrafast ultrasound imaging technology. Develop an understanding of potential applications of ultrafast ultrasound imaging for diagnosis and therapeutic monitoring. Dr. Tanter is a co-founder of Supersonic Imagine,a French company positioned in the field of medical ultrasound imaging and therapy.« less

Review of Quantitative Ultrasound: Envelope Statistics and Backscatter Coefficient Imaging and Contributions to Diagnostic Ultrasound.

PubMed

Oelze, Michael L; Mamou, Jonathan

2016-02-01

Conventional medical imaging technologies, including ultrasound, have continued to improve over the years. For example, in oncology, medical imaging is characterized by high sensitivity, i.e., the ability to detect anomalous tissue features, but the ability to classify these tissue features from images often lacks specificity. As a result, a large number of biopsies of tissues with suspicious image findings are performed each year with a vast majority of these biopsies resulting in a negative finding. To improve specificity of cancer imaging, quantitative imaging techniques can play an important role. Conventional ultrasound B-mode imaging is mainly qualitative in nature. However, quantitative ultrasound (QUS) imaging can provide specific numbers related to tissue features that can increase the specificity of image findings leading to improvements in diagnostic ultrasound. QUS imaging can encompass a wide variety of techniques including spectral-based parameterization, elastography, shear wave imaging, flow estimation, and envelope statistics. Currently, spectral-based parameterization and envelope statistics are not available on most conventional clinical ultrasound machines. However, in recent years, QUS techniques involving spectral-based parameterization and envelope statistics have demonstrated success in many applications, providing additional diagnostic capabilities. Spectral-based techniques include the estimation of the backscatter coefficient (BSC), estimation of attenuation, and estimation of scatterer properties such as the correlation length associated with an effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) of scatterers. Envelope statistics include the estimation of the number density of scatterers and quantification of coherent to incoherent signals produced from the tissue. Challenges for clinical application include correctly accounting for attenuation effects and transmission losses and implementation of QUS on clinical devices. Successful clinical and preclinical applications demonstrating the ability of QUS to improve medical diagnostics include characterization of the myocardium during the cardiac cycle, cancer detection, classification of solid tumors and lymph nodes, detection and quantification of fatty liver disease, and monitoring and assessment of therapy.

Review of quantitative ultrasound: envelope statistics and backscatter coefficient imaging and contributions to diagnostic ultrasound

PubMed Central

Oelze, Michael L.; Mamou, Jonathan

2017-01-01

Conventional medical imaging technologies, including ultrasound, have continued to improve over the years. For example, in oncology, medical imaging is characterized by high sensitivity, i.e., the ability to detect anomalous tissue features, but the ability to classify these tissue features from images often lacks specificity. As a result, a large number of biopsies of tissues with suspicious image findings are performed each year with a vast majority of these biopsies resulting in a negative finding. To improve specificity of cancer imaging, quantitative imaging techniques can play an important role. Conventional ultrasound B-mode imaging is mainly qualitative in nature. However, quantitative ultrasound (QUS) imaging can provide specific numbers related to tissue features that can increase the specificity of image findings leading to improvements in diagnostic ultrasound. QUS imaging techniques can encompass a wide variety of techniques including spectral-based parameterization, elastography, shear wave imaging, flow estimation and envelope statistics. Currently, spectral-based parameterization and envelope statistics are not available on most conventional clinical ultrasound machines. However, in recent years QUS techniques involving spectral-based parameterization and envelope statistics have demonstrated success in many applications, providing additional diagnostic capabilities. Spectral-based techniques include the estimation of the backscatter coefficient, estimation of attenuation, and estimation of scatterer properties such as the correlation length associated with an effective scatterer diameter and the effective acoustic concentration of scatterers. Envelope statistics include the estimation of the number density of scatterers and quantification of coherent to incoherent signals produced from the tissue. Challenges for clinical application include correctly accounting for attenuation effects and transmission losses and implementation of QUS on clinical devices. Successful clinical and pre-clinical applications demonstrating the ability of QUS to improve medical diagnostics include characterization of the myocardium during the cardiac cycle, cancer detection, classification of solid tumors and lymph nodes, detection and quantification of fatty liver disease, and monitoring and assessment of therapy. PMID:26761606

Right Upper Quadrant Pain: Ultrasound First!

PubMed

Revzin, Margarita V; Scoutt, Leslie M; Garner, Joseph G; Moore, Christopher L

2017-10-01

Acute right upper quadrant (RUQ) pain is a common presenting symptom in emergency departments and outpatient medical practices, and is most commonly attributable to biliary and hepatic pathology. Ultrasound should be used as a first-line imaging modality for the diagnosis of gallstones and cholecystitis, as it allows the differentiation of medical and surgical causes of upper abdominal pathology, and in many circumstances is sufficient to guide patient management. Knowledge of strengths and limitations of ultrasound in the evaluation of RUQ is paramount in correct diagnosis. A spectrum of RUQ pathology for which a RUQ ultrasound examination should reasonably be considered as the initial imaging modality of choice will be reviewed. © 2017 by the American Institute of Ultrasound in Medicine.

Medical Ultrasound Imaging.

ERIC Educational Resources Information Center

Hughes, Stephen

2001-01-01

Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

Enhanced ultrasound for advanced diagnostics, ultrasound tomography for volume limb imaging and prosthetic fitting

NASA Astrophysics Data System (ADS)

Anthony, Brian W.

2016-04-01

Ultrasound imaging methods hold the potential to deliver low-cost, high-resolution, operator-independent and nonionizing imaging systems - such systems couple appropriate algorithms with imaging devices and techniques. The increasing demands on general practitioners motivate us to develop more usable and productive diagnostic imaging equipment. Ultrasound, specifically freehand ultrasound, is a low cost and safe medical imaging technique. It doesn't expose a patient to ionizing radiation. Its safety and versatility make it very well suited for the increasing demands on general practitioners, or for providing improved medical care in rural regions or the developing world. However it typically suffers from sonographer variability; we will discuss techniques to address user variability. We also discuss our work to combine cylindrical scanning systems with state of the art inversion algorithms to deliver ultrasound systems for imaging and quantifying limbs in 3-D in vivo. Such systems have the potential to track the progression of limb health at a low cost and without radiation exposure, as well as, improve prosthetic socket fitting. Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and quantitative process for prosthetic cup design and fabrication has not been fully demonstrated. Medical ultrasonography may inform the design process of prosthetic sockets in a more objective manner. This keynote talk presents the results of progress in this area.

Medical Imaging.

ERIC Educational Resources Information Center

Barker, M. C. J.

1996-01-01

Discusses four main types of medical imaging (x-ray, radionuclide, ultrasound, and magnetic resonance) and considers their relative merits. Describes important recent and possible future developments in image processing. (Author/MKR)

High-frequency transducers for point-of-care ultrasound applications: what is the optimal frequency range?

PubMed

Adhikari, Srikar

2014-06-01

To compare images obtained using two linear transducers with a different range of frequencies, and to determine if there is a significant difference in the quality of images between the two transducers for medical decision-making. This was a single-blinded, cross-sectional study at an academic medical center. Twenty-five emergency medicine clinical scenarios with ultrasound images (using both 10-5 and 14-5 MHz transducers) covering a variety of point-of-care ultrasound applications were presented to four emergency physician sonographers. They were blinded to the study hypothesis and type of the transducer used to obtain the images. On a scale of 1-10, the mean image quality rating for 10-5 MHz transducer was 7.09 (95 % CI 6.73-7.45) and 6.49 (95 % CI 5.99-6.99) for 14-5 MHz transducer. In the majority of cases (84 %, 95 % CI 75.7-92.3 %), sonographers indicated that images obtained with a 10-5 MHz transducer were satisfactory for medical decision-making. They preferred images obtained with a 10-5 MHz transducer over 14-5 MHz transducer in 39 % (95 % CI 30-50 %) of cases. The images obtained with a 14-5 MHz transducer were preferred over 10-5 MHz transducer in only 16 % (95 % CI 7.7-24.3 %) of the cases. The 14-5 MHz transducer has a slight advantage over 10-5 MHz transducer for ocular, upper airway, and musculoskeletal (tendon) ultrasound applications. A 10-5 MHz linear transducer is adequate to obtain images that can be used for medical decision-making for a variety of point-of-care ultrasound applications.

Hunger Games: Interactive Ultrasound Imaging for Learning Gastrointestinal Physiology.

PubMed

Kafer, Ilana; Rennie, William; Noor, Ali; Pellerito, John S

2017-02-01

Ultrasound is playing an increasingly important role in medical student education. Although most uses of ultrasound have focused on learning purely anatomic relationships or augmentation of the physical examination, there is little documentation of the value of ultrasound as a learning tool regarding physiology alone or in association with anatomy. We devised an interactive learning session for first-year medical students using ultrasound to combine both anatomic and physiologic principles as an integration of gastrointestinal and vascular function. The incorporation of our activity, The Hunger Games, provides the foundation for a powerful integration tool for medical student education. © 2016 by the American Institute of Ultrasound in Medicine.

WE-B-210-02: The Advent of Ultrafast Imaging in Biomedical Ultrasound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanter, M.

In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafastmore » doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented spatial and temporal resolution compared to fMRI. Combined with contrast agents, our group demonstrated that Ultrafast Ultrasound Localization could provide a first in vivo and non invasive imaging modality at microscopic scales deep into organs. Many of these ultrafast modes should lead to major improvements in ultrasound screening, diagnosis, and therapeutic monitoring. Learning Objectives: Achieve familiarity with recent advances in ultrafast ultrasound imaging technology. Develop an understanding of potential applications of ultrafast ultrasound imaging for diagnosis and therapeutic monitoring. Dr. Tanter is a co-founder of Supersonic Imagine,a French company positioned in the field of medical ultrasound imaging and therapy.« less

MO-D-218-01: Overview of Methodology and Standards (QIBA, IEC, AIUM and AAPM).

PubMed

Carson, P

2012-06-01

Ultrasound system standards and professional guidelines can facilitate efficient provision of medical physics services and growth of ultrasound imaging if the documents are well designed and are utilized. We too often develop our own phantoms and procedures and never converge to obtain a critical mass of data on system performance and value of such services. Standards can also produce unnecessary costs and limit innovation if not carefully developed, reviewed, and changed as needed. There are quite a few new initiatives that, if followed vigorously, could improve medical ultrasound and medical physicists' contributions thereto. This talk is to explain many of the existing standards and recommendations for ultrasound system quality control, performance evaluation, and safety, as well as current and suggested efforts in these areas. The primary standards body for medical ultrasound systems is now the International Electrotechnical Commission (IEC). Uniformity across the world is helpful to all if the documents are reasonably current. There still is a role for traditional bodies such as the AAPM with its valuable report series and the American Inst. of Ultras. in Med. (AIUM) with its own standards and reports and its joint work with the Medical Imaging Technology Alliance (MITA). All three, with strong involvement of FDA scientists and with some efforts from the Acoustical Society of America have historically provided the main standards affecting medical physicists. Now that the lengthy IEC process is moving more smoothly, our national bodies still can provide new developments and drafts that can be offered as needed for international standardization. The ACR in particular can provide meaningful incentives through ultrasound service accreditation. Without any regulatory or strong consumer push, reports and standards on ultrasound system performance have received only modest use in the USA. A consistent consumer or accreditation push might be justified now. A series of three standards on performance evaluation is well on its way to covering pulse echo ultrasound well, with IEC 61319-1 on spatial measurements, IEC 61319-2 on depth of penetration and local dynamic range and one draft and one Technical Specification 62558 on small void imaging. A new effort has just been initiated to help drive more and better use of quantitative ultrasound imaging in human and surrogate studies and in clinical use. A shear wave speed ultrasound technical committee will carry out this effort in the Quantitative Imaging Biomarkers Alliance (QIBA) that is managed by the RSNA. 1. Understand the coverage of the two current and third planned IEC medical ultrasound performance evaluation standards that could form a basis for stable performance evaluation tests. 2. Understand the coverage of the Current AIUM and ACR QC documents and the drafting and support efforts in the IEC. 3. Understand the need for and partial availability of simplified software and instructions to improve and facilitate performance of these tests? 4. Understand how standards development can lead to improved understanding and performance of medical ultrasound imaging as is anticipated for the new QIBA effort. © 2012 American Association of Physicists in Medicine.

The management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust

PubMed Central

Peacock, M

2013-01-01

Management of ultrasound equipment at Sheffield Teaching Hospitals NHS Foundation Trust is described. The organisation and input of various stakeholders and their involvement with ultrasound equipment management and scientific ultrasound is discussed. Two important stakeholders are the Medical Equipment Management Group and the Radiation Safety Steering Committee. The Medical Equipment Management Group has a specific sub-group, the Ultrasound sub-group, and its role is to coordinate the purchase, replacement and quality assurance of ultrasound equipment in the Trust. The Radiation Safety Steering Committee has a non-ionising radiation representative and the role of this committee is to provide corporate assurance that any health and safety issues arising from the use of radiation to either patients, members of the public or staff within the Trust are being effectively managed. The Ultrasound sub-group of the Medical Equipment Management Group has successfully brought together management of all ultrasound equipment within the Trust and is in the process of fulfilling the quality assurance and training milestones set out by the Medical Equipment Management Group. Advice from the Radiation Safety Steering Committee has helped to increase awareness of ultrasound safety and good scanning practice, especially in the case of neonatal ultrasound imaging, within the Trust. In addition, the RSSC has given advice on clinical pathways for patients undergoing ionising radiation imaging while being treated by extra-corporeal shockwave lithotripsy. PMID:27433195

Nonlocal Total-Variation-Based Speckle Filtering for Ultrasound Images.

PubMed

Wen, Tiexiang; Gu, Jia; Li, Ling; Qin, Wenjian; Wang, Lei; Xie, Yaoqin

2016-07-01

Ultrasound is one of the most important medical imaging modalities for its real-time and portable imaging advantages. However, the contrast resolution and important details are degraded by the speckle in ultrasound images. Many speckle filtering methods have been developed, but they are suffered from several limitations, difficult to reach a balance between speckle reduction and edge preservation. In this paper, an adaptation of the nonlocal total variation (NLTV) filter is proposed for speckle reduction in ultrasound images. The speckle is modeled via a signal-dependent noise distribution for the log-compressed ultrasound images. Instead of the Euclidian distance, the statistical Pearson distance is introduced in this study for the similarity calculation between image patches via the Bayesian framework. And the Split-Bregman fast algorithm is used to solve the adapted NLTV despeckling functional. Experimental results on synthetic and clinical ultrasound images and comparisons with some classical and recent algorithms are used to demonstrate its improvements in both speckle noise reduction and tissue boundary preservation for ultrasound images. © The Author(s) 2015.

Ultrasound introscopic image quantitative characteristics for medical diagnosis

NASA Astrophysics Data System (ADS)

Novoselets, Mikhail K.; Sarkisov, Sergey S.; Gridko, Alexander N.; Tcheban, Anatoliy K.

1993-09-01

The results on computer aided extraction of quantitative characteristics (QC) of ultrasound introscopic images for medical diagnosis are presented. Thyroid gland (TG) images of Chernobil Accident sufferers are considered. It is shown that TG diseases can be associated with some values of selected QCs of random echo distribution in the image. The possibility of these QCs usage for TG diseases recognition in accordance with calculated values is analyzed. The role of speckle noise elimination in the solution of the problem on TG diagnosis is considered too.

Ultra-fast bright field and fluorescence imaging of the dynamics of micrometer-sized objects

NASA Astrophysics Data System (ADS)

Chen, Xucai; Wang, Jianjun; Versluis, Michel; de Jong, Nico; Villanueva, Flordeliza S.

2013-06-01

High speed imaging has application in a wide area of industry and scientific research. In medical research, high speed imaging has the potential to reveal insight into mechanisms of action of various therapeutic interventions. Examples include ultrasound assisted thrombolysis, drug delivery, and gene therapy. Visual observation of the ultrasound, microbubble, and biological cell interaction may help the understanding of the dynamic behavior of microbubbles and may eventually lead to better design of such delivery systems. We present the development of a high speed bright field and fluorescence imaging system that incorporates external mechanical waves such as ultrasound. Through collaborative design and contract manufacturing, a high speed imaging system has been successfully developed at the University of Pittsburgh Medical Center. We named the system "UPMC Cam," to refer to the integrated imaging system that includes the multi-frame camera and its unique software control, the customized modular microscope, the customized laser delivery system, its auxiliary ultrasound generator, and the combined ultrasound and optical imaging chamber for in vitro and in vivo observations. This system is capable of imaging microscopic bright field and fluorescence movies at 25 × 106 frames per second for 128 frames, with a frame size of 920 × 616 pixels. Example images of microbubble under ultrasound are shown to demonstrate the potential application of the system.

Ultra-fast bright field and fluorescence imaging of the dynamics of micrometer-sized objects

PubMed Central

Chen, Xucai; Wang, Jianjun; Versluis, Michel; de Jong, Nico; Villanueva, Flordeliza S.

2013-01-01

High speed imaging has application in a wide area of industry and scientific research. In medical research, high speed imaging has the potential to reveal insight into mechanisms of action of various therapeutic interventions. Examples include ultrasound assisted thrombolysis, drug delivery, and gene therapy. Visual observation of the ultrasound, microbubble, and biological cell interaction may help the understanding of the dynamic behavior of microbubbles and may eventually lead to better design of such delivery systems. We present the development of a high speed bright field and fluorescence imaging system that incorporates external mechanical waves such as ultrasound. Through collaborative design and contract manufacturing, a high speed imaging system has been successfully developed at the University of Pittsburgh Medical Center. We named the system “UPMC Cam,” to refer to the integrated imaging system that includes the multi-frame camera and its unique software control, the customized modular microscope, the customized laser delivery system, its auxiliary ultrasound generator, and the combined ultrasound and optical imaging chamber for in vitro and in vivo observations. This system is capable of imaging microscopic bright field and fluorescence movies at 25 × 106 frames per second for 128 frames, with a frame size of 920 × 616 pixels. Example images of microbubble under ultrasound are shown to demonstrate the potential application of the system. PMID:23822346

Ultrasound imaging in medical student education: Impact on learning anatomy and physical diagnosis.

PubMed

So, Sokpoleak; Patel, Rita M; Orebaugh, Steven L

2017-03-01

Ultrasound use has expanded dramatically among the medical specialties for diagnostic and interventional purposes, due to its affordability, portability, and practicality. This imaging modality, which permits real-time visualization of anatomic structures and relationships in vivo, holds potential for pre-clinical instruction of students in anatomy and physical diagnosis, as well as providing a bridge to the eventual use of bedside ultrasound by clinicians to assess patients and guide invasive procedures. In many studies, but not all, improved understanding of anatomy has been demonstrated, and in others, improved accuracy in selected aspects of physical diagnosis is evident. Most students have expressed a highly favorable impression of this technology for anatomy education when surveyed. Logistic issues or obstacles to the integration of ultrasound imaging into anatomy teaching appear to be readily overcome. The enthusiasm of students and anatomists for teaching with ultrasound has led to widespread implementation of ultrasound-based teaching initiatives in medical schools the world over, including some with integration throughout the entire curriculum; a trend that likely will continue to grow. Anat Sci Educ 10: 176-189. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Enabling the mission through trans-atlantic remote mentored musculoskeletal ultrasound: case report of a portable hand-carried tele-ultrasound system for medical relief missions.

PubMed

Kirkpatrick, Andrew W; Blaivas, Michael; Sargsyan, Ashot E; McBeth, Paul B; Patel, Chirag; Xiao, Zhengwen; Pian, Linping; Panebianco, Nova; Hamilton, Douglas R; Ball, Chad G; Dulchavsky, Scott A

2013-07-01

Modern medical practice has become extremely dependent upon diagnostic imaging technologies to confirm the results of clinical examination and to guide the response to therapies. Of the various diagnostic imaging techniques, ultrasound is the most portable modality and one that is repeatable, dynamic, relatively cheap, and safe as long as the imaging provided is accurately interpreted. It is, however, the most user-dependent, a characteristic that has prompted the development of remote guidance techniques, wherein remote experts guide distant users through the use of information technologies. Medical mission work often brings specialist physicians to less developed locations, where they wish to provide the highest levels of care but are often bereft of diagnostic imaging resources on which they depend. Furthermore, if these personnel become ill or injured, their own care received may not be to the standard they have left at home. We herein report the utilization of a compact hand-carried remote tele-ultrasound system that allowed real-time diagnosis and follow-up of an acutely torn adductor muscle by a team of ultrasonographers, surgeons, and physicians. The patient was one of the mission surgeons who was guided to self-image. The virtual network of supporting experts was located across North America, whereas the patient was in Lome, Togo, West Africa. The system consisted of a hand-carried ultrasound, the output of which was digitized and streamed to the experts within standard voice-over-Internet-protocol software with an embedded simultaneous videocamera image of the ultrasonographer's hands using a customized graphical user interface. The practical concept of a virtual tele-ultrasound support network was illustrated through the clinical guidance of multiple physicians, including National Aeronautics and Space Administration Medical Operations remote guiders, Olympic team-associated surgeons, and ultrasound-focused emergentologists.

Fusion of Ultrasound Tissue-Typing Images with Multiparametric MRI for Image-guided Prostate Cancer Radiation Therapy

DTIC Science & Technology

2014-10-01

work under the guidance of an outstanding mentor team at Emory Winship Cancer Institute. I took three courses ( Medical Health Physics, Radiation...and Late Normal-Tissue Toxicity in Breast- Cancer Radiotherapy”, Medical Physics, 40(6):379, 2013. 5. Yang X, Liu T, Curran W and Torres M...Analysis for Normal-tissue Toxicity: A Prospective Ultrasound Study of Acute Toxicity in Breast- Cancer Radiotherapy", Medical Physics 41 (6), 482-482

Survey of the prevalence and methodology of quality assurance for B-mode ultrasound image quality among veterinary sonographers.

PubMed

Hoscheit, Larry P; Heng, Hock Gan; Lim, Chee Kin; Weng, Hsin-Yi

2018-05-01

Image quality in B-mode ultrasound is important as it reflects the diagnostic accuracy and diagnostic information provided during clinical scanning. Quality assurance programs for B-mode ultrasound systems/components are comprised of initial quality acceptance testing and subsequent regularly scheduled quality control testing. The importance of quality assurance programs for B-mode ultrasound image quality using ultrasound phantoms is well documented in the human medical and medical physics literature. The purpose of this prospective, cross-sectional, survey study was to determine the prevalence and methodology of quality acceptance testing and quality control testing of image quality for ultrasound system/components among veterinary sonographers. An online electronic survey was sent to 1497 members of veterinary imaging organizations: the American College of Veterinary Radiology, the Veterinary Ultrasound Society, and the European Association of Veterinary Diagnostic Imaging, and a total of 167 responses were received. The results showed that the percentages of veterinary sonographers performing quality acceptance testing and quality control testing are 42% (64/151; 95% confidence interval 34-52%) and 26% (40/156: 95% confidence interval 19-33%) respectively. Of the respondents who claimed to have quality acceptance testing or quality control testing of image quality in place for their ultrasound system/components, 0% have performed quality acceptance testing or quality control testing correctly (quality acceptance testing 95% confidence interval: 0-6%, quality control testing 95% confidence interval: 0-11%). Further education and guidelines are recommended for veterinary sonographers in the area of quality acceptance testing and quality control testing for B-mode ultrasound equipment/components. © 2018 American College of Veterinary Radiology.

Iterative Minimum Variance Beamformer with Low Complexity for Medical Ultrasound Imaging.

PubMed

Deylami, Ali Mohades; Asl, Babak Mohammadzadeh

2018-06-04

Minimum variance beamformer (MVB) improves the resolution and contrast of medical ultrasound images compared with delay and sum (DAS) beamformer. The weight vector of this beamformer should be calculated for each imaging point independently, with a cost of increasing computational complexity. The large number of necessary calculations limits this beamformer to application in real-time systems. A beamformer is proposed based on the MVB with lower computational complexity while preserving its advantages. This beamformer avoids matrix inversion, which is the most complex part of the MVB, by solving the optimization problem iteratively. The received signals from two imaging points close together do not vary much in medical ultrasound imaging. Therefore, using the previously optimized weight vector for one point as initial weight vector for the new neighboring point can improve the convergence speed and decrease the computational complexity. The proposed method was applied on several data sets, and it has been shown that the method can regenerate the results obtained by the MVB while the order of complexity is decreased from O(L 3 ) to O(L 2 ). Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

An interventional multispectral photoacoustic imaging platform for the guidance of minimally invasive procedures

NASA Astrophysics Data System (ADS)

Xia, Wenfeng; Nikitichev, Daniil I.; Mari, Jean Martial; West, Simeon J.; Ourselin, Sebastien; Beard, Paul C.; Desjardins, Adrien E.

2015-07-01

Precise and efficient guidance of medical devices is of paramount importance for many minimally invasive procedures. These procedures include fetal interventions, tumor biopsies and treatments, central venous catheterisations and peripheral nerve blocks. Ultrasound imaging is commonly used for guidance, but it often provides insufficient contrast with which to identify soft tissue structures such as vessels, tumors, and nerves. In this study, a hybrid interventional imaging system that combines ultrasound imaging and multispectral photoacoustic imaging for guiding minimally invasive procedures was developed and characterized. The system provides both structural information from ultrasound imaging and molecular information from multispectral photoacoustic imaging. It uses a commercial linear-array ultrasound imaging probe as the ultrasound receiver, with a multimode optical fiber embedded in a needle to deliver pulsed excitation light to tissue. Co-registration of ultrasound and photoacoustic images is achieved with the use of the same ultrasound receiver for both modalities. Using tissue ex vivo, the system successfully discriminated deep-located fat tissue from the surrounding muscle tissue. The measured photoacoustic spectrum of the fat tissue had good agreement with the lipid spectrum in literature.

Real-time registration of video with ultrasound using stereo disparity

NASA Astrophysics Data System (ADS)

Wang, Jihang; Horvath, Samantha; Stetten, George; Siegel, Mel; Galeotti, John

2012-02-01

Medical ultrasound typically deals with the interior of the patient, with the exterior left to the original medical imaging modality, direct human vision. For the human operator scanning the patient, the view of the external anatomy is essential for correctly locating the ultrasound probe on the body and making sense of the resulting ultrasound images in their proper anatomical context. The operator, after all, is not expected to perform the scan with his eyes shut. Over the past decade, our laboratory has developed a method of fusing these two information streams in the mind of the operator, the Sonic Flashlight, which uses a half silvered mirror and miniature display mounted on an ultrasound probe to produce a virtual image within the patient at its proper location. We are now interested in developing a similar data fusion approach within the ultrasound machine itself, by, in effect, giving vision to the transducer. Our embodiment of this concept consists of an ultrasound probe with two small video cameras mounted on it, with software capable of locating the surface of an ultrasound phantom using stereo disparity between the two video images. We report its first successful operation, demonstrating a 3D rendering of the phantom's surface with the ultrasound data superimposed at its correct relative location. Eventually, automated analysis of these registered data sets may permit the scanner and its associated computational apparatus to interpret the ultrasound data within its anatomical context, much as the human operator does today.

A single FPGA-based portable ultrasound imaging system for point-of-care applications.

PubMed

Kim, Gi-Duck; Yoon, Changhan; Kye, Sang-Bum; Lee, Youngbae; Kang, Jeeun; Yoo, Yangmo; Song, Tai-kyong

2012-07-01

We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications.

Evaluation of chest ultrasound integrated teaching of respiratory system physiology to medical students.

PubMed

Paganini, Matteo; Bondì, Michela; Rubini, Alessandro

2017-12-01

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term concept retention. A lecture about respiratory physiology was integrated with ultrasound and delivered to third-year medical students. It included basic concepts of ultrasound imaging and the physiology of four anatomic sectors of the body of a male volunteer, shown with a portable ultrasound device (pleural sliding, diaphragmatic movement, inferior vena cava diameter variations, cardiac movements). Students' perceptions of the integrated lecture were assessed, and attendance recorded. After 4 mo, four multiple-choice questions about respiratory physiology were administered during the normal human physiology examinations, and the results of students who attended the lesson and those of who did not were compared. One hundred thirty-four students attended the lecture. Most of them showed encouragement for the study of the subject and considered the ultrasound integrated lecture more interesting than a traditional one and pertinent to the syllabus. Exposed students achieved a better score at the examination and committed less errors than did nonexposed students. The chest ultrasound integrated lecture was appreciated by students. A possible association between the exposure to the lecture and short-term concept retention is shown by better performances of the exposed cohort at the examination. A systematic introduction of ultrasound into physiology traditional teaching will be promoted by the Ultrasound-Based Medical Education movement. Copyright © 2017 the American Physiological Society.

[Mobile hospital -real time mobile telehealthcare system with ultrasound and CT van using high-speed satellite communication-].

PubMed

Takizawa, Masaomi; Miyashita, Toyohisa; Murase, Sumio; Kanda, Hirohito; Karaki, Yoshiaki; Yagi, Kazuo; Ohue, Toru

2003-01-01

A real-time telescreening system is developed to detect early diseases for rural area residents using two types of mobile vans with a portable satellite station. The system consists of a satellite communication system with 1.5Mbps of the JCSAT-1B satellite, a spiral CT van, an ultrasound imaging van with two video conference system, a DICOM server and a multicast communication unit. The video image and examination image data are transmitted from the van to hospitals and the university simultaneously. Physician in the hospital observes and interprets exam images from the van and watches the video images of the position of ultrasound transducer on screenee in the van. After the observation images, physician explains a results of the examination by the video conference system. Seventy lung CT screening and 203 ultrasound screening were done from March to June 2002. The trial of this real time screening suggested that rural residents are given better healthcare without visit to the hospital. And it will open the gateway to reduce the medical cost and medical divide between city area and rural area.

New NIH-funded Ultrasound Technology is Changing Lives around the World | NIH MedlinePlus the Magazine

MedlinePlus

... please turn Javascript on. New NIH-funded Ultrasound Technology is Changing Lives around the World Past Issues / ... to high-quality medical images. Vscan uses advanced technology to produce high-quality images of internal organs. ...

Seeing Is Believing: Evaluating a Point-of-Care Ultrasound Curriculum for 1st-Year Medical Students.

PubMed

Nelson, Bret P; Hojsak, Joanne; Dei Rossi, Elizabeth; Karani, Reena; Narula, Jagat

2017-01-01

Point-of-care ultrasound has been a novel addition to undergraduate medical education at a few medical schools. The impact is not fully understood, and few rigorous assessments of educational outcomes exist. This study assessed the impact of a point-of-care ultrasound curriculum on image acquisition, interpretation, and student and faculty perceptions of the course. All 142 first-year medical students completed a curriculum on ultrasound physics and instrumentation, cardiac, thoracic, and abdominal imaging. A flipped classroom model of preclass tutorials and tests augmenting live, hands-on scanning sessions was incorporated into the physical examination course. Students and faculty completed surveys on impressions of the curriculum, and all students under-went competency assessments with standardized patients. The curriculum was a mandatory part of the physical examination course and was taught by experienced clinician-sonographers as well as faculty who do not routinely perform sonography in their clinical practice. Students and faculty agreed that the physical examination course was the right time to introduce ultrasound (87% and 80%). Students demonstrated proper use of the ultrasound machine functions (M score = 91.55), and cardiac, thoracic, and abdominal system assessments (M score = 80.35, 79.58, and 71.57, respectively). Students and faculty valued the curriculum, and students demonstrated basic competency in performance and interpretation of ultrasound. Further study is needed to determine how to best incorporate this emerging technology into a robust learning experience for medical students.

Source Book of Educational Materials for Diagnostic Medical Ultrasound. Radiological Health Series.

ERIC Educational Resources Information Center

Pijar, Mary Lou, Comp; And Others

This report is a compilation of educational materials that are available in the field of diagnostic medical ultrasound. Materials, which include publications, audiovisual aids, and teaching aids, are listed under the following categories: abdominal imaging; anatomy and physiology; anatomy and embryology; bioeffects; cardiology and vasculature;…

Ultrasound Use in Urinary Stones: Adapting Old Technology for a Modern-Day Disease.

PubMed

Tzou, David T; Usawachintachit, Manint; Taguchi, Kazumi; Chi, Thomas

2017-04-01

Ultrasound has become a mainstay tool in urologists' armamentarium for the diagnosis and management of nephrolithiasis. From starting as a rudimentary form of imaging, it has come to play a more prominent role over time, paralleling evolution in ultrasound technology. Throughout the medical community there is a growing emphasis on reducing the amount of ionizing radiation delivered to patients during routine imaging. As such there has been a resurgence of interest in ultrasound given its lack of associated radiation exposure and proven effectiveness as a diagnostic and therapeutic imaging modality. Herein, we provide a review of the history of ultrasound, how the use of ultrasound is expanding in both diagnosis and treatment of urinary stone disease, and finally how promising applications of ultrasound are shaping the future of kidney stone management.

Ultrasound Use in Urinary Stones: Adapting Old Technology for a Modern-Day Disease

PubMed Central

Tzou, David T.; Usawachintachit, Manint; Taguchi, Kazumi

2017-01-01

Abstract Ultrasound has become a mainstay tool in urologists' armamentarium for the diagnosis and management of nephrolithiasis. From starting as a rudimentary form of imaging, it has come to play a more prominent role over time, paralleling evolution in ultrasound technology. Throughout the medical community there is a growing emphasis on reducing the amount of ionizing radiation delivered to patients during routine imaging. As such there has been a resurgence of interest in ultrasound given its lack of associated radiation exposure and proven effectiveness as a diagnostic and therapeutic imaging modality. Herein, we provide a review of the history of ultrasound, how the use of ultrasound is expanding in both diagnosis and treatment of urinary stone disease, and finally how promising applications of ultrasound are shaping the future of kidney stone management. PMID:27733052

Programmable Real-time Clinical Photoacoustic and Ultrasound Imaging System

PubMed Central

Kim, Jeesu; Park, Sara; Jung, Yuhan; Chang, Sunyeob; Park, Jinyong; Zhang, Yumiao; Lovell, Jonathan F.; Kim, Chulhong

2016-01-01

Photoacoustic imaging has attracted interest for its capacity to capture functional spectral information with high spatial and temporal resolution in biological tissues. Several photoacoustic imaging systems have been commercialized recently, but they are variously limited by non-clinically relevant designs, immobility, single anatomical utility (e.g., breast only), or non-programmable interfaces. Here, we present a real-time clinical photoacoustic and ultrasound imaging system which consists of an FDA-approved clinical ultrasound system integrated with a portable laser. The system is completely programmable, has an intuitive user interface, and can be adapted for different applications by switching handheld imaging probes with various transducer types. The customizable photoacoustic and ultrasound imaging system is intended to meet the diverse needs of medical researchers performing both clinical and preclinical photoacoustic studies. PMID:27731357

Programmable Real-time Clinical Photoacoustic and Ultrasound Imaging System.

PubMed

Kim, Jeesu; Park, Sara; Jung, Yuhan; Chang, Sunyeob; Park, Jinyong; Zhang, Yumiao; Lovell, Jonathan F; Kim, Chulhong

2016-10-12

Photoacoustic imaging has attracted interest for its capacity to capture functional spectral information with high spatial and temporal resolution in biological tissues. Several photoacoustic imaging systems have been commercialized recently, but they are variously limited by non-clinically relevant designs, immobility, single anatomical utility (e.g., breast only), or non-programmable interfaces. Here, we present a real-time clinical photoacoustic and ultrasound imaging system which consists of an FDA-approved clinical ultrasound system integrated with a portable laser. The system is completely programmable, has an intuitive user interface, and can be adapted for different applications by switching handheld imaging probes with various transducer types. The customizable photoacoustic and ultrasound imaging system is intended to meet the diverse needs of medical researchers performing both clinical and preclinical photoacoustic studies.

Introduction of basic obstetrical ultrasound screening in undergraduate medical education.

PubMed

Hamza, A; Solomayer, E-F; Takacs, Z; Juhasz-Boes, I; Joukhadar, R; Radosa, J C; Mavrova, R; Marc, W; Volk, T; Meyberg-Solomayer, G

2016-09-01

Teaching ultrasound procedures to undergraduates has recently been proposed to improve the quality of medical education. We address the impact of applying standardized ultrasound teaching to our undergraduates. Medical students received an additional theoretical and practical course involving hands-on ultrasound screening during their mandatory practical training week in obstetrics and gynecology. The students' theoretical knowledge and fetal image recognition skills were tested before and after the course. After the course, the students were asked to answer a course evaluation questionnaire. To standardize the teaching procedure, we used Peyton's 4-Step Approach to teach the skills needed for a German Society of Ultrasound in Medicine Level 1 ultrasound examiner. The multiple-choice question scores after the course showed statistically significant improvement (50 vs. 80 %; P < 0.001). The questionnaire revealed that students were satisfied with the course, felt that it increased their ultrasound knowledge, and indicated that they wanted more sonographic hands-on training in both obstetrics and gynecology and other medical fields. Using practical, hands-on medical teaching is an emerging method for undergraduate education that should be further evaluated, standardized, and developed.

Studies on the foundation and development of diagnostic ultrasound

PubMed Central

Wagai, Toshio

2007-01-01

In recent years, various types of diagnostic imaging methods, such as CT, MRI, PET and Ultrasound, have been developed rapidly and become indispensable as clinical diagnostic tools. Among these imaging modalities, CT, MRI and PET all apply electromagnetic waves like radiation rays. In contrast, an ultrasound imaging method uses a completely different mechanical pressure wave: “sound”. Ultrasound has various features, including inaudible sound at very high frequencies, which allows its use in medical diagnoses. That is, ultrasound techniques can be applied in transmission, reflection and Doppler methods. Moreover, the sharp directivity of an ultrasound beam can also improve image resolution. Another big advantage of diagnostic ultrasound is that it does not harm the human body or cause any pain to patients. Given these various advantages, diagnostic ultrasound has recently been widely used in diagnosing cancer and cardiovascular disease and scanning fetuses (Fig. 1) as well as routine clinical examinations in hospitals. In this paper, I outline my almost 50-year history of diagnostic ultrasound research, particularly that performed at the early stage from 1950–56. PMID:24367150

High Resolution X-Ray Phase Contrast Imaging with Acoustic Tissue-Selective Contrast Enhancement

DTIC Science & Technology

2005-06-01

Ultrasonics Symp 1319 (1999). 17. Sarvazyan, A. P. Shear Wave Elasticity Imaging: A New Ultrasonic Technology of Medical Diagnostics. Ultrasound in...samples using acoustically modulated X-ray phase contrast imaging. 15. SUBJECT TERMS x-ray, ultrasound, phase contrast, imaging, elastography 16...x-rays, phase contrast imaging is based on phase changes as x-rays traverse a body resulting in wave interference that result in intensity changes in

A tele-operated mobile ultrasound scanner using a light-weight robot.

PubMed

Delgorge, Cécile; Courrèges, Fabien; Al Bassit, Lama; Novales, Cyril; Rosenberger, Christophe; Smith-Guerin, Natalie; Brù, Concepció; Gilabert, Rosa; Vannoni, Maurizio; Poisson, Gérard; Vieyres, Pierre

2005-03-01

This paper presents a new tele-operated robotic chain for real-time ultrasound image acquisition and medical diagnosis. This system has been developed in the frame of the Mobile Tele-Echography Using an Ultralight Robot European Project. A light-weight six degrees-of-freedom serial robot, with a remote center of motion, has been specially designed for this application. It holds and moves a real probe on a distant patient according to the expert gesture and permits an image acquisition using a standard ultrasound device. The combination of mechanical structure choice for the robot and dedicated control law, particularly nearby the singular configuration allows a good path following and a robotized gesture accuracy. The choice of compression techniques for image transmission enables a compromise between flow and quality. These combined approaches, for robotics and image processing, enable the medical specialist to better control the remote ultrasound probe holder system and to receive stable and good quality ultrasound images to make a diagnosis via any type of communication link from terrestrial to satellite. Clinical tests have been performed since April 2003. They used both satellite or Integrated Services Digital Network lines with a theoretical bandwidth of 384 Kb/s. They showed the tele-echography system helped to identify 66% of lesions and 83% of symptomatic pathologies.

Fiber optic photoacoustic probe with ultrasonic tracking for guiding minimally invasive procedures

NASA Astrophysics Data System (ADS)

Xia, Wenfeng; Mosse, Charles A.; Colchester, Richard J.; Mari, Jean Martial; Nikitichev, Daniil I.; West, Simeon J.; Ourselin, Sebastien; Beard, Paul C.; Desjardins, Adrien E.

2015-07-01

In a wide range of clinical procedures, accurate placement of medical devices such as needles and catheters is critical to optimize patient outcomes. Ultrasound imaging is often used to guide minimally invasive procedures, as it can provide real-time visualization of patient anatomy and medical devices. However, this modality can provide low image contrast for soft tissues, and poor visualization of medical devices that are steeply angled with respect to the incoming ultrasound beams. Photoacoustic sensors can provide information about the spatial distributions of tissue chromophores that could be valuable for guiding minimally invasive procedures. In this study, a system for guiding minimally invasive procedures using photoacoustic sensing was developed. This system included a miniature photoacoustic probe with three optical fibers: one with a bare end for photoacoustic excitation of tissue, a second for photoacoustic excitation of an optically absorbing coating at the distal end to transmit ultrasound, and a third with a Fabry-Perot cavity at the distal end for receiving ultrasound. The position of the photoacoustic probe was determined with ultrasonic tracking, which involved transmitting pulses from a linear-array ultrasound imaging probe at the tissue surface, and receiving them with the fiber-optic ultrasound receiver in the photoacoustic probe. The axial resolution of photoacoustic sensing was better than 70 μm, and the tracking accuracy was better than 1 mm in both axial and lateral dimensions. By translating the photoacoustic probe, depth scans were obtained from different spatial positions, and two-dimensional images were reconstructed using a frequency-domain algorithm.

Ultrasound Image Despeckling Using Stochastic Distance-Based BM3D.

PubMed

Santos, Cid A N; Martins, Diego L N; Mascarenhas, Nelson D A

2017-06-01

Ultrasound image despeckling is an important research field, since it can improve the interpretability of one of the main categories of medical imaging. Many techniques have been tried over the years for ultrasound despeckling, and more recently, a great deal of attention has been focused on patch-based methods, such as non-local means and block-matching collaborative filtering (BM3D). A common idea in these recent methods is the measure of distance between patches, originally proposed as the Euclidean distance, for filtering additive white Gaussian noise. In this paper, we derive new stochastic distances for the Fisher-Tippett distribution, based on well-known statistical divergences, and use them as patch distance measures in a modified version of the BM3D algorithm for despeckling log-compressed ultrasound images. State-of-the-art results in filtering simulated, synthetic, and real ultrasound images confirm the potential of the proposed approach.

Virtual guidance as a tool to obtain diagnostic ultrasound for spaceflight and remote environments.

PubMed

Martin, David S; Caine, Timothy L; Matz, Timothy; Lee, Stuart M C; Stenger, Michael B; Sargsyan, Ashot E; Platts, Steven H

2012-10-01

With missions planned to travel greater distances from Earth at ranges that make real-time two-way communication impractical, astronauts will be required to perform autonomous medical diagnostic procedures during future exploration missions. Virtual guidance is a form of just-in-time training developed to allow novice ultrasound operators to acquire diagnostically-adequate images of clinically relevant anatomical structures using a prerecorded audio/visual tutorial viewed in real-time. Individuals without previous experience in ultrasound were recruited to perform carotid artery (N = 10) and ophthalmic (N = 9) ultrasound examinations using virtual guidance as their only training tool. In the carotid group, each untrained operator acquired two-dimensional, pulsed and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. Of the studies, 8 of the 10 carotid and 17 of 18 of the ophthalmic images (2 images collected per study) were judged to be diagnostically adequate. The quality of all but one of the ophthalmic images ranged from adequate to excellent. Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by previously untrained operators with assistance from only an audio/video tutorial viewed in real time while scanning. This form of just-in-time training, which can be applied to other examinations, represents an opportunity to acquire important information for NASA flight surgeons and researchers when trained medical personnel are not available or when remote guidance is impractical.

Towards ontology-based decision support systems for complex ultrasound diagnosis in obstetrics and gynecology.

PubMed

Maurice, P; Dhombres, F; Blondiaux, E; Friszer, S; Guilbaud, L; Lelong, N; Khoshnood, B; Charlet, J; Perrot, N; Jauniaux, E; Jurkovic, D; Jouannic, J-M

2017-05-01

We have developed a new knowledge base intelligent system for obstetrics and gynecology ultrasound imaging, based on an ontology and a reference image collection. This study evaluates the new system to support accurate annotations of ultrasound images. We have used the early ultrasound diagnosis of ectopic pregnancies as a model clinical issue. The ectopic pregnancy ontology was derived from medical texts (4260 ultrasound reports of ectopic pregnancy from a specialist center in the UK and 2795 Pubmed abstracts indexed with the MeSH term "Pregnancy, Ectopic") and the reference image collection was built on a selection from 106 publications. We conducted a retrospective analysis of the signs in 35 scans of ectopic pregnancy by six observers using the new system. The resulting ectopic pregnancy ontology consisted of 1395 terms, and 80 images were collected for the reference collection. The observers used the knowledge base intelligent system to provide a total of 1486 sign annotations. The precision, recall and F-measure for the annotations were 0.83, 0.62 and 0.71, respectively. The global proportion of agreement was 40.35% 95% CI [38.64-42.05]. The ontology-based intelligent system provides accurate annotations of ultrasound images and suggests that it may benefit non-expert operators. The precision rate is appropriate for accurate input of a computer-based clinical decision support and could be used to support medical imaging diagnosis of complex conditions in obstetrics and gynecology. Copyright © 2017. Published by Elsevier Masson SAS.

An effective non-rigid registration approach for ultrasound image based on "demons" algorithm.

PubMed

Liu, Yan; Cheng, H D; Huang, Jianhua; Zhang, Yingtao; Tang, Xianglong; Tian, Jiawei

2013-06-01

Medical image registration is an important component of computer-aided diagnosis system in diagnostics, therapy planning, and guidance of surgery. Because of its low signal/noise ratio (SNR), ultrasound (US) image registration is a difficult task. In this paper, a fully automatic non-rigid image registration algorithm based on demons algorithm is proposed for registration of ultrasound images. In the proposed method, an "inertia force" derived from the local motion trend of pixels in a Moore neighborhood system is produced and integrated into optical flow equation to estimate the demons force, which is helpful to handle the speckle noise and preserve the geometric continuity of US images. In the experiment, a series of US images and several similarity measure metrics are utilized for evaluating the performance. The experimental results demonstrate that the proposed method can register ultrasound images efficiently, robust to noise, quickly and automatically.

Development of the ultrasonography learning model for undergraduate medical students: A case study of the Faculty of Medicine, Burapha University.

PubMed

Limchareon, Sornsupha; Asawaworarit, Nattawat; Klinwichit, Wethaka; Dinchuthai, Pakaphun

2016-08-01

Ultrasound technology is generally considered to be reliable and widely used by physicians today. Therefore, given the efficacy and popularity of the technology, the need for quality ultrasound education is evident. Ultrasound training for undergraduate medical students has been increasingly incorporated into school curriculums, but the teaching methods can vary significantly among medical schools. Among many different choices, one effective teaching model was proposed which added hands-on ultrasound experience on live patients that was supervised by radiologists in the last clinical year. A 2-week radiology elective course was offered for 6(th)-year medical students at Burapha University Hospital, Chonburi, Thailand in the academic year 2014. Fourteen medical students participated in the elective course. Additionally, students who chose radiology as their elective were provided an ultrasound experience on live patients in real-life clinical settings. All 6(th)-year medical students then completed a 25-ultrasound image quiz, and completed a questionnaire at the end of the academic year. The ultrasound test scores were compared between the elective and nonelective students. The students' background characteristics were determined by a grade point average and the ultrasound experience was determined by the number of scans. These were collected, and analyzed to establish their relationship with the ultrasound test scores. The students' opinions were also surveyed. Fourteen medical students participated in the elective course. The ultrasound test scores in the elective group were significantly higher than those in the nonelective group (p=0.013). The students' background characteristics and ultrasound experience had no significant relationship with the ultrasound test scores. By adding hands-on ultrasound experience using live patients proctored by radiologists for final year medical students, in the space of 2 weeks, an effective ultrasound learning model for undergraduate medical students can be provided. This model should be considered in the curricular design. Copyright © 2016. Published by Elsevier Taiwan LLC.

Chest Ultrasound Integrated Teaching of Respiratory System Physiology to Medical Students: A First Experience

ERIC Educational Resources Information Center

Paganini, M.; Rubini, A.

2015-01-01

Ultrasound imaging is a useful diagnostic technique that has spread among several different medical specialties within the last few years. Initially restricted to radiology, cardiology, obstetrics, and gynecology, today it is widely used by many specialists, especially in critical care. New graduate physicians will need to be comfortable with…

Imaging in anatomy: a comparison of imaging techniques in embalmed human cadavers

PubMed Central

2013-01-01

Background A large variety of imaging techniques is an integral part of modern medicine. Introducing radiological imaging techniques into the dissection course serves as a basis for improved learning of anatomy and multidisciplinary learning in pre-clinical medical education. Methods Four different imaging techniques (ultrasound, radiography, computed tomography, and magnetic resonance imaging) were performed in embalmed human body donors to analyse possibilities and limitations of the respective techniques in this peculiar setting. Results The quality of ultrasound and radiography images was poor, images of computed tomography and magnetic resonance imaging were of good quality. Conclusion Computed tomography and magnetic resonance imaging have a superior image quality in comparison to ultrasound and radiography and offer suitable methods for imaging embalmed human cadavers as a valuable addition to the dissection course. PMID:24156510

Integrated medical school ultrasound: development of an ultrasound vertical curriculum.

PubMed

Bahner, David P; Adkins, Eric J; Hughes, Daralee; Barrie, Michael; Boulger, Creagh T; Royall, Nelson A

2013-07-02

Physician-performed focused ultrasonography is a rapidly growing field with numerous clinical applications. Focused ultrasound is a clinically useful tool with relevant applications across most specialties. Ultrasound technology has outpaced the education, necessitating an early introduction to the technology within the medical education system. There are many challenges to integrating ultrasound into medical education including identifying appropriately trained faculty, access to adequate resources, and appropriate integration into existing medical education curricula. As focused ultrasonography increasingly penetrates academic and community practices, access to ultrasound equipment and trained faculty is improving. However, there has remained the major challenge of determining at which level is integrating ultrasound training within the medical training paradigm most appropriate. The Ohio State University College of Medicine has developed a novel vertical curriculum for focused ultrasonography which is concordant with the 4-year medical school curriculum. Given current evidenced-based practices, a curriculum was developed which provides medical students an exposure in focused ultrasonography. The curriculum utilizes focused ultrasonography as a teaching aid for students to gain a more thorough understanding of basic and clinical science within the medical school curriculum. The objectives of the course are to develop student understanding in indications for use, acquisition of images, interpretation of an ultrasound examination, and appropriate decision-making of ultrasound findings. Preliminary data indicate that a vertical ultrasound curriculum is a feasible and effective means of teaching focused ultrasonography. The foreseeable limitations include faculty skill level and training, initial cost of equipment, and incorporating additional information into an already saturated medical school curriculum. Focused ultrasonography is an evolving concept in medicine. It has been shown to improve education and patient care. The indications for and implementation of focused ultrasound is rapidly expanding in all levels of medicine. The ideal method for teaching ultrasound has yet to be established. The vertical curriculum in ultrasound at The Ohio State University College of Medicine is a novel evidenced-based training regimen at the medical school level which integrates ultrasound training into medical education and serves as a model for future integrated ultrasound curricula.

Measuring Ultrasonic Backscatter in the Presence of Nonlinear Propagation

NASA Astrophysics Data System (ADS)

Stiles, Timothy; Guerrero, Quinton

2011-11-01

A goal of medical ultrasound is the formation of quantitative ultrasound images in which contrast is determined by acoustic or physical properties of tissue rather than relative echo amplitude. Such images could greatly enhance early detection of many diseases, including breast cancer and liver cirrhosis. Accurate determination of the ultrasonic backscatter coefficient from patients remains a difficult task. One reason for this difficulty is the inherent nonlinear propagation of ultrasound at high intensities used for medical imaging. The backscatter coefficient from several tissue-mimicking samples were measured using the planar reflector method. In this method, the power spectrum from a sample is compared to the power spectrum of an optically flat sample of quartz. The results should be independent of incident pressure amplitude. Results demonstrate that backscatter coefficients can vary by more than an order of magnitude when ultrasound pressure varies from 0.1 MPa to 1.5 MPa at 5.0 MHz. A new method that incorporates nonlinear propagation is proposed to explain these discrepancies.

All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

2016-02-01

High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

A Fast and Robust Beamspace Adaptive Beamformer for Medical Ultrasound Imaging.

PubMed

Mohades Deylami, Ali; Mohammadzadeh Asl, Babak

2017-06-01

Minimum variance beamformer (MVB) increases the resolution and contrast of medical ultrasound imaging compared with nonadaptive beamformers. These advantages come at the expense of high computational complexity that prevents this adaptive beamformer to be applied in a real-time imaging system. A new beamspace (BS) based on discrete cosine transform is proposed in which the medical ultrasound signals can be represented with less dimensions compared with the standard BS. This is because of symmetric beampattern of the beams in the proposed BS compared with the asymmetric ones in the standard BS. This lets us decrease the dimensions of data to two, so a high complex algorithm, such as the MVB, can be applied faster in this BS. The results indicated that by keeping only two beams, the MVB in the proposed BS provides very similar resolution and also better contrast compared with the standard MVB (SMVB) with only 0.44% of needed flops. Also, this beamformer is more robust against sound speed estimation errors than the SMVB.

Synergistic advances in diagnostic and therapeutic medical ultrasound

NASA Astrophysics Data System (ADS)

Lizzi, Frederic L.

2003-04-01

Significant advances are more fully exploiting ultrasound's potential for noninvasive diagnosis and treatment. Therapeutic systems employ intense focused beams to thermally kill cancer cells in, e.g., prostate; to stop bleeding; and to treat specific diseases (e.g., glaucoma). Diagnostic ultrasound techniques can quantitatively image an increasingly broad spectrum of physical tissue attributes. An exciting aspect of this progress is the emerging synergy between these modalities. Advanced diagnostic techniques may contribute at several stages in therapy. For example, treatment planning for small ocular tumors uses 50-MHz, 3-D ultrasonic images with 0.05-mm resolution. Thermal simulations employ these images to evaluate desired and undesired effects using exposure stategies with specially designed treatment beams. Therapy beam positioning can use diagnostic elastography to sense tissue motion induced by radiation pressure from high-intensity treatment beams. Therapy monitoring can sense lesion formation using elastography motion sensing (to detect the increased stiffness in lesions); harmonic imaging (to sense altered nonlinear properties); and spectrum analysis images (depicting changes in the sizes, concentration, and configuration of sub-resolution structures.) Experience from these applications will greatly expand the knowledge of acoustic phenomena in living tissues and should lead to further advances in medical ultrasound.

Synthetic aperture ultrasound imaging with a ring transducer array: preliminary ex vivo results.

PubMed

Qu, Xiaolei; Azuma, Takashi; Yogi, Takeshi; Azuma, Shiho; Takeuchi, Hideki; Tamano, Satoshi; Takagi, Shu

2016-10-01

The conventional medical ultrasound imaging has a low lateral spatial resolution, and the image quality depends on the depth of the imaging location. To overcome these problems, this study presents a synthetic aperture (SA) ultrasound imaging method using a ring transducer array. An experimental ring transducer array imaging system was constructed. The array was composed of 2048 transducer elements, and had a diameter of 200 mm and an inter-element pitch of 0.325 mm. The imaging object was placed in the center of the ring transducer array, which was immersed in water. SA ultrasound imaging was then employed to scan the object and reconstruct the reflection image. Both wire phantom and ex vivo experiments were conducted. The proposed method was found to be capable of producing isotropic high-resolution images of the wire phantom. In addition, preliminary ex vivo experiments using porcine organs demonstrated the ability of the method to reconstruct high-quality images without any depth dependence. The proposed ring transducer array and SA ultrasound imaging method were shown to be capable of producing isotropic high-resolution images whose quality was independent of depth.

Breast ultrasound image segmentation: an optimization approach based on super-pixels and high-level descriptors

NASA Astrophysics Data System (ADS)

Massich, Joan; Lemaître, Guillaume; Martí, Joan; Mériaudeau, Fabrice

2015-04-01

Breast cancer is the second most common cancer and the leading cause of cancer death among women. Medical imaging has become an indispensable tool for its diagnosis and follow up. During the last decade, the medical community has promoted to incorporate Ultra-Sound (US) screening as part of the standard routine. The main reason for using US imaging is its capability to differentiate benign from malignant masses, when compared to other imaging techniques. The increasing usage of US imaging encourages the development of Computer Aided Diagnosis (CAD) systems applied to Breast Ultra-Sound (BUS) images. However accurate delineations of the lesions and structures of the breast are essential for CAD systems in order to extract information needed to perform diagnosis. This article proposes a highly modular and flexible framework for segmenting lesions and tissues present in BUS images. The proposal takes advantage of optimization strategies using super-pixels and high-level descriptors, which are analogous to the visual cues used by radiologists. Qualitative and quantitative results are provided stating a performance within the range of the state-of-the-art.

Three dimensional ultrasound and hdlive technology as possible tools in teaching embryology.

PubMed

Popovici, Razvan; Pristavu, Anda; Sava, Anca

2017-10-01

Embryology is an important subject in order to gain an understanding of medicine and surgery; however, sometimes students find the subject difficult to grasp and apply to clinical practice. Modern imaging techniques can be useful aids in teaching and understanding embryology. Imaging techniques have very rapidly evolved over the last few years, advancing from two- to three-dimensional (3D) ultrasound. HDlive is an innovative ultrasound technique that generates near-realistic images of the human fetus. In order to evince the capabilities of 3D ultrasound and HDlive technology in teaching embryology, we evaluated using this technique the normal evolution of the embryo and fetus from the fifth to eleventh week of amenorrhea. Our conclusion is that by yielding clear and impressive images, 3D ultrasound and HDlive could be useful tools in teaching embryology to medical students. Clin. Anat. 30:953-957, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Bedside imaging of intracranial hemorrhage in the neonate using light: comparison with ultrasound, computed tomography, and magnetic resonance imaging.

PubMed

Hintz, S R; Cheong, W F; van Houten, J P; Stevenson, D K; Benaron, D A

1999-01-01

Medical optical imaging (MOI) uses light emitted into opaque tissues to determine the interior structure. Previous reports detailed a portable time-of-flight and absorbance system emitting pulses of near infrared light into tissues and measuring the emerging light. Using this system, optical images of phantoms, whole rats, and pathologic neonatal brain specimens have been tomographically reconstructed. We have now modified the existing instrumentation into a clinically relevant headband-based system to be used for optical imaging of structure in the neonatal brain at the bedside. Eight medical optical imaging studies in the neonatal intensive care unit were performed in a blinded clinical comparison of optical images with ultrasound, computed tomography, and magnetic resonance imaging. Optical images were interpreted as correct in six of eight cases, with one error attributed to the age of the clot, and one small clot not seen. In addition, one disagreement with ultrasound, not reported as an error, was found to be the result of a mislabeled ultrasound report rather than because of an inaccurate optical scan. Optical scan correlated well with computed tomography and magnetic resonance imaging findings in one patient. We conclude that light-based imaging using a portable time-of-flight system is feasible and represents an important new noninvasive diagnostic technique, with potential for continuous monitoring of critically ill neonates at risk for intraventricular hemorrhage or stroke. Further studies are now underway to further investigate the functional imaging capabilities of this new diagnostic tool.

Developing a knowledge base to support the annotation of ultrasound images of ectopic pregnancy.

PubMed

Dhombres, Ferdinand; Maurice, Paul; Friszer, Stéphanie; Guilbaud, Lucie; Lelong, Nathalie; Khoshnood, Babak; Charlet, Jean; Perrot, Nicolas; Jauniaux, Eric; Jurkovic, Davor; Jouannic, Jean-Marie

2017-01-31

Ectopic pregnancy is a frequent early complication of pregnancy associated with significant rates of morbidly and mortality. The positive diagnosis of this condition is established through transvaginal ultrasound scanning. The timing of diagnosis depends on the operator expertise in identifying the signs of ectopic pregnancy, which varies dramatically among medical staff with heterogeneous training. Developing decision support systems in this context is expected to improve the identification of these signs and subsequently improve the quality of care. In this article, we present a new knowledge base for ectopic pregnancy, and we demonstrate its use on the annotation of clinical images. The knowledge base is supported by an application ontology, which provides the taxonomy, the vocabulary and definitions for 24 types and 81 signs of ectopic pregnancy, 484 anatomical structures and 32 technical elements for image acquisition. The knowledge base provides a sign-centric model of the domain, with the relations of signs to ectopic pregnancy types, anatomical structures and the technical elements. The evaluation of the ontology and knowledge base demonstrated a positive feedback from a panel of 17 medical users. Leveraging these semantic resources, we developed an application for the annotation of ultrasound images. Using this application, 6 operators achieved a precision of 0.83 for the identification of signs in 208 ultrasound images corresponding to 35 clinical cases of ectopic pregnancy. We developed a new ectopic pregnancy knowledge base for the annotation of ultrasound images. The use of this knowledge base for the annotation of ultrasound images of ectopic pregnancy showed promising results from the perspective of clinical decision support system development. Other gynecological disorders and fetal anomalies may benefit from our approach.

Design and development of an ultrasound calibration phantom and system

NASA Astrophysics Data System (ADS)

Cheng, Alexis; Ackerman, Martin K.; Chirikjian, Gregory S.; Boctor, Emad M.

2014-03-01

Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the ultrasound transducer and the ultrasound image. A phantom or model with known geometry is also required. In this work, we design and test an ultrasound calibration phantom and software. The two main considerations in this work are utilizing our knowledge of ultrasound physics to design the phantom and delivering an easy to use calibration process to the user. We explore the use of a three-dimensional printer to create the phantom in its entirety without need for user assembly. We have also developed software to automatically segment the three-dimensional printed rods from the ultrasound image by leveraging knowledge about the shape and scale of the phantom. In this work, we present preliminary results from using this phantom to perform ultrasound calibration. To test the efficacy of our method, we match the projection of the points segmented from the image to the known model and calculate a sum squared difference between each point for several combinations of motion generation and filtering methods. The best performing combination of motion and filtering techniques had an error of 1.56 mm and a standard deviation of 1.02 mm.

Watermarking of ultrasound medical images in teleradiology using compressed watermark

PubMed Central

Badshah, Gran; Liew, Siau-Chuin; Zain, Jasni Mohamad; Ali, Mushtaq

2016-01-01

Abstract. The open accessibility of Internet-based medical images in teleradialogy face security threats due to the nonsecured communication media. This paper discusses the spatial domain watermarking of ultrasound medical images for content authentication, tamper detection, and lossless recovery. For this purpose, the image is divided into two main parts, the region of interest (ROI) and region of noninterest (RONI). The defined ROI and its hash value are combined as watermark, lossless compressed, and embedded into the RONI part of images at pixel’s least significant bits (LSBs). The watermark lossless compression and embedding at pixel’s LSBs preserve image diagnostic and perceptual qualities. Different lossless compression techniques including Lempel-Ziv-Welch (LZW) were tested for watermark compression. The performances of these techniques were compared based on more bit reduction and compression ratio. LZW was found better than others and used in tamper detection and recovery watermarking of medical images (TDARWMI) scheme development to be used for ROI authentication, tamper detection, localization, and lossless recovery. TDARWMI performance was compared and found to be better than other watermarking schemes. PMID:26839914

Comparative evaluation of ultrasound scanner accuracy in distance measurement

NASA Astrophysics Data System (ADS)

Branca, F. P.; Sciuto, S. A.; Scorza, A.

2012-10-01

The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

A hybrid algorithm for speckle noise reduction of ultrasound images.

PubMed

Singh, Karamjeet; Ranade, Sukhjeet Kaur; Singh, Chandan

2017-09-01

Medical images are contaminated by multiplicative speckle noise which significantly reduce the contrast of ultrasound images and creates a negative effect on various image interpretation tasks. In this paper, we proposed a hybrid denoising approach which collaborate the both local and nonlocal information in an efficient manner. The proposed hybrid algorithm consist of three stages in which at first stage the use of local statistics in the form of guided filter is used to reduce the effect of speckle noise initially. Then, an improved speckle reducing bilateral filter (SRBF) is developed to further reduce the speckle noise from the medical images. Finally, to reconstruct the diffused edges we have used the efficient post-processing technique which jointly considered the advantages of both bilateral and nonlocal mean (NLM) filter for the attenuation of speckle noise efficiently. The performance of proposed hybrid algorithm is evaluated on synthetic, simulated and real ultrasound images. The experiments conducted on various test images demonstrate that our proposed hybrid approach outperforms the various traditional speckle reduction approaches included recently proposed NLM and optimized Bayesian-based NLM. The results of various quantitative, qualitative measures and by visual inspection of denoise synthetic and real ultrasound images demonstrate that the proposed hybrid algorithm have strong denoising capability and able to preserve the fine image details such as edge of a lesion better than previously developed methods for speckle noise reduction. The denoising and edge preserving capability of hybrid algorithm is far better than existing traditional and recently proposed speckle reduction (SR) filters. The success of proposed algorithm would help in building the lay foundation for inventing the hybrid algorithms for denoising of ultrasound images. Copyright © 2017 Elsevier B.V. All rights reserved.

Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

NASA Technical Reports Server (NTRS)

Hurst, Victor; Dulchavsky, Scott; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Doug

2009-01-01

To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance.

Potential of coded excitation in medical ultrasound imaging.

PubMed

Misaridis, T X; Gammelmark, K; Jørgensen, C H; Lindberg, N; Thomsen, A H; Pedersen, M H; Jensen, J A

2000-03-01

Improvement in signal-to-noise ratio (SNR) and/or penetration depth can be achieved in medical ultrasound by using long coded waveforms, in a similar manner as in radars or sonars. However, the time-bandwidth product (TB) improvement, and thereby SNR improvement is considerably lower in medical ultrasound, due to the lower available bandwidth. There is still space for about 20 dB improvement in the SNR, which will yield a penetration depth up to 20 cm at 5 MHz [M. O'Donnell, IEEE Trans. Ultrason. Ferroelectr. Freq. Contr., 39(3) (1992) 341]. The limited TB additionally yields unacceptably high range sidelobes. However, the frequency weighting from the ultrasonic transducer's bandwidth, although suboptimal, can be beneficial in sidelobe reduction. The purpose of this study is an experimental evaluation of the above considerations in a coded excitation ultrasound system. A coded excitation system based on a modified commercial scanner is presented. A predistorted FM signal is proposed in order to keep the resulting range sidelobes at acceptably low levels. The effect of the transducer is taken into account in the design of the compression filter. Intensity levels have been considered and simulations on the expected improvement in SNR are also presented. Images of a wire phantom and clinical images have been taken with the coded system. The images show a significant improvement in penetration depth and they preserve both axial resolution and contrast.

Performance analysis of medical video streaming over mobile WiMAX.

PubMed

Alinejad, Ali; Philip, N; Istepanian, R H

2010-01-01

Wireless medical ultrasound streaming is considered one of the emerging application within the broadband mobile healthcare domain. These applications are considered as bandwidth demanding services that required high data rates with acceptable diagnostic quality of the transmitted medical images. In this paper, we present the performance analysis of a medical ultrasound video streaming acquired via special robotic ultrasonography system over emulated WiMAX wireless network. The experimental set-up of this application is described together with the performance of the relevant medical quality of service (m-QoS) metrics.

An ergonomic, instrumented ultrasound probe for 6-axis force/torque measurement.

PubMed

Gilbertson, Matthew W; Anthony, Brian W

2013-01-01

An ergonomic, instrumented ultrasound probe has been developed for medical imaging applications. The device, which fits compactly in the hand of sonographers and permits rapid attachment & removal of the ultrasound probe, measures ultrasound probe-to-patient contact forces and torques in all six axes. The device was used to measure contact forces and torques applied by ten professional sonographers on five patients during thirty-six abdominal exams. Of the three contact forces, those applied along the probe axis were found to be largest, averaging 7.0N. Measurement noise was quantified for each axis, and found to be small compared with the axial force. Understanding the range of forces applied during ultrasound imaging enables the design of more accurate robotic imaging systems and could also improve understanding of the correlation between contact force and sonographer fatigue and injury.

Measuring the morphological characteristics of thoracolumbar fascia in ultrasound images: an inter-rater reliability study.

PubMed

De Coninck, Kyra; Hambly, Karen; Dickinson, John W; Passfield, Louis

2018-06-01

Chronic lower back pain is still regarded as a poorly understood multifactorial condition. Recently, the thoracolumbar fascia complex has been found to be a contributing factor. Ultrasound imaging has shown that people with chronic lower back pain demonstrate both a significant decrease in shear strain, and a 25% increase in thickness of the thoracolumbar fascia. There is sparse data on whether medical practitioners agree on the level of disorganisation in ultrasound images of thoracolumbar fascia. The purpose of this study was to establish inter-rater reliability of the ranking of architectural disorganisation of thoracolumbar fascia on a scale from 'very disorganised' to 'very organised'. An exploratory analysis was performed using a fully crossed design of inter-rater reliability. Thirty observers were recruited, consisting of 21 medical doctors, 7 physiotherapists and 2 radiologists, with an average of 13.03 ± 9.6 years of clinical experience. All 30 observers independently rated the architectural disorganisation of the thoracolumbar fascia in 30 ultrasound scans, on a Likert-type scale with rankings from 1 = very disorganised to 10 = very organised. Internal consistency was assessed using Cronbach's alpha. Krippendorff's alpha was used to calculate the overall inter-rater reliability. The Krippendorf's alpha was .61, indicating a modest degree of agreement between observers on the different morphologies of thoracolumbar fascia.The Cronbach's alpha (0.98), indicated that there was a high degree of consistency between observers. Experience in ultrasound image analysis did not affect constancy between observers (Cronbach's range between experienced and inexperienced raters: 0.95 and 0.96 respectively). Medical practitioners agree on morphological features such as levels of organisation and disorganisation in ultrasound images of thoracolumbar fascia, regardless of experience. Further analysis by an expert panel is required to develop specific classification criteria for thoracolumbar fascia.

Bridging the Gap between Basic and Clinical Sciences: A Description of a Radiological Anatomy Course

ERIC Educational Resources Information Center

Torres, Anna; Staskiewicz, Grzegorz J.; Lisiecka, Justyna; Pietrzyk, Lukasz; Czekajlo, Michael; Arancibia, Carlos U.; Maciejewski, Ryszard; Torres, Kamil

2016-01-01

A wide variety of medical imaging techniques pervade modern medicine, and the changing portability and performance of tools like ultrasound imaging have brought these medical imaging techniques into the everyday practice of many specialties outside of radiology. However, proper interpretation of ultrasonographic and computed tomographic images…

From Roentgen to magnetic resonance imaging: the history of medical imaging.

PubMed

Scatliff, James H; Morris, Peter J

2014-01-01

Medical imaging has advanced in remarkable ways since the discovery of x-rays 120 years ago. Today's radiologists can image the human body in intricate detail using computed tomography, magnetic resonance imaging, positron emission tomography, ultrasound, and various other modalities. Such technology allows for improved screening, diagnosis, and monitoring of disease, but it also comes with risks. Many imaging modalities expose patients to ionizing radiation, which potentially increases their risk of developing cancer in the future, and imaging may also be associated with possible allergic reactions or risks related to the use of intravenous contrast agents. In addition, the financial costs of imaging are taxing our health care system, and incidental findings can trigger anxiety and further testing. This issue of the NCMJ addresses the pros and cons of medical imaging and discusses in detail the following uses of medical imaging: screening for breast cancer with mammography, screening for osteoporosis and monitoring of bone mineral density with dual-energy x-ray absorptiometry, screening for congenital hip dysplasia in infants with ultrasound, and evaluation of various heart conditions with cardiac imaging. Together, these articles show the challenges that must be met as we seek to harness the power of today's imaging technologies, as well as the potential benefits that can be achieved when these hurdles are overcome.

Multiresolution generalized N dimension PCA for ultrasound image denoising

PubMed Central

2014-01-01

Background Ultrasound images are usually affected by speckle noise, which is a type of random multiplicative noise. Thus, reducing speckle and improving image visual quality are vital to obtaining better diagnosis. Method In this paper, a novel noise reduction method for medical ultrasound images, called multiresolution generalized N dimension PCA (MR-GND-PCA), is presented. In this method, the Gaussian pyramid and multiscale image stacks on each level are built first. GND-PCA as a multilinear subspace learning method is used for denoising. Each level is combined to achieve the final denoised image based on Laplacian pyramids. Results The proposed method is tested with synthetically speckled and real ultrasound images, and quality evaluation metrics, including MSE, SNR and PSNR, are used to evaluate its performance. Conclusion Experimental results show that the proposed method achieved the lowest noise interference and improved image quality by reducing noise and preserving the structure. Our method is also robust for the image with a much higher level of speckle noise. For clinical images, the results show that MR-GND-PCA can reduce speckle and preserve resolvable details. PMID:25096917

Quantitative Ultrasound: Transition from the Laboratory to the Clinic

NASA Astrophysics Data System (ADS)

Hall, Timothy

2014-03-01

There is a long history of development and testing of quantitative methods in medical ultrasound. From the initial attempts to scan breasts with ultrasound in the early 1950's, there was a simultaneous attempt to classify tissue as benign or malignant based on the appearance of the echo signal on an oscilloscope. Since that time, there has been substantial improvement in the ultrasound systems used, the models to describe wave propagation in random media, the methods of signal detection theory, and the combination of those models and methods into parameter estimation techniques. One particularly useful measure in ultrasonics is the acoustic differential scattering cross section per unit volume in the special case of the 180° (as occurs in pulse-echo ultrasound imaging) which is known as the backscatter coefficient. The backscatter coefficient, and parameters derived from it, can be used to objectively measure quantities that are used clinically to subjectively describe ultrasound images. For example, the ``echogenicity'' (relative ultrasound image brightness) of the renal cortex is commonly compared to that of the liver. Investigating the possibility of liver disease, it is assumed the renal cortex echogenicity is normal. Investigating the kidney, it is assumed the liver echogenicity is normal. Objective measures of backscatter remove these assumptions. There is a 30-year history of accurate estimates of acoustic backscatter coefficients with laboratory systems. Twenty years ago that ability was extended to clinical imaging systems with array transducers. Recent studies involving multiple laboratories and a variety of clinical imaging systems has demonstrated system-independent estimates of acoustic backscatter coefficients in well-characterized media (agreement within about 1.5dB over about a 1-decade frequency range). Advancements that made this possible, transition of this and similar capabilities into medical practice and the prospects for quantitative image-based biomarkers will be discussed. This work was supported, in part, by NIH grants R01CA140271 and R01HD072077.

Hepatobiliary ultrasonography

NASA Astrophysics Data System (ADS)

Sembiring, J.

2018-03-01

Ultrasound is one of the most widely used imaging technologies in medicine. It is portable, free of radiation risk, non-invasive and relatively inexpensive when compared with other imaging modalities, such as magnetic resonance and computed tomography. Ultrasound is a useful procedure for evaluating many structures organ in our body. An examination may include the entirety of the abdomen and retroperitoneum from a single organ to several organs. An abdominal ultrasound examination survey would include the liver, gallbladder, biliary tree, pancreas, spleen, kidneys and retroperitoneal structures. It needsperforming when there is a valid medical reason.

Goal-Directed Ultrasound for the Diagnosis of Long-Bone Fractures by Crew Medical Officer Analogs

NASA Technical Reports Server (NTRS)

Marshburn, Thomas H.; Legome, Eric; Li, James; Melton, Shannon; Sargsyan, Ashot; Noble, Vickie; Sims, Carrie; Thomsen, Todd; Peralta, Ruben; Briggs, Sue

2002-01-01

Current construction activities on-board the International space Station (ISS) may increase fracture incidence in space, and ultrasound (US) is the only tm-board diagnostic imaging capability. The clinical utility of US in identifying long-bone fractures is un1aowe, particularly using non-radiologist operators. We sought to determine the accuracy of US in identifying fractures of the humerus and femur, as performed by emergency medicine physicians and surgeons with minimal experience in ultrasound image acquisition and interpretation, after a standardized taming session.

Development of an Anthropomorphic Breast Phantom for Combined PET, B-Mode Ultrasound and Elastographic Imaging

NASA Astrophysics Data System (ADS)

Dang, Jun; Frisch, Benjamin; Lasaygues, Philippe; Zhang, Dachun; Tavernier, Stefaan; Felix, Nicolas; Lecoq, Paul; Auffray, Etiennette; Varela, Joao; Mensah, Serge; Wan, Mingxi

2011-06-01

Combining the advantages of different imaging modalities leads to improved clinical results. For example, ultrasound provides good real-time structural information without any radiation and PET provides sensitive functional information. For the ongoing ClearPEM-Sonic project combining ultrasound and PET for breast imaging, we developed a dual-modality PET/Ultrasound (US) phantom. The phantom reproduces the acoustic and elastic properties of human breast tissue and allows labeling the different tissues in the phantom with different concentrations of FDG. The phantom was imaged with a whole-body PET/CT and with the Supersonic Imagine Aixplorer system. This system allows both B-mode US and shear wave elastographic imaging. US elastography is a new imaging method for displaying the tissue elasticity distribution. It was shown to be useful in breast imaging. We also tested the phantom with static elastography. A 6D magnetic positioning system allows fusing the images obtained with the two modalities. ClearPEM-Sonic is a project of the Crystal Clear Collaboration and the European Centre for Research on Medical Imaging (CERIMED).

High-Sensitivity Fiber-Optic Ultrasound Sensors for Medical Imaging Applications

PubMed Central

Wen, H.; Wiesler, D.G.; Tveten, A.; Danver, B.; Dandridge, A.

2010-01-01

This paper presents several designs of high-sensitivity, compact fiber-optic ultrasound sensors that may be used for medical imaging applications. These sensors translate ultrasonic pulses into strains in single-mode optical fibers, which are measured with fiber-based laser interferometers at high precision. The sensors are simpler and less expensive to make than piezoelectric sensors, and are not susceptible to electromagnetic interference. It is possible to make focal sensors with these designs, and several schemes are discussed. Because of the minimum bending radius of optical fibers, the designs are suitable for single element sensors rather than for arrays. PMID:9691368

A De-Identification Pipeline for Ultrasound Medical Images in DICOM Format.

PubMed

Monteiro, Eriksson; Costa, Carlos; Oliveira, José Luís

2017-05-01

Clinical data sharing between healthcare institutions, and between practitioners is often hindered by privacy protection requirements. This problem is critical in collaborative scenarios where data sharing is fundamental for establishing a workflow among parties. The anonymization of patient information burned in DICOM images requires elaborate processes somewhat more complex than simple de-identification of textual information. Usually, before sharing, there is a need for manual removal of specific areas containing sensitive information in the images. In this paper, we present a pipeline for ultrasound medical image de-identification, provided as a free anonymization REST service for medical image applications, and a Software-as-a-Service to streamline automatic de-identification of medical images, which is freely available for end-users. The proposed approach applies image processing functions and machine-learning models to bring about an automatic system to anonymize medical images. To perform character recognition, we evaluated several machine-learning models, being Convolutional Neural Networks (CNN) selected as the best approach. For accessing the system quality, 500 processed images were manually inspected showing an anonymization rate of 89.2%. The tool can be accessed at https://bioinformatics.ua.pt/dicom/anonymizer and it is available with the most recent version of Google Chrome, Mozilla Firefox and Safari. A Docker image containing the proposed service is also publicly available for the community.

Lung ultrasound training: curriculum implementation and learning trajectory among respiratory therapists.

PubMed

See, K C; Ong, V; Wong, S H; Leanda, R; Santos, J; Taculod, J; Phua, J; Teoh, C M

2016-01-01

Guidelines recommend teaching of lung ultrasound for critical care, though little information exists on how much training is required for independent practice, especially for non-physician trainees. We thus aimed to elucidate a threshold number of cases above which competency for independent practice may be attained for respiratory therapists (RTs). We conducted a prospective audit of lung ultrasound training between July 2014 and April 2015 in our 20-bed medical intensive care unit. Following theoretical instruction and self-learning, trainees acquired images from 12 lung zones under direct supervision and classified images into six patterns. Assistance during image acquisition and correct interpretation of ultrasound images were recorded. Eleven ultrasound-naïve RTs scanned an average of 15 patients each (170 patients in total). Among supervisor-adjudicated lung ultrasound findings, 35.5% were abnormal. Blinded verification of the adjudicated findings was done for the first 92 patients (1104 images), with an agreement of 95.4%. As RTs scanned more patients, there was a significant decrease in the proportion of images requiring supervisor assistance (Cuzick's P < 0.001), and a significant increase in the proportion of correctly identified images (Cuzick's P = 0.008). After trainees performed at least ten scans, less than 2% of images required assistance with acquisition and less than 5% were wrongly interpreted. Our training method allowed RTs to independently perform lung ultrasound after at least ten directly supervised scans. Given that RTs are likely to have less ultrasound knowledge and less clinical know-how compared to physicians, we believe that the same threshold number of scans may be also safely applied to the latter.

TH-A-207B-01: Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, S.

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will targetmore » these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: Introduction: Importance of tissue elasticity measurement Strain vs. shear wave elastography (SWE), beneficial features of SWE The link between shear wave speed and material properties, influence of viscosity Generation of shear waves External vibration (Fibroscan) ultrasound radiation force Point push Supersonic push (Aixplorer) Comb push (GE Logiq E9) Detection of shear waves Motion detection from pulse-echo ultrasound Importance of frame rate for shear wave imaging Plane wave imaging detection How to achieve high effective frame rate using line-by-line scanners Shear wave speed calculation Time to peak Random sample consensus (RANSAC) Cross correlation Sources of bias and variation in SWE Tissue viscosity Transducer compression or internal pressure of organ Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: Goals Review the need for quantitative medical imaging Provide examples of quantitative imaging biomarkers Acquaint the participant with the purpose of the RSNA Quantitative Imaging Biomarker Alliance and the need for such an organization Review the QIBA process for creating a quantitative biomarker Summarize steps needed to verify adherence of site, operators, and imaging systems to a QIBA profile Underlying Premise and Assumptions Objective, quantifiable results are needed to enhance the value of diagnostic imaging in clinical practice Reasons for quantification Evidence based medicine requires objective, not subjective observer data Computerized decision support tools (eg CAD) generally require quantitative input. Quantitative, reproducible measures are more easily used to develop personalized molecular medical diagnostic and treatment systems What is quantitative imaging? Definition from Imaging Metrology Workshop The Quantitative Imaging Biomarker Alliance Formation 2008 Mission Structure Example Imaging Biomarkers Being Explored Biomarker Selection Groundwork Draft Protocol for imaging and data evaluation QIBA Profile Drafting Equipment and Site Validation Technical Clinical Site and Equipment QA and Compliance Checking Ultrasound Elasticity Estimation Biomarker US Elasticity Estimation Background Current Status and Problems Biomarker Selection-process and outcome US SWS for Liver Fibrosis Biomarker Work Groundwork Literature search and analysis results Phase I phantom testing-Elastic phantoms Phase II phantom testing-Viscoelastic phantoms Digital Simulated Data Protocol and Profile Drafting Protocol: based on UPICT and existing literature and standards bodies protocols Profile-Current claims, Manufacturer specific appendices What comes after the profile Profile Validation Technical validation Clinical validation QA and Compliance Possible approaches Site Operator testing Site protocol re-evaluation Imaging system Manufacturer testing and attestation User acceptance testing and periodic QA Phantom Tests Digital Phantom Based Testing Standard QA Testing Remediation Schemes Profile Evolution Towards additional applications Towards higher accuracy and precision Supported in part by NIH contract HHSN268201300071C from NIBIB. Collaboration with GE Global Research, no personal support.; S. Chen, Some technologies described in this presentation have been licensed. Mayo Clinic and Dr. Chen have financial interests these technologies.« less

TH-A-207B-02: QIBA Ultrasound Elasticity Imaging System Biomarker Qualification and User Testing of Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garra, B.

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will targetmore » these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: Introduction: Importance of tissue elasticity measurement Strain vs. shear wave elastography (SWE), beneficial features of SWE The link between shear wave speed and material properties, influence of viscosity Generation of shear waves External vibration (Fibroscan) ultrasound radiation force Point push Supersonic push (Aixplorer) Comb push (GE Logiq E9) Detection of shear waves Motion detection from pulse-echo ultrasound Importance of frame rate for shear wave imaging Plane wave imaging detection How to achieve high effective frame rate using line-by-line scanners Shear wave speed calculation Time to peak Random sample consensus (RANSAC) Cross correlation Sources of bias and variation in SWE Tissue viscosity Transducer compression or internal pressure of organ Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: Goals Review the need for quantitative medical imaging Provide examples of quantitative imaging biomarkers Acquaint the participant with the purpose of the RSNA Quantitative Imaging Biomarker Alliance and the need for such an organization Review the QIBA process for creating a quantitative biomarker Summarize steps needed to verify adherence of site, operators, and imaging systems to a QIBA profile Underlying Premise and Assumptions Objective, quantifiable results are needed to enhance the value of diagnostic imaging in clinical practice Reasons for quantification Evidence based medicine requires objective, not subjective observer data Computerized decision support tools (eg CAD) generally require quantitative input. Quantitative, reproducible measures are more easily used to develop personalized molecular medical diagnostic and treatment systems What is quantitative imaging? Definition from Imaging Metrology Workshop The Quantitative Imaging Biomarker Alliance Formation 2008 Mission Structure Example Imaging Biomarkers Being Explored Biomarker Selection Groundwork Draft Protocol for imaging and data evaluation QIBA Profile Drafting Equipment and Site Validation Technical Clinical Site and Equipment QA and Compliance Checking Ultrasound Elasticity Estimation Biomarker US Elasticity Estimation Background Current Status and Problems Biomarker Selection-process and outcome US SWS for Liver Fibrosis Biomarker Work Groundwork Literature search and analysis results Phase I phantom testing-Elastic phantoms Phase II phantom testing-Viscoelastic phantoms Digital Simulated Data Protocol and Profile Drafting Protocol: based on UPICT and existing literature and standards bodies protocols Profile-Current claims, Manufacturer specific appendices What comes after the profile Profile Validation Technical validation Clinical validation QA and Compliance Possible approaches Site Operator testing Site protocol re-evaluation Imaging system Manufacturer testing and attestation User acceptance testing and periodic QA Phantom Tests Digital Phantom Based Testing Standard QA Testing Remediation Schemes Profile Evolution Towards additional applications Towards higher accuracy and precision Supported in part by NIH contract HHSN268201300071C from NIBIB. Collaboration with GE Global Research, no personal support.; S. Chen, Some technologies described in this presentation have been licensed. Mayo Clinic and Dr. Chen have financial interests these technologies.« less

Multimedia systems in ultrasound image boundary detection and measurements

NASA Astrophysics Data System (ADS)

Pathak, Sayan D.; Chalana, Vikram; Kim, Yongmin

1997-05-01

Ultrasound as a medical imaging modality offers the clinician a real-time of the anatomy of the internal organs/tissues, their movement, and flow noninvasively. One of the applications of ultrasound is to monitor fetal growth by measuring biparietal diameter (BPD) and head circumference (HC). We have been working on automatic detection of fetal head boundaries in ultrasound images. These detected boundaries are used to measure BPD and HC. The boundary detection algorithm is based on active contour models and takes 32 seconds on an external high-end workstation, SUN SparcStation 20/71. Our goal has been to make this tool available within an ultrasound machine and at the same time significantly improve its performance utilizing multimedia technology. With the advent of high- performance programmable digital signal processors (DSP), the software solution within an ultrasound machine instead of the traditional hardwired approach or requiring an external computer is now possible. We have integrated our boundary detection algorithm into a programmable ultrasound image processor (PUIP) that fits into a commercial ultrasound machine. The PUIP provides both the high computing power and flexibility needed to support computationally-intensive image processing algorithms within an ultrasound machine. According to our data analysis, BPD/HC measurements made on PUIP lie within the interobserver variability. Hence, the errors in the automated BPD/HC measurements using the algorithm are on the same order as the average interobserver differences. On PUIP, it takes 360 ms to measure the values of BPD/HC on one head image. When processing multiple head images in sequence, it takes 185 ms per image, thus enabling 5.4 BPD/HC measurements per second. Reduction in the overall execution time from 32 seconds to a fraction of a second and making this multimedia system available within an ultrasound machine will help this image processing algorithm and other computer-intensive imaging applications become a practical tool for the sonographers in the feature.

Cognitive load predicts point-of-care ultrasound simulator performance.

PubMed

Aldekhyl, Sara; Cavalcanti, Rodrigo B; Naismith, Laura M

2018-02-01

The ability to maintain good performance with low cognitive load is an important marker of expertise. Incorporating cognitive load measurements in the context of simulation training may help to inform judgements of competence. This exploratory study investigated relationships between demographic markers of expertise, cognitive load measures, and simulator performance in the context of point-of-care ultrasonography. Twenty-nine medical trainees and clinicians at the University of Toronto with a range of clinical ultrasound experience were recruited. Participants answered a demographic questionnaire then used an ultrasound simulator to perform targeted scanning tasks based on clinical vignettes. Participants were scored on their ability to both acquire and interpret ultrasound images. Cognitive load measures included participant self-report, eye-based physiological indices, and behavioural measures. Data were analyzed using a multilevel linear modelling approach, wherein observations were clustered by participants. Experienced participants outperformed novice participants on ultrasound image acquisition. Ultrasound image interpretation was comparable between the two groups. Ultrasound image acquisition performance was predicted by level of training, prior ultrasound training, and cognitive load. There was significant convergence between cognitive load measurement techniques. A marginal model of ultrasound image acquisition performance including prior ultrasound training and cognitive load as fixed effects provided the best overall fit for the observed data. In this proof-of-principle study, the combination of demographic and cognitive load measures provided more sensitive metrics to predict ultrasound simulator performance. Performance assessments which include cognitive load can help differentiate between levels of expertise in simulation environments, and may serve as better predictors of skill transfer to clinical practice.

Might telesonography be a new useful diagnostic tool aboard merchant ships? A pilot study.

PubMed

Nikolić, Nebojsa; Mozetić, Vladimir; Modrcin, Bob; Jaksić, Slaven

2006-01-01

Developments of new, ultra-light diagnostic ultrasound systems (UTS) and modern satellite telecommunication networks are opening new potential applications for diagnostic sonography. One such area is maritime medicine. It is our belief that ship officers can be trained to use diagnostic ultrasound systems with the aim to generate ultrasound images of sufficient quality to be interpreted by medical professionals qualified to read sonograms. To test our thesis we included lectures and hands on scanning practice to the current maritime medicine curriculum at the Faculty of Maritime Studies at the University of Rijeka. Following the didactic and practical training all participating students examined several patients, some with pathology some without. Images obtained by students were then submitted for interpretation to a qualified physician (specialist of general surgery trained in UTS) who was unaware of the patient's pathology. In total, 37 students performed 37 examinations and made 45 ultrasound images, on 3 patients. In this paper, results on this pilot study are presented. It is possible to teach ship officers to produce diagnostically usable ultrasound pictures aboard ships at sea. But before reaching final conclusion about applicability of telesonography on board merchant ships, further studies are necessary, that would include studies of economic feasibility, and on validity of introducing such a diagnostic tool to the maritime medical practice.

Plantar fascia: imaging diagnosis and guided treatment.

PubMed

McNally, Eugene G; Shetty, Shilpa

2010-09-01

Plantar fasciopathy is a common cause of heel pain. This article covers the imaging anatomy of the hindfoot, the imaging findings on ultrasound and magnetic resonance imaging (MRI) of plantar fasciopathy, plantar fibromas, trauma, Achilles tendonopathy, neural compression, stress fractures of the os calcis and other heel pad lesions. Thickening of the plantar fascia insertion more than 5 mm either on ultrasound or MRI is suggestive of plantar fasciopathy. Ultrasound is superior to MRI for diagnosis of plantar fibroma as small low signal lesions on MRI are similar to the normal plantar fascia signal. Ultrasound demonstrates low echogenicity compared with the echogenic plantar fascia. Penetrating injuries can appear bizarre due to associated foreign body impaction and infection. Achilles tendonopathy can cause heel pain and should be considered as a possible diagnosis. Treatment options include physical therapy, ECSWT, corticosteroid injection, and dry needling. Percutaneous US guided treatment methods will be described. Thieme Medical Publishers.

Cassava flour slurry as a low-cost alternative to commercially available gel for obstetrical ultrasound: a blinded non-inferiority trial comparison of image quality.

PubMed

Aziz, A; Dar, P; Hughes, F; Solorzano, C; Muller, M M; Salmon, C; Salmon, M; Benfield, N

2018-01-12

To evaluate the quality of ultrasound images obtained with cassava flour slurry (CFS) compared with conventional gel in order to determine objectively whether CFS could be a true low-cost alternative. Blinded non-inferiority trial. Obstetrical ultrasound unit in an academic medical centre. Women with a singleton pregnancy, undergoing anatomy ultrasounds. Thirty pregnant women had standard biometry measures obtained with CFS and conventional gel. Images were compared side-by-side in random order by two blinded sonologists and rated for image resolution, detail and total image quality using a 10-cm visual analogue scale. Ratings were compared using paired t-tests. Participant and sonographer experience was measured using five-point Likert scales. Image resolution, detail, and total image quality. Participant experience of gel regarding irritation, messiness, and ease of removal. We found no significant difference between perceived image quality obtained with CFS (mean = 6.2, SD = 1.2) and commercial gel (mean = 6.4, SD = 1.2) [t (28) = -1.1; P = 0.3]. Images were not rated significantly differently for either reviewer in any measure, any standardized image or any view of a specific anatomic structure. All five sonographers rated CFS as easy to obtain clear images and easy for patient and machine cleanup. Only one participant reported itching with CFS. CFS produces comparable image quality to commercial ultrasound gel. The dissemination of these results and the simple CFS recipe could significantly increase access to ultrasound for screening, monitoring and diagnostic purposes in resource-limited settings. This study was internally funded by our department. Low-cost homemade cassava flour slurry creates images equal to commercial ultrasound gel, improving access. © 2018 Royal College of Obstetricians and Gynaecologists.

Optimising probe holder design for sentinel lymph node imaging using clinical photoacoustic system with Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Sivasubramanian, Kathyayini; Periyasamy, Vijitha; Wen, Kew Kok; Pramanik, Manojit

2017-03-01

Photoacoustic tomography is a hybrid imaging modality that combines optical and ultrasound imaging. It is rapidly gaining attention in the field of medical imaging. The challenge is to translate it into a clinical setup. In this work, we report the development of a handheld clinical photoacoustic imaging system. A clinical ultrasound imaging system is modified to integrate photoacoustic imaging with the ultrasound imaging. Hence, light delivery has been integrated with the ultrasound probe. The angle of light delivery is optimized in this work with respect to the depth of imaging. Optimization was performed based on Monte Carlo simulation for light transport in tissues. Based on the simulation results, the probe holders were fabricated using 3D printing. Similar results were obtained experimentally using phantoms. Phantoms were developed to mimic sentinel lymph node imaging scenario. Also, in vivo sentinel lymph node imaging was done using the same system with contrast agent methylene blue up to a depth of 1.5 cm. The results validate that one can use Monte Carlo simulation as a tool to optimize the probe holder design depending on the imaging needs. This eliminates a trial and error approach generally used for designing a probe holder.

An integrated circuit with transmit beamforming flip-chip bonded to a 2-D CMUT array for 3-D ultrasound imaging.

PubMed

Wygant, Ira O; Jamal, Nafis S; Lee, Hyunjoo J; Nikoozadeh, Amin; Oralkan, Omer; Karaman, Mustafa; Khuri-Yakub, Butrus T

2009-10-01

State-of-the-art 3-D medical ultrasound imaging requires transmitting and receiving ultrasound using a 2-D array of ultrasound transducers with hundreds or thousands of elements. A tight combination of the transducer array with integrated circuitry eliminates bulky cables connecting the elements of the transducer array to a separate system of electronics. Furthermore, preamplifiers located close to the array can lead to improved receive sensitivity. A combined IC and transducer array can lead to a portable, high-performance, and inexpensive 3-D ultrasound imaging system. This paper presents an IC flip-chip bonded to a 16 x 16-element capacitive micromachined ultrasonic transducer (CMUT) array for 3-D ultrasound imaging. The IC includes a transmit beamformer that generates 25-V unipolar pulses with programmable focusing delays to 224 of the 256 transducer elements. One-shot circuits allow adjustment of the pulse widths for different ultrasound transducer center frequencies. For receiving reflected ultrasound signals, the IC uses the 32-elements along the array diagonals. The IC provides each receiving element with a low-noise 25-MHz-bandwidth transimpedance amplifier. Using a field-programmable gate array (FPGA) clocked at 100 MHz to operate the IC, the IC generated properly timed transmit pulses with 5-ns accuracy. With the IC flip-chip bonded to a CMUT array, we show that the IC can produce steered and focused ultrasound beams. We present 2-D and 3-D images of a wire phantom and 2-D orthogonal cross-sectional images (Bscans) of a latex heart phantom.

Active point out-of-plane ultrasound calibration

NASA Astrophysics Data System (ADS)

Cheng, Alexis; Guo, Xiaoyu; Zhang, Haichong K.; Kang, Hyunjae; Etienne-Cummings, Ralph; Boctor, Emad M.

2015-03-01

Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common intraoperative medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the transducer and the ultrasound image. Point-based phantoms are considered to be accurate, but their calibration framework assumes that the point is in the image plane. In this work, we present the use of an active point phantom and a calibration framework that accounts for the elevational uncertainty of the point. Given the lateral and axial position of the point in the ultrasound image, we approximate a circle in the axial-elevational plane with a radius equal to the axial position. The standard approach transforms all of the imaged points to be a single physical point. In our approach, we minimize the distances between the circular subsets of each image, with them ideally intersecting at a single point. We simulated in noiseless and noisy cases, presenting results on out-of-plane estimation errors, calibration estimation errors, and point reconstruction precision. We also performed an experiment using a robot arm as the tracker, resulting in a point reconstruction precision of 0.64mm.

CUQI: cardiac ultrasound video quality index

PubMed Central

Razaak, Manzoor; Martini, Maria G.

2016-01-01

Abstract. Medical images and videos are now increasingly part of modern telecommunication applications, including telemedicinal applications, favored by advancements in video compression and communication technologies. Medical video quality evaluation is essential for modern applications since compression and transmission processes often compromise the video quality. Several state-of-the-art video quality metrics used for quality evaluation assess the perceptual quality of the video. For a medical video, assessing quality in terms of “diagnostic” value rather than “perceptual” quality is more important. We present a diagnostic-quality–oriented video quality metric for quality evaluation of cardiac ultrasound videos. Cardiac ultrasound videos are characterized by rapid repetitive cardiac motions and distinct structural information characteristics that are explored by the proposed metric. Cardiac ultrasound video quality index, the proposed metric, is a full reference metric and uses the motion and edge information of the cardiac ultrasound video to evaluate the video quality. The metric was evaluated for its performance in approximating the quality of cardiac ultrasound videos by testing its correlation with the subjective scores of medical experts. The results of our tests showed that the metric has high correlation with medical expert opinions and in several cases outperforms the state-of-the-art video quality metrics considered in our tests. PMID:27014715

Ultrasound: from Earth to space.

PubMed

Law, Jennifer; Macbeth, Paul B

2011-06-01

Ultrasonography is a versatile imaging modality that offers many advantages over radiography, computed tomography, and magnetic resonance imaging. On Earth, the use of ultrasound has become standard in many areas of medicine including diagnosis of medical and surgical diseases, management of obstetric and gynecologic conditions, assessment of critically ill patients, and procedural guidance. Advances in telecommunications have enabled remotely-guided ultrasonography for both geographically isolated populations and astronauts aboard the International Space Station. While ultrasound has traditionally been used in spaceflight to study anatomical and physiological adaptations to microgravity and evaluate countermeasures, recent years have seen a growth of applications adapted from terrestrial techniques. Terrestrial, remote, and space applications for ultrasound are reviewed in this paper.

Ultrasound: From Earth to Space

PubMed Central

Law, Jennifer; Macbeth, Paul. B.

2011-01-01

Ultrasonography is a versatile imaging modality that offers many advantages over radiography, computed tomography, and magnetic resonance imaging. On Earth, the use of ultrasound has become standard in many areas of medicine including diagnosis of medical and surgical diseases, management of obstetric and gynecologic conditions, assessment of critically ill patients, and procedural guidance. Advances in telecommunications have enabled remotely-guided ultrasonography for both geographically isolated populations and astronauts aboard the International Space Station. While ultrasound has traditionally been used in spaceflight to study anatomical and physiological adaptations to microgravity and evaluate countermeasures, recent years have seen a growth of applications adapted from terrestrial techniques. Terrestrial, remote, and space applications for ultrasound are reviewed in this paper. PMID:22399873

Evaluation of Human Research Facility Ultrasound With the ISS Video System

NASA Technical Reports Server (NTRS)

Melton, Shannon; Sargsyan, Ashot

2003-01-01

Most medical equipment on the International Space Station (ISS) is manifested as part of the U.S. or the Russian medical hardware systems. However, certain medical hardware is also available as part of the Human Research Facility. The HRF and the JSC Medical Operations Branch established a Memorandum of Agreement for joint use of certain medical hardware, including the HRF ultrasound system, the only diagnostic imaging device currently manifested to fly on ISS. The outcome of a medical contingency may be changed drastically, or an unnecessary evacuation may be prevented, if clinical decisions are supported by timely and objective diagnostic information. In many higher-probability medical scenarios, diagnostic ultrasound is a first-choice modality or provides significant diagnostic information. Accordingly, the Clinical Care Capability Development Project is evaluating the HRF ultrasound system for its utility in relevant clinical situations on board ISS. For effective management of these ultrasound-supported ISS medical scenarios, the resulting data should be available for viewing and interpretation on the ground, and bidirectional voice communication should be readily available to allow ground experts (sonographers, physicians) to provide guidance to the Crew Medical Officer. It may also be vitally important to have the capability of real-time guidance via video uplink to the CMO-operator during an exam to facilitate the diagnosis in a timely fashion. In this document, we strove to verify that the HRF ultrasound video output is compatible with the ISS video system, identify ISS video system field rates and resolutions that are acceptable for varying clinical scenaiios, and evaluate the HRF ultrasound video with a commercial, off-the-shelf video converter, and compare it with the ISS video system.

Speckle noise removal applied to ultrasound image of carotid artery based on total least squares model.

PubMed

Yang, Lei; Lu, Jun; Dai, Ming; Ren, Li-Jie; Liu, Wei-Zong; Li, Zhen-Zhou; Gong, Xue-Hao

2016-10-06

An ultrasonic image speckle noise removal method by using total least squares model is proposed and applied onto images of cardiovascular structures such as the carotid artery. On the basis of the least squares principle, the related principle of minimum square method is applied to cardiac ultrasound image speckle noise removal process to establish the model of total least squares, orthogonal projection transformation processing is utilized for the output of the model, and the denoising processing for the cardiac ultrasound image speckle noise is realized. Experimental results show that the improved algorithm can greatly improve the resolution of the image, and meet the needs of clinical medical diagnosis and treatment of the cardiovascular system for the head and neck. Furthermore, the success in imaging of carotid arteries has strong implications in neurological complications such as stroke.

A flexible ultrasound transducer array with micro-machined bulk PZT.

PubMed

Wang, Zhe; Xue, Qing-Tang; Chen, Yuan-Quan; Shu, Yi; Tian, He; Yang, Yi; Xie, Dan; Luo, Jian-Wen; Ren, Tian-Ling

2015-01-23

This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications.

"On the other hand ...": the evidence does not support the use of hand-carried ultrasound by hospitalists.

PubMed

Feldman, Mitchell D; Petersen, Amy Jean; Tice, Jeffrey A

2010-03-01

In the right hands, ultrasound is a safe and helpful diagnostic imaging tool. However, evidence supporting the use of hand-carried ultrasound (HCU) by hospitalist physicians has not kept pace with expanding application of these devices. In spite of its strategic point-of-care benefit, use of this technology by hospitalists may not ultimately translate into improved efficiency and better clinical outcomes. Optimal levels of training in image acquisition and interpretation remain to be established. Novelty, availability, and the results of a few small studies lacking patient-centered outcomes remain insufficient grounds to justify the expanded clinical utilization of these medical imaging devices by nonspecialists.

High-intensity focused ultrasound (HIFU) array system for image-guided ablative therapy (IGAT)

NASA Astrophysics Data System (ADS)

Kaczkowski, Peter J.; Keilman, George W.; Cunitz, Bryan W.; Martin, Roy W.; Vaezy, Shahram; Crum, Lawrence A.

2003-06-01

Recent interest in using High Intensity Focused Ultrasound (HIFU) for surgical applications such as hemostasis and tissue necrosis has stimulated the development of image-guided systems for non-invasive HIFU therapy. Seeking an all-ultrasound therapeutic modality, we have developed a clinical HIFU system comprising an integrated applicator that permits precisely registered HIFU therapy delivery and high quality ultrasound imaging using two separate arrays, a multi-channel signal generator and RF amplifier system, and a software program that provides the clinician with a graphical overlay of the ultrasound image and therapeutic protocol controls. Electronic phasing of a 32 element 2 MHz HIFU annular array allows adjusting the focus within the range of about 4 to 12 cm from the face. A central opening in the HIFU transducer permits mounting a commercial medical imaging scanhead (ATL P7-4) that is held in place within a special housing. This mechanical fixture ensures precise coaxial registration between the HIFU transducer and the image plane of the imaging probe. Recent enhancements include development of an acoustic lens using numerical simulations for use with a 5-element array. Our image-guided therapy system is very flexible and enables exploration of a variety of new HIFU therapy delivery and monitoring approaches in the search for safe, effective, and efficient treatment protocols.

Endocavity Ultrasound Probe Manipulators

PubMed Central

Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

2014-01-01

We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

Ultrasound Images of the Tongue: A Tutorial for Assessment and Remediation of Speech Sound Errors.

PubMed

Preston, Jonathan L; McAllister Byun, Tara; Boyce, Suzanne E; Hamilton, Sarah; Tiede, Mark; Phillips, Emily; Rivera-Campos, Ahmed; Whalen, Douglas H

2017-01-03

Diagnostic ultrasound imaging has been a common tool in medical practice for several decades. It provides a safe and effective method for imaging structures internal to the body. There has been a recent increase in the use of ultrasound technology to visualize the shape and movements of the tongue during speech, both in typical speakers and in clinical populations. Ultrasound imaging of speech has greatly expanded our understanding of how sounds articulated with the tongue (lingual sounds) are produced. Such information can be particularly valuable for speech-language pathologists. Among other advantages, ultrasound images can be used during speech therapy to provide (1) illustrative models of typical (i.e. "correct") tongue configurations for speech sounds, and (2) a source of insight into the articulatory nature of deviant productions. The images can also be used as an additional source of feedback for clinical populations learning to distinguish their better productions from their incorrect productions, en route to establishing more effective articulatory habits. Ultrasound feedback is increasingly used by scientists and clinicians as both the expertise of the users increases and as the expense of the equipment declines. In this tutorial, procedures are presented for collecting ultrasound images of the tongue in a clinical context. We illustrate these procedures in an extended example featuring one common error sound, American English /r/. Images of correct and distorted /r/ are used to demonstrate (1) how to interpret ultrasound images, (2) how to assess tongue shape during production of speech sounds, (3), how to categorize tongue shape errors, and (4), how to provide visual feedback to elicit a more appropriate and functional tongue shape. We present a sample protocol for using real-time ultrasound images of the tongue for visual feedback to remediate speech sound errors. Additionally, example data are shown to illustrate outcomes with the procedure.

Developing an ultrasound correlation velocimetry system

NASA Astrophysics Data System (ADS)

Surup, Gerrit; White, Christopher; UNH Team

2011-11-01

The process of building an ultrasound correlation velocimetry (UCV) system by integrating a commercial medical ultrasound with a PC running commercial PIV software is described and preliminary validation measurements in pipe flow using UCV and optical particle image velocimetry (PIV) are reported. In principles of operation, UCV is similar to the technique of PIV, differing only in the image acquisition process. The benefits of UCV are that it does not require optical access to the flow field and can be used for measuring flows of opaque fluids. While the limitations of UVC are the inherently low frame rates (limited by the imaging capabilities of the commercial ultrasound system) and low spatial resolution, which limits the range of velocities and transient flow behavior that can be measured. The support of the NSF (CBET0846359, grant monitor Horst Henning Winter) is gratefully acknowledged.

Remotely Guided Breast Sonography for Long-Term Space Missions: A Case Report and Discussion.

PubMed

Silva-Martinez, Jackelynne P; Sorice Genaro, Andreia; Wen, Hui Annie; Glauber, Naama; Russomano, Thais

2017-12-01

Space radiation can cause different types of cancers in crewmembers, especially during long-term space missions. To date, a complete bilateral breast ultrasound has not been performed at the International Space Station (ISS). A breast screening imaging technique could be a useful tool for early identification of breast cancer in astronauts. We hypothesized that breast ultrasound performed by a crewmember while being remotely guided by a specialist from the ground could be an essential tool for medical diagnosis in space. This project aimed to test an ultrasound screening protocol for breast tissue using real-time remotely guided telemedicine techniques. One female volunteer, with no previous medical experience, performed a self-scanned bilateral breast ultrasound exam guided by a remote sonographer. Dynamic ultrasound images were collected using a 25 mm broadband linear array transducer. To simulate fluid shift on the volunteer during microgravity, the bed was tilted -6°. Recorded ultrasound images were analyzed by radiologists, comparing the findings with a gold standard. The experiment demonstrated that real-time remotely guided sonography exam is feasible and can yield meaningful clinical results. This case study showed that remotely guided breast ultrasound can be performed and might become an important tool for diagnosis of breast cancer in space missions. The results cannot be generalized based on one subject, and additional research is warranted in this area in addition to its validation on the ISS. This technique, however, has potential for use as part of preventive medicine procedures for long-term space missions at the ISS, and eventually for human settlements on the Moon and Mars.

Characteristics and Echogenicity of Clinical Ultrasound Contrast Agents: An In Vitro and In Vivo Comparison Study.

PubMed

Hyvelin, Jean-Marc; Gaud, Emmanuel; Costa, Maria; Helbert, Alexandre; Bussat, Philippe; Bettinger, Thierry; Frinking, Peter

2017-05-01

To compare physicochemical characteristics and in vitro and in vivo contrast-enhanced ultrasound imaging performance of 3 commercially available ultrasound contrast agents: SonoVue (Bracco Imaging SpA, Colleretto Giacosa, Italy; also marketed as Lumason in the USA), Definity (Lantheus Medical Imaging, North Billerica, MA) and Optison (GE Healthcare AS, Oslo, Norway). Physicochemical characteristics were measured with a Multisizer Coulter Counter (Beckman Coulter, Fullerton, CA). Two ultrasound systems (Aplio 500; Toshiba Medical Systems Corp, Tochigi-ken, Japan; and Logiq E9; GE Healthcare, Little Chalfont, England) were used with different transducers. Contrast enhancement was measured in vitro by dose-ranging measurements using a custom-built beaker setup; in vivo imaging performances were compared in pigs (heart and liver) and rabbits (liver). Quantitative analyses were performed with VueBox quantification software (Bracco Suisse SA, Plan-les-Ouates, Switzerland). Measured physicochemical characteristics were in agreement with those provided by the manufacturers. In vitro data demonstrated that the performance of SonoVue was similar to or better than that of Definity but superior to Optison (normalized scattered power 2- to 10-fold higher with SonoVue). Similar results were obtained in vivo, although the duration of enhancement in the pig heart was longer for SonoVue compared to Definity, and quantitative analysis revealed higher enhancement for SonoVue (1.5-fold increase). For liver imaging, SonoVue and Definity showed similar contrast enhancement and duration of enhancement, but compared to Optison, both peak enhancement and duration of enhancement were superior for SonoVue (up to 2-fold increase). Imaging performance of SonoVue was similar to or slightly better than that of Definity, but it was superior to Optison for the conditions used in this study. © 2017 by the American Institute of Ultrasound in Medicine.

Towards a new tool for the evaluation of the quality of ultrasound compressed images.

PubMed

Delgorge, Cécile; Rosenberger, Christophe; Poisson, Gérard; Vieyres, Pierre

2006-11-01

This paper presents a new tool for the evaluation of ultrasound image compression. The goal is to measure the image quality as easily as with a statistical criterion, and with the same reliability as the one provided by the medical assessment. An initial experiment is proposed to medical experts and represents our reference value for the comparison of evaluation criteria. Twenty-one statistical criteria are selected from the literature. A cumulative absolute similarity measure is defined as a distance between the criterion to evaluate and the reference value. A first fusion method based on a linear combination of criteria is proposed to improve the results obtained by each of them separately. The second proposed approach combines different statistical criteria and uses the medical assessment in a training phase with a support vector machine. Some experimental results are given and show the benefit of fusion.

Children's (Pediatric) Abdominal Ultrasound Imaging

MedlinePlus Videos and Cool Tools

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Constrained Adaptive Beamforming for Improved Contrast in Breast Ultrasound

DTIC Science & Technology

2008-06-01

Medical Imaging 2007: Ultrasonic Imaging and Signal Processing Proceedings, vol. 6513, San Diego , CA, Feb. 18, 2007. 12. Guenther, D.A., Walker...Transactions on, vol. 6, pp. 185-192, 1987. [23] A. P. Schachat, R. P. Murphy, and A. Patz, Medical Retina, vol. 2, 1 ed. St. Louis: The C. V. Mosby

The feasibility of non-contact ultrasound for medical imaging.

PubMed

Clement, G T; Nomura, H; Adachi, H; Kamakura, T

2013-09-21

High intensity focused ultrasound in air may provide a means for medical and biological imaging without direct coupling of an ultrasound probe. In this study, an approach based on highly focused ultrasound in air is described and the feasibility of the technique is assessed. The overall method is based on the observations that (1) ultrasound in air has superior focusing ability and stronger nonlinear harmonic generation as compared to tissue propagation and (2) a tightly focused field directed into tissue causes point-like spreading that may be regarded as a source for generalized diffraction tomography. Simulations of a spherically-curved transducer are performed, where the transducer's radiation pattern is directed from air into tissue. It is predicted that a focal pressure of 162 dB (2.5 kPa) is sufficient to direct ultrasound through the body, and provide a small but measurable signal (∼1 mPa) upon exit. Based on the simulations, a 20 cm diameter array consisting of 298 transducers is constructed. For this feasibility study, a 40 kHz resonance frequency is selected based on the commercial availability of such transducers. The array is used to focus through water and acrylic phantoms, and the time history of the exiting signal is evaluated. Sufficient data are acquired to demonstrate a low-resolution tomographic reconstruction. Finally, to demonstrate the feasibility to record a signal in vivo, a 75 mm × 55 mm section of a human hand is imaged in a C-mode configuration.

Introducing a Fresh Cadaver Model for Ultrasound-guided Central Venous Access Training in Undergraduate Medical Education

PubMed Central

Miller, Ryan; Ho, Hang; Ng, Vivienne; Tran, Melissa; Rappaport, Douglas; Rappaport, William J.A.; Dandorf, Stewart J.; Dunleavy, James; Viscusi, Rebecca; Amini, Richard

2016-01-01

Introduction Over the past decade, medical students have witnessed a decline in the opportunities to perform technical skills during their clinical years. Ultrasound-guided central venous access (USG-CVA) is a critical procedure commonly performed by emergency medicine, anesthesia, and general surgery residents, often during their first month of residency. However, the acquisition of skills required to safely perform this procedure is often deficient upon graduation from medical school. To ameliorate this lack of technical proficiency, ultrasound simulation models have been introduced into undergraduate medical education to train venous access skills. Criticisms of simulation models are the innate lack of realistic tactile qualities, as well as the lack of anatomical variances when compared to living patients. The purpose of our investigation was to design and evaluate a life-like and reproducible training model for USG-CVA using a fresh cadaver. Methods This was a cross-sectional study at an urban academic medical center. An 18-point procedural knowledge tool and an 18-point procedural skill evaluation tool were administered during a cadaver lab at the beginning and end of the surgical clerkship. During the fresh cadaver lab, procedure naïve third-year medical students were trained on how to perform ultrasound-guided central venous access of the femoral and internal jugular vessels. Preparation of the fresh cadaver model involved placement of a thin-walled latex tubing in the anatomic location of the femoral and internal jugular vein respectively. Results Fifty-six third-year medical students participated in this study during their surgical clerkship. The fresh cadaver model provided high quality and lifelike ultrasound images despite numerous cannulation attempts. Technical skill scores improved from an average score of 3 to 12 (p<0.001) and procedural knowledge scores improved from an average score of 4 to 8 (p<0.001). Conclusion The use of this novel cadaver model prevented extravasation of fluid, maintained ultrasound-imaging quality, and proved to be an effective educational model allowing third-year medical students to improve and maintain their technical skills. PMID:27330672

Introducing a Fresh Cadaver Model for Ultrasound-guided Central Venous Access Training in Undergraduate Medical Education.

PubMed

Miller, Ryan; Ho, Hang; Ng, Vivienne; Tran, Melissa; Rappaport, Douglas; Rappaport, William J A; Dandorf, Stewart J; Dunleavy, James; Viscusi, Rebecca; Amini, Richard

2016-05-01

Over the past decade, medical students have witnessed a decline in the opportunities to perform technical skills during their clinical years. Ultrasound-guided central venous access (USG-CVA) is a critical procedure commonly performed by emergency medicine, anesthesia, and general surgery residents, often during their first month of residency. However, the acquisition of skills required to safely perform this procedure is often deficient upon graduation from medical school. To ameliorate this lack of technical proficiency, ultrasound simulation models have been introduced into undergraduate medical education to train venous access skills. Criticisms of simulation models are the innate lack of realistic tactile qualities, as well as the lack of anatomical variances when compared to living patients. The purpose of our investigation was to design and evaluate a life-like and reproducible training model for USG-CVA using a fresh cadaver. This was a cross-sectional study at an urban academic medical center. An 18-point procedural knowledge tool and an 18-point procedural skill evaluation tool were administered during a cadaver lab at the beginning and end of the surgical clerkship. During the fresh cadaver lab, procedure naïve third-year medical students were trained on how to perform ultrasound-guided central venous access of the femoral and internal jugular vessels. Preparation of the fresh cadaver model involved placement of a thin-walled latex tubing in the anatomic location of the femoral and internal jugular vein respectively. Fifty-six third-year medical students participated in this study during their surgical clerkship. The fresh cadaver model provided high quality and lifelike ultrasound images despite numerous cannulation attempts. Technical skill scores improved from an average score of 3 to 12 (p<0.001) and procedural knowledge scores improved from an average score of 4 to 8 (p<0.001). The use of this novel cadaver model prevented extravasation of fluid, maintained ultrasound-imaging quality, and proved to be an effective educational model allowing third-year medical students to improve and maintain their technical skills.

Development and evaluation of a novel VEGFR2-targeted nanoscale ultrasound contrast agents

NASA Astrophysics Data System (ADS)

Yu, Houqiang; Li, Chunfang; He, Xiaoling; Zhou, Qibing; Ding, Mingyue

2016-04-01

Recent literatures have reported that the targeted nanoscale ultrasound contrast agents are becoming more and more important in medical application, like ultrasound imaging, detection of perfusion, drug delivery and molecular imaging and so on. In this study, we fabricated an uniform nanoscale bubbles (257 nm with the polydispersity index of 0.458) by incorporation of antibody targeted to vascular endothelial growth factor receptor 2 (VEGFR2) into the nanobubbles membrane by using avidin-biotin interaction. Some fundamental characterizations such as nanobubble suspension, surface morphology, particle size distribution and zeta potential were investigated. The concentration and time-intensity curves (TICs) were obtained with a self-made ultrasound experimental setup in vitro evaluation. In addition, in order to evaluate the contrast enhancement ability and the potential tumor-targeted ability in vivo, normal Wistar rats and nude female BALB/c mice were intravascular administration of the nanobubbles via tail vein injection, respectively. Significant contrast enhancement of ultrasound imaging within liver and tumor were visualized. These experiments demonstrated that the targeted nanobubbles is efficient in ultrasound molecular imaging by enhancement of the contrast effect and have potential capacity for targeted tumor diagnosis and therapy in the future.

Focused ultrasound: concept for automated transcutaneous control of hemorrhage in austere settings.

PubMed

Kucewicz, John C; Bailey, Michael R; Kaczkowski, Peter J; Carter, Stephen J

2009-04-01

High intensity focused ultrasound (HIFU) is being developed for a range of clinical applications. Of particular interest to NASA and the military is the use of HIFU for traumatic injuries because HIFU has the unique ability to transcutaneously stop bleeding. Automation of this technology would make possible its use in remote, austere settings by personnel not specialized in medical ultrasound. Here a system to automatically detect and target bleeding is tested and reported. The system uses Doppler ultrasound images from a clinical ultrasound scanner for bleeding detection and hardware for HIFU therapy. The system was tested using a moving string to simulate blood flow and targeting was visualized by Schlieren imaging to show the focusing of the HIFU acoustic waves. When instructed by the operator, a Doppler ultrasound image is acquired and processed to detect and localize the moving string, and the focus of the HIFU array is electronically adjusted to target the string. Precise and accurate targeting was verified in the Schlieren images. An automated system to detect and target simulated bleeding has been built and tested. The system could be combined with existing algorithms to detect, target, and treat clinical bleeding.

MO-FG-210-02: Implementation of Image-Guided Prostate HDR Brachytherapy Using MR-Ultrasound Fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libby, B.

Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefitmore » from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.« less

An Approach towards Ultrasound Kidney Cysts Detection using Vector Graphic Image Analysis

NASA Astrophysics Data System (ADS)

Mahmud, Wan Mahani Hafizah Wan; Supriyanto, Eko

2017-08-01

This study develops new approach towards detection of kidney ultrasound image for both with single cyst as well as multiple cysts. 50 single cyst images and 25 multiple cysts images were used to test the developed algorithm. Steps involved in developing this algorithm were vector graphic image formation and analysis, thresholding, binarization, filtering as well as roundness test. Performance evaluation to 50 single cyst images gave accuracy of 92%, while for multiple cysts images, the accuracy was about 86.89% when tested to 25 multiple cysts images. This developed algorithm may be used in developing a computerized system such as computer aided diagnosis system to help medical experts in diagnosis of kidney cysts.

High-resolution, low-delay, and error-resilient medical ultrasound video communication using H.264/AVC over mobile WiMAX networks.

PubMed

Panayides, Andreas; Antoniou, Zinonas C; Mylonas, Yiannos; Pattichis, Marios S; Pitsillides, Andreas; Pattichis, Constantinos S

2013-05-01

In this study, we describe an effective video communication framework for the wireless transmission of H.264/AVC medical ultrasound video over mobile WiMAX networks. Medical ultrasound video is encoded using diagnostically-driven, error resilient encoding, where quantization levels are varied as a function of the diagnostic significance of each image region. We demonstrate how our proposed system allows for the transmission of high-resolution clinical video that is encoded at the clinical acquisition resolution and can then be decoded with low-delay. To validate performance, we perform OPNET simulations of mobile WiMAX Medium Access Control (MAC) and Physical (PHY) layers characteristics that include service prioritization classes, different modulation and coding schemes, fading channels conditions, and mobility. We encode the medical ultrasound videos at the 4CIF (704 × 576) resolution that can accommodate clinical acquisition that is typically performed at lower resolutions. Video quality assessment is based on both clinical (subjective) and objective evaluations.

High resolution three-dimensional robotic synthetic tracked aperture ultrasound imaging: feasibility study

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Fang, Ting Yun; Finocchi, Rodolfo; Boctor, Emad M.

2017-03-01

Three dimensional (3D) ultrasound imaging is becoming a standard mode for medical ultrasound diagnoses. Conventional 3D ultrasound imaging is mostly scanned either by using a two dimensional matrix array or by motorizing a one dimensional array in the elevation direction. However, the former system is not widely assessable due to its cost, and the latter one has limited resolution and field-of-view in the elevation axis. Here, we propose a 3D ultrasound imaging system based on the synthetic tracked aperture approach, in which a robotic arm is used to provide accurate tracking and motion. While the ultrasound probe is moved by a robotic arm, each probe position is tracked and can be used to reconstruct a wider field-of-view as there are no physical barriers that restrict the elevational scanning. At the same time, synthetic aperture beamforming provides a better resolution in the elevation axis. To synthesize the elevational information, the single focal point is regarded as the virtual element, and forward and backward delay-andsum are applied to the radio-frequency (RF) data collected through the volume. The concept is experimentally validated using a general ultrasound phantom, and the elevational resolution improvement of 2.54 and 2.13 times was measured at the target depths of 20 mm and 110 mm, respectively.

Design of an ergonomic ultrasound system: accommodation of user anthropometrics.

PubMed

Park, Sung; Yim, Jinho; Lee, Goeun

2012-01-01

Long-term use of medical imaging devices requires significant improvements to the user experience. One factor that impact upon such experience is whether the device is ergonomically built, ecologically designed, and leverages the current medical practice. In this research, we took a holistic and systematic approach to design an effective and biomechanically-fit ultrasound system. Research methods from behavior science (e.g., contextual inquiry, pseudo experiments) had been adopted to involve the users (sonographers) early in the design process. The end results - product design guideline for a cart type ultrasound system and control panel layout - were reviewed by the users and adjusted so that the design is within the range of an acceptable learning curve while maintaining innovativeness, a differentiated value over competitor's ultrasound devices.

Contrast-enhanced and targeted ultrasound.

PubMed

Postema, Michiel; Gilja, Odd Helge

2011-01-07

Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

Contrast-enhanced and targeted ultrasound

PubMed Central

Postema, Michiel; Gilja, Odd Helge

2011-01-01

Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested. PMID:21218081

Automatic nipple detection on 3D images of an automated breast ultrasound system (ABUS)

NASA Astrophysics Data System (ADS)

Javanshir Moghaddam, Mandana; Tan, Tao; Karssemeijer, Nico; Platel, Bram

2014-03-01

Recent studies have demonstrated that applying Automated Breast Ultrasound in addition to mammography in women with dense breasts can lead to additional detection of small, early stage breast cancers which are occult in corresponding mammograms. In this paper, we proposed a fully automatic method for detecting the nipple location in 3D ultrasound breast images acquired from Automated Breast Ultrasound Systems. The nipple location is a valuable landmark to report the position of possible abnormalities in a breast or to guide image registration. To detect the nipple location, all images were normalized. Subsequently, features have been extracted in a multi scale approach and classification experiments were performed using a gentle boost classifier to identify the nipple location. The method was applied on a dataset of 100 patients with 294 different 3D ultrasound views from Siemens and U-systems acquisition systems. Our database is a representative sample of cases obtained in clinical practice by four medical centers. The automatic method could accurately locate the nipple in 90% of AP (Anterior-Posterior) views and in 79% of the other views.

SURGE: Smart Ultrasound Remote Guidance Experiment

NASA Technical Reports Server (NTRS)

Peterson, Sean

2009-01-01

Exploration-class missions lead to longer communication delays with mission control. May not always have communication capability to stream real-time ultrasound images. SURGE explores use of a "just-in-time" learning tool, called OPEL = On-Board Proficiency Enhancer Light as an aid to a hypothetical crew medical officer working autonomously.

A Review on Real-Time 3D Ultrasound Imaging Technology

PubMed Central

Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail. PMID:28459067

A Review on Real-Time 3D Ultrasound Imaging Technology.

PubMed

Huang, Qinghua; Zeng, Zhaozheng

2017-01-01

Real-time three-dimensional (3D) ultrasound (US) has attracted much more attention in medical researches because it provides interactive feedback to help clinicians acquire high-quality images as well as timely spatial information of the scanned area and hence is necessary in intraoperative ultrasound examinations. Plenty of publications have been declared to complete the real-time or near real-time visualization of 3D ultrasound using volumetric probes or the routinely used two-dimensional (2D) probes. So far, a review on how to design an interactive system with appropriate processing algorithms remains missing, resulting in the lack of systematic understanding of the relevant technology. In this article, previous and the latest work on designing a real-time or near real-time 3D ultrasound imaging system are reviewed. Specifically, the data acquisition techniques, reconstruction algorithms, volume rendering methods, and clinical applications are presented. Moreover, the advantages and disadvantages of state-of-the-art approaches are discussed in detail.

Eigenspace-based minimum variance beamformer combined with Wiener postfilter for medical ultrasound imaging.

PubMed

Zeng, Xing; Chen, Cheng; Wang, Yuanyuan

2012-12-01

In this paper, a new beamformer which combines the eigenspace-based minimum variance (ESBMV) beamformer with the Wiener postfilter is proposed for medical ultrasound imaging. The primary goal of this work is to further improve the medical ultrasound imaging quality on the basis of the ESBMV beamformer. In this method, we optimize the ESBMV weights with a Wiener postfilter. With the optimization of the Wiener postfilter, the output power of the new beamformer becomes closer to the actual signal power at the imaging point than the ESBMV beamformer. Different from the ordinary Wiener postfilter, the output signal and noise power needed in calculating the Wiener postfilter are estimated respectively by the orthogonal signal subspace and noise subspace constructed from the eigenstructure of the sample covariance matrix. We demonstrate the performance of the new beamformer when resolving point scatterers and cyst phantom using both simulated data and experimental data and compare it with the delay-and-sum (DAS), the minimum variance (MV) and the ESBMV beamformer. We use the full width at half maximum (FWHM) and the peak-side-lobe level (PSL) to quantify the performance of imaging resolution and the contrast ratio (CR) to quantify the performance of imaging contrast. The FWHM of the new beamformer is only 15%, 50% and 50% of those of the DAS, MV and ESBMV beamformer, while the PSL is 127.2dB, 115dB and 60dB lower. What is more, an improvement of 239.8%, 232.5% and 32.9% in CR using simulated data and an improvement of 814%, 1410.7% and 86.7% in CR using experimental data are achieved compared to the DAS, MV and ESBMV beamformer respectively. In addition, the effect of the sound speed error is investigated by artificially overestimating the speed used in calculating the propagation delay and the results show that the new beamformer provides better robustness against the sound speed errors. Therefore, the proposed beamformer offers a better performance than the DAS, MV and ESBMV beamformer, showing its potential in medical ultrasound imaging. Copyright © 2012 Elsevier B.V. All rights reserved.

US Emergency Department Trends in Imaging for Pediatric Nontraumatic Abdominal Pain.

PubMed

Niles, Lauren M; Goyal, Monika K; Badolato, Gia M; Chamberlain, James M; Cohen, Joanna S

2017-10-01

To describe national emergency department (ED) trends in computed tomography (CT) and ultrasound imaging for the evaluation of pediatric nontraumatic abdominal pain from 2007 through 2014. We used data from the National Hospital Ambulatory Medical Care Survey to measure trends in CT and ultrasound use among children with nontraumatic abdominal pain. We performed multivariable logistic regression to measure the strength of the association of ED type (pediatric versus general ED) with CT and ultrasound use adjusting for potential confounding variables. Of an estimated 21.1 million ED visits for nontraumatic abdominal pain, 14.6% (95% confidence interval [CI], 13.2%-16.0%) had CT imaging only, 10.9% (95% CI, 9.7%-12.1%) had ultrasound imaging only, and 1.9% (95% CI, 1.4%-2.4%) received both CT and ultrasound. The overall use of CT and ultrasound did not significantly change over the study period ( P trend .63 and .90, respectively). CT use was lower among children treated in pediatric EDs compared with general EDs (adjusted odds ratio 0.34; 95% CI, 0.17-0.69). Conversely, ultrasound use was higher among children treated in pediatric EDs compared with general EDs (adjusted odds ratio 2.14; 95% CI, 1.29-3.55). CT imaging for pediatric patients with nontraumatic abdominal pain has plateaued since 2007 after the steady increase seen in the preceding 9 years. Among this population, an increased likelihood of CT imaging was demonstrated in general EDs compared with pediatric EDs, in which there was a higher likelihood of ultrasound imaging. Dissemination of pediatric-focused radiology protocols to general EDs may help optimize radiation exposure in children. Copyright © 2017 by the American Academy of Pediatrics.

TH-A-207B-00: Shear-Wave Imaging and a QIBA US Biomarker Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will targetmore » these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: Introduction: Importance of tissue elasticity measurement Strain vs. shear wave elastography (SWE), beneficial features of SWE The link between shear wave speed and material properties, influence of viscosity Generation of shear waves External vibration (Fibroscan) ultrasound radiation force Point push Supersonic push (Aixplorer) Comb push (GE Logiq E9) Detection of shear waves Motion detection from pulse-echo ultrasound Importance of frame rate for shear wave imaging Plane wave imaging detection How to achieve high effective frame rate using line-by-line scanners Shear wave speed calculation Time to peak Random sample consensus (RANSAC) Cross correlation Sources of bias and variation in SWE Tissue viscosity Transducer compression or internal pressure of organ Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: Goals Review the need for quantitative medical imaging Provide examples of quantitative imaging biomarkers Acquaint the participant with the purpose of the RSNA Quantitative Imaging Biomarker Alliance and the need for such an organization Review the QIBA process for creating a quantitative biomarker Summarize steps needed to verify adherence of site, operators, and imaging systems to a QIBA profile Underlying Premise and Assumptions Objective, quantifiable results are needed to enhance the value of diagnostic imaging in clinical practice Reasons for quantification Evidence based medicine requires objective, not subjective observer data Computerized decision support tools (eg CAD) generally require quantitative input. Quantitative, reproducible measures are more easily used to develop personalized molecular medical diagnostic and treatment systems What is quantitative imaging? Definition from Imaging Metrology Workshop The Quantitative Imaging Biomarker Alliance Formation 2008 Mission Structure Example Imaging Biomarkers Being Explored Biomarker Selection Groundwork Draft Protocol for imaging and data evaluation QIBA Profile Drafting Equipment and Site Validation Technical Clinical Site and Equipment QA and Compliance Checking Ultrasound Elasticity Estimation Biomarker US Elasticity Estimation Background Current Status and Problems Biomarker Selection-process and outcome US SWS for Liver Fibrosis Biomarker Work Groundwork Literature search and analysis results Phase I phantom testing-Elastic phantoms Phase II phantom testing-Viscoelastic phantoms Digital Simulated Data Protocol and Profile Drafting Protocol: based on UPICT and existing literature and standards bodies protocols Profile-Current claims, Manufacturer specific appendices What comes after the profile Profile Validation Technical validation Clinical validation QA and Compliance Possible approaches Site Operator testing Site protocol re-evaluation Imaging system Manufacturer testing and attestation User acceptance testing and periodic QA Phantom Tests Digital Phantom Based Testing Standard QA Testing Remediation Schemes Profile Evolution Towards additional applications Towards higher accuracy and precision Supported in part by NIH contract HHSN268201300071C from NIBIB. Collaboration with GE Global Research, no personal support.; S. Chen, Some technologies described in this presentation have been licensed. Mayo Clinic and Dr. Chen have financial interests these technologies.« less

Smartphone based automatic organ validation in ultrasound video.

PubMed

Vaish, Pallavi; Bharath, R; Rajalakshmi, P

2017-07-01

Telesonography involves transmission of ultrasound video from remote areas to the doctors for getting diagnosis. Due to the lack of trained sonographers in remote areas, the ultrasound videos scanned by these untrained persons do not contain the proper information that is required by a physician. As compared to standard methods for video transmission, mHealth driven systems need to be developed for transmitting valid medical videos. To overcome this problem, we are proposing an organ validation algorithm to evaluate the ultrasound video based on the content present. This will guide the semi skilled person to acquire the representative data from patient. Advancement in smartphone technology allows us to perform high medical image processing on smartphone. In this paper we have developed an Application (APP) for a smartphone which can automatically detect the valid frames (which consist of clear organ visibility) in an ultrasound video and ignores the invalid frames (which consist of no-organ visibility), and produces a compressed sized video. This is done by extracting the GIST features from the Region of Interest (ROI) of the frame and then classifying the frame using SVM classifier with quadratic kernel. The developed application resulted with the accuracy of 94.93% in classifying valid and invalid images.

AAPM/RSNA physics tutorial for residents. Topics in US: B-mode US: basic concepts and new technology.

PubMed

Hangiandreou, Nicholas J

2003-01-01

Ultrasonography (US) has been used in medical imaging for over half a century. Current US scanners are based largely on the same basic principles used in the initial devices for human imaging. Modern equipment uses a pulse-echo approach with a brightness-mode (B-mode) display. Fundamental aspects of the B-mode imaging process include basic ultrasound physics, interactions of ultrasound with tissue, ultrasound pulse formation, scanning the ultrasound beam, and echo detection and signal processing. Recent technical innovations that have been developed to improve the performance of modern US equipment include the following: tissue harmonic imaging, spatial compound imaging, extended field of view imaging, coded pulse excitation, electronic section focusing, three-dimensional and four-dimensional imaging, and the general trend toward equipment miniaturization. US is a relatively inexpensive, portable, safe, and real-time modality, all of which make it one of the most widely used imaging modalities in medicine. Although B-mode US is sometimes referred to as a mature technology, this modality continues to experience a significant evolution in capability with even more exciting developments on the horizon. Copyright RSNA, 2003

The TERESA project: from space research to ground tele-echography

NASA Technical Reports Server (NTRS)

Vieyres, Pierre; Poisson, Gerard; Courreges, Fabien; Merigeaux, Olivier; Arbeille, Philippe

2003-01-01

Ultrasound examinations represent one of the major diagnostic modalities of future healthcare. They are currently used to support medical space research but require a high skilled operator for both probe positioning on the patient's skin and image interpretation. TERESA is a tele-echography project that proposes a solution to bring astronauts and remotely located patients on ground quality ultrasound examinations despite the lack of a specialist at the location of the wanted medical act.

Ultrasound-guided pleural access.

PubMed

Shojaee, Samira; Argento, A Christine

2014-12-01

Ultrasonography of the thorax has become a more recognized tool in pulmonary medicine, thanks to continuing clinical research that has proven its many valuable roles in the day-to-day management of pulmonary and pleural diseases. Ultrasound examination is a cost-effective imaging modality that permits the pulmonologist to obtain information about the pathologies in the thorax without the risk of exposure to ionizing radiation, providing the examiner with real-time and immediate results. Its ease of use and training along with its portability to the patient's bedside and accurate examination of the pleural space has allowed for safer pleural procedures such as thoracentesis, chest tube placement, tunneled pleural catheter placement, and medical thoracoscopy. In this review, we summarize the technique of chest ultrasonography, compare ultrasound to other frequently used thoracic imaging modalities, and focus on its use in obtaining pleural access while performing invasive pleural procedures. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Lunar Surface Reference Missions: A Description of Human and Robotic Surface Activities

NASA Technical Reports Server (NTRS)

Duke, Michael B.; Hoffman, Stephen J.; Snook, Kelly

2003-01-01

Most medical equipment to the International Space Station (ISS) is manisfested as part of the U.S. or the Russian medical hardware systems. However, certain medical hardware is also available as part of the Human Research Facility. The HRF and the JSC Medical Operations Branch established a Memorandum of Agreement for joint use of certain medical hardware, including the HRF ultrasound system, the only diagnostic imaging device currently manifested to fly on ISS. The outcome of a medical contingency may be changed drastically, or an unnecessary evacuation may be prevented, if clinical decisions are supported by timely and objective diagnostic information. In many higher-probability medical scenarios, diagnostic ultrasound is a first-choice modality or provides significant diagnostic information. Accordingly, the Clinical Care Capability Development Project is evaluating the HRF ultrasound system for its utility in relevant clinical siruations on board ISS. For effective management of these ultrasound-supported ISS medical scenarios, the resulting data should be available for viewing and interpretation on the ground, and bidirectional voice communication should be readily available to allow ground experts (sonographers, physicians) to provide guidance to the Crew Medical Officer. It may also be vitally important to have the capability of real-time guidance via video uplink to the CMO-opertor during an exam to facilitate the diagnosis in a timely fashion.

Robust boundary detection of left ventricles on ultrasound images using ASM-level set method.

PubMed

Zhang, Yaonan; Gao, Yuan; Li, Hong; Teng, Yueyang; Kang, Yan

2015-01-01

Level set method has been widely used in medical image analysis, but it has difficulties when being used in the segmentation of left ventricular (LV) boundaries on echocardiography images because the boundaries are not very distinguish, and the signal-to-noise ratio of echocardiography images is not very high. In this paper, we introduce the Active Shape Model (ASM) into the traditional level set method to enforce shape constraints. It improves the accuracy of boundary detection and makes the evolution more efficient. The experiments conducted on the real cardiac ultrasound image sequences show a positive and promising result.

[Anterior segment tumor imaging: advantages of ultrasound (10, 20 and 50 MHz) and optical coherence tomography].

PubMed

Siahmed, K; Berges, O; Desjardins, L; Lumbroso, L; Brasseur, G

2004-02-01

Detail the role of different imaging techniques for diagnosis of tumors of the iris. Sixty-one tumors of the iris were explored using ultrasound at 10 and 20MHz (Cinescan, BVI Quantel Medical) and 50MHz (UBM, Paradigm) and optical coherence tomography (OCT) (Humphrey Zeiss). Ultrasound should be used at frequencies of 20MHz or greater to precisely characterize, localize and measure a lesion. Ultrasound biomicroscopy (UBM) is inadequate to measure large tumors (extending toward the back of the ciliary body), because of the transducer and the considerably lower image quality caused by the lesion. Ultrasound alone cannot characterize a solid lesion, and moreover cannot differentiate benign and malignant lesions. Clinical notions are also important in diagnosis and patient management. OCT recognizes whether a lesion is liquid or solid in certain cases. With a tumor that seems solid, a 50MHz examination must be done rapidly, and if the entire lesion is difficult to see, a 20MHz ultrasound should be used. With a protruding iris, high-frequency ultrasound and OCT differentiate a cystic lesion from a solid mass, but only BMU provides a precise measurement and regular surveillance capabilities.

Teaching point of care ultrasound skills in medical school: keeping radiology in the driver's seat.

PubMed

Webb, Emily M; Cotton, James B; Kane, Kevin; Straus, Christopher M; Topp, Kimberly S; Naeger, David M

2014-07-01

Ultrasound is used increasingly in medical practice as a tool for focused bedside diagnosis and technical assistance during procedures. Widespread availability of small portable units has put this technology into the hands of many physicians and medical students who lack dedicated training, leaving the education and introduction of this key modality increasingly to physicians from other specialties. We developed a radiology-led program to teach ultrasound skills to preclinical medical students. To develop this new ultrasound program we 1) established a program leader, 2) developed teaching materials, 3) created a hands-on interactive program, and 4) recruited the necessary instructors. The program was piloted with the first-year medical student class of 154 students. The introductory session was assessed by pre- and post-activity Likert scale-based surveys. Of 154 (68.8%) students, 106 completed a voluntary online survey before starting the program and 145 students (94.2%) completed a voluntary survey after the session. Students found the program educationally valuable (4.64 of 5) and reported that it improved their understanding of ultrasound imaging (4.7 of 5). Students' reported confidence in identifying abdominal organs, intra-abdominal fluid, and Morison pouch that was significantly higher on the postactivity survey compared to the presurvey (P < .001 for all). We piloted a radiology-led program to teach ultrasound skills to preclinical medical students. Students found the experience enjoyable and educationally valuable. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Single element ultrasonic imaging of limb geometry: an in-vivo study with comparison to MRI

NASA Astrophysics Data System (ADS)

Zhang, Xiang; Fincke, Jonathan R.; Anthony, Brian W.

2016-04-01

Despite advancements in medical imaging, current prosthetic fitting methods remain subjective, operator dependent, and non-repeatable. The standard plaster casting method relies on prosthetist experience and tactile feel of the limb to design the prosthetic socket. Often times, many fitting iterations are required to achieve an acceptable fit. Use of improper socket fittings can lead to painful pathologies including neuromas, inflammation, soft tissue calcification, and pressure sores, often forcing the wearer to into a wheelchair and reducing mobility and quality of life. Computer software along with MRI/CT imaging has already been explored to aid the socket design process. In this paper, we explore the use of ultrasound instead of MRI/CT to accurately obtain the underlying limb geometry to assist the prosthetic socket design process. Using a single element ultrasound system, multiple subjects' proximal limbs were imaged using 1, 2.25, and 5 MHz single element transducers. Each ultrasound transducer was calibrated to ensure acoustic exposure within the limits defined by the FDA. To validate image quality, each patient was also imaged in an MRI. Fiducial markers visible in both MRI and ultrasound were used to compare the same limb cross-sectional image for each patient. After applying a migration algorithm, B-mode ultrasound cross-sections showed sufficiently high image resolution to characterize the skin and bone boundaries along with the underlying tissue structures.

Medical ultrasonic tomographic system

NASA Technical Reports Server (NTRS)

Heyser, R. C.; Lecroissette, D. H.; Nathan, R.; Wilson, R. L.

1977-01-01

An electro-mechanical scanning assembly was designed and fabricated for the purpose of generating an ultrasound tomogram. A low cost modality was demonstrated in which analog instrumentation methods formed a tomogram on photographic film. Successful tomogram reconstructions were obtained on in vitro test objects by using the attenuation of the fist path ultrasound signal as it passed through the test object. The nearly half century tomographic methods of X-ray analysis were verified as being useful for ultrasound imaging.

Ultrasound and Cadaveric Prosections as Methods for Teaching Cardiac Anatomy: A Comparative Study

ERIC Educational Resources Information Center

Griksaitis, Michael J.; Sawdon, Marina A.; Finn, Gabrielle M.

2012-01-01

This study compared the efficacy of two cardiac anatomy teaching modalities, ultrasound imaging and cadaveric prosections, for learning cardiac gross anatomy. One hundred and eight first-year medical students participated. Two weeks prior to the teaching intervention, students completed a pretest to assess their prior knowledge and to ensure that…

Point-of-Care Ultrasound Assessment of Tropical Infectious Diseases--A Review of Applications and Perspectives.

PubMed

Bélard, Sabine; Tamarozzi, Francesca; Bustinduy, Amaya L; Wallrauch, Claudia; Grobusch, Martin P; Kuhn, Walter; Brunetti, Enrico; Joekes, Elizabeth; Heller, Tom

2016-01-01

The development of good quality and affordable ultrasound machines has led to the establishment and implementation of numerous point-of-care ultrasound (POCUS) protocols in various medical disciplines. POCUS for major infectious diseases endemic in tropical regions has received less attention, despite its likely even more pronounced benefit for populations with limited access to imaging infrastructure. Focused assessment with sonography for HIV-associated TB (FASH) and echinococcosis (FASE) are the only two POCUS protocols for tropical infectious diseases, which have been formally investigated and which have been implemented in routine patient care today. This review collates the available evidence for FASH and FASE, and discusses sonographic experiences reported for urinary and intestinal schistosomiasis, lymphatic filariasis, viral hemorrhagic fevers, amebic liver abscess, and visceral leishmaniasis. Potential POCUS protocols are suggested and technical as well as training aspects in the context of resource-limited settings are reviewed. Using the focused approach for tropical infectious diseases will make ultrasound diagnosis available to patients who would otherwise have very limited or no access to medical imaging. © The American Society of Tropical Medicine and Hygiene.

Point-of-Care Ultrasound Assessment of Tropical Infectious Diseases—A Review of Applications and Perspectives

PubMed Central

Bélard, Sabine; Tamarozzi, Francesca; Bustinduy, Amaya L.; Wallrauch, Claudia; Grobusch, Martin P.; Kuhn, Walter; Brunetti, Enrico; Joekes, Elizabeth; Heller, Tom

2016-01-01

The development of good quality and affordable ultrasound machines has led to the establishment and implementation of numerous point-of-care ultrasound (POCUS) protocols in various medical disciplines. POCUS for major infectious diseases endemic in tropical regions has received less attention, despite its likely even more pronounced benefit for populations with limited access to imaging infrastructure. Focused assessment with sonography for HIV-associated TB (FASH) and echinococcosis (FASE) are the only two POCUS protocols for tropical infectious diseases, which have been formally investigated and which have been implemented in routine patient care today. This review collates the available evidence for FASH and FASE, and discusses sonographic experiences reported for urinary and intestinal schistosomiasis, lymphatic filariasis, viral hemorrhagic fevers, amebic liver abscess, and visceral leishmaniasis. Potential POCUS protocols are suggested and technical as well as training aspects in the context of resource-limited settings are reviewed. Using the focused approach for tropical infectious diseases will make ultrasound diagnosis available to patients who would otherwise have very limited or no access to medical imaging. PMID:26416111

Software phantom with realistic speckle modeling for validation of image analysis methods in echocardiography

NASA Astrophysics Data System (ADS)

Law, Yuen C.; Tenbrinck, Daniel; Jiang, Xiaoyi; Kuhlen, Torsten

2014-03-01

Computer-assisted processing and interpretation of medical ultrasound images is one of the most challenging tasks within image analysis. Physical phenomena in ultrasonographic images, e.g., the characteristic speckle noise and shadowing effects, make the majority of standard methods from image analysis non optimal. Furthermore, validation of adapted computer vision methods proves to be difficult due to missing ground truth information. There is no widely accepted software phantom in the community and existing software phantoms are not exible enough to support the use of specific speckle models for different tissue types, e.g., muscle and fat tissue. In this work we propose an anatomical software phantom with a realistic speckle pattern simulation to _ll this gap and provide a exible tool for validation purposes in medical ultrasound image analysis. We discuss the generation of speckle patterns and perform statistical analysis of the simulated textures to obtain quantitative measures of the realism and accuracy regarding the resulting textures.

Identifying regions of interest in medical images using self-organizing maps.

PubMed

Teng, Wei-Guang; Chang, Ping-Lin

2012-10-01

Advances in data acquisition, processing and visualization techniques have had a tremendous impact on medical imaging in recent years. However, the interpretation of medical images is still almost always performed by radiologists. Developments in artificial intelligence and image processing have shown the increasingly great potential of computer-aided diagnosis (CAD). Nevertheless, it has remained challenging to develop a general approach to process various commonly used types of medical images (e.g., X-ray, MRI, and ultrasound images). To facilitate diagnosis, we recommend the use of image segmentation to discover regions of interest (ROI) using self-organizing maps (SOM). We devise a two-stage SOM approach that can be used to precisely identify the dominant colors of a medical image and then segment it into several small regions. In addition, by appropriately conducting the recursive merging steps to merge smaller regions into larger ones, radiologists can usually identify one or more ROIs within a medical image.

Real-time sound speed correction using golden section search to enhance ultrasound imaging quality

NASA Astrophysics Data System (ADS)

Yoon, Chong Ook; Yoon, Changhan; Yoo, Yangmo; Song, Tai-Kyong; Chang, Jin Ho

2013-03-01

In medical ultrasound imaging, high-performance beamforming is important to enhance spatial and contrast resolutions. A modern receive dynamic beamfomer uses a constant sound speed that is typically assumed to 1540 m/s in generating receive focusing delays [1], [2]. However, this assumption leads to degradation of spatial and contrast resolutions particularly when imaging obese patients or breast since the sound speed is significantly lower than the assumed sound speed [3]; the true sound speed in the fatty tissue is around 1450 m/s. In our previous study, it was demonstrated that the modified nonlinear anisotropic diffusion is capable of determining an optimal sound speed and the proposed method is a useful tool to improve ultrasound image quality [4], [5]. In the previous study, however, we utilized at least 21 iterations to find an optimal sound speed, which may not be viable for real-time applications. In this paper, we demonstrates that the number of iterations can be dramatically reduced using the GSS(golden section search) method with a minimal error. To evaluate performances of the proposed method, in vitro experiments were conducted with a tissue mimicking phantom. To emulate a heterogeneous medium, the phantom was immersed in the water. From the experiments, the number of iterations was reduced from 21 to 7 with GSS method and the maximum error of the lateral resolution between direct and GSS was less than 1%. These results indicate that the proposed method can be implemented in real time to improve the image quality in the medical ultrasound imaging.

Hybrid Photoacoustic/Ultrasound Tomograph for Real-Time Finger Imaging.

PubMed

Oeri, Milan; Bost, Wolfgang; Sénégond, Nicolas; Tretbar, Steffen; Fournelle, Marc

2017-10-01

We report a target-enclosing, hybrid tomograph with a total of 768 elements based on capacitive micromachined ultrasound transducer technology and providing fast, high-resolution 2-D/3-D photoacoustic and ultrasound tomography tailored to finger imaging. A freely programmable ultrasound beamforming platform sampling data at 80 MHz was developed to realize plane wave transmission under multiple angles. A multiplexing unit enables the connection and control of a large number of elements. Fast image reconstruction is provided by GPU processing. The tomograph is composed of four independent and fully automated movable arc-shaped transducers, allowing imaging of all three finger joints. The system benefits from photoacoustics, yielding high optical contrast and enabling visualization of finger vascularization, and ultrasound provides morphologic information on joints and surrounding tissue. A diode-pumped, Q-switched Nd:YAG laser and an optical parametric oscillator are used to broaden the spectrum of emitted wavelengths to provide multispectral imaging. Custom-made optical fiber bundles enable illumination of the region of interest in the plane of acoustic detection. Precision in positioning of the probe in motion is ensured by use of a motor-driven guide slide. The current position of the probe is encoded by the stage and used to relate ultrasound and photoacoustic signals to the corresponding region of interest of the suspicious finger joint. The system is characterized in phantoms and a healthy human finger in vivo. The results obtained promise to provide new opportunities in finger diagnostics and establish photoacoustic/ultrasound-tomography in medical routine. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Development of ultrasound transducer diffractive field theory for nonlinear propagation-based imaging

NASA Astrophysics Data System (ADS)

Kharin, Nikolay A.

2000-04-01

In nonlinear ultrasound imaging the images are formed using the second harmonic energy generated due to the nonlinear nature of finite amplitude propagation. This propagation can be modeled using the KZK wave equation. This paper presents further development of nonlinear diffractive field theory based on the KZK equation and its solution by means of the slowly changing profile method for moderate nonlinearity. The analytical expression for amplitudes and phases of sum frequency wave are obtained in addition to the second harmonic wave. Also, the analytical expression for the relative curvature of the wave fronts of fundamental and second harmonic signals are derived. The media with different nonlinear properties and absorption coefficients were investigated to characterize the diffractive field of the transducer at medical frequencies. All expressions demonstrate good agreement with experimental results. The expressions are novel and provide an easy way for prediction of amplitude and phase structure of nonlinearly distorted field of a transducer. The sum frequency signal technique could be implemented as well as second harmonic technique to improve the quality of biomedical images. The results obtained are of importance for medical diagnostic ultrasound equipment design.

Generalized sidelobe canceler beamforming applied to medical ultrasound imaging

NASA Astrophysics Data System (ADS)

Li, Jiake; Chen, Xiaodong; Wang, Yi; Shi, Yifeng; Yu, Daoyin

2017-03-01

A generalized sidelobe canceler (GSC) approach is proposed for medical ultrasound imaging. The approach uses a set of adaptive weights instead of traditional non-adaptive weights, thus suppressing the interference and noise signal of echo data. In order to verify the validity of the proposed approach, Field II is applied to obtain the echo data of synthetic aperture (SA) for 13 scattering points and circular cysts. The performance of GSC is compared with SA using boxcar weights and Hamming weights, and is quantified by the full width at half maximum (FWHM) and peak signal-to-noise ratio (PSNR). Imaging of scattering point utilizing SA, SA (hamming), GSC provides FWHMs of 1.13411, 1.68910, 0.36195 mm and PSNRs of 60.65, 57.51, 66.72 dB, respectively. The simulation results of circular cyst also show that GSC can perform better lateral resolution than non-adaptive beamformers. Finally, an experiment is conducted on the basis of actual echo data of an ultrasound system, the imaging result after SA, SA (hamming), GSC provides PWHMs of 2.55778, 3.66776, 1.01346 mm at z = 75.6 mm, and 2.65430, 3.76428, 1.27889 mm at z = 77.3 mm, respectively.

Remotely supported prehospital ultrasound: A feasibility study of real-time image transmission and expert guidance to aid diagnosis in remote and rural communities.

PubMed

Eadie, Leila; Mulhern, John; Regan, Luke; Mort, Alasdair; Shannon, Helen; Macaden, Ashish; Wilson, Philip

2017-01-01

Introduction Our aim is to expedite prehospital assessment of remote and rural patients using remotely-supported ultrasound and satellite/cellular communications. In this paradigm, paramedics are remotely-supported ultrasound operators, guided by hospital-based specialists, to record images before receiving diagnostic advice. Technology can support users in areas with little access to medical imaging and suboptimal communications coverage by connecting to multiple cellular networks and/or satellites to stream live ultrasound and audio-video. Methods An ambulance-based demonstrator system captured standard trauma and novel transcranial ultrasound scans from 10 healthy volunteers at 16 locations across the Scottish Highlands. Volunteers underwent brief scanning training before receiving expert guidance via the communications link. Ultrasound images were streamed with an audio/video feed to reviewers for interpretation. Two sessions were transmitted via satellite and 21 used cellular networks. Reviewers rated image and communication quality, and their utility for diagnosis. Transmission latency and bandwidth were recorded, and effects of scanner and reviewer experience were assessed. Results Appropriate views were provided in 94% of the simulated trauma scans. The mean upload rate was 835/150 kbps and mean latency was 114/2072 ms for cellular and satellite networks, respectively. Scanning experience had a significant impact on time to achieve a diagnostic image, and review of offline scans required significantly less time than live-streamed scans. Discussion This prehospital ultrasound system could facilitate early diagnosis and streamlining of treatment pathways for remote emergency patients, being particularly applicable in rural areas worldwide with poor communications infrastructure and extensive transport times.

Limited angle breast ultrasound tomography with a priori information and artifact removal

NASA Astrophysics Data System (ADS)

Jintamethasawat, Rungroj; Zhu, Yunhao; Kripfgans, Oliver D.; Yuan, Jie; Goodsitt, Mitchell M.; Carson, Paul L.

2017-03-01

In B-mode images from dual-sided ultrasound, it has been shown that by delineating structures suspected of being relatively homogeneous, one can enhance limited angle tomography to produce speed of sound images in the same view as X-ray Digital Breast Tomography (DBT). This could allow better breast cancer detection and discrimination, as well as improved registration of the ultrasound and X-ray images, because of the similarity of SOS and X-ray contrast in the breast. However, this speed of sound reconstruction method relies strongly on B-mode or other reflection mode segmentation. If that information is limited or incorrect, artifacts will appear in the reconstructed images. Therefore, the iterative speed of sound reconstruction algorithm has been modified in a manner of simultaneously utilizing the image segmentations and removing most artifacts. The first step of incorporating a priori information is solved by any nonlinearnonconvex optimization method while artifact removal is accomplished by employing the fast split Bregman method to perform total-variation (TV) regularization for image denoising. The proposed method was demonstrated in simplified simulations of our dual-sided ultrasound scanner. To speed these computations two opposed 40-element ultrasound linear arrays with 0.5 MHz center frequency were simulated for imaging objects in a uniform background. The proposed speed of sound reconstruction method worked well with both bent-ray and full-wave inversion methods. This is also the first demonstration of successful full-wave medical ultrasound tomography in the limited angle geometry. Presented results lend credibility to a possible translation of this method to clinical breast imaging.

Needle tip visualization by bevel-point ultrasound generator and prototype photoacoustic imaging system

NASA Astrophysics Data System (ADS)

Irisawa, Kaku; Murakoshi, Dai; Hashimoto, Atsushi; Yamamoto, Katsuya; Hayakawa, Toshiro

2017-03-01

Visualization of the tip of medical devices like needles or catheters under ultrasound imaging has been a continuous topic since the early 1980's. In this study, a needle tip visualization system utilizing photoacoustic effects is proposed. In order to visualize the needle tip, an optical fiber was inserted into a needle. The optical fiber tip is placed on the needle bevel and affixed with black glue. The pulsed laser light from laser diode was transferred to the optical fiber and converted to ultrasound due to laser light absorption of the black glue and the subsequent photoacoustic effect. The ultrasound is detected by transducer array and reconstructed into photoacoustic images in the ultrasound unit. The photoacoustic image is displayed with a superposed ultrasound B-mode image. As a system evaluation, the needle is punctured into bovine meat and the needle tip is observed with commercialized conventional linear transducers or convex transducers. The needle tip is visualized clearly at 7 and 12 cm depths with linear and convex probes, respectively, even with a steep needle puncture angle of around 90 degrees. Laser and acoustic outputs, and thermal rise at the needle tip, were measured and were well below the limits of the safety standards. Compared with existing needle tip visualization technologies, the photoacoustic needle tip visualization system has potential distinguishable features for clinical procedures related with needle puncture and injection.

In-line positioning of ultrasound images using wireless remote display system with tablet computer facilitates ultrasound-guided radial artery catheterization.

PubMed

Tsuchiya, Masahiko; Mizutani, Koh; Funai, Yusuke; Nakamoto, Tatsuo

2016-02-01

Ultrasound-guided procedures may be easier to perform when the operator's eye axis, needle puncture site, and ultrasound image display form a straight line in the puncture direction. However, such methods have not been well tested in clinical settings because that arrangement is often impossible due to limited space in the operating room. We developed a wireless remote display system for ultrasound devices using a tablet computer (iPad Mini), which allows easy display of images at nearly any location chosen by the operator. We hypothesized that the in-line layout of ultrasound images provided by this system would allow for secure and quick catheterization of the radial artery. We enrolled first-year medical interns (n = 20) who had no prior experience with ultrasound-guided radial artery catheterization to perform that using a short-axis out-of-plane approach with two different methods. With the conventional method, only the ultrasound machine placed at the side of the head of the patient across the targeted forearm was utilized. With the tablet method, the ultrasound images were displayed on an iPad Mini positioned on the arm in alignment with the operator's eye axis and needle puncture direction. The success rate and time required for catheterization were compared between the two methods. Success rate was significantly higher (100 vs. 70 %, P = 0.02) and catheterization time significantly shorter (28.5 ± 7.5 vs. 68.2 ± 14.3 s, P < 0.001) with the tablet method as compared to the conventional method. An ergonomic straight arrangement of the image display is crucial for successful and quick completion of ultrasound-guided arterial catheterization. The present remote display system is a practical method for providing such an arrangement.

Cadaver-based Necrotizing Fasciitis Model for Medical Training.

PubMed

Mohty, Kurt M; Cravens, Matthew G; Adamas-Rappaport, William J; Amini-Shervin, Bahareh; Irving, Steven C; Stea, Nicholas; Adhikari, Srikar; Amini, Richard

2017-04-14

Necrotizing fasciitis is a devastating infectious disease process that is characterized by extensive soft tissue necrosis along deep fascial planes, systemic toxicity, and high mortality. Ultrasound imaging is a rapid and non-invasive tool that can be used to help make the diagnosis of necrotizing fasciitis by identifying several distinctive sonographic findings. The purpose of this study is to describe the construction of a realistic diagnostic training model for necrotizing fasciitis using fresh frozen cadavers and common, affordable materials. Presently, fresh non-embalmed cadavers have been used at medical institutions for various educational sessions including cadaver-based ultrasound training sessions. Details for the preparation and construction of a necrotizing fasciitis cadaver model are presented here. This paper shows that the images obtained from the cadaver model closely imitate the ultrasound appearance of fluid and gas seen in actual clinical cases of necrotizing fasciitis. Therefore, it can be concluded that this cadaver-based model produces high-quality sonographic images that simulate those found in true cases of necrotizing fasciitis and is ideal for demonstrating the sonographic findings of necrotizing fasciitis.

The role for peer-assisted ultrasound teaching in medical school.

PubMed

Dickerson, Jonathan; Paul, Katie; Vila, Pierre; Whiticar, Rebecca

2017-06-01

Bedside ultrasonography has an increasing role in medicine yet medical students have limited exposure. Although countless hours are devoted to plain radiograph and electrocardiogram (ECG) interpretation, ultrasound is frequently glossed over. Yet this imaging modality could enhance students' understanding of anatomy, physiology and pathology, and may increase their integration into hospital teams. We aimed to investigate whether a peer-assisted ultrasound course has a place within the undergraduate medical curriculum. We describe the implementation of a course and discuss its acceptability and utility in student education. Bedside ultrasonography has an increasing role in medicine yet medical students have limited exposure METHODS: Following consultation with the medical school, an improved ultrasonography course was developed with expert guidance from an ultrasonographer and with new equipment. Sessions involved peer-tutors teaching ultrasonography techniques to medical students during emergency medicine placements. Tutees completed questionnaires to assess the quality and perceived benefits of the course and of learning ultrasonography. Both quantitative and thematic analyses of the responses were conducted by the authors. Over a period of 8 months, 105 medical students received teaching across four sessions. A total of 103 students (98%) returned questionnaires on their evaluation of the course and tutors, and on their confidence in using ultrasound. Ninety-eight per cent felt that the teaching was well delivered, 100 per cent felt that their knowledge of ultrasound had improved and 100 per cent would recommend the course. The peer-assisted ultrasound course described here enabled the majority of students to feel confident gaining elementary ultrasound views, and performing abdominal aneurysm screening and trauma assessments: techniques that they could hopefully put to use during their placements. The peer-assisted model has an acceptable role in teaching emerging clinical skills to medical students. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

The complexity of fetal imaging: reconciling clinical care with patient entertainment.

PubMed

Simonsen, Sara Ellis; Branch, D Ware; Rose, Nancy C

2008-12-01

Currently in the United States, pregnant women may obtain both medical fetal ultrasonography for screening and commercial fetal ultrasonography for entertainment purposes. The proliferation of commercial fetal ultrasonography suggests that medical screening alone does not satisfy patient expectations regarding fetal imaging. We investigated the prevalence of nonmedical fetal imaging and patient experiences and perceptions with both medical and nonmedical ultrasonography in our metropolitan area. We initiate a dialogue to explore the distinctions between medical and nonmedical fetal ultrasound imaging and the role of entertainment imaging in the medical setting. Concerns about safety, false reassurance, and unnecessary anxiety that might be generated by nonmedical ultrasonography should prompt us to examine the expectations of women regarding entertainment imaging, current clinical practice, and the potential for regulation of this commercial industry.

The effects of transducer geometry on artifacts common to diagnostic bone imaging with conventional medical ultrasound.

PubMed

Mauldin, F William; Owen, Kevin; Tiouririne, Mohamed; Hossack, John A

2012-06-01

The portability, low cost, and non-ionizing radiation associated with medical ultrasound suggest that it has potential as a superior alternative to X-ray for bone imaging. However, when conventional ultrasound imaging systems are used for bone imaging, clinical acceptance is frequently limited by artifacts derived from reflections occurring away from the main axis of the acoustic beam. In this paper, the physical source of off-axis artifacts and the effect of transducer geometry on these artifacts are investigated in simulation and experimental studies. In agreement with diffraction theory, the sampled linear-array geometry possessed increased off-axis energy compared with single-element piston geometry, and therefore, exhibited greater levels of artifact signal. Simulation and experimental results demonstrated that the linear-array geometry exhibited increased artifact signal when the center frequency increased, when energy off-axis to the main acoustic beam (i.e., grating lobes) was perpendicularly incident upon off-axis surfaces, and when off-axis surfaces were specular rather than diffusive. The simulation model used to simulate specular reflections was validated experimentally and a correlation coefficient of 0.97 between experimental and simulated peak reflection contrast was observed. In ex vivo experiments, the piston geometry yielded 4 and 6.2 dB average contrast improvement compared with the linear array when imaging the spinous process and interlaminar space of an animal spine, respectively. This work indicates that off-axis reflections are a major source of ultrasound image artifacts, particularly in environments comprising specular reflecting (i.e., bone or bone-like) objects. Transducer geometries with reduced sensitivity to off-axis surface reflections, such as a piston transducer geometry, yield significant reductions in image artifact.

Bedside ultrasound curriculum for medical students: report of a blended learning curriculum implementation and validation.

PubMed

Blackstock, Uché; Munson, Jaclyn; Szyld, Demian

2015-03-01

Medical students on clinical rotations rarely receive formal bedside ultrasound (BUS) training. We designed, implemented, and evaluated a standardized BUS curriculum for medical students on their Emergency Medicine (EM) rotation. Teaching was aimed toward influencing four cognitive and psychomotor learning domains: BUS instrumentation knowledge, image interpretation, image acquisition, and procedural guidance. Participants viewed three instructional Web-based tutorials on BUS instrumentation, the Focused Assessment for Sonography in Trauma (FAST) examination and ultrasound-guided central venous catheter (CVC) placement. Subsequently, participants attended a 3-hour hands-on training session to discuss the same content area and practice with faculty coaches. A Web-based, multiple-choice questionnaire was administered before and after the session. During the final week of the rotation, students returned for skills assessments on FAST image acquisition and CVC placement. Forty-five medical students on an EM rotation were enrolled. Sonographic knowledge overall mean score improved significantly from 66.6% (SD ±11.2) to 85.7% (SD ±10.0), corresponding to a mean difference of 19.1% (95% CI 15.5-22.7; p < 0.001). There were high pass rates for FAST (89.0%, 40/45) and CVC (96.0%, 43/45) skills assessments. There was no significant difference between medical student posttest and EM resident test scores 85.7% (SD ±10.0) and 88.1% (SD ± 7.6) (p = 0.40), respectively. A formal BUS curriculum for medical students on EM rotation positively influenced performance in several key learning domains. As BUS competency is required for residency in EM and other specialties, medical schools could consider routinely incorporating BUS teaching into their clinical rotation curricula. © 2014 Wiley Periodicals, Inc.

Automatic segmentation and classification of gestational sac based on mean sac diameter using medical ultrasound image

NASA Astrophysics Data System (ADS)

Khazendar, Shan; Farren, Jessica; Al-Assam, Hisham; Sayasneh, Ahmed; Du, Hongbo; Bourne, Tom; Jassim, Sabah A.

2014-05-01

Ultrasound is an effective multipurpose imaging modality that has been widely used for monitoring and diagnosing early pregnancy events. Technology developments coupled with wide public acceptance has made ultrasound an ideal tool for better understanding and diagnosing of early pregnancy. The first measurable signs of an early pregnancy are the geometric characteristics of the Gestational Sac (GS). Currently, the size of the GS is manually estimated from ultrasound images. The manual measurement involves multiple subjective decisions, in which dimensions are taken in three planes to establish what is known as Mean Sac Diameter (MSD). The manual measurement results in inter- and intra-observer variations, which may lead to difficulties in diagnosis. This paper proposes a fully automated diagnosis solution to accurately identify miscarriage cases in the first trimester of pregnancy based on automatic quantification of the MSD. Our study shows a strong positive correlation between the manual and the automatic MSD estimations. Our experimental results based on a dataset of 68 ultrasound images illustrate the effectiveness of the proposed scheme in identifying early miscarriage cases with classification accuracies comparable with those of domain experts using K nearest neighbor classifier on automatically estimated MSDs.

Web-Based Quality Assurance Process Drives Improvements in Obstetric Ultrasound in 5 Low- and Middle-Income Countries

PubMed Central

Swanson, Jonathan O; Plotner, David; Franklin, Holly L; Swanson, David L; Lokomba Bolamba, Victor; Lokangaka, Adrien; Sayury Pineda, Irma; Figueroa, Lester; Garces, Ana; Muyodi, David; Esamai, Fabian; Kanaiza, Nancy; Mirza, Waseem; Naqvi, Farnaz; Saleem, Sarah; Mwenechanya, Musaku; Chiwila, Melody; Hamsumonde, Dorothy; McClure, Elizabeth M; Goldenberg, Robert L; Nathan, Robert O

2016-01-01

ABSTRACT High quality is important in medical imaging, yet in many geographic areas, highly skilled sonographers are in short supply. Advances in Internet capacity along with the development of reliable portable ultrasounds have created an opportunity to provide centralized remote quality assurance (QA) for ultrasound exams performed at rural sites worldwide. We sought to harness these advances by developing a web-based tool to facilitate QA activities for newly trained sonographers who were taking part in a cluster randomized trial investigating the role of limited obstetric ultrasound to improve pregnancy outcomes in 5 low- and middle-income countries. We were challenged by connectivity issues, by country-specific needs for website usability, and by the overall need for a high-throughput system. After systematically addressing these needs, the resulting QA website helped drive ultrasound quality improvement across all 5 countries. It now offers the potential for adoption by future ultrasound- or imaging-based global health initiatives. PMID:28031304

Non-rigid ultrasound image registration using generalized relaxation labeling process

NASA Astrophysics Data System (ADS)

Lee, Jong-Ha; Seong, Yeong Kyeong; Park, MoonHo; Woo, Kyoung-Gu; Ku, Jeonghun; Park, Hee-Jun

2013-03-01

This research proposes a novel non-rigid registration method for ultrasound images. The most predominant anatomical features in medical images are tissue boundaries, which appear as edges. In ultrasound images, however, other features can be identified as well due to the specular reflections that appear as bright lines superimposed on the ideal edge location. In this work, an image's local phase information (via the frequency domain) is used to find the ideal edge location. The generalized relaxation labeling process is then formulated to align the feature points extracted from the ideal edge location. In this work, the original relaxation labeling method was generalized by taking n compatibility coefficient values to improve non-rigid registration performance. This contextual information combined with a relaxation labeling process is used to search for a correspondence. Then the transformation is calculated by the thin plate spline (TPS) model. These two processes are iterated until the optimal correspondence and transformation are found. We have tested our proposed method and the state-of-the-art algorithms with synthetic data and bladder ultrasound images of in vivo human subjects. Experiments show that the proposed method improves registration performance significantly, as compared to other state-of-the-art non-rigid registration algorithms.

Completely automated estimation of prostate volume for 3-D side-fire transrectal ultrasound using shape prior approach

NASA Astrophysics Data System (ADS)

Li, Lu; Narayanan, Ramakrishnan; Miller, Steve; Shen, Feimo; Barqawi, Al B.; Crawford, E. David; Suri, Jasjit S.

2008-02-01

Real-time knowledge of capsule volume of an organ provides a valuable clinical tool for 3D biopsy applications. It is challenging to estimate this capsule volume in real-time due to the presence of speckles, shadow artifacts, partial volume effect and patient motion during image scans, which are all inherent in medical ultrasound imaging. The volumetric ultrasound prostate images are sliced in a rotational manner every three degrees. The automated segmentation method employs a shape model, which is obtained from training data, to delineate the middle slices of volumetric prostate images. Then a "DDC" algorithm is applied to the rest of the images with the initial contour obtained. The volume of prostate is estimated with the segmentation results. Our database consists of 36 prostate volumes which are acquired using a Philips ultrasound machine using a Side-fire transrectal ultrasound (TRUS) probe. We compare our automated method with the semi-automated approach. The mean volumes using the semi-automated and complete automated techniques were 35.16 cc and 34.86 cc, with the error of 7.3% and 7.6% compared to the volume obtained by the human estimated boundary (ideal boundary), respectively. The overall system, which was developed using Microsoft Visual C++, is real-time and accurate.

Despeckle filtering software toolbox for ultrasound imaging of the common carotid artery.

PubMed

Loizou, Christos P; Theofanous, Charoula; Pantziaris, Marios; Kasparis, Takis

2014-04-01

Ultrasound imaging of the common carotid artery (CCA) is a non-invasive tool used in medicine to assess the severity of atherosclerosis and monitor its progression through time. It is also used in border detection and texture characterization of the atherosclerotic carotid plaque in the CCA, the identification and measurement of the intima-media thickness (IMT) and the lumen diameter that all are very important in the assessment of cardiovascular disease (CVD). Visual perception, however, is hindered by speckle, a multiplicative noise, that degrades the quality of ultrasound B-mode imaging. Noise reduction is therefore essential for improving the visual observation quality or as a pre-processing step for further automated analysis, such as image segmentation of the IMT and the atherosclerotic carotid plaque in ultrasound images. In order to facilitate this preprocessing step, we have developed in MATLAB(®) a unified toolbox that integrates image despeckle filtering (IDF), texture analysis and image quality evaluation techniques to automate the pre-processing and complement the disease evaluation in ultrasound CCA images. The proposed software, is based on a graphical user interface (GUI) and incorporates image normalization, 10 different despeckle filtering techniques (DsFlsmv, DsFwiener, DsFlsminsc, DsFkuwahara, DsFgf, DsFmedian, DsFhmedian, DsFad, DsFnldif, DsFsrad), image intensity normalization, 65 texture features, 15 quantitative image quality metrics and objective image quality evaluation. The software is publicly available in an executable form, which can be downloaded from http://www.cs.ucy.ac.cy/medinfo/. It was validated on 100 ultrasound images of the CCA, by comparing its results with quantitative visual analysis performed by a medical expert. It was observed that the despeckle filters DsFlsmv, and DsFhmedian improved image quality perception (based on the expert's assessment and the image texture and quality metrics). It is anticipated that the system could help the physician in the assessment of cardiovascular image analysis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Low-amplitude non-linear volume vibrations of single microbubbles measured with an "acoustical camera".

PubMed

Renaud, Guillaume; Bosch, Johan G; Van Der Steen, Antonius F W; De Jong, Nico

2014-06-01

Contrast-enhanced ultrasound imaging is based on the detection of non-linear vibrational responses of a contrast agent after its intravenous administration. Improving contrast-enhanced images requires an accurate understanding of the vibrational response to ultrasound of the lipid-coated gas microbubbles that constitute most ultrasound contrast agents. Variations in the volume of microbubbles provide the most efficient radiation of ultrasound and, therefore, are the most important bubble vibrations for medical diagnostic ultrasound imaging. We developed an "acoustical camera" that measures the dynamic volume change of individual microbubbles when excited by a pressure wave. In the work described here, the technique was applied to the characterization of low-amplitude non-linear behaviors of BR14 microbubbles (Bracco Research, Geneva, Switzerland). The amplitude dependence of the resonance frequency and the damping, the prevalence of efficient subharmonic and ultraharmonic vibrations and the amplitude dependence of the response at the fundamental frequency and at the second harmonic frequency were investigated. Because of the large number of measurements, we provide a statistical characterization of the low-amplitude non-linear properties of the contrast agent. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

TH-E-9A-01: Medical Physics 1.0 to 2.0, Session 4: Computed Tomography, Ultrasound and Nuclear Medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samei, E; Nelson, J; Hangiandreou, N

Medical Physics 2.0 is a bold vision for an existential transition of clinical imaging physics in face of the new realities of value-based and evidencebased medicine, comparative effectiveness, and meaningful use. It speaks to how clinical imaging physics can expand beyond traditional insular models of inspection and acceptance testing, oriented toward compliance, towards team-based models of operational engagement, prospective definition and assurance of effective use, and retrospective evaluation of clinical performance. Organized into four sessions of the AAPM, this particular session focuses on three specific modalities as outlined below. CT 2.0: CT has been undergoing a dramatic transition in themore » last few decades. While the changes in the technology merits discussions of their own, an important question is how clinical medical physicists are expected to effectively engage with the new realities of CT technology and practice. Consistent with the upcoming paradigm of Medical Physics 2.0, this CT presentation aims to provide definitions and demonstration of the components of the new clinical medical physics practice pertaining CT. The topics covered include physics metrics and analytics that aim to provide higher order clinicallyrelevant quantification of system performance as pertains to new (and not so new) technologies. That will include the new radiation and dose metrics (SSDE, organ dose, risk indices), image quality metrology (MTF/NPS/d’), task-based phantoms, and the effect of patient size. That will follow with a discussion of the testing implication of new CT hardware (detectors, tubes), acquisition methods (innovative helical geometries, AEC, wide beam CT, dual energy, inverse geometry, application specialties), and image processing and analysis (iterative reconstructions, quantitative CT, advanced renditions). The presentation will conclude with a discussion of clinical and operational aspects of Medical Physics 2.0 including training and communication, use optimization (dose and technique factors), automated analysis and data management (automated QC methods, protocol tracking, dose monitoring, issue tracking), and meaningful QC considerations. US 2.0: Ultrasound imaging is evolving at a rapid pace, adding new imaging functions and modes that continue to enhance its clinical utility and benefits to patients. The ultrasound talk will look ahead 10–15 years and consider how medical physicists can bring maximal value to the clinical ultrasound practices of the future. The roles of physics in accreditation and regulatory compliance, image quality and exam optimization, clinical innovation, and education of staff and trainees will all be considered. A detailed examination of expected technology evolution and impact on image quality metrics will be presented. Clinical implementation of comprehensive physics services will also be discussed. Nuclear Medicine 2.0: Although the basic science of nuclear imaging has remained relatively unchanged since its inception, advances in instrumentation continue to advance the field into new territories. With a great number of these advances occurring over the past decade, the role and testing strategies of clinical nuclear medicine physicists must evolve in parallel. The Nuclear Medicine 2.0 presentation is designed to highlight some of the recent advances from a clinical medical physicist perspective and provide ideas and motivation for designing better evaluation strategies. Topics include improvement of traditional physics metrics and analytics, testing implications of hybrid imaging and advanced detector technologies, and strategies for effective implementation into the clinic. Learning Objectives: Become familiar with new physics metrics and analytics in nuclear medicine, CT, and ultrasound. To become familiar with the major new developments of clinical physics support. To understand the physics testing implications of new technologies, hardware, software, and applications. Identify approaches for implementing comprehensive medical physics services in future imaging practices.« less

Ultrasound-mediated oxygen delivery from chitosan nanobubbles.

PubMed

Cavalli, Roberta; Bisazza, Agnese; Rolfo, Alessandro; Balbis, Sonia; Madonnaripa, Daniele; Caniggia, Isabella; Guiot, Caterina

2009-08-13

Ultrasound (US) energy combined with gas-filled microbubbles has been used for several years in medical imaging. This study investigated the ability of oxygen-loaded chitosan bubbles to exchange oxygen in the presence or in the absence of US. Oxygen delivery is enhanced by sonication and both frequency and time duration of US affected the exchange kinetics.

Visualizing and Measuring the Temperature Field Produced by Medical Diagnostic Ultrasound Using Thermography

ERIC Educational Resources Information Center

Vachutka, J.; Grec, P.; Mornstein, V.; Caruana, C. J.

2008-01-01

The heating of tissues by diagnostic ultrasound can pose a significant hazard particularly in the imaging of the unborn child. The demonstration of the temperature field in tissue is therefore an important objective in the teaching of biomedical physics to healthcare professionals. The temperature field in a soft tissue model was made visible and…

MO-FG-210-00: US Guided Systems for Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefitmore » from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.« less

MO-FG-210-01: Commissioning An US System for Brachytherapy: An Overview of Physics, Instrumentation, and Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Z.

Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefitmore » from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.« less

MO-FG-210-03: Intraoperative Ultrasonography-Guided Positioning of Plaque Brachytherapy in the Treatment of Choroidal Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamb, J.

2015-06-15

Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefitmore » from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.« less

An image registration based ultrasound probe calibration

NASA Astrophysics Data System (ADS)

Li, Xin; Kumar, Dinesh; Sarkar, Saradwata; Narayanan, Ram

2012-02-01

Reconstructed 3D ultrasound of prostate gland finds application in several medical areas such as image guided biopsy, therapy planning and dose delivery. In our application, we use an end-fire probe rotated about its axis to acquire a sequence of rotational slices to reconstruct 3D TRUS (Transrectal Ultrasound) image. The image acquisition system consists of an ultrasound transducer situated on a cradle directly attached to a rotational sensor. However, due to system tolerances, axis of probe does not align exactly with the designed axis of rotation resulting in artifacts in the 3D reconstructed ultrasound volume. We present a rigid registration based automatic probe calibration approach. The method uses a sequence of phantom images, each pair acquired at angular separation of 180 degrees and registers corresponding image pairs to compute the deviation from designed axis. A modified shadow removal algorithm is applied for preprocessing. An attribute vector is constructed from image intensity and a speckle-insensitive information-theoretic feature. We compare registration between the presented method and expert-corrected images in 16 prostate phantom scans. Images were acquired at multiple resolutions, and different misalignment settings from two ultrasound machines. Screenshots from 3D reconstruction are shown before and after misalignment correction. Registration parameters from automatic and manual correction were found to be in good agreement. Average absolute differences of translation and rotation between automatic and manual methods were 0.27 mm and 0.65 degree, respectively. The registration parameters also showed lower variability for automatic registration (pooled standard deviation σtranslation = 0.50 mm, σrotation = 0.52 degree) compared to the manual approach (pooled standard deviation σtranslation = 0.62 mm, σrotation = 0.78 degree).

Microbubbles induce renal hemorrhage when exposed to diagnostic ultrasound in anesthetized rats.

PubMed

Wible, James H; Galen, Karen P; Wojdyla, Jolette K; Hughes, Michael S; Klibanov, Alexander L; Brandenburger, Gary H

2002-01-01

The generation of ultrasound (US) bioeffects using a clinical imaging system is controversial. We tested the hypothesis that the presence of microbubbles in the US field of a medical imager induces biologic effects. Both kidneys of anesthetized rats were insonified for 5 min using a medical imaging system after the administration of microbubbles. One kidney was insonified using a continuous mode (30 Hz) and the opposite kidney was insonified using an intermittent (1 Hz) technique. The microbubbles were exposed to three different transducer frequencies and four transducer output powers. After insonification, the animals were euthanized, the kidneys were removed and their gross appearance scored under "blinded" conditions using a defined scale. After the administration of microbubbles, US imaging of the kidney caused hemorrhage in the renal tissue. The severity and area of hemorrhage increased with an increase in the transducer power and a decrease in the transducer frequency. Intermittent insonification in the presence of microbubbles produced a greater degree of renal hemorrhage than continuous imaging techniques.

Use of diagnostic imaging procedures and fetal monitoring devices in the care of pregnant women.

PubMed

Moore, R M; Jeng, L L; Kaczmarek, R G; Placek, P J

1990-01-01

Medical devices and diagnostic imaging procedures such as ultrasound, X-rays, and electronic fetal monitoring devices are used in the medical care of many pregnant women today. The responsibility for the safety and effectiveness of these diagnostic technologies is shared by a number of Public Health Service agencies, one of which is the Center for Devices and Radiological Health (CDRH), a unit within the Food and Drug Administration. The CDRH collaborated with the National Center for Health Statistics (NCHS) in conducting a study of recent trends in the uses of diagnostic ultrasound, medical X-rays, and electronic fetal monitoring devices in the medical care of pregnant women. This study used data from the 1980 National Natality and Fetal Mortality Surveys and the 1987 pretest to the National Maternal and Infant Health Survey. Hospitals and prenatal care providers of the pregnant women contributed information regarding the use of these medical devices. Between 1980 and 1987, ultrasound use more than doubled, increasing from 33.5 percent of pregnancies in 1980 to 78.8 percent in 1987 (P less than 0.001). More ultrasound examinations were performed earlier in gestation in 1987 than in 1980, with 10.1 percent being performed during the first trimester in 1987, compared with 6.9 percent in 1980 (P less than 0.001). Use of external electronic fetal monitoring devices during delivery also increased significantly between 1980 and 1987, from 33.5 percent to 74.6 percent (P less than 0.001). Use of medical X-rays among women with live births remained relatively unchanged, 15.0 percent in 1980 and 15.3 percent in 1987 (P = .282). The implications of these trends are discussed.

Automatic Robotic Steering of Flexible Needles from 3D Ultrasound Images in Phantoms and Ex Vivo Biological Tissue.

PubMed

Mignon, Paul; Poignet, Philippe; Troccaz, Jocelyne

2018-05-29

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. Since ultrasound-based automatic needle steering is often made difficult by the needle localization in biological tissue, we quantify the benefit of using flexible echogenic needles for robotized guidance under 3D ultrasound. The "echogenic" term refers to the etching of microstructures on the needle shaft. We prove that these structures improve needle visibility and detection robustness in ultrasound images. We finally present promising results when reaching targets using needle steering. The experiments were conducted with various needles in different media (synthetic phantoms and ex vivo biological tissue). For instance, with nitinol needles the mean accuracy is 1.2 mm (respectively 3.8 mm) in phantoms (resp. biological tissue).

Developing the Clinical Psychomotor Skills of Musculoskeletal Sonography Using a Multimedia DVD: A Pilot Study

ERIC Educational Resources Information Center

Thoirs, Kerry; Coffee, Jane

2012-01-01

Sonographers are medical or non-medical health professionals in the radiology field who skilfully manipulate ultrasound equipment to produce images that are used to diagnose medical conditions and abnormalities. This technique is also becoming popular amongst the wider community in other medical specialities and allied health professionals, due to…

Counter-propagating wave interaction for contrast-enhanced ultrasound imaging

NASA Astrophysics Data System (ADS)

Renaud, G.; Bosch, J. G.; ten Kate, G. L.; Shamdasani, V.; Entrekin, R.; de Jong, N.; van der Steen, A. F. W.

2012-11-01

Most techniques for contrast-enhanced ultrasound imaging require linear propagation to detect nonlinear scattering of contrast agent microbubbles. Waveform distortion due to nonlinear propagation impairs their ability to distinguish microbubbles from tissue. As a result, tissue can be misclassified as microbubbles, and contrast agent concentration can be overestimated; therefore, these artifacts can significantly impair the quality of medical diagnoses. Contrary to biological tissue, lipid-coated gas microbubbles used as a contrast agent allow the interaction of two acoustic waves propagating in opposite directions (counter-propagation). Based on that principle, we describe a strategy to detect microbubbles that is free from nonlinear propagation artifacts. In vitro images were acquired with an ultrasound scanner in a phantom of tissue-mimicking material with a cavity containing a contrast agent. Unlike the default mode of the scanner using amplitude modulation to detect microbubbles, the pulse sequence exploiting counter-propagating wave interaction creates no pseudoenhancement behind the cavity in the contrast image.

Cost-effectiveness of sialendoscopy versus medical management for radioiodine-induced sialadenitis.

PubMed

Kowalczyk, David M; Jordan, J Randall; Stringer, Scott P

2018-03-30

The medical management and radiographic identification of radioiodine-induced sialadenitis (RAIS) is challenging. This study utilizes a cost-effectiveness analysis to compare upfront sialendoscopy as both a diagnostic and therapeutic option versus multiple modalities of diagnostic radiography along with medical management. Literature review and cost-effectiveness analysis. A literature review was performed to identify the outcomes of medical management, sialendoscopy, diagnostic radiography, and surgical complications. All charges were obtained from the University of Mississippi Budget Office in 2017 US dollars and converted to costs using the 2017 Medicare Cost-to-Charge Ratio for urban medical centers. A cost-effectiveness analysis was used to evaluate the four treatment arms-sialendoscopy, medical management- ultrasound, medical management-computed tomography (CT) sialography, and medical management-magnetic resonance (MR) sialography. Sensitivity analyses were used to evaluate the confidence levels of the economic evaluation. The incremental cost-effectiveness ratio for upfront sialendoscopy versus medical management-ultrasound was $30,402.30, which demonstrates that sialendoscopy is the more cost-effective option given a willingness-to-pay threshold of $50,000. The probability that this decision is correct at a willingness-to-pay of $50,000 is 64.5%. Sialendoscopic improvement was the most sensitive variable requiring a threshold of 0.70. Of the three imaging modalities, ultrasound dominated MR and CT sialography, both of which required a willingness-to-pay of greater than $90,000 to realize a difference. Upfront sialendoscopy is more cost-effective compared to medical management utilizing diagnostic ultrasound assuming a willingness-to-pay threshold of $50,000. There is a clear cost-effectiveness to using ultrasound with medical management over CT and MR sialography in the diagnosis and management of RAIS. NA. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

How 3D immersive visualization is changing medical diagnostics

NASA Astrophysics Data System (ADS)

Koning, Anton H. J.

2011-03-01

Originally the only way to look inside the human body without opening it up was by means of two dimensional (2D) images obtained using X-ray equipment. The fact that human anatomy is inherently three dimensional leads to ambiguities in interpretation and problems of occlusion. Three dimensional (3D) imaging modalities such as CT, MRI and 3D ultrasound remove these drawbacks and are now part of routine medical care. While most hospitals 'have gone digital', meaning that the images are no longer printed on film, they are still being viewed on 2D screens. However, this way valuable depth information is lost, and some interactions become unnecessarily complex or even unfeasible. Using a virtual reality (VR) system to present volumetric data means that depth information is presented to the viewer and 3D interaction is made possible. At the Erasmus MC we have developed V-Scope, an immersive volume visualization system for visualizing a variety of (bio-)medical volumetric datasets, ranging from 3D ultrasound, via CT and MRI, to confocal microscopy, OPT and 3D electron-microscopy data. In this talk we will address the advantages of such a system for both medical diagnostics as well as for (bio)medical research.

The Physics of Physical Examinations.

ERIC Educational Resources Information Center

Patterson, James D.

1989-01-01

Discussed are several topics on medical imaging including x-rays and Computer Assisted Tomography (CAT) scans, magnetic resonance imaging, fiber optics endoscopy, nuclear medicine and bone scans, positron-emission tomography, and ultrasound. The concepts of radiation dosage, electrocardiograms, and laser therapy are included. (YP)

Digital management and regulatory submission of medical images from clinical trials: role and benefits of the core laboratory

NASA Astrophysics Data System (ADS)

Robbins, William L.; Conklin, James J.

1995-10-01

Medical images (angiography, CT, MRI, nuclear medicine, ultrasound, x ray) play an increasingly important role in the clinical development and regulatory review process for pharmaceuticals and medical devices. Since medical images are increasingly acquired and archived digitally, or are readily digitized from film, they can be visualized, processed and analyzed in a variety of ways using digital image processing and display technology. Moreover, with image-based data management and data visualization tools, medical images can be electronically organized and submitted to the U.S. Food and Drug Administration (FDA) for review. The collection, processing, analysis, archival, and submission of medical images in a digital format versus an analog (film-based) format presents both challenges and opportunities for the clinical and regulatory information management specialist. The medical imaging 'core laboratory' is an important resource for clinical trials and regulatory submissions involving medical imaging data. Use of digital imaging technology within a core laboratory can increase efficiency and decrease overall costs in the image data management and regulatory review process.

CISUS: an integrated 3D ultrasound system for IGT using a modular tracking API

NASA Astrophysics Data System (ADS)

Boctor, Emad M.; Viswanathan, Anand; Pieper, Steve; Choti, Michael A.; Taylor, Russell H.; Kikinis, Ron; Fichtinger, Gabor

2004-05-01

Ultrasound has become popular in clinical/surgical applications, both as the primary image guidance modality and also in conjunction with other modalities like CT or MRI. Three dimensional ultrasound (3DUS) systems have also demonstrated usefulness in image-guided therapy (IGT). At the same time, however, current lack of open-source and open-architecture multi-modal medical visualization systems prevents 3DUS from fulfilling its potential. Several stand-alone 3DUS systems, like Stradx or In-Vivo exist today. Although these systems have been found to be useful in real clinical setting, it is difficult to augment their functionality and integrate them in versatile IGT systems. To address these limitations, a robotic/freehand 3DUS open environment (CISUS) is being integrated into the 3D Slicer, an open-source research tool developed for medical image analysis and surgical planning. In addition, the system capitalizes on generic application programming interfaces (APIs) for tracking devices and robotic control. The resulting platform-independent open-source system may serve as a valuable tool to the image guided surgery community. Other researchers could straightforwardly integrate the generic CISUS system along with other functionalities (i.e. dual view visualization, registration, real-time tracking, segmentation, etc) to rapidly create their medical/surgical applications. Our current driving clinical application is robotically assisted and freehand 3DUS-guided liver ablation, which is fully being integrated under the CISUS-3D Slicer. Initial functionality and pre-clinical feasibility are demonstrated on phantom and ex-vivo animal models.

Application of Ultrasound Energy as a New Drug Delivery System

NASA Astrophysics Data System (ADS)

Tachibana, Katsuro; Tachibana, Shunro

1999-05-01

Ultrasound has been in use for the last three decades as amodality for diagnostic imaging in medicine. Recently, there have beennumerous reports on the application of nonthermal ultrasound energyfor targeting or controlling drug release. This new concept oftherapeutic ultrasound combined with drugs has led to much excitementin various medical fields. Ultrasound energy can enhance the effectsof thrombolytic agents such as urokinase. Therapeutic ultrasoundcatheters are currently being developed for treatment ofcardiovascular diseases. Devices with ultrasound transducers implantedin transdermal drug patches are also being evaluated for possibledelivery of insulin through the skin. Chemical activation of drugs byultrasound energy for treatment of cancers is another new fieldrecently termed “Sonodynamic Therapy”. Various examples of ultrasoundapplication are under investigation which could lead to revolutionarydrug delivery systems in the future.

Point-of-Care Ultrasound: A Trend in Health Care.

PubMed

Buerger, Anita M; Clark, Kevin R

2017-11-01

To discuss the current and growing use of point-of-care (POC) ultrasound in the management and care of patients. Several electronic research databases were searched to find articles that emphasized the use of POC ultrasound by health care providers who manage and treat critically ill or injured patients. Thirty-five relevant peer-reviewed journal articles were selected for this literature review. Common themes identified in the literature included the use of POC ultrasound in emergency medicine, military medicine, and remote care; comparison of POC ultrasound to other medical imaging modalities; investigation of the education and training required for nonimaging health care professionals who perform POC ultrasound in their practices; and discussion of the financial implications and limitations of POC ultrasound. POC ultrasound provides clinicians with real-time information to better manage and treat critically ill or injured patients in emergency medicine, military medicine, and remote care. In addition to providing immediate bedside diagnostic information, use of POC ultrasound has increased because of concerns regarding radiation protection. Finally, the expansion of POC ultrasound to other specialty areas requires nonimaging health care professionals to perform bedside ultrasound examinations and interpret the resulting images. Because POC ultrasound is user-dependent, adequate training is essential for all who perform and interpret the examinations. Research involving POC ultrasound will continue as innovations and confidence in ultrasound applications advance. Future research should continue to examine the broad use of POC ultrasound in patient care and management. ©2017 American Society of Radiologic Technologists.

[Present status and trend of heart fluid mechanics research based on medical image analysis].

PubMed

Gan, Jianhong; Yin, Lixue; Xie, Shenghua; Li, Wenhua; Lu, Jing; Luo, Anguo

2014-06-01

With introduction of current main methods for heart fluid mechanics researches, we studied the characteristics and weakness for three primary analysis methods based on magnetic resonance imaging, color Doppler ultrasound and grayscale ultrasound image, respectively. It is pointed out that particle image velocity (PIV), speckle tracking and block match have the same nature, and three algorithms all adopt block correlation. The further analysis shows that, with the development of information technology and sensor, the research for cardiac function and fluid mechanics will focus on energy transfer process of heart fluid, characteristics of Chamber wall related to blood fluid and Fluid-structure interaction in the future heart fluid mechanics fields.

Ultrasonic computed tomography imaging of iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Perlman, Or; Azhari, Haim

2017-02-01

Iron oxide nanoparticles (IONPs) are becoming increasingly used and intensively investigated in the field of medical imaging. They are currently FDA approved for magnetic resonance imaging (MRI), and it would be highly desirable to visualize them by ultrasound as well. Previous reports using the conventional ultrasound B-scan (pulse-echo) imaging technique have shown very limited detectability of these particles. The aim of this study is to explore the feasibility of imaging IONPs using the through-transmission ultrasound methodology and demonstrate their detectability using ultrasonic computed tomography (UCT). Commercially available IONPs were acoustically analysed to quantify their effect on the speed of sound (SOS) and acoustic attenuation as a function of concentration. Next, through-transmission projection and UCT imaging were performed on a breast mimicking phantom and on an ex vivo tissue model, to which IONPs were injected. Finally, an MRI scan was performed to verify that the same particles examined in the ultrasound experiment can be imaged by magnetic resonance, using the same clinically relevant concentrations. The results have shown a consistent concentration dependent speed of sound increase (1.86 \\text{m}{{\\text{s}}^{-1}} rise per 100 µg · ml-1 IONPs). Imaging based on this property has shown a substantial contrast-to-noise ratio improvement (up to 5 fold, p  <  0.01). The SOS-related effect generated a well discernible image contrast and allowed the detection of the particles existence and location, in both raster-scan projection and UCT imaging. Conversely, no significant change in the acoustic attenuation coefficient was noted. Based on these findings, it is concluded that IONPs can be used as an effective SOS-based contrast agent, potentially useful for ultrasonic breast imaging. Furthermore, the particle offers the capacity of significantly enhancing diagnosis accuracy using multimodal MRI-ultrasound imaging capabilities.

Improved Image-Guided Laparoscopic Prostatectomy

DTIC Science & Technology

2011-08-01

standard daVinci tool . The ultrasound probe is driven by a Sonix RP ultrasound system (Ultrasonix Medical Corp., Richmond BC Canada), which provides...probe (Intuitive Surgical, Sunnyvale, CA) was integrated with the daVinci surgical system for use in Robot-Assisted Laparoscopic Prostatectomy (RALP...laparoscopy using the daVinci Surgical System (Intuitive Surgical, Sunnyvale, CA). The surgical robot introduces many benefits, including three

Validation of Ultrasound Imaging to Rule-out Thoracic Trauma on the International Space Station

NASA Technical Reports Server (NTRS)

Hamilton, Douglas R.; Sargsyan, Ashot E.; Melton, Shannon; Martin, David; Dulchavsky, Scott A.

2006-01-01

Introduction: Aboard the International Space Station (ISS) an intra-thoracic injury may be disastrous to the crew member if the diagnosis is missed or even delayed. Pneumothorax and hemothorax commonly seen in trauma patients; the diagnosis is usually confirmed by chest X-ray or computed tomography. In this study, the ability of ultrasound to rule out pneumothorax by the presence "lung sliding" and hemothorax by the absence of pleural fluid was validated. Methods: The research activities were approved by the NASA Johnson Space Center Committee for the Protection of Human Subjects, and the participating crewmembers signed informed consent prior to the activity. ISS crewmembers received 2-hours of "hands on" ultrasound training 8 months prior to the on-orbit ultrasound exam. Baseline ultrasound images of the thorax were acquired on the crewmebers of Increment 8 and 9 prior to launch from Bakonur, Russia. Ultrasound examination of the thorax were performed on crewmembers at 30 day intervals (n=??) throughout their flight. Post flight images were acquired on or about landing day 10. Ultrasound images were acquired using the ISS Health Research Facility ultrasound system and examined by experts on the ground to rule out the presence of pneumothorax and hemothorax. Results: The presence of "lung sliding" which excludes pneumothorax, was seen in all subjects. The absence of pleural fluid, which excludes hemothorax was seen in all subjects. The optimal position between sonographer and patient under microgravity conditions and the amount and type of training for a non-physician crew medical officer for these procedures was also established for this procedure. Conclusion: Ultrasound can be performed on orbit under microgravity condition to rule thoracic trauma, such as pneumothorax and hemothorax.

Automatic finger joint synovitis localization in ultrasound images

NASA Astrophysics Data System (ADS)

Nurzynska, Karolina; Smolka, Bogdan

2016-04-01

A long-lasting inflammation of joints results between others in many arthritis diseases. When not cured, it may influence other organs and general patients' health. Therefore, early detection and running proper medical treatment are of big value. The patients' organs are scanned with high frequency acoustic waves, which enable visualization of interior body structures through an ultrasound sonography (USG) image. However, the procedure is standardized, different projections result in a variety of possible data, which should be analyzed in short period of time by a physician, who is using medical atlases as a guidance. This work introduces an efficient framework based on statistical approach to the finger joint USG image, which enables automatic localization of skin and bone regions, which are then used for localization of the finger joint synovitis area. The processing pipeline realizes the task in real-time and proves high accuracy when compared to annotation prepared by the expert.

Temperature imaging with speed of ultrasonic transmission tomography for medical treatment control: A physical model-based method

NASA Astrophysics Data System (ADS)

Chu, Zhe-Qi; Yuan, Jie; Stephen, Z. Pinter; Oliver, D. Kripfgans; Wang, Xue-Ding; Paul, L. Carson; Liu, Xiao-Jun

2015-10-01

Hyperthermia is a promising method to enhance chemo and radiation therapy of breast cancer. In the process of hyperthermia, temperature monitoring is of great importance to assure the effectiveness of treatment. The transmission speed of ultrasound in biomedical tissue changes with temperature. However, when mapping the speed of sound directly to temperature in each pixel as desired for using all speeds of ultrasound data, temperature bipolar edge enhancement artifacts occur near the boundary of two tissues with different speeds of ultrasound. After the analysis of the reasons for causing these artifacts, an optimized method is introduced to rebuild the temperature field image by using the continuity constraint as the judgment criterion. The significant smoothness of the rebuilding image in the transitional area shows that our proposed method can build a more precise temperature image for controlling the medical thermal treatment. Project supported in part by DoD/BCRP Idea Award, BC095397P1, the National Natural Science Foundation of China (Grant No. 61201425), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20131280), the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions, China, and the National Institutes of Health (NIH) of United States (Grant Nos. R01AR060350, R01CA91713, and R01AR055179).

Two-dimensional airborne ultrasound real-time linear array scanner--applied to screening for scoliosis.

PubMed

Mauritzson, L; Ilver, J; Benoni, G; Lindström, K; Willner, S

1991-01-01

Diagnostic ultrasound is an established, noninvasive and harmless method for imaging the shape and appearance of organs and other tissues inside the body, and it has been used in many clinical applications for more than three decades. We have now applied some of this well-known technique together with the use of airborne ultrasound in medical applications, to build an equipment for anthropometrical investigation outside the body, e.g., measuring and registration of the shape and form of the human back. This is mostly done for screening purposes of young people in an attempt to find patients developing scoliosis, and in order to circumvent some of the disadvantages with the traditional screening method in this field of medical application.

Survey of ultrasound practice amongst podiatrists in the UK.

PubMed

Siddle, Heidi J; Patience, Aimie; Coughtrey, James; Mooney, Jean; Fox, Martin; Cherry, Lindsey

2018-01-01

Ultrasound in podiatry practice encompasses musculoskeletal ultrasound imaging, vascular hand-held Doppler ultrasound and therapeutic ultrasound. Sonography practice is not regulated by the Health and Care Professions Council (HCPC), with no requirement to hold a formal qualification. The College of Podiatry does not currently define ultrasound training and competencies.This study aimed to determine the current use of ultrasound, training received and mentorship received and/or provided by podiatrists using ultrasound. A quantitative study utilising a cross-sectional, on-line, single-event survey was undertaken within the UK. Completed surveys were received from 284 podiatrists; 173 (70%) use ultrasound as part of their general practice, 139 (49%) for musculoskeletal problems, 131 (46%) for vascular assessment and 39 (14%) to support their surgical practice. Almost a quarter ( n  = 62) worked for more than one organisation; 202 (71%) were employed by the NHS and/or private sector ( n  = 118, 41%).Nearly all (93%) respondents report using a hand-held vascular Doppler in their daily practice; 216 (82%) to support decisions regarding treatment options, 102 (39%) to provide diagnostic reports for other health professionals, and 34 (13%) to guide nerve blocks.Ultrasound imaging was used by 104 (37%) respondents primarily to aid clinical decision making ( n  = 81) and guide interventions (steroid injections n  = 67; nerve blocks n  = 39). Ninety-three percent stated they use ultrasound imaging to treat their own patients, while others scan at the request of other podiatrists ( n  = 28) or health professionals ( n  = 18). Few use ultrasound imaging for research ( n  = 7) or education ( n  = 2).Only 32 (11%) respondents ( n  = 20 private sector) use therapeutic ultrasound to treat patients presenting with musculoskeletal complaints, namely tendon pathologies.Few respondents (18%) had completed formal post-graduate CASE (Consortium for the Accreditation of Sonographic Education) accredited ultrasound courses.Forty (14%) respondents receive ultrasound mentorship; the majority from fellow podiatrists ( n  = 17) or medical colleagues ( n  = 15). Over half ( n  = 127) who do not have ultrasound mentorship indicated they would like a mentor predominantly for ultrasound imaging. Fifty-five (19%) report they currently provide ultrasound mentorship for others. Understanding the scope of ultrasound practice, the training undertaken and the requirements for mentorship will underpin the development of competencies and recommendations defined by the College of Podiatry to support professional development and ensure safe practice.

Fast integrated intravascular photoacoustic/ultrasound catheter

NASA Astrophysics Data System (ADS)

Choi, Changhoon; Cho, Seunghee; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Jang, Kiyuk; Kim, Chulhong

2016-03-01

In cardiology, a vulnerable plaque is considered to be a key subject because it is strongly related to atherosclerosis and acute myocardial infarction. Because conventional intravascular imaging devices exhibit several limitations with regard to vulnerable plaque detection, the need for an effective lipid imaging modality has been continuously suggested. Photoacoustic (PA) imaging is a medical imaging technique with a high level of ultrasound (US) resolution and strong optical contrast. In this study, we successfully developed an integrated intravascular photoacoustic/ultrasound (IV-PAUS) imaging system with a catheter diameter of 1.2 mm for lipid-rich atherosclerosis imaging. An Nd:YAG pulsed laser with an excitation wavelength of 1064 nm was utilized. IV-PAUS offers 5-mm depth penetration and axial and lateral PA imaging resolutions of 94 μm and 203 μm, respectively, as determined by imaging a 6-μm carbon fiber. We initially obtained 3-dimensional (3D) co-registered PA/US images of metal stents. Subsequently, we successfully obtained 3D coregistered PA/US ex vivo images using an iliac artery from a rabbit atherosclerosis model. Accordingly, lipid-rich plaques were sufficiently differentiated from normal tissue in the ex vivo experiment. We validated these findings histologically to confirm the lipid content.

Medical image processing on the GPU - past, present and future.

PubMed

Eklund, Anders; Dufort, Paul; Forsberg, Daniel; LaConte, Stephen M

2013-12-01

Graphics processing units (GPUs) are used today in a wide range of applications, mainly because they can dramatically accelerate parallel computing, are affordable and energy efficient. In the field of medical imaging, GPUs are in some cases crucial for enabling practical use of computationally demanding algorithms. This review presents the past and present work on GPU accelerated medical image processing, and is meant to serve as an overview and introduction to existing GPU implementations. The review covers GPU acceleration of basic image processing operations (filtering, interpolation, histogram estimation and distance transforms), the most commonly used algorithms in medical imaging (image registration, image segmentation and image denoising) and algorithms that are specific to individual modalities (CT, PET, SPECT, MRI, fMRI, DTI, ultrasound, optical imaging and microscopy). The review ends by highlighting some future possibilities and challenges. Copyright © 2013 Elsevier B.V. All rights reserved.

The Utility of Teleultrasound to Guide Acute Patient Management.

PubMed

Becker, Christian; Fusaro, Mario; Patel, Dhruv; Shalom, Isaac; Frishman, William H; Scurlock, Corey

Ultrasound has evolved into a core bedside tool for diagnostic and management purposes for all subsets of adult and pediatric critically-ill patients. Teleintensive care unit coverage has undergone a similar rapid expansion period throughout the United States. Round-the-clock access to ultrasound equipment is very common in today's intensive care unit, but 24/7 coverage with staff trained to acquire and interpret point-of-care ultrasound in real time is lagging behind equipment availability. Medical trainees and physician extenders require attending level supervision to ensure consistent image acquisition and accurate interpretation. Teleintensivists can extend the utility of ultrasound by supervising and guiding providers without or with only partial training in ultrasound, and also by extending direct trainee ultrasound supervision to time periods when no direct bedside attending supervisor is available, and when treatment decisions otherwise would have been made without supervision and feedback on image acquisition and interpretation. Nursing staff without ultrasound training can also be directed to perform basic ultrasound exams, which may have immediate diagnostic and/or treatment consequences, thereby overcoming access barriers in the absence of physicians or physician extenders. We discuss 4 real-life clinical scenarios in which teleintensivist supervision extended and standardized bedside ultrasound exams to guide management decisions which significantly impacted patient outcomes.

Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance

PubMed Central

Mela, Christopher A.; Patterson, Carrie; Thompson, William K.; Papay, Francis; Liu, Yang

2015-01-01

We have developed novel stereoscopic wearable multimodal intraoperative imaging and display systems entitled Integrated Imaging Goggles for guiding surgeries. The prototype systems offer real time stereoscopic fluorescence imaging and color reflectance imaging capacity, along with in vivo handheld microscopy and ultrasound imaging. With the Integrated Imaging Goggle, both wide-field fluorescence imaging and in vivo microscopy are provided. The real time ultrasound images can also be presented in the goggle display. Furthermore, real time goggle-to-goggle stereoscopic video sharing is demonstrated, which can greatly facilitate telemedicine. In this paper, the prototype systems are described, characterized and tested in surgeries in biological tissues ex vivo. We have found that the system can detect fluorescent targets with as low as 60 nM indocyanine green and can resolve structures down to 0.25 mm with large FOV stereoscopic imaging. The system has successfully guided simulated cancer surgeries in chicken. The Integrated Imaging Goggle is novel in 4 aspects: it is (a) the first wearable stereoscopic wide-field intraoperative fluorescence imaging and display system, (b) the first wearable system offering both large FOV and microscopic imaging simultaneously, (c) the first wearable system that offers both ultrasound imaging and fluorescence imaging capacities, and (d) the first demonstration of goggle-to-goggle communication to share stereoscopic views for medical guidance. PMID:26529249

Renal denervation by intravascular ultrasound: Preliminary in vivo study

NASA Astrophysics Data System (ADS)

Sinelnikov, Yegor; McClain, Steve; Zou, Yong; Smith, David; Warnking, Reinhard

2012-10-01

Ultrasound denervation has recently become a subject of intense research in connection with the treatment of complex medical conditions including neurological conditions, development of pain management, reproduction of skin sensation, neuropathic pain and spasticity. The objective of this study is to investigate the use of intravascular ultrasound to produce nerve damage in renal sympathetic nerves without significant injury to the renal artery. This technique may potentially be used to treat various medical conditions, such as hypertension. The study was approved by the Institutional Animal Care and Use Committee. Ultrasound was applied to renal nerves of the swine model for histopathological evaluation. Therapeutic ultrasound energy was delivered circumferentially by an intravascular catheter maneuvered into the renal arteries. Fluoroscopic imaging was conducted pre-and post-ultrasound treatment. Animals were recovered and euthanized up to 30 hours post procedure, followed by necropsy and tissue sample collection. Histopathological examination showed evidence of extensive damage to renal nerves, characterized by nuclear pyknosis, hyalinization of stroma and multifocal hemorrhages, with little or no damage to renal arteries. This study demonstrates the feasibility of intravascular ultrasound as a minimally invasive renal denervation technique. Further studies are necessary to evaluate the long-term safety and efficacy of this technique and its related clinical significance.

Photo acoustic imaging: technology, systems and market trends

NASA Astrophysics Data System (ADS)

Faucheux, Marc; d'Humières, Benoît; Cochard, Jacques

2017-03-01

Although the Photo Acoustic effect was observed by Graham Bell in 1880, the first applications (gas analysis) occurred in 1970's using the required energetic light pulses from lasers. During mid 1990's medical imaging research begun to use Photo Acoustic effect and in vivo images were obtained in mid-2000. Since 2009, the number of patent related to Photo Acoustic Imaging (PAI) has dramatically increased. PAI machines for pre-clinical and small animal imaging have been being used in a routine way for several years. Based on its very interesting features (non-ionizing radiation, noninvasive, high depth resolution ratio, scalability, moderate price) and because it is able to deliver not only anatomical, but functional and molecular information, PAI is a very promising clinical imaging modality. It penetrates deeper into tissue than OCT (Optical Coherence Tomography) and provides a higher resolution than ultrasounds. The PAI is one of the most growing imaging modality and some innovative clinical systems are planned to be on market in 2017. Our study analyzes the different approaches such as photoacoustic computed tomography, 3D photoacoustic microscopy, multispectral photoacoustic tomography and endoscopy with the recent and tremendous technological progress over the past decade: advances in image reconstruction algorithms, laser technology, ultrasound detectors and miniaturization. We analyze which medical domains and applications are the most concerned and explain what should be the forthcoming medical system in the near future. We segment the market in four parts: Components and R&D, pre-clinical, analytics, clinical. We analyzed what should be, quantitatively and qualitatively, the PAI medical markets in each segment and its main trends. We point out the market accessibility (patents, regulations, clinical evaluations, clinical acceptance, funding). In conclusion, we explain the main market drivers and challenges to overcome and give a road map for medical approved PAI products.

Ultrasonography in lung pathologies: new perspectives.

PubMed

Demi, Libertario; Demi, Marcello; Smargiassi, Andrea; Inchingolo, Riccardo; Faita, Francesco; Soldati, Gino

2014-01-01

Nowadays, ultrasound techniques have not gained importance in the diagnosis and monitoring of lung pathologies yet because of the high mismatch in acoustic impedance between air and intercostal tissues. However, it is evident that B-mode imaging provides important information on pulmonary tissue, although in the form of image artifacts. Notwithstanding medical evidences, there exists no ultrasound-based method dedicated to the lung, hampering de facto the full exploitation of ultrasound potentials. A chance is given by the experience acquired in other fields, where acoustic attenuation is used to estimate concentrations of suspended particles in liquids and of air-bubbles in aerated foods. Custom hardware must be developed since commercial echographic equipment has been optimized to work with low acoustic impedance mismatches, and, in general, does not provide the primitive radiofrequency (RF) signals nor the possibility to tune key acquisition parameters such as ultrasound carrier frequency and pulse bandwidth, which are surely needed for our application.

Ultrasonography in lung pathologies: new perspectives

PubMed Central

2014-01-01

Background Nowadays, ultrasound techniques have not gained importance in the diagnosis and monitoring of lung pathologies yet because of the high mismatch in acoustic impedance between air and intercostal tissues. However, it is evident that B-mode imaging provides important information on pulmonary tissue, although in the form of image artifacts. Findings Notwithstanding medical evidences, there exists no ultrasound-based method dedicated to the lung, hampering de facto the full exploitation of ultrasound potentials. A chance is given by the experience acquired in other fields, where acoustic attenuation is used to estimate concentrations of suspended particles in liquids and of air-bubbles in aerated foods. Conclusions Custom hardware must be developed since commercial echographic equipment has been optimized to work with low acoustic impedance mismatches, and, in general, does not provide the primitive radiofrequency (RF) signals nor the possibility to tune key acquisition parameters such as ultrasound carrier frequency and pulse bandwidth, which are surely needed for our application. PMID:24834347

Stable phantom materials for ultrasound and optical imaging.

PubMed

Cabrelli, Luciana C; Pelissari, Pedro I B G B; Deana, Alessandro M; Carneiro, Antonio A O; Pavan, Theo Z

2017-01-21

Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

Stable phantom materials for ultrasound and optical imaging

NASA Astrophysics Data System (ADS)

Cabrelli, Luciana C.; Pelissari, Pedro I. B. G. B.; Deana, Alessandro M.; Carneiro, Antonio A. O.; Pavan, Theo Z.

2017-01-01

Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

Ultrasound imaging using all-optical power and signal transfer in catheters (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pekar, Martin; van der Mark, Martin B.

2017-02-01

Smart medical catheters face a connectivity challenge. An example is found in ultrasound imaging where the supply of power at the distal end and the signal transmission requires many thin and fragile wires in order to keep the catheter thin and flexible and this leads to a relatively high cost of production. We have built a fully functional benchtop demonstrator that is immediately scalable to catheter dimensions, in which all electrical wires are replaced by just two optical fibers. We show signal transfer of synthetic aperture ultrasound images as well as photovoltaic conversion to supply all electronics. The absence of conductors provides excellent galvanic isolation as well as RF and MRI compatibility and the simple design utilizing off the shelf components holds a promise of cost effectiveness all of which may help translation of these advanced devices into the clinic. We show photovoltaic conversion of 405 nm light to 45 V and 1.8 V by two blue LEDs as well as 200 MHz broad-band signal transfer using modulated 850 nm VCSEL light. Synthetic aperture ultrasound images are acquired at a frequency of 12 MHz with a collapse-mode capacitive-micromachined ultrasonic transducer. Bandwidth, noise level and dynamic range are nearly identical as shown in comparison of the images acquired with the optical link and its electrical equivalent. In conclusion, we have successfully demonstrated low-cost and scalable optical signal and power transmission for an ultrasound imaging system enjoying intrinsic RF / MRI compatibility and galvanic isolation.

A Novel Segmentation Approach Combining Region- and Edge-Based Information for Ultrasound Images

PubMed Central

Luo, Yaozhong; Liu, Longzhong; Li, Xuelong

2017-01-01

Ultrasound imaging has become one of the most popular medical imaging modalities with numerous diagnostic applications. However, ultrasound (US) image segmentation, which is the essential process for further analysis, is a challenging task due to the poor image quality. In this paper, we propose a new segmentation scheme to combine both region- and edge-based information into the robust graph-based (RGB) segmentation method. The only interaction required is to select two diagonal points to determine a region of interest (ROI) on the original image. The ROI image is smoothed by a bilateral filter and then contrast-enhanced by histogram equalization. Then, the enhanced image is filtered by pyramid mean shift to improve homogeneity. With the optimization of particle swarm optimization (PSO) algorithm, the RGB segmentation method is performed to segment the filtered image. The segmentation results of our method have been compared with the corresponding results obtained by three existing approaches, and four metrics have been used to measure the segmentation performance. The experimental results show that the method achieves the best overall performance and gets the lowest ARE (10.77%), the second highest TPVF (85.34%), and the second lowest FPVF (4.48%). PMID:28536703

Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy

NASA Astrophysics Data System (ADS)

Hynynen, Kullervo; Jones, Ryan M.

2016-09-01

Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy.

Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy.

PubMed

Hynynen, Kullervo; Jones, Ryan M

2016-09-07

Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy.

Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy

PubMed Central

Hynynen, Kullervo; Jones, Ryan M.

2016-01-01

Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy. PMID:27494561

Coded excitation ultrasonic needle tracking: An in vivo study.

PubMed

Xia, Wenfeng; Ginsberg, Yuval; West, Simeon J; Nikitichev, Daniil I; Ourselin, Sebastien; David, Anna L; Desjardins, Adrien E

2016-07-01

Accurate and efficient guidance of medical devices to procedural targets lies at the heart of interventional procedures. Ultrasound imaging is commonly used for device guidance, but determining the location of the device tip can be challenging. Various methods have been proposed to track medical devices during ultrasound-guided procedures, but widespread clinical adoption has remained elusive. With ultrasonic tracking, the location of a medical device is determined by ultrasonic communication between the ultrasound imaging probe and a transducer integrated into the medical device. The signal-to-noise ratio (SNR) of the transducer data is an important determinant of the depth in tissue at which tracking can be performed. In this paper, the authors present a new generation of ultrasonic tracking in which coded excitation is used to improve the SNR without spatial averaging. A fiber optic hydrophone was integrated into the cannula of a 20 gauge insertion needle. This transducer received transmissions from the ultrasound imaging probe, and the data were processed to obtain a tracking image of the needle tip. Excitation using Barker or Golay codes was performed to improve the SNR, and conventional bipolar excitation was performed for comparison. The performance of the coded excitation ultrasonic tracking system was evaluated in an in vivo ovine model with insertions to the brachial plexus and the uterine cavity. Coded excitation significantly increased the SNRs of the tracking images, as compared with bipolar excitation. During an insertion to the brachial plexus, the SNR was increased by factors of 3.5 for Barker coding and 7.1 for Golay coding. During insertions into the uterine cavity, these factors ranged from 2.9 to 4.2 for Barker coding and 5.4 to 8.5 for Golay coding. The maximum SNR was 670, which was obtained with Golay coding during needle withdrawal from the brachial plexus. Range sidelobe artifacts were observed in tracking images obtained with Barker coded excitation, and they were visually absent with Golay coded excitation. The spatial tracking accuracy was unaffected by coded excitation. Coded excitation is a viable method for improving the SNR in ultrasonic tracking without compromising spatial accuracy. This method provided SNR increases that are consistent with theoretical expectations, even in the presence of physiological motion. With the ultrasonic tracking system in this study, the SNR increases will have direct clinical implications in a broad range of interventional procedures by improving visibility of medical devices at large depths.

Steering Microbubbles in Physiologically Realistic Flows Using the Bjerknes Force

NASA Astrophysics Data System (ADS)

Clark, Alicia; Aliseda, Alberto

2017-11-01

Ultrasound contrast agents (UCAs) are lipid-coated microbubbles that are used to increase contrast in ultrasound imaging due to their ability to scatter sound. Additionally, UCAs can be used in conjunction with ultrasound in medical applications such as targeted drug delivery and thrombolysis. These applications utilize the Bjerknes force, an ultrasound-induced force caused by the phase difference between the incoming ultrasound pressure wave and the microbubble volume oscillations. The dynamics of microbubbles under ultrasound excitation have been studied thoroughly in stagnant fluid baths; however, understanding of the fundamental physics of microbubbles in physiologically realistic flows is lacking. An in vitroexperiment that reproduces the dynamics (Reynolds and Womersley numbers) of a medium-sized blood vessel was used to explore the behavior of microbubbles. Using Lagrangian tracking, the trajectory of each individual bubble was reconstructed using information obtained from high speed imaging. The balance of hydrodynamic forces (lift, drag, added mass, etc.) against the primary Bjerknes force was analyzed. The results show that an increase in ultrasound pulse repetition frequency leads to a linear increase in the Bjerknes force and the increase in the force is quadratic with the amplitude of the excitation.

3D optical imagery for motion compensation in a limb ultrasound system

NASA Astrophysics Data System (ADS)

Ranger, Bryan J.; Feigin, Micha; Zhang, Xiang; Mireault, Al; Raskar, Ramesh; Herr, Hugh M.; Anthony, Brian W.

2016-04-01

Conventional processes for prosthetic socket fabrication are heavily subjective, often resulting in an interface to the human body that is neither comfortable nor completely functional. With nearly 100% of amputees reporting that they experience discomfort with the wearing of their prosthetic limb, designing an effective interface to the body can significantly affect quality of life and future health outcomes. Active research in medical imaging and biomechanical tissue modeling of residual limbs has led to significant advances in computer aided prosthetic socket design, demonstrating an interest in moving toward more quantifiable processes that are still patient-specific. In our work, medical ultrasonography is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets while greatly reducing cost compared to an MRI-based framework. This paper presents a prototype limb imaging system that uses a medical ultrasound probe, mounted to a mechanical positioning system and submerged in a water bath. The limb imaging is combined with three-dimensional optical imaging for motion compensation. Images are collected circumferentially around the limb and combined into cross-sectional axial image slices, resulting in a compound image that shows tissue distributions and anatomical boundaries similar to magnetic resonance imaging. In this paper we provide a progress update on our system development, along with preliminary results as we move toward full volumetric imaging of residual limbs for prosthetic socket design. This demonstrates a novel multi-modal approach to residual limb imaging.

Ultrasound-based teaching of cardiac anatomy and physiology to undergraduate medical students.

PubMed

Hammoudi, Nadjib; Arangalage, Dimitri; Boubrit, Lila; Renaud, Marie Christine; Isnard, Richard; Collet, Jean-Philippe; Cohen, Ariel; Duguet, Alexandre

2013-10-01

Ultrasonography is a non-invasive imaging modality that offers the opportunity to teach living cardiac anatomy and physiology. The objectives of this study were to assess the feasibility of integrating an ultrasound-based course into the conventional undergraduate medical teaching programme and to analyse student and teacher feedback. An ultrasound-based teaching course was implemented and proposed to all second-year medical students (n=348) at the end of the academic year, after all the conventional modules at our faculty. After a brief theoretical and practical demonstration, students were allowed to take the probe and use the ultrasound machine. Students and teachers were asked to complete a survey and were given the opportunity to provide open feedback. Two months were required to implement the entire module; 330 (95%) students (divided into 39 groups) and 37 teachers participated in the course. Student feedback was very positive: 98% of students agreed that the course was useful; 85% and 74% considered that their understanding of cardiac anatomy and physiology, respectively, was improved. The majority of the teachers (97%) felt that the students were interested, 81% agreed that the course was appropriate for second-year medical students and 84% were willing to participate to future sessions. Cardiac anatomy and physiology teaching using ultrasound is feasible for undergraduate medical students and enhances their motivation to improve their knowledge. Student and teacher feedback on the course was very positive. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Demonstration of novel, secure, real-time, portable ultrasound transmission from an austere international location.

PubMed

Ogedegbe, Chinwe; Morchel, Herman; Hazelwood, Vikki; Hassler, Cynthia; Feldman, Joseph

2012-01-01

There is not sufficient access to medical care or medical expertise in many parts of the world. An innovative telemedicine system has been developed to provide expert medical guidance to field caregivers [who have less medical expertise but can reach the patient population in need]. Real-time ultrasound video images have been securely transmitted from the Dominican Republic to Hackensack University Medical Center, Hackensack NJ (HackensackUMC), while the expert physician at HackensackUMC maintained direct voice communication with the field caregiver. Utilizing a portable ultrasound machine (Sonosite) integrated with portable broadcasting device (LiveU), extended Focused Assessment Sonography in Trauma (e-FAST) examinations were performed on healthy volunteers and transmitted via the local cellular network. Additionally, two e-FAST examinations were conducted from a remote location without cellular coverage and transmitted via broad ground area network (BGAN) satellites. The demonstration took the technology "out of the lab" and into a real life, austere environment. The conditions of the Dominican Republic ultrasound mission provided experience on how to manage and utilize this innovative technology in areas where reliable communications and medical coverage are not readily available. The resilient transmission capabilities coupled with the security features deem this portable Telesonography (TS) equipment highly useful in the telemedicine forefront by offering healthcare in underdeveloped areas as well as potentially enhancing throughput in disaster situations.

Nonlinear acoustics in biomedical ultrasound

NASA Astrophysics Data System (ADS)

Cleveland, Robin O.

2015-10-01

Ultrasound is widely used to image inside the body; it is also used therapeutically to treat certain medical conditions. In both imaging and therapy applications the amplitudes employed in biomedical ultrasound are often high enough that nonlinear acoustic effects are present in the propagation: the effects have the potential to be advantageous in some scenarios but a hindrance in others. In the case of ultrasound imaging the nonlinearity produces higher harmonics that result in images of greater quality. However, nonlinear effects interfere with the imaging of ultrasound contrast agents (typically micron sized bubbles with a strong nonlinear response of their own) and nonlinear effects also result in complications when derating of pressure measurements in water to in situ values in tissue. High intensity focused ultrasound (HIFU) is emerging as a non-invasive therapeutic modality which can result in thermal ablation of tissue. For thermal ablation, the extra effective attenuation resulting from nonlinear effects can result in enhanced heating of tissue if shock formation occurs in the target region for ablation - a highly desirable effect. However, if nonlinearity is too strong it can also result in undesired near-field heating and reduced ablation in the target region. The disruption of tissue (histotripsy) and fragmentation of kidney stones (lithotripsy) exploits shock waves to produce mechanically based effects, with minimal heating present. In these scenarios it is necessary for the waves to be of sufficient amplitude that a shock exists when the waveform reaches the target region. This talk will discuss how underlying nonlinear phenomenon act in all the diagnostic and therapeutic applications described above.

SU-C-207B-07: Deep Convolutional Neural Network Image Matching for Ultrasound Guidance in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, N; Najafi, M; Hancock, S

Purpose: Robust matching of ultrasound images is a challenging problem as images of the same anatomy often present non-trivial differences. This poses an obstacle for ultrasound guidance in radiotherapy. Thus our objective is to overcome this obstacle by designing and evaluating an image blocks matching framework based on a two channel deep convolutional neural network. Methods: We extend to 3D an algorithmic structure previously introduced for 2D image feature learning [1]. To obtain the similarity between two 3D image blocks A and B, the 3D image blocks are divided into 2D patches Ai and Bi. The similarity is then calculatedmore » as the average similarity score of Ai and Bi. The neural network was then trained with public non-medical image pairs, and subsequently evaluated on ultrasound image blocks for the following scenarios: (S1) same image blocks with/without shifts (A and A-shift-x); (S2) non-related random block pairs; (S3) ground truth registration matched pairs of different ultrasound images with/without shifts (A-i and A-reg-i-shift-x). Results: For S1 the similarity scores of A and A-shift-x were 32.63, 18.38, 12.95, 9.23, 2.15 and 0.43 for x=ranging from 0 mm to 10 mm in 2 mm increments. For S2 the average similarity score for non-related block pairs was −1.15. For S3 the average similarity score of ground truth registration matched blocks A-i and A-reg-i-shift-0 (1≤i≤5) was 12.37. After translating A-reg-i-shift-0 by 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the average similarity scores of A-i and A-reg-i-shift-x were 11.04, 8.42, 4.56, 2.27, and 0.29 respectively. Conclusion: The proposed method correctly assigns highest similarity to corresponding 3D ultrasound image blocks despite differences in image content and thus can form the basis for ultrasound image registration and tracking.[1] Zagoruyko, Komodakis, “Learning to compare image patches via convolutional neural networks', IEEE CVPR 2015,pp.4353–4361.« less

Classification of breast cancer in ultrasound imaging using a generic deep learning analysis software: a pilot study.

PubMed

Becker, Anton S; Mueller, Michael; Stoffel, Elina; Marcon, Magda; Ghafoor, Soleen; Boss, Andreas

2018-02-01

To train a generic deep learning software (DLS) to classify breast cancer on ultrasound images and to compare its performance to human readers with variable breast imaging experience. In this retrospective study, all breast ultrasound examinations from January 1, 2014 to December 31, 2014 at our institution were reviewed. Patients with post-surgical scars, initially indeterminate, or malignant lesions with histological diagnoses or 2-year follow-up were included. The DLS was trained with 70% of the images, and the remaining 30% were used to validate the performance. Three readers with variable expertise also evaluated the validation set (radiologist, resident, medical student). Diagnostic accuracy was assessed with a receiver operating characteristic analysis. 82 patients with malignant and 550 with benign lesions were included. Time needed for training was 7 min (DLS). Evaluation time for the test data set were 3.7 s (DLS) and 28, 22 and 25 min for human readers (decreasing experience). Receiver operating characteristic analysis revealed non-significant differences (p-values 0.45-0.47) in the area under the curve of 0.84 (DLS), 0.88 (experienced and intermediate readers) and 0.79 (inexperienced reader). DLS may aid diagnosing cancer on breast ultrasound images with an accuracy comparable to radiologists, and learns better and faster than a human reader with no prior experience. Further clinical trials with dedicated algorithms are warranted. Advances in knowledge: DLS can be trained classify cancer on breast ultrasound images high accuracy even with comparably few training cases. The fast evaluation speed makes real-time image analysis feasible.

Sounding out the future of ultrasound education

PubMed Central

Dawson, M; Goudie, A; Mallin, M

2014-01-01

As in so many other fields, the internet has revolutionised medical education. It has done this by circumventing the traditional constraints of medical education, in particular the availability of local resources such as teachers and textbooks. This “education revolution” has been most successful in the areas of theoretical knowledge. This article explores the available resources, and the challenges that arise when attempting to teach point-of-care ultrasound via the internet, such as the visuomotor and visuospatial skills required to create a diagnostic image. This article also describes the progress to date in this field. PMID:27433235

Ultrasound-Guided Breast Biopsy

MedlinePlus

... the type of biopsy being performed or the design of the biopsy machine, a biopsy of tissue ... cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. ...

Incidence of abnormal imaging and recurrent pyelonephritis after first febrile urinary tract infection in children 2 to 24 months old.

PubMed

Juliano, Trisha M; Stephany, Heidi A; Clayton, Douglass B; Thomas, John C; Pope, John C; Adams, Mark C; Brock, John W; Tanaka, Stacy T

2013-10-01

The AAP (American Academy of Pediatrics) no longer recommends voiding cystourethrogram in children 2 to 24 months old who present with a first urinary tract infection if renal-bladder ultrasound is normal. We identified factors associated with abnormal imaging and recurrent pyelonephritis in this population. We retrospectively evaluated children diagnosed with a first episode of pyelonephritis at age 2 to 24 months using de-identified electronic medical record data from an institutional database. Data included age at first urinary tract infection, gender, race/ethnicity, need for hospitalization, intravenous antibiotic use, history of abnormal prenatal ultrasound, renal-bladder ultrasound and voiding cystourethrogram results, urinary tract infection recurrence and surgical intervention. Risk factors for abnormal imaging and urinary tract infection recurrence were analyzed by univariate logistic regression, the chi-square test and survival analysis. We identified 174 patients. Of the 154 renal-bladder ultrasounds performed 59 (38%) were abnormal. Abnormal prenatal ultrasound (p = 0.01) and the need for hospitalization (p = 0.02) predicted abnormal renal-bladder ultrasound. Of the 95 patients with normal renal-bladder ultrasound 84 underwent voiding cystourethrogram. Vesicoureteral reflux was more likely in patients who were white (p = 0.003), female (p = 0.02) and older (p = 0.04). Despite normal renal-bladder ultrasound, 23 of 84 patients (24%) had dilating vesicoureteral reflux. Of the 95 patients with normal renal-bladder ultrasound 14 (15%) had recurrent pyelonephritis and 7 (7%) went on to surgical intervention. Despite normal renal-bladder ultrasound after a first pyelonephritis episode, a child may still have vesicoureteral reflux, recurrent pyelonephritis and the need for surgical intervention. If voiding cystourethrogram is deferred, parents should be counseled on these risks. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

ASSOCIATIONS BETWEEN ULTRASOUND AND CLINICAL FINDINGS IN 87 CATS WITH URETHRAL OBSTRUCTION.

PubMed

Nevins, Jonathan R; Mai, Wilfried; Thomas, Emily

2015-01-01

Urethral obstruction is a life-threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross-sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six-month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54-21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction. © 2015 American College of Veterinary Radiology.

Drug delivery monitoring by photoacoustic tomography with an ICG encapsulated double emulsion

NASA Astrophysics Data System (ADS)

Rajian, Justin Rajesh; Fabiilli, Mario L.; Fowlkes, J. Brian; Carson, Paul L.; Wang, Xueding

2011-07-01

The absorption spectrum of indocyanine green (ICG), a nontoxic dye used for medical diagnostics, depends upon its concentration as well as the nature of its environment, i.e., the solvent medium into which it is dissolved. In blood, ICG binds with plasma proteins, thus causing changes in its photoacoustic spectrum. We successfully encapsulated ICG in an ultrasound-triggerable perfluorocarbon double emulsion that prevents ICG from binding with plasma proteins. Photoacoustic spectral measurements on point target as well as 2-D photoacoustic images of blood vessels revealed that the photoacoustic spectrum changes significantly in blood when the ICG-loaded emulsion undergoes acoustic droplet vaporization (ADV), which is the conversion of liquid droplets into gas bubbles using ultrasound. We propose that these changes in the photoacoustic spectrum of the ICG emulsion in blood, coupled with photoacoustic tomography, could be used to spatially and quantitatively monitor ultrasound initiated drug delivery. In addition, we suggest that the photoacoustic spectral change induced by ultrasound exposure could also be used as contrast in photoacoustic imaging to obtain a background free image.

Optimal apodization design for medical ultrasound using constrained least squares part I: theory.

PubMed

Guenther, Drake A; Walker, William F

2007-02-01

Aperture weighting functions are critical design parameters in the development of ultrasound systems because beam characteristics affect the contrast and point resolution of the final output image. In previous work by our group, we developed a metric that quantifies a broadband imaging system's contrast resolution performance. We now use this metric to formulate a novel general ultrasound beamformer design method. In our algorithm, we use constrained least squares (CLS) techniques and a linear algebra formulation to describe the system point spread function (PSF) as a function of the aperture weightings. In one approach, we minimize the energy of the PSF outside a certain boundary and impose a linear constraint on the aperture weights. In a second approach, we minimize the energy of the PSF outside a certain boundary while imposing a quadratic constraint on the energy of the PSF inside the boundary. We present detailed analysis for an arbitrary ultrasound imaging system and discuss several possible applications of the CLS techniques, such as designing aperture weightings to maximize contrast resolution and improve the system depth of field.

Twofold processing for denoising ultrasound medical images.

PubMed

Kishore, P V V; Kumar, K V V; Kumar, D Anil; Prasad, M V D; Goutham, E N D; Rahul, R; Krishna, C B S Vamsi; Sandeep, Y

2015-01-01

Ultrasound medical (US) imaging non-invasively pictures inside of a human body for disease diagnostics. Speckle noise attacks ultrasound images degrading their visual quality. A twofold processing algorithm is proposed in this work to reduce this multiplicative speckle noise. First fold used block based thresholding, both hard (BHT) and soft (BST), on pixels in wavelet domain with 8, 16, 32 and 64 non-overlapping block sizes. This first fold process is a better denoising method for reducing speckle and also inducing object of interest blurring. The second fold process initiates to restore object boundaries and texture with adaptive wavelet fusion. The degraded object restoration in block thresholded US image is carried through wavelet coefficient fusion of object in original US mage and block thresholded US image. Fusion rules and wavelet decomposition levels are made adaptive for each block using gradient histograms with normalized differential mean (NDF) to introduce highest level of contrast between the denoised pixels and the object pixels in the resultant image. Thus the proposed twofold methods are named as adaptive NDF block fusion with hard and soft thresholding (ANBF-HT and ANBF-ST). The results indicate visual quality improvement to an interesting level with the proposed twofold processing, where the first fold removes noise and second fold restores object properties. Peak signal to noise ratio (PSNR), normalized cross correlation coefficient (NCC), edge strength (ES), image quality Index (IQI) and structural similarity index (SSIM), measure the quantitative quality of the twofold processing technique. Validation of the proposed method is done by comparing with anisotropic diffusion (AD), total variational filtering (TVF) and empirical mode decomposition (EMD) for enhancement of US images. The US images are provided by AMMA hospital radiology labs at Vijayawada, India.

AN OVERVIEW OF ELASTOGRAPHY – AN EMERGING BRANCH OF MEDICAL IMAGING

PubMed Central

Sarvazyan, Armen; Hall, Timothy J.; Urban, Matthew W.; Fatemi, Mostafa; Aglyamov, Salavat R.; Garra, Brian S.

2011-01-01

From times immemorial manual palpation served as a source of information on the state of soft tissues and allowed detection of various diseases accompanied by changes in tissue elasticity. During the last two decades, the ancient art of palpation gained new life due to numerous emerging elasticity imaging (EI) methods. Areas of applications of EI in medical diagnostics and treatment monitoring are steadily expanding. Elasticity imaging methods are emerging as commercial applications, a true testament to the progress and importance of the field. In this paper we present a brief history and theoretical basis of EI, describe various techniques of EI and, analyze their advantages and limitations, and overview main clinical applications. We present a classification of elasticity measurement and imaging techniques based on the methods used for generating a stress in the tissue (external mechanical force, internal ultrasound radiation force, or an internal endogenous force), and measurement of the tissue response. The measurement method can be performed using differing physical principles including magnetic resonance imaging (MRI), ultrasound imaging, X-ray imaging, optical and acoustic signals. Until recently, EI was largely a research method used by a few select institutions having the special equipment needed to perform the studies. Since 2005 however, increasing numbers of mainstream manufacturers have added EI to their ultrasound systems so that today the majority of manufacturers offer some sort of Elastography or tissue stiffness imaging on their clinical systems. Now it is safe to say that some sort of elasticity imaging may be performed on virtually all types of focal and diffuse disease. Most of the new applications are still in the early stages of research, but a few are becoming common applications in clinical practice. PMID:22308105

Children's (Pediatric) Magnetic Resonance Imaging

MedlinePlus Videos and Cool Tools

... ultrasound), computed tomography and catheter angiography to provide information both before and after treatment. Cardiac MRI may ... use it after appropriate pre-medication. For more information on adverse reactions to gadolinium-based contrast agents, ...

Super-Resolution Image Reconstruction Applied to Medical Ultrasound

NASA Astrophysics Data System (ADS)

Ellis, Michael

Ultrasound is the preferred imaging modality for many diagnostic applications due to its real-time image reconstruction and low cost. Nonetheless, conventional ultrasound is not used in many applications because of limited spatial resolution and soft tissue contrast. Most commercial ultrasound systems reconstruct images using a simple delay-and-sum architecture on receive, which is fast and robust but does not utilize all information available in the raw data. Recently, more sophisticated image reconstruction methods have been developed that make use of far more information in the raw data to improve resolution and contrast. One such method is the Time-Domain Optimized Near-Field Estimator (TONE), which employs a maximum a priori estimation to solve a highly underdetermined problem, given a well-defined system model. TONE has been shown to significantly improve both the contrast and resolution of ultrasound images when compared to conventional methods. However, TONE's lack of robustness to variations from the system model and extremely high computational cost hinder it from being readily adopted in clinical scanners. This dissertation aims to reduce the impact of TONE's shortcomings, transforming it from an academic construct to a clinically viable image reconstruction algorithm. By altering the system model from a collection of individual hypothetical scatterers to a collection of weighted, diffuse regions, dTONE is able to achieve much greater robustness to modeling errors. A method for efficient parallelization of dTONE is presented that reduces reconstruction time by more than an order of magnitude with little loss in image fidelity. An alternative reconstruction algorithm, called qTONE, is also developed and is able to reduce reconstruction times by another two orders of magnitude while simultaneously improving image contrast. Each of these methods for improving TONE are presented, their limitations are explored, and all are used in concert to reconstruct in vivo images of a human testicle. In all instances, the methods presented here outperform conventional image reconstruction methods by a significant margin. As TONE and its variants are general image reconstruction techniques, the theories and research presented here have the potential to significantly improve not only ultrasound's clinical utility, but that of other imaging modalities as well.

Emergent ultrasound evaluation of the pediatric female pelvis.

PubMed

Back, Susan J; Maya, Carolina L; Zewdneh, Daniel; Epelman, Monica

2017-08-01

Ultrasound is the primary imaging modality of the pediatric female pelvis and is often requested to evaluate girls with pelvic or abdominal pain or abnormal bleeding. The US interpretation can help guide the clinician toward medical or surgical management. Here we discuss the normal US anatomy of the female pelvis and illustrate, through case examples, conditions encountered when performing emergent pelvic US for common and uncommon clinical scenarios.

Sparse dictionary for synthetic transmit aperture medical ultrasound imaging.

PubMed

Wang, Ping; Jiang, Jin-Yang; Li, Na; Luo, Han-Wu; Li, Fang; Cui, Shi-Gang

2017-07-01

It is possible to recover a signal below the Nyquist sampling limit using a compressive sensing technique in ultrasound imaging. However, the reconstruction enabled by common sparse transform approaches does not achieve satisfactory results. Considering the ultrasound echo signal's features of attenuation, repetition, and superposition, a sparse dictionary with the emission pulse signal is proposed. Sparse coefficients in the proposed dictionary have high sparsity. Images reconstructed with this dictionary were compared with those obtained with the three other common transforms, namely, discrete Fourier transform, discrete cosine transform, and discrete wavelet transform. The performance of the proposed dictionary was analyzed via a simulation and experimental data. The mean absolute error (MAE) was used to quantify the quality of the reconstructions. Experimental results indicate that the MAE associated with the proposed dictionary was always the smallest, the reconstruction time required was the shortest, and the lateral resolution and contrast of the reconstructed images were also the closest to the original images. The proposed sparse dictionary performed better than the other three sparse transforms. With the same sampling rate, the proposed dictionary achieved excellent reconstruction quality.

Accuracy of ultrasonography and magnetic resonance imaging in the diagnosis of placenta accreta.

PubMed

Riteau, Anne-Sophie; Tassin, Mikael; Chambon, Guillemette; Le Vaillant, Claudine; de Laveaucoupet, Jocelyne; Quéré, Marie-Pierre; Joubert, Madeleine; Prevot, Sophie; Philippe, Henri-Jean; Benachi, Alexandra

2014-01-01

To evaluate the accuracy of ultrasonography and magnetic resonance imaging (MRI) in the diagnosis of placenta accreta and to define the most relevant specific ultrasound and MRI features that may predict placental invasion. This study was approved by the institutional review board of the French College of Obstetricians and Gynecologists. We retrospectively reviewed the medical records of all patients referred for suspected placenta accreta to two university hospitals from 01/2001 to 05/2012. Our study population included 42 pregnant women who had been investigated by both ultrasonography and MRI. Ultrasound images and MRI were blindly reassessed for each case by 2 raters in order to score features that predict abnormal placental invasion. Sensitivity in the diagnosis of placenta accreta was 100% with ultrasound and 76.9% for MRI (P = 0.03). Specificity was 37.5% with ultrasonography and 50% for MRI (P = 0.6). The features of greatest sensitivity on ultrasonography were intraplacental lacunae and loss of the normal retroplacental clear space. Increased vascularization in the uterine serosa-bladder wall interface and vascularization perpendicular to the uterine wall had the best positive predictive value (92%). At MRI, uterine bulging had the best positive predictive value (85%) and its combination with the presence of dark intraplacental bands on T2-weighted images improved the predictive value to 90%. Ultrasound imaging is the mainstay of screening for placenta accreta. MRI appears to be complementary to ultrasonography, especially when there are few ultrasound signs.

Use of ultrasound imaging for the diagnosis of abnormal uterine bleeding in the bonnet macaque ( Macaca radiata).

PubMed

Chaudhari, Uddhav K; Imran, M; Manjramkar, Dhananjay D; Metkari, Siddhanath M; Sable, Nilesh P; Gavhane, Dnyaneshwar S; Katkam, Rajendra R; Sachdeva, Geetanjali; Thakur, Meenakshi H; Kholkute, Sanjeeva D

2017-02-01

Ultrasound is a powerful, low-cost, non-invasive medical tool used by laboratory animal veterinarians for diagnostic imaging. Sonohysterography and transvaginal ultrasound are frequently used to assess uterine anomalies in women presenting with abnormal uterine bleeding (AUB). In the present study, we have evaluated the abdominal ultrasound of bonnet monkeys ( n = 8) showing spontaneous ovulatory ( n = 5) and anovulatory ( n = 3) AUB. The ovulatory ( n = 5) macaques showed cyclic AUB for 7-8 days. The anovulatory ( n = 3) macaques had irregular AUB with menstrual cycles of 40-45 days. The B-mode abdominal, colour Doppler and 3D ultrasound scans were performed during the proliferative phase of the menstrual cycle. Ultrasound examination revealed endometrial polyps in five macaques and endometrial hyperplasia in three animals. The width and length of endometrial polyps was around 0.5-1 cm (average 0.51 ± 0.23 cm × 0.96 ± 0.16 cm) with significant increase in endometrial thickness ( P < 0.0002). 3D ultrasound also showed a homogeneous mass in the uterine cavity and colour Doppler ultrasound showed increased vascularity in the endometrial polyps. Endometrial hyperplasia characteristically appeared as a thickened echogenic endometrium ( P < 0.0002). This study demonstrates the use of non-invasive ultrasound techniques in the diagnosis of AUB in macaques.

Interference-free ultrasound imaging during HIFU therapy, using software tools

NASA Technical Reports Server (NTRS)

Vaezy, Shahram (Inventor); Held, Robert (Inventor); Sikdar, Siddhartha (Inventor); Managuli, Ravi (Inventor); Zderic, Vesna (Inventor)

2010-01-01

Disclosed herein is a method for obtaining a composite interference-free ultrasound image when non-imaging ultrasound waves would otherwise interfere with ultrasound imaging. A conventional ultrasound imaging system is used to collect frames of ultrasound image data in the presence of non-imaging ultrasound waves, such as high-intensity focused ultrasound (HIFU). The frames are directed to a processor that analyzes the frames to identify portions of the frame that are interference-free. Interference-free portions of a plurality of different ultrasound image frames are combined to generate a single composite interference-free ultrasound image that is displayed to a user. In this approach, a frequency of the non-imaging ultrasound waves is offset relative to a frequency of the ultrasound imaging waves, such that the interference introduced by the non-imaging ultrasound waves appears in a different portion of the frames.

Grid-Enabled Quantitative Analysis of Breast Cancer

DTIC Science & Technology

2009-10-01

large-scale, multi-modality computerized image analysis . The central hypothesis of this research is that large-scale image analysis for breast cancer...pilot study to utilize large scale parallel Grid computing to harness the nationwide cluster infrastructure for optimization of medical image ... analysis parameters. Additionally, we investigated the use of cutting edge dataanalysis/ mining techniques as applied to Ultrasound, FFDM, and DCE-MRI Breast

Pulsed magneto-motive ultrasound imaging to detect intracellular trafficking of magnetic nanoparticles

PubMed Central

Mehrmohamamdi, Mohammad; Qu, Min; Ma, Li L.; Romanovicz, Dwight K.; Johnston, Keith P.; Sokolov, Konstantin V.; Emelianov, Stanislav Y.

2012-01-01

As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular trafficking of nanoparticles – an important part of cell-nanoparticle interaction, has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique – pulsed magneto-motive ultrasound (pMMUS), to identify intracellular trafficking of endocytosed magnetic nanoparticles. In pulsed magneto-motive ultrasound imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular aggregation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular trafficking non-invasively and in real-time. PMID:21926454

Segmenting Images for a Better Diagnosis

NASA Technical Reports Server (NTRS)

2004-01-01

NASA's Hierarchical Segmentation (HSEG) software has been adapted by Bartron Medical Imaging, LLC, for use in segmentation feature extraction, pattern recognition, and classification of medical images. Bartron acquired licenses from NASA Goddard Space Flight Center for application of the HSEG concept to medical imaging, from the California Institute of Technology/Jet Propulsion Laboratory to incorporate pattern-matching software, and from Kennedy Space Center for data-mining and edge-detection programs. The Med-Seg[TM] united developed by Bartron provides improved diagnoses for a wide range of medical images, including computed tomography scans, positron emission tomography scans, magnetic resonance imaging, ultrasound, digitized Z-ray, digitized mammography, dental X-ray, soft tissue analysis, and moving object analysis. It also can be used in analysis of soft-tissue slides. Bartron's future plans include the application of HSEG technology to drug development. NASA is advancing it's HSEG software to learn more about the Earth's magnetosphere.

A sensitive optical micro-machined ultrasound sensor (OMUS) based on a silicon photonic ring resonator on an acoustical membrane.

PubMed

Leinders, S M; Westerveld, W J; Pozo, J; van Neer, P L M J; Snyder, B; O'Brien, P; Urbach, H P; de Jong, N; Verweij, M D

2015-09-22

With the increasing use of ultrasonography, especially in medical imaging, novel fabrication techniques together with novel sensor designs are needed to meet the requirements for future applications like three-dimensional intercardiac and intravascular imaging. These applications require arrays of many small elements to selectively record the sound waves coming from a certain direction. Here we present proof of concept of an optical micro-machined ultrasound sensor (OMUS) fabricated with a semi-industrial CMOS fabrication line. The sensor is based on integrated photonics, which allows for elements with small spatial footprint. We demonstrate that the first prototype is already capable of detecting pressures of 0.4 Pa, which matches the performance of the state of the art piezo-electric transducers while having a 65 times smaller spatial footprint. The sensor is compatible with MRI due to the lack of electronical wiring. Another important benefit of the use of integrated photonics is the easy interrogation of an array of elements. Hence, in future designs only two optical fibers are needed to interrogate an entire array, which minimizes the amount of connections of smart catheters. The demonstrated OMUS has potential applications in medical ultrasound imaging, non destructive testing as well as in flow sensing.

Ultrasound Enhanced Matrix Metalloproteinase-9 Triggered Release of Contents from Echogenic Liposomes

PubMed Central

Nahire, Rahul; Paul, Shirshendu; Scott, Michael D.; Singh, Raushan K.; Muhonen, Wallace W.; Shabb, John; Gange, Kara N.; Srivastava, D. K.; Sarkar, Kausik; Mallik, Sanku

2012-01-01

The extracellular enzyme matrix metalloproteinase-9 (MMP-9) is overexpressed in atherosclerotic plaques and in metastatic cancers. The enzyme is responsible for rupture of the plaques and for the invasion and metastasis of a large number of cancers. The ability of ultrasonic excitation to induce thermal and mechanical effects has been used to release drugs from different carriers. However, majority of these studies were performed with low frequency ultrasound (LFUS) at kHz frequencies. Clinical usage of LFUS excitations will be limited due to harmful biological effects. Herein, we report our results on the release of encapsulated contents from substrate lipopeptide incorporated echogenic liposomes triggered by recombinant human MMP-9. The contents release was further enhanced by the application of diagnostic frequency (3 MHz) ultrasound. The echogenic liposomes were successfully imaged employing a medical ultrasound transducer (4 – 15 MHz). The conditioned cell culture media from cancer cells (secreting MMP-9) released the encapsulated dye from the liposomes (30 – 50%) and this release is also increased (50 – 80%) by applying diagnostic frequency ultrasound (3 MHz) for 3 minutes. With further developments, these liposomes have the potential to serve as multimodal carriers for triggered release and simultaneous ultrasound imaging. PMID:22849291

Contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) 2017 – a review of important differences compared to the CT/MRI system

PubMed Central

Noh, Seung Yeon; Wilson, Stephanie R; Kono, Yuko; Piscaglia, Fabio; Jang, Hyun-Jung; Lyshchik, Andrej; Dietrich, Christoph F.; Willmann, Juergen K.; Vezeridis, Alexander; Sirlin, Claude B

2017-01-01

Medical imaging plays an important role in the diagnosis and management of hepatocellular carcinoma (HCC). The Liver Imaging Reporting and Data System (LI-RADS) was initially created to standardize the reporting and data collection of CT and MR imaging for patients at risk for HCC. As contrast-enhanced ultrasound (CEUS) has been widely used in clinical practice, it has recently been added to the LI-RADS. While CEUS LI-RADS shares fundamental concepts with CT/MRI LI-RADS, there are key differences between the modalities reflecting dissimilarities in the underlying methods of image acquisition and types of contrast material. This review introduces a recent update of CEUS LI-RADS and explains the key differences from CT/MRI LI-RADS. PMID:28911220

Effects of Student-Performed Point-of-Care Ultrasound on Physician Diagnosis and Management of Patients in the Emergency Department.

PubMed

Udrea, Daniel S; Sumnicht, Andrew; Lo, Deanna; Villarreal, Logan; Gondra, Stephanie; Chyan, Richard; Wisham, Audra; Dinh, Vi Am

2017-07-01

Despite the increasing integration of ultrasound training into medical education, there is an inadequate body of research demonstrating the benefits and practicality of medical student-performed point-of-care ultrasound (SP-POCUS) in the clinical setting. The primary purpose of this study was to evaluate the effects that SP-POCUS can have on physician diagnosis and management of patients in the emergency department, with a secondary purpose of evaluating the diagnostic accuracy of SP-POCUS. SP-POCUS examinations were performed in the emergency department by medical students who completed year one of a 4-year medical school curriculum with integrated ultrasound training. Scans were evaluated by an emergency physician who then completed a survey to record any changes in diagnosis and management. A total of 641 scans were performed on the 482 patients enrolled in this study. SP-POCUS resulted in a change in management in 17.3% of scans performed. For 12.4% of scans, SP-POCUS discovered a new diagnosis. SP-POCUS reduced time to disposition 33.5% of the time. Because of SP-POCUS, physicians avoided ordering an additional imaging study for 53.0% of the scans performed. There was 94.7% physician agreement with SP-POCUS diagnosis. This study showed that SP-POCUS is feasible and may potentially have a meaningful impact on physician diagnosis and management of patients in the emergency department. In addition, the implementation of SP-POCUS could serve as an ideal method of developing ultrasound skills in medical school while positively impacting patient care. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrasound transducer selection in clinical imaging practice.

PubMed

Szabo, Thomas L; Lewin, Peter A

2013-04-01

Many types of medical ultrasound transducers are used in clinical practice. They operate at different center frequencies, have different physical dimensions, footprints, and shapes, and provide different image formats. However, little information is available about which transducers are most appropriate for a given application, and the purpose of this article is to address this deficiency. Specifically, the relationship between the transducer, imaging format, and clinical applications is discussed, and systematic selection criteria that allow matching of transducers to specific clinical needs are presented. These criteria include access to and coverage of the region of interest, maximum scan depth, and coverage of essential diagnostic modes required to optimize a patient's diagnosis. Three comprehensive figures organize and summarize the imaging planes, scanning modes, and types of diagnostic transducers to facilitate their selection in clinical diagnosis.

Automated flow quantification in valvular heart disease based on backscattered Doppler power analysis: implementation on matrix-array ultrasound imaging systems.

PubMed

Buck, Thomas; Hwang, Shawn M; Plicht, Björn; Mucci, Ronald A; Hunold, Peter; Erbel, Raimund; Levine, Robert A

2008-06-01

Cardiac ultrasound imaging systems are limited in the noninvasive quantification of valvular regurgitation due to indirect measurements and inaccurate hemodynamic assumptions. We recently demonstrated that the principle of integration of backscattered acoustic Doppler power times velocity can be used for flow quantification in valvular regurgitation directly at the vena contracta of a regurgitant flow jet. We now aimed to accomplish implementation of automated Doppler power flow analysis software on a standard cardiac ultrasound system utilizing novel matrix-array transducer technology with detailed description of system requirements, components and software contributing to the system. This system based on a 3.5 MHz, matrix-array cardiac ultrasound scanner (Sonos 5500, Philips Medical Systems) was validated by means of comprehensive experimental signal generator trials, in vitro flow phantom trials and in vivo testing in 48 patients with mitral regurgitation of different severity and etiology using magnetic resonance imaging (MRI) for reference. All measurements displayed good correlation to the reference values, indicating successful implementation of automated Doppler power flow analysis on a matrix-array ultrasound imaging system. Systematic underestimation of effective regurgitant orifice areas >0.65 cm(2) and volumes >40 ml was found due to currently limited Doppler beam width that could be readily overcome by the use of new generation 2D matrix-array technology. Automated flow quantification in valvular heart disease based on backscattered Doppler power can be fully implemented on board a routinely used matrix-array ultrasound imaging systems. Such automated Doppler power flow analysis of valvular regurgitant flow directly, noninvasively, and user independent overcomes the practical limitations of current techniques.

Incidentally detected non-palpable testicular tumours in adults at scrotal ultrasound: impact of radiological findings on management Radiologic review and recommendations of the ESUR scrotal imaging subcommittee.

PubMed

Rocher, Laurence; Ramchandani, Parvati; Belfield, Jane; Bertolotto, Michele; Derchi, Lorenzo E; Correas, Jean Michel; Oyen, Raymond; Tsili, Athina C; Turgut, Ahmet Tuncay; Dogra, Vikram; Fizazi, Karim; Freeman, Simon; Richenberg, Jonathan

2016-07-01

The increasing detection of small testicular lesions by ultrasound (US) in adults can lead to unnecessary orchiectomies. This article describes their nature, reviews the available literature on this subject and illustrates some classical lesions. We also suggest recommendations to help characterization and management. The ESUR scrotal imaging subcommittee searched for original and review articles published before May 2015 using the Pubmed and Medline databases. Key words used were 'testicular ultrasound', 'contrast-enhanced sonography', 'sonoelastography', 'magnetic resonance imaging', 'testis-sparing surgery', 'testis imaging', 'Leydig cell tumour', 'testicular cyst'. Consensus was obtained amongst the members of the subcommittee, urologist and medical oncologist. Simple cysts are frequent and benign, and do not require follow up or surgery. Incidentally discovered small solid testicular lesions detected are benign in up to 80 %, with Leydig cell tumours being the most frequent. However, the presence of microliths, macrocalcifications and hypoechoic areas surrounding the nodule are findings suggestive of malignant disease. Asymptomatic small testicular lesions found on ultrasound are mainly benign, but findings such as microliths or hypoechoic regions surrounding the nodules may indicate malignancy. Colour Doppler US remains the basic examination for characterization. The role of newer imaging modalities in characterization is evolving. • Characterization of testicular lesions is primarily based on US examination. • The role of MRI, sonoelastography, contrast-enhanced ultrasound is evolving. • Most small non-palpable testicular lesions seen on ultrasound are benign simple cysts. • Leydig cell tumours are the most frequent benign lesions. • Associated findings like microliths or hypoechoic regions may indicate malignancy.

Human abdomen recognition using camera and force sensor in medical robot system for automatic ultrasound scan.

PubMed

Bin Mustafa, Ammar Safwan; Ishii, Takashi; Matsunaga, Yoshiki; Nakadate, Ryu; Ishii, Hiroyuki; Ogawa, Kouji; Saito, Akiko; Sugawara, Motoaki; Niki, Kiyomi; Takanishi, Atsuo

2013-01-01

Physicians use ultrasound scans to obtain real-time images of internal organs, because such scans are safe and inexpensive. However, people in remote areas face difficulties to be scanned due to aging society and physician's shortage. Hence, it is important to develop an autonomous robotic system to perform remote ultrasound scans. Previously, we developed a robotic system for automatic ultrasound scan focusing on human's liver. In order to make it a completely autonomous system, we present in this paper a way to autonomously localize the epigastric region as the starting position for the automatic ultrasound scan. An image processing algorithm marks the umbilicus and mammary papillae on a digital photograph of the patient's abdomen. Then, we made estimation for the location of the epigastric region using the distances between these landmarks. A supporting algorithm distinguishes rib position from epigastrium using the relationship between force and displacement. We implemented these algorithms with the automatic scanning system into an apparatus: a Mitsubishi Electric's MELFA RV-1 six axis manipulator. Tests on 14 healthy male subjects showed the apparatus located the epigastric region with a success rate of 94%. The results suggest that image recognition was effective in localizing a human body part.

[Assessment of the sonographer's knowledge on the second trimester ultrasound recommendations of the National Technical Committee of Ultrasound].

PubMed

Matar, M; Picone, O; Dalmon, C; Ayoubi, J-M

2013-09-01

To evaluate the sonographers' knowledge of the National Technical Committee of Ultrasound's recommendations concerning second trimester ultrasound. Anonymous questionnaire was sent by e-mails containing 25 questions about demographic elements, the practice of second trimester ultrasound and the recommendations of the National Technical Committee of Ultrasound about second trimester ultrasound. Six hundred and eighty-four responses were obtained. Six hundred and fifty-three upon 684 (95%) of respondents practice second trimester ultrasound and 635 upon 653 (97%) know about the existence of the report of the National Technical Committee of Ultrasound. The rates of correct answers concerning recommended biometrical images vary between 97% for the biparietal diameter and head circumference, 98% for abdominal circumference and 100% for the femur length. While for morphological images, rates vary between 52% and 100%. A subgroup analysis (whether the respondents have already read the recommendations or not) showed that those who had read the recommendations have significantly better results than those who did not. Those who have already read the recommendations have better knowledge and global knowledge can be improved. National recommendations serve to promote a policy of quality assurance of ultrasound and may be used in medicolegal issues. The societies that make recommendations should more diffuse their work and practitioners should make effort to pursue the continuing medical education and to implement the recommendations. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Virtual Ultrasound Guidance for Inexperienced Operators

NASA Technical Reports Server (NTRS)

Caine, Timothy; Martin, Davis

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit, in which the time delay inherent with communication will make remote guidance impractical.

Design, Fabrication and Characterization of A Bi-Frequency Co-Linear Array

PubMed Central

Wang, Zhuochen; Li, Sibo; Czernuszewicz, Tomasz J; Gallippi, Caterina M.; Liu, Ruibin; Geng, Xuecang

2016-01-01

Ultrasound imaging with high resolution and large penetration depth has been increasingly adopted in medical diagnosis, surgery guidance, and treatment assessment. Conventional ultrasound works at a particular frequency, with a −6 dB fractional bandwidth of ~70 %, limiting the imaging resolution or depth of field. In this paper, a bi-frequency co-linear array with resonant frequencies of 8 MHz and 20 MHz was investigated to meet the requirements of resolution and penetration depth for a broad range of ultrasound imaging applications. Specifically, a 32-element bi-frequency co-linear array was designed and fabricated, followed by element characterization and real-time sectorial scan (S-scan) phantom imaging using a Verasonics system. The bi-frequency co-linear array was tested in four different modes by switching between low and high frequencies on transmit and receive. The four modes included the following: (1) transmit low, receive low, (2) transmit low, receive high, (3) transmit high, receive low, (4) transmit high, receive high. After testing, the axial and lateral resolutions of all modes were calculated and compared. The results of this study suggest that bi-frequency co-linear arrays are potential aids for wideband fundamental imaging and harmonic/sub-harmonic imaging. PMID:26661069

A Comparison of Ultrasound Tomography Methods in Circular Geometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leach, R R; Azevedo, S G; Berryman, J G

2002-01-24

Extremely high quality data was acquired using an experimental ultrasound scanner developed at Lawrence Livermore National Laboratory using a 2D ring geometry with up to 720 transmitter/receiver transducer positions. This unique geometry allows reflection and transmission modes and transmission imaging and quantification of a 3D volume using 2D slice data. Standard image reconstruction methods were applied to the data including straight-ray filtered back projection, reflection tomography, and diffraction tomography. Newer approaches were also tested such as full wave, full wave adjoint method, bent-ray filtered back projection, and full-aperture tomography. A variety of data sets were collected including a formalin-fixed humanmore » breast tissue sample, a commercial ultrasound complex breast phantom, and cylindrical objects with and without inclusions. The resulting reconstruction quality of the images ranges from poor to excellent. The method and results of this study are described including like-data reconstructions produced by different algorithms with side-by-side image comparisons. Comparisons to medical B-scan and x-ray CT scan images are also shown. Reconstruction methods with respect to image quality using resolution, noise, and quantitative accuracy, and computational efficiency metrics will also be discussed.« less

Deep-tissue focal fluorescence imaging with digitally time-reversed ultrasound-encoded light

PubMed Central

Wang, Ying Min; Judkewitz, Benjamin; DiMarzio, Charles A.; Yang, Changhuei

2012-01-01

Fluorescence imaging is one of the most important research tools in biomedical sciences. However, scattering of light severely impedes imaging of thick biological samples beyond the ballistic regime. Here we directly show focusing and high-resolution fluorescence imaging deep inside biological tissues by digitally time-reversing ultrasound-tagged light with high optical gain (~5×105). We confirm the presence of a time-reversed optical focus along with a diffuse background—a corollary of partial phase conjugation—and develop an approach for dynamic background cancellation. To illustrate the potential of our method, we image complex fluorescent objects and tumour microtissues at an unprecedented depth of 2.5 mm in biological tissues at a lateral resolution of 36 μm×52 μm and an axial resolution of 657 μm. Our results set the stage for a range of deep-tissue imaging applications in biomedical research and medical diagnostics. PMID:22735456

Outcomes of an Advanced Ultrasound Elective: Preparing Medical Students for Residency and Practice.

PubMed

Prats, Michael I; Royall, Nelson A; Panchal, Ashish R; Way, David P; Bahner, David P

2016-05-01

Many medical specialties have adopted the use of ultrasound, creating demands for higher-quality ultrasound training at all levels of medical education. Little is known about the long-term benefit of integrating ultrasound training during undergraduate medical education. This study evaluated the effect of a longitudinal fourth-year undergraduate medical education elective in ultrasound and its impact on the future use of ultrasound in clinical practice. A cross-sectional survey of medical graduates from The Ohio State University College of Medicine (2006-2011) was done, comparing those who participated and those who did not participate in a rigorous ultrasound program for fourth-year medical students. A 38-item questionnaire queried graduates concerning ultrasound education in residency, their proficiency, and their current use of ultrasound in clinical practice. Surveys were completed by 116 respondents, for a return rate of 40.8% (116 of 284). The participants of the undergraduate medical education ultrasound elective (n = 61) reported more hours of ultrasound training after graduation (hands-on training, bedside scanning, and number of scans performed; P < .001), higher ultrasound proficiency (proficiency in using ultrasound for clinical decision making, use in emergency settings, and use of novel techniques; P< .001), and higher rates of ultrasound use in clinical practice (P < .001). The longitudinal undergraduate medical education ultrasound elective produced physicians who were more likely to seek additional training in residency, evaluate themselves as more proficient, and use ultrasound in their clinical practice. Early training in bedside ultrasound during undergraduate medical education yields physicians who are better prepared for integration of ultrasound into clinical practice. © 2016 by the American Institute of Ultrasound in Medicine.

All-Optical Ultrasound Transducers for High Resolution Imaging

NASA Astrophysics Data System (ADS)

Sheaff, Clay Smith

High frequency ultrasound (HFUS) has increasingly been used within the past few decades to provide high resolution (< 200 mum) imaging in medical applications such as endoluminal imaging, intravascular imaging, ophthalmology, and dermatology. The optical detection and generation of HFUS using thin films offers numerous advantages over traditional piezoelectric technology. Circumvention of an electronic interface with the device head is one of the most significant given the RF noise, crosstalk, and reduced capacitance that encumbers small-scale electronic transducers. Thin film Fabry-Perot interferometers - also known as etalons - are well suited for HFUS receivers on account of their high sensitivity, wide bandwidth, and ease of fabrication. In addition, thin films can be used to generate HFUS when irradiated with optical pulses - a method referred to as Thermoelastic Ultrasound Generation (TUG). By integrating a polyimide (PI) film for TUG into an etalon receiver, we have created for the first time an all-optical ultrasound transducer that is both thermally stable and capable of forming fully sampled 2-D imaging arrays of arbitrary configuration. Here we report (1) the design and fabrication of PI-etalon transducers; (2) an evaluation of their optical and acoustic performance parameters; (3) the ability to conduct high-resolution imaging with synthetic 2-D arrays of PI-etalon elements; and (4) work towards a fiber optic PI-etalon for in vivo use. Successful development of a fiber optic imager would provide a unique field-of-view thereby exposing an abundance of prospects for minimally-invasive analysis, diagnosis, and treatment of disease.

Cognitive load imposed by ultrasound-facilitated teaching does not adversely affect gross anatomy learning outcomes.

PubMed

Jamniczky, Heather A; Cotton, Darrel; Paget, Michael; Ramji, Qahir; Lenz, Ryan; McLaughlin, Kevin; Coderre, Sylvain; Ma, Irene W Y

2017-03-01

Ultrasonography is increasingly used in medical education, but its impact on learning outcomes is unclear. Adding ultrasound may facilitate learning, but may also potentially overwhelm novice learners. Based upon the framework of cognitive load theory, this study seeks to evaluate the relationship between cognitive load associated with using ultrasound and learning outcomes. The use of ultrasound was hypothesized to facilitate learning in anatomy for 161 novice first-year medical students. Using linear regression analyses, the relationship between reported cognitive load on using ultrasound and learning outcomes as measured by anatomy laboratory examination scores four weeks after ultrasound-guided anatomy training was evaluated in consenting students. Second anatomy examination scores of students who were taught anatomy with ultrasound were compared with historical controls (those not taught with ultrasound). Ultrasound's perceived utility for learning was measured on a five-point scale. Cognitive load on using ultrasound was measured on a nine-point scale. Primary outcome was the laboratory examination score (60 questions). Learners found ultrasound useful for learning. Weighted factor score on "image interpretation" was negatively, but insignificantly, associated with examination scores [F (1,135) = 0.28, beta = -0.22; P = 0.61]. Weighted factor score on "basic knobology" was positively and insignificantly associated with scores; [F (1,138) = 0.27, beta = 0.42; P = 0.60]. Cohorts exposed to ultrasound had significantly higher scores than historical controls (82.4% ± SD 8.6% vs. 78.8% ± 8.5%, Cohen's d = 0.41, P < 0.001). Using ultrasound to teach anatomy does not negatively impact learning and may improve learning outcomes. Anat Sci Educ 10: 144-151. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Time-resolved nanoseconds dynamics of ultrasound contrast agent microbubbles manipulated and controlled by optical tweezers

NASA Astrophysics Data System (ADS)

Garbin, Valeria; Cojoc, Dan; Ferrari, Enrico; Di Fabrizio, Enzo; Overvelde, Marlies L. J.; Versluis, Michel; van der Meer, Sander M.; de Jong, Nico; Lohse, Detlef

2006-08-01

Optical tweezers enable non-destructive, contact-free manipulation of ultrasound contrast agent (UCA) microbubbles, which are used in medical imaging for enhancing the echogenicity of the blood pool and to quantify organ perfusion. The understanding of the fundamental dynamics of ultrasound-driven contrast agent microbubbles is a first step for exploiting their acoustical properties and to develop new diagnostic and therapeutic applications. In this respect, optical tweezers can be used to study UCA microbubbles under controlled and repeatable conditions, by positioning them away from interfaces and from neighboring bubbles. In addition, a high-speed imaging system is required to record the dynamics of UCA microbubbles in ultrasound, as their oscillations occur on the nanoseconds timescale. In this work, we demonstrate the use of an optical tweezers system combined with a high-speed camera capable of 128-frame recordings at up to 25 million frames per second (Mfps), for the study of individual UCA microbubble dynamics as a function of the distance from solid interfaces.

Numerical evaluation of the skull for human neuromodulation with transcranial focused ultrasound

NASA Astrophysics Data System (ADS)

Mueller, Jerel K.; Ai, Leo; Bansal, Priya; Legon, Wynn

2017-12-01

Objective. Transcranial focused ultrasound is an emerging field for human non-invasive neuromodulation, but its dosing in humans is difficult to know due to the skull. The objective of the present study was to establish modeling methods based on medical images to assess skull differences between individuals on the wave propagation of ultrasound. Approach. Computational models of transcranial focused ultrasound were constructed using CT and MR scans to solve for intracranial pressure. We explored the effect of including the skull base in models, different transducer placements on the head, and differences between 250 kHz or 500 kHz acoustic frequency for both female and male models. We further tested these features using linear, nonlinear, and elastic simulations. To better understand inter-subject skull thickness and composition effects we evaluated the intracranial pressure maps between twelve individuals at two different skull sites. Main results. Nonlinear acoustic simulations resulted in virtually identical intracranial pressure maps with linear acoustic simulations. Elastic simulations showed a difference in max pressures and full width half maximum volumes of 15% at most. Ultrasound at an acoustic frequency of 250 kHz resulted in the creation of more prominent intracranial standing waves compared to 500 kHz. Finally, across twelve model human skulls, a significant linear relationship to characterize intracranial pressure maps was not found. Significance. Despite its appeal, an inherent problem with the use of a noninvasive transcranial ultrasound method is the difficulty of knowing intracranial effects because of the skull. Here we develop detailed computational models derived from medical images of individuals to simulate the propagation of neuromodulatory ultrasound across the skull and solve for intracranial pressure maps. These methods allow for a much better understanding of the intracranial effects of ultrasound for an individual in order to ensure proper targeting and more tightly control dosing.

Portable radiography: a reality and necessity for ISS and explorer-class missions.

PubMed

Lerner, David J; Parmet, Allen J

2015-02-01

On ISS missions and explorer class missions, unexpected medical and surgical emergencies could be disastrous. Lack of ability to rapidly assess and make critical decisions affects mission capability. Current imaging modalities on ISS consist only of ultrasound. There are many acute diagnoses which ultrasound alone cannot diagnose. Portable X-Ray imaging (radiography) technology has advanced far enough to where it is now small enough, cheap enough, and accurate enough to give diagnostic quality images sent wirelessly to the onboard computer and on Earth for interpretation while fitting in something the size of a briefcase. Although further research is warranted, Portable Radiography is an important addition to have on ISS and future Explorer Class Missions while maintaining a very small footprint.

Quantitative shear-wave optical coherence elastography with a programmable phased array ultrasound as the wave source.

PubMed

Song, Shaozhen; Le, Nhan Minh; Huang, Zhihong; Shen, Tueng; Wang, Ruikang K

2015-11-01

The purpose of this study is to implement a beam-steering ultrasound as the wave source for shear-wave optical coherence elastography (SW-OCE) to achieve an extended range of elastic imaging of the tissue sample. We introduce a linear phased array ultrasound transducer (LPAUT) as the remote and programmable wave source and a phase-sensitive optical coherence tomography (OCT) as the sensitive shear-wave detector. The LPAUT is programmed to launch acoustic radiation force impulses (ARFI) focused at desired locations within the range of OCT imaging, upon which the elasticity map of the entire OCT B-scan cross section is recovered by spatial compounding of the elastic maps derived from each launch of AFRIs. We also propose a directional filter to separate the shear-wave propagation at different directions in order to reduce the effect of tissue heterogeneity on the shear-wave propagation within tissue. The feasibility of this proposed approach is then demonstrated by determining the stiffness of tissue-mimicking phantoms with agarose concentrations of 0.5% and 1% and also by imaging the Young's modulus of retinal and choroidal tissues within a porcine eye ball ex vivo. The approach opens up opportunities to combine medical ultrasound imaging and SW-OCE for high-resolution localized quantitative assessment of tissue biomechanical property.

Effects of ultrasound implementation on physical examination learning and teaching during the first year of medical education.

PubMed

Dinh, Vi Am; Frederick, Jon; Bartos, Rebekah; Shankel, Tamara M; Werner, Leonard

2015-01-01

Increasing emphasis has been placed on point-of-care ultrasound in medical school. The overall effects of ultrasound curriculum implementation on the traditional physical examination skills of medical students are still unknown. We studied the effects on the Objective Standardized Clinical Examination (OSCE) scores of year 1 medical students before and after ultrasound curriculum implementation. An ultrasound curriculum was incorporated into the physical diagnosis course for year 1 medical students in the 2012-2013 academic year. We performed a prospective observational study comparing traditional OSCE scores of year 1 medical students exposed to the ultrasound curriculum (post-ultrasound) versus historic year 1 medical student controls (pre-ultrasound) with no ultrasound exposure. Questionnaire data were also obtained from year 1 medical students and physical diagnosis faculty to assess attitudes toward ultrasound implementation. The final overall OSCE scores were graded with a 5-point Likert-type scale from unsatisfactory to outstanding. There was a significant increase in outstanding scores in the post-ultrasound compared to the pre-ultrasound group (27.0% versus 10.9%; P< .001). The post-ultrasound group had significantly (P< .05) increased first-time pass rates on blood pressure measurements, the abdominal examination, and professionalism. Student and physical diagnosis faculty questionnaire data showed an overall positive response, with most agreeing or strongly agreeing that ultrasound should be included in the future year 1 medical student curriculum. Ultrasound implementation into a physical diagnosis curriculum for year 1 medical students is feasible and may improve their overall traditional physical examination skills. © 2015 by the American Institute of Ultrasound in Medicine.

Mobile tele-echography: user interface design.

PubMed

Cañero, Cristina; Thomos, Nikolaos; Triantafyllidis, George A; Litos, George C; Strintzis, Michael Gerassimos

2005-03-01

Ultrasound imaging allows the evaluation of the degree of emergency of a patient. However, in some instances, a well-trained sonographer is unavailable to perform such echography. To cope with this issue, the Mobile Tele-Echography Using an Ultralight Robot (OTELO) project aims to develop a fully integrated end-to-end mobile tele-echography system using an ultralight remote-controlled robot for population groups that are not served locally by medical experts. This paper focuses on the user interface of the OTELO system, consisting of the following parts: an ultrasound video transmission system providing real-time images of the scanned area, an audio/video conference to communicate with the paramedical assistant and with the patient, and a virtual-reality environment, providing visual and haptic feedback to the expert, while capturing the expert's hand movements. These movements are reproduced by the robot at the patient site while holding the ultrasound probe against the patient skin. In addition, the user interface includes an image processing facility for enhancing the received images and the possibility to include them into a database.

Accuracy of Ultrasonography and Magnetic Resonance Imaging in the Diagnosis of Placenta Accreta

PubMed Central

Riteau, Anne-Sophie; Tassin, Mikael; Chambon, Guillemette; Le Vaillant, Claudine; de Laveaucoupet, Jocelyne; Quéré, Marie-Pierre; Joubert, Madeleine; Prevot, Sophie; Philippe, Henri-Jean; Benachi, Alexandra

2014-01-01

Purpose To evaluate the accuracy of ultrasonography and magnetic resonance imaging (MRI) in the diagnosis of placenta accreta and to define the most relevant specific ultrasound and MRI features that may predict placental invasion. Material and Methods This study was approved by the institutional review board of the French College of Obstetricians and Gynecologists. We retrospectively reviewed the medical records of all patients referred for suspected placenta accreta to two university hospitals from 01/2001 to 05/2012. Our study population included 42 pregnant women who had been investigated by both ultrasonography and MRI. Ultrasound images and MRI were blindly reassessed for each case by 2 raters in order to score features that predict abnormal placental invasion. Results Sensitivity in the diagnosis of placenta accreta was 100% with ultrasound and 76.9% for MRI (P = 0.03). Specificity was 37.5% with ultrasonography and 50% for MRI (P = 0.6). The features of greatest sensitivity on ultrasonography were intraplacental lacunae and loss of the normal retroplacental clear space. Increased vascularization in the uterine serosa-bladder wall interface and vascularization perpendicular to the uterine wall had the best positive predictive value (92%). At MRI, uterine bulging had the best positive predictive value (85%) and its combination with the presence of dark intraplacental bands on T2-weighted images improved the predictive value to 90%. Conclusion Ultrasound imaging is the mainstay of screening for placenta accreta. MRI appears to be complementary to ultrasonography, especially when there are few ultrasound signs. PMID:24733409

Ultrasound guidance to perform intra-articular injection of gadolinium-based contrast material for magnetic resonance arthrography as an alternative to fluoroscopy: the time is now.

PubMed

Messina, Carmelo; Banfi, Giuseppe; Aliprandi, Alberto; Mauri, Giovanni; Secchi, Francesco; Sardanelli, Francesco; Sconfienza, Luca Maria

2016-05-01

Magnetic resonance (MR) imaging has been definitively established as the reference standard in the evaluation of joints in the body. Similarly, magnetic resonance arthrography has emerged as a technique that has been proven to increase significantly the diagnostic performance if compared with conventional MR imaging, especially when dealing with fibrocartilage and articular cartilage abnormalities. Diluted gadolinium can be injected in the joint space using different approaches: under palpation using anatomic landmarks or using an imaging guidance, such as fluoroscopy, computed tomography, or ultrasound. Fluoroscopy has been traditionally used, but the involvement of ionizing radiation should represent a remarkable limitation of this modality. Conversely, ultrasound has emerged as a feasible, cheap, quick, and radiation-free modality that can be used to inject joints, with comparable accuracy of fluoroscopy. In the present paper, we discuss the advantages and disadvantages of using fluoroscopy or ultrasound in injecting gadolinium-based contrast agents in joints to perform magnetic resonance arthrography, also in view of the new EuroSAFE Imaging initiative promoted by the European Society of Radiology and the recent updates to the European Atomic Energy Community 2013/59 directive on the medical use of ionizing radiation. • Intra-articular contrast agent injection can be performed using different imaging modalities • Fluoroscopy is widely used, but uses ionizing radiation • Ultrasound is an accurate, quick, and radiation-free modality for joint injection • X-rays should be avoided when other radiation-free modalities can be used.

Does Ultrasound-Enhanced Instruction of Musculoskeletal Anatomy Improve Physical Examination Skills of First-Year Medical Students?

PubMed

Walrod, Bryant J; Schroeder, Allison; Conroy, Mark J; Boucher, Laura C; Bockbrader, Marcia; Way, David P; McCamey, Kendra L; Hartz, Clinton A; Jonesco, Michael A; Bahner, David P

2018-01-01

Ultrasound imaging is commonly used to teach basic anatomy to medical students. The purpose of this study was to determine whether learning musculoskeletal anatomy with ultrasound improved performance on medical students' musculoskeletal physical examination skills. Twenty-seven first-year medical students were randomly assigned to 1 of 2 instructional groups: either shoulder or knee. Both groups received a lecture followed by hands-on ultrasound scanning on live human models of the assigned joint. After instruction, students were assessed on their ability to accurately palpate 4 anatomic landmarks: the acromioclavicular joint, the proximal long-head biceps tendon, and the medial and lateral joint lines of the knee. Performance scores were based on both accuracy and time. A total physical examination performance score was derived for each joint. Scores for instructional groups were compared by a 2-way analysis of variance with 1 repeated measure. Significant findings were further analyzed with post hoc tests. All students performed significantly better on the knee examination, irrespective of instructional group (F = 14.9; df = 1.25; P = .001). Moreover, the shoulder instruction group performed significantly better than the knee group on the overall assessment (t = -3.0; df = 25; P < .01). Post hoc analyses revealed that differences in group performance were due to the shoulder group's higher scores on palpation of the biceps tendon (t = -2.8; df = 25; P = .01), a soft tissue landmark. Both groups performed similarly on palpation of all other anatomic structures. The use of ultrasound appears to provide an educational advantage when learning musculoskeletal physical examination of soft tissue landmarks. © 2017 by the American Institute of Ultrasound in Medicine.

Detecting breast microcalcifications using super-resolution ultrasound imaging: a clinical study

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Labyed, Yassin; Hanson, Kenneth; Sandoval, Daniel; Pohl, Jennifer; Williamson, Michael

2013-03-01

Imaging breast microcalcifications is crucial for early detection and diagnosis of breast cancer. It is challenging for current clinical ultrasound to image breast microcalcifications. However, new imaging techniques using data acquired with a synthetic-aperture ultrasound system have the potential to significantly improve ultrasound imaging. We recently developed a super-resolution ultrasound imaging method termed the phase-coherent multiple-signal classification (PC-MUSIC). This signal subspace method accounts for the phase response of transducer elements to improve image resolution. In this paper, we investigate the clinical feasibility of our super-resolution ultrasound imaging method for detecting breast microcalcifications. We use our custom-built, real-time synthetic-aperture ultrasound system to acquire breast ultrasound data for 40 patients whose mammograms show the presence of breast microcalcifications. We apply our super-resolution ultrasound imaging method to the patient data, and produce clear images of breast calcifications. Our super-resolution ultrasound PC-MUSIC imaging with synthetic-aperture ultrasound data can provide a new imaging modality for detecting breast microcalcifications in clinic without using ionizing radiation.

Reducing Unnecessary Shoulder MRI Examinations Within a Capitated Health Care System: A Potential Role for Shoulder Ultrasound.

PubMed

Sheehan, Scott E; Coburn, John A; Singh, Hardeep; Vanness, David J; Sittig, Dean F; Moberg, D Paul; Safdar, Nasia; Lee, Kenneth S; Brunner, Michael C

2016-07-01

MRI is frequently overused. The aim of this study was to analyze shoulder MRI ordering practices within a capitated health care system and explore the potential effects of shoulder ultrasound substitution. We reviewed medical records of 237 consecutive shoulder MRI examinations performed in 2013 at a Department of Veterans Affairs tertiary care hospital. Using advanced imaging guidelines, we assessed ordering appropriateness of shoulder MRI and estimated the proportion of examinations for which musculoskeletal ultrasound could have been an acceptable substitute, had it been available. We then reviewed MRI findings and assessed if ultrasound with preceding radiograph would have been adequate for diagnosis, based on literature reports of shoulder ultrasound diagnostic performance. Of the 237 examinations reviewed, 106 (45%) were deemed to be inappropriately ordered, most commonly because of an absent preceding radiograph (n = 98; 92%). Nonorthopedic providers had a higher frequency of inappropriate ordering (44%) relative to orthopedic specialists (17%) (P = .016; odds ratio = 3.15, 95% confidence interval = 1.24-8.01). In the 237 examinations, ultrasound could have been the indicated advanced imaging modality for 157 (66%), and most of these (133/157; 85%) could have had all relevant pathologies characterized when combined with radiographs. Regardless of indicated modality, ultrasound could have characterized 80% of all cases ordered by nonorthopedic providers and 50% of cases ordered by orthopedic specialists (P = .007). Advanced shoulder imaging is often not ordered according to published appropriateness criteria. While nonorthopedic provider orders were more likely to be inappropriate, inappropriateness persisted among orthopedic providers. A combined ultrasound and radiograph evaluation strategy could accurately characterize shoulder pathologies for most cases. Published by Elsevier Inc.

Computer-aided diagnostic system for detection of Hashimoto thyroiditis on ultrasound images from a Polish population.

PubMed

Acharya, U Rajendra; Sree, S Vinitha; Krishnan, M Muthu Rama; Molinari, Filippo; Zieleźnik, Witold; Bardales, Ricardo H; Witkowska, Agnieszka; Suri, Jasjit S

2014-02-01

Computer-aided diagnostic (CAD) techniques aid physicians in better diagnosis of diseases by extracting objective and accurate diagnostic information from medical data. Hashimoto thyroiditis is the most common type of inflammation of the thyroid gland. The inflammation changes the structure of the thyroid tissue, and these changes are reflected as echogenic changes on ultrasound images. In this work, we propose a novel CAD system (a class of systems called ThyroScan) that extracts textural features from a thyroid sonogram and uses them to aid in the detection of Hashimoto thyroiditis. In this paradigm, we extracted grayscale features based on stationary wavelet transform from 232 normal and 294 Hashimoto thyroiditis-affected thyroid ultrasound images obtained from a Polish population. Significant features were selected using a Student t test. The resulting feature vectors were used to build and evaluate the following 4 classifiers using a 10-fold stratified cross-validation technique: support vector machine, decision tree, fuzzy classifier, and K-nearest neighbor. Using 7 significant features that characterized the textural changes in the images, the fuzzy classifier had the highest classification accuracy of 84.6%, sensitivity of 82.8%, specificity of 87.0%, and a positive predictive value of 88.9%. The proposed ThyroScan CAD system uses novel features to noninvasively detect the presence of Hashimoto thyroiditis on ultrasound images. Compared to manual interpretations of ultrasound images, the CAD system offers a more objective interpretation of the nature of the thyroid. The preliminary results presented in this work indicate the possibility of using such a CAD system in a clinical setting after evaluating it with larger databases in multicenter clinical trials.

Ultrasound microscope: the new field in ultrasound diagnostics

NASA Astrophysics Data System (ADS)

Novyc'kyy, Victor V.; Lushchyk, Ulyana B.

2001-06-01

A device which is a new stage in the development of medical equipment has been developed. The device works as an ultrasound microscope in vivo and provides 4 up to 32 colored histological image. It gives possibility to estimate tissue acoustic density with the help of 4 up to 32 gradation coloring different tissues and enables tissue microcirculation visualization. With the help of the device a doctor can objectify fatty hepatitis and cirrhosis, edema of different organs and tissues as well as microcirculation in organs and tissues (e.g. muscles, myocard and bone system). New promising applications of ultrasound systems in diagnostics and for choosing individual treatment tactics, with pathogenesis being taken into account, may be developed with the help of the device.

Breast imaging with the SoftVue imaging system: first results

NASA Astrophysics Data System (ADS)

Duric, Neb; Littrup, Peter; Schmidt, Steven; Li, Cuiping; Roy, Olivier; Bey-Knight, Lisa; Janer, Roman; Kunz, Dave; Chen, Xiaoyang; Goll, Jeffrey; Wallen, Andrea; Zafar, Fouzaan; Allada, Veerendra; West, Erik; Jovanovic, Ivana; Li, Kuo; Greenway, William

2013-03-01

For women with dense breast tissue, who are at much higher risk for developing breast cancer, the performance of mammography is at its worst. Consequently, many early cancers go undetected when they are the most treatable. Improved cancer detection for women with dense breasts would decrease the proportion of breast cancers diagnosed at later stages, which would significantly lower the mortality rate. The emergence of whole breast ultrasound provides good performance for women with dense breast tissue, and may eliminate the current trade-off between the cost effectiveness of mammography and the imaging performance of more expensive systems such as magnetic resonance imaging. We report on the performance of SoftVue, a whole breast ultrasound imaging system, based on the principles of ultrasound tomography. SoftVue was developed by Delphinus Medical Technologies and builds on an early prototype developed at the Karmanos Cancer Institute. We present results from preliminary testing of the SoftVue system, performed both in the lab and in the clinic. These tests aimed to validate the expected improvements in image performance. Initial qualitative analyses showed major improvements in image quality, thereby validating the new imaging system design. Specifically, SoftVue's imaging performance was consistent across all breast density categories and had much better resolution and contrast. The implications of these results for clinical breast imaging are discussed and future work is described.

Ultrasound applications in mass casualties and extreme environments.

PubMed

Ma, O John; Norvell, Jeffrey G; Subramanian, Srikala

2007-05-01

A mass-casualty incident is one in which the number of patients with injuries exceeds the available medical resources to care for them in a timely manner. In such a situation, the numerous advantages of ultrasonography make it an ideal triage tool for helping clinicians rapidly screen patients. Experiences during the 1988 Armenian earthquake and the 1999 Turkish earthquake demonstrated the proficiency of ultrasound in providing rapid clinical data to the physicians caring for the mass-casualty patients. Wireless and satellite transmission of ultrasound images also has been shown to be feasible and may be applied to mass-casualty situations. In addition, ultrasound applications have been demonstrated to aid in the diagnosis of various conditions, including pneumothorax, in the International Space Station. Ultrasound's portability, reproducibility, accuracy, and ease of use will make it an important diagnostic instrument for future space missions.

Endoscopic surgery and telemedicine in microgravity: developing contingency procedures for exploratory class spaceflight.

PubMed

Jones, J A; Johnston, S; Campbell, M; Miles, B; Billica, R

1999-05-01

The risk of a urinary calculus during an extended duration mission into the reduced gravity environment of space is significant. For medical operations to develop a comprehensive strategy for the spaceflight stone risk, both preventive countermeasures and contingency management (CM) plans must be included. A feasibility study was conducted to demonstrate the potential CM technique of endoscopic ureteral stenting with ultrasound guidance for the possible in-flight urinary calculus contingency. The procedure employed the International Space Station/Human Research Facility ultrasound unit for guide wire and stent localization, a flexible cystoscope for visual guidance, and banded, biocompatible soft ureteral stents to successfully stent porcine ureters bilaterally in zero gravity (0g). The study demonstrated that downlinked endoscopic surgical and ultrasound images obtained in 0g are comparable in quality to 1g images, and therefore are useful for diagnostic clinical utility via telemedicine transmission. In order to be successful, surgical procedures in 0g require excellent positional stability of the operating surgeon, assistant, and patient, relative to one another. The technological development of medical procedures for long-duration spaceflight contingencies may lead to improved terrestrial patient care methodology and subsequently reduced morbidity.

Endoscopic surgery and telemedicine in microgravity: developing contingency procedures for exploratory class spaceflight

NASA Technical Reports Server (NTRS)

Jones, J. A.; Johnston, S.; Campbell, M.; Miles, B.; Billica, R.

1999-01-01

OBJECTIVES: The risk of a urinary calculus during an extended duration mission into the reduced gravity environment of space is significant. For medical operations to develop a comprehensive strategy for the spaceflight stone risk, both preventive countermeasures and contingency management (CM) plans must be included. METHODS: A feasibility study was conducted to demonstrate the potential CM technique of endoscopic ureteral stenting with ultrasound guidance for the possible in-flight urinary calculus contingency. The procedure employed the International Space Station/Human Research Facility ultrasound unit for guide wire and stent localization, a flexible cystoscope for visual guidance, and banded, biocompatible soft ureteral stents to successfully stent porcine ureters bilaterally in zero gravity (0g). RESULTS: The study demonstrated that downlinked endoscopic surgical and ultrasound images obtained in 0g are comparable in quality to 1g images, and therefore are useful for diagnostic clinical utility via telemedicine transmission. CONCLUSIONS: In order to be successful, surgical procedures in 0g require excellent positional stability of the operating surgeon, assistant, and patient, relative to one another. The technological development of medical procedures for long-duration spaceflight contingencies may lead to improved terrestrial patient care methodology and subsequently reduced morbidity.

Evaluating the risk of appendiceal perforation when using ultrasound as the initial diagnostic imaging modality in children with suspected appendicitis.

PubMed

Alerhand, Stephen; Meltzer, James; Tay, Ee Tein

2017-08-01

Ultrasound scan has gained attention for diagnosing appendicitis due to its avoidance of ionizing radiation. However, studies show that ultrasound scan carries inferior sensitivity to computed tomography scan. A non-diagnostic ultrasound scan could increase the time to diagnosis and appendicectomy, particularly if follow-up computed tomography scan is needed. Some studies suggest that delaying appendicectomy increases the risk of perforation. To investigate the risk of appendiceal perforation when using ultrasound scan as the initial diagnostic imaging modality in children with suspected appendicitis. We retrospectively reviewed 1411 charts of children ≤17 years old diagnosed with appendicitis at two urban academic medical centers. Patients who underwent ultrasound scan first were compared to those who underwent computed tomography scan first. In the sub-group analysis, patients who only received ultrasound scan were compared to those who received initial ultrasound scan followed by computed tomography scan. Main outcome measures were appendiceal perforation rate and time from triage to appendicectomy. In 720 children eligible for analysis, there was no significant difference in perforation rate between those who had initial ultrasound scan and those who had initial computed tomography scan (7.3% vs. 8.9%, p = 0.44), nor in those who had ultrasound scan only and those who had initial ultrasound scan followed by computed tomography scan (8.0% vs. 5.6%, p = 0.42). Those patients who had ultrasound scan first had a shorter triage-to-incision time than those who had computed tomography scan first (9.2 (IQR: 5.9, 14.0) vs. 10.2 (IQR: 7.3, 14.3) hours, p = 0.03), whereas those who had ultrasound scan followed by computed tomography scan took longer than those who had ultrasound scan only (7.8 (IQR: 5.3, 11.6) vs. 15.1 (IQR: 10.6, 20.6), p < 0.001). Children < 12 years old receiving ultrasound scan first had lower perforation rate (p = 0.01) and shorter triage-to-incision time (p = 0.003). Children with suspected appendicitis receiving ultrasound scan as the initial diagnostic imaging modality do not have increased risk of perforation compared to those receiving computed tomography scan first. We recommend that children <12 years of age receive ultrasound scan first.

Improved Image-Guided Laparoscopic Prostatectomy

DTIC Science & Technology

2012-08-01

prevalent technique used in widening the field of view (FOV) of medical ultrasound images. Also referred to as stitching or panorama , the ultra- sound mosaic...tissue which can add valu- able features to the B-mode panorama . Many clinical applications deal with large cancerous lesions which expand beyond the...1999) 203–233 2. Varghese, T., Zagzebski, J., Lee Jr., F.: Elastographic imaging of thermal lesions in the liver in vivo following radiofrequency

Myositis and Fasciitis: Role of Imaging.

PubMed

Endo, Yoshimi; Miller, Theodore T

2018-07-01

Imaging plays an important role in the evaluation of patients presenting with possible myositis, with magnetic resonance imaging the most appropriate modality but ultrasound also playing a complementary role. This article reviews the imaging appearance of the inflammatory myopathies, other forms of myositis, and mimickers of myositis, with a discussion of distinguishing features for each entity. The fascia and disease processes that preferentially involve the fascia are also reviewed. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Second Harmonic Imaging improves Echocardiograph Quality on board the International Space Station

NASA Technical Reports Server (NTRS)

Garcia, Kathleen; Sargsyan, Ashot; Hamilton, Douglas; Martin, David; Ebert, Douglas; Melton, Shannon; Dulchavsky, Scott

2008-01-01

Ultrasound (US) capabilities have been part of the Human Research Facility (HRF) on board the International Space Station (ISS) since 2001. The US equipment on board the ISS includes a first-generation Tissue Harmonic Imaging (THI) option. Harmonic imaging (HI) is the second harmonic response of the tissue to the ultrasound beam and produces robust tissue detail and signal. Since this is a first-generation THI, there are inherent limitations in tissue penetration. As a breakthrough technology, HI extensively advanced the field of ultrasound. In cardiac applications, it drastically improves endocardial border detection and has become a common imaging modality. U.S. images were captured and stored as JPEG stills from the ISS video downlink. US images with and without harmonic imaging option were randomized and provided to volunteers without medical education or US skills for identification of endocardial border. The results were processed and analyzed using applicable statistical calculations. The measurements in US images using HI improved measurement consistency and reproducibility among observers when compared to fundamental imaging. HI has been embraced by the imaging community at large as it improves the quality and data validity of US studies, especially in difficult-to-image cases. Even with the limitations of the first generation THI, HI improved the quality and measurability of many of the downlinked images from the ISS and should be an option utilized with cardiac imaging on board the ISS in all future space missions.

Human Space Flight

NASA Technical Reports Server (NTRS)

Woolford, Barbara

2006-01-01

The performance of complex tasks on the International Space Station (ISS) requires significant preflight crew training commitments and frequent skill and knowledge refreshment. This report documents a recently developed just-in-time training methodology, which integrates preflight hardware familiarization and procedure training with an on-orbit CD-ROM-based skill enhancement. This just-in-time concept was used to support real-time remote expert guidance to complete medical examinations using the ISS Human Research Facility (HRF). An American md Russian ISS crewmember received 2-hours of hands on ultrasound training 8 months prior to the on-orbit ultrasound exam. A CD-ROM-based Onboard Proficiency Enhancement (OPE) interactive multimedia program consisting of memory enhancing tutorials, and skill testing exercises, was completed by the crewmember six days prior to the on-orbit ultrasound exam. The crewmember was then remotely guided through a thoracic, vascular, and echocardiographic examination by ultrasound imaging experts. Results of the CD ROM based OPE session were used to modify the instructions during a complete 35 minute real-time thoracic, cardiac, and carotid/jugular ultrasound study. Following commands from the ground-based expert, the crewmember acquired all target views and images without difficulty. The anatomical content and fidelity of ultrasound video were excellent and adequate for clinical decision-making. Complex ultrasound experiments with expert guidance were performed with high accuracy following limited pre-flight training and CD-ROM-based in-flight review, despite a 2-second communication latency.

Poster - 09: A MATLAB-based Program for Automated Quality Assurance of a Prostate Brachytherapy Ultrasound System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poon, Justin; Sabondjian, Eric; Sankreacha, Raxa

Purpose: A robust Quality Assurance (QA) program is essential for prostate brachytherapy ultrasound systems due to the importance of imaging accuracy during treatment and planning. Task Group 128 of the American Association of Physicists in Medicine has recommended a set of QA tests covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, and template/electronic grid alignment. Making manual measurements on the ultrasound system can be slow and inaccurate, so a MATLAB program was developed for automation of the described tests. Methods: Test images were acquired using a BK Medical Flex Focus 400 ultrasoundmore » scanner and 8848 transducer with the CIRS Brachytherapy QA Phantom – Model 045A. For each test, the program automatically segments the inputted image(s), makes the appropriate measurements, and indicates if the test passed or failed. The program was tested by analyzing two sets of images, where the measurements from the first set were used as baseline values. Results: The program successfully analyzed the images for each test and determined if any action limits were exceeded. All tests passed – the measurements made by the program were consistent and met the requirements outlined by Task Group 128. Conclusions: The MATLAB program we have developed can be used for automated QA of an ultrasound system for prostate brachytherapy. The GUI provides a user-friendly way to analyze images without the need for any manual measurement, potentially removing intra- and inter-user variability for more consistent results.« less

Development and evaluation of a novel, real time mobile telesonography system in management of patients with abdominal trauma: study protocol.

PubMed

Ogedegbe, Chinwe; Morchel, Herman; Hazelwood, Vikki; Chaplin, William F; Feldman, Joseph

2012-12-18

Despite the use of e-FAST in management of patients with abdominal trauma, its utility in prehospital setting is not widely adopted. The goal of this study is to develop a novel portable telesonography (TS) system and evaluate the comparability of the quality of images obtained via this system among healthy volunteers who undergo e-FAST abdominal examination in a moving ambulance and at the ED. We hypothesize that: (1) real-time ultrasound images of acute trauma patients in the pre-hospital setting can be obtained and transmitted to the ED via the novel TS system; and (2) Ultrasound images transmitted to the hospital from the real-time TS system will be comparable in quality to those obtained in the ED. Study participants are three healthy volunteers (one each with normal, overweight and obese BMI category). The ultrasound images will be obtained by two ultrasound-trained physicians The TS is a portable sonogram (by Sonosite) interfaced with a portable broadcast unit (by Live-U). Two UTPs will conduct e-FAST examinations on healthy volunteers in moving ambulances and transmit the images via cellular network to the hospital server, where they are stored. Upon arrival in the ED, the same UTPs will obtain another set of images from the volunteers, which are then compared to those obtained in the moving ambulances by another set of blinded UTPs (evaluators) using a validated image quality scale, the Questionnaire for User Interaction Satisfaction (QUIS). Findings from this study will provide needed data on the validity of the novel TS in transmitting live images from moving ambulances to images obtained in the ED thus providing opportunity to facilitate medical care of a patient located in a remote or austere setting.

Development of photoacoustic imaging technology overlaid on ultrasound imaging and its clinical application

NASA Astrophysics Data System (ADS)

Ishihara, Miya; Tsujita, Kazuhiro; Horiguchi, Akio; Irisawa, Kaku; Komatsu, Tomohiro; Ayaori, Makoto; Hirasawa, Takeshi; Kasamatsu, Tadashi; Hirota, Kazuhiro; Tsuda, Hitoshi; Ikewaki, Katsunori; Asano, Tomohiko

2015-03-01

Purpose: Photoacoustic imaging (PAI) enables one to visualize the distribution of hemoglobin and acquire a map of microvessels without using contrast agents. The purpose of our study is to develop a clinically applicable PAI system integrated with a clinical ultrasound (US) array system with handheld PAI probes providing coregistered PAI and US images. Clinical research trials were performed to evaluate the performance and feasibility of clinical value. Materials and Methods: We developed two types of handheld PAI probes: a linear PAI probe combining a conventional linear-array US probe with optical illumination and a transrectal ultrasonography (TRUS)-type PAI probe. We performed experiments with Japanese white rabbits and conducted clinical research trials of urology and vascular medicine with the approval of the medical human ethics committee of the National Defense Medical College. Results: We successfully acquired high-dynamic-range images of the vascular network ranging from capillaries to landmark arteries and identified the femoral vein, deep femoral vein, and great saphenous vein of rabbits. These major vessels in the rabbits groin are surrounded with microvessels connected to each other. Periprostatic microvessels were monitored during radical prostatectomy for localized prostate cancer and they were colocalized with nerve fibers, and their distribution was consistent with the corresponding PAI. The TRUS-type PAI probe clearly demonstrated the location and extent of the neurovascular bundle (NVB) better than does TRUS alone. Conclusions: The system, which can obtain a PAI, a US image, and a merged image, was innovatively designed so that medical doctors can easily find the location without any prior knowledge or extended skills to analyze the obtained images. Our pilot feasibility study confirms that PAI could be an imaging modality useful in the screening study and diagnostic biopsy.

Dependence of thresholds for pulmonary capillary hemorrhage on diagnostic ultrasound frequency.

PubMed

Miller, Douglas L; Dou, Chunyan; Raghavendran, Krishnan

2015-06-01

Pulmonary ultrasound examination has become routine for diagnosis in many clinical and point-of-care medical settings. However, the phenomenon of pulmonary capillary hemorrhage (PCH) induction during diagnostic ultrasound imaging presents a poorly understood risk factor. PCH was observed in anesthetized rats exposed to 1.5-, 4.5- and 12.0-MHz diagnostic ultrasound to investigate the frequency dependence of PCH thresholds. PCH was detected in the ultrasound images as growing comet tail artifacts and was assessed using photographs of the surface of excised lungs. Previous photographs acquired after exposure to 7.6-MHz diagnostic ultrasound were included for analysis. In addition, at each frequency we measured dosimetric parameters, including peak rarefactional pressure amplitude and spatial peak, pulse average intensity attenuated by rat chest wall samples. Peak rarefactional pressure amplitude thresholds determined at each frequency, based on the proportion of PCH in groups of five rats, were 1.03 ± 0.02, 1.28 ± 0.14, 1.18 ± 0.12 and 1.36 ± 0.15 MPa at 1.5, 4.5, 7.6 and 12.0 MHz, respectively. Although the PCH lesions decreased in size with increasing ultrasonic frequency, owing to the smaller beam widths and scan lengths, the peak rarefactional pressure amplitude thresholds remained approximately constant. This dependence was different from that of the mechanical index, which indicates a need for a specific dosimetric parameter for safety guidance in pulmonary ultrasound. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Ultrasound guided double injection of blood into cisterna magna: a rabbit model for treatment of cerebral vasospasm.

PubMed

Chen, Yongchao; Zhu, Youzhi; Zhang, Yu; Zhang, Zixuan; Lian, Juan; Luo, Fucheng; Deng, Xuefei; Wong, Kelvin K L

2016-02-06

Double injection of blood into cisterna magna using a rabbit model results in cerebral vasospasm. An unacceptably high mortality rate tends to limit the application of model. Ultrasound guided puncture can provide real-time imaging guidance for operation. The aim of this paper is to establish a safe and effective rabbit model of cerebral vasospasm after subarachnoid hemorrhage with the assistance of ultrasound medical imaging. A total of 160 New Zealand white rabbits were randomly divided into four groups of 40 each: (1) manual control group, (2) manual model group, (3) ultrasound guided control group, and (4) ultrasound guided model group. The subarachnoid hemorrhage was intentionally caused by double injection of blood into their cisterna magna. Then, basilar artery diameters were measured using magnetic resonance angiography before modeling and 5 days after modeling. The depth of needle entering into cisterna magna was determined during the process of ultrasound guided puncture. The mortality rates in manual control group and model group were 15 and 23 %, respectively. No rabbits were sacrificed in those two ultrasound guided groups. We found that the mortality rate in ultrasound guided groups decreased significantly compared to manual groups. Compared with diameters before modeling, the basilar artery diameters after modeling were significantly lower in manual and ultrasound guided model groups. The vasospasm aggravated and the proportion of severe vasospasms was greater in ultrasound guided model group than that of manual group. In manual model group, no vasospasm was found in 8 % of rabbits. The ultrasound guided double injection of blood into cisterna magna is a safe and effective rabbit model for treatment of cerebral vasospasm.

Breast ultrasound tomography with two parallel transducer arrays

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Gao, Kai; Intrator, Miranda; Hanson, Kenneth

2016-03-01

Breast ultrasound tomography is an emerging imaging modality to reconstruct the sound speed, density, and ultrasound attenuation of the breast in addition to ultrasound reflection/beamforming images for breast cancer detection and characterization. We recently designed and manufactured a new synthetic-aperture breast ultrasound tomography prototype with two parallel transducer arrays consisting of a total of 768 transducer elements. The transducer arrays are translated vertically to scan the breast in a warm water tank from the chest wall/axillary region to the nipple region to acquire ultrasound transmission and reflection data for whole-breast ultrasound tomography imaging. The distance of these two ultrasound transducer arrays is adjustable for scanning breasts with different sizes. We use our breast ultrasound tomography prototype to acquire phantom and in vivo patient ultrasound data to study its feasibility for breast imaging. We apply our recently developed ultrasound imaging and tomography algorithms to ultrasound data acquired using our breast ultrasound tomography system. Our in vivo patient imaging results demonstrate that our breast ultrasound tomography can detect breast lesions shown on clinical ultrasound and mammographic images.

4D ultrasound imaging - ethically justifiable in India?

PubMed

Indiran, Venkatraman

2017-01-01

Four-dimensional (4D) ultrasound (real-time volume sonography), which has been used in the West since the last decade for the determination of gender as well as for bonding and entertainment of the parents, has become widely available in India in this decade. Here, I would like to discuss the ethical issues associated with 4D ultrasonography in India. These are self-referral, the use of the technology for non-medical indications, a higher possibility of the disclosure of the foetus' gender and safety concerns.

The ultrasound brain helmet: feasibility study of multiple simultaneous 3D scans of cerebral vasculature.

PubMed

Smith, Stephen W; Ivancevich, Nikolas M; Lindsey, Brooks D; Whitman, John; Light, Edward; Fronheiser, Matthew; Nicoletto, Heather A; Laskowitz, Daniel T

2009-02-01

We describe early stage experiments to test the feasibility of an ultrasound brain helmet to produce multiple simultaneous real-time three-dimensional (3D) scans of the cerebral vasculature from temporal and suboccipital acoustic windows of the skull. The transducer hardware and software of the Volumetrics Medical Imaging (Durham, NC, USA) real-time 3D scanner were modified to support dual 2.5 MHz matrix arrays of 256 transmit elements and 128 receive elements which produce two simultaneous 64 degrees pyramidal scans. The real-time display format consists of two coronal B-mode images merged into a 128 degrees sector, two simultaneous parasagittal images merged into a 128 degrees x 64 degrees C-mode plane and a simultaneous 64 degrees axial image. Real-time 3D color Doppler scans from a skull phantom with latex blood vessel were obtained after contrast agent injection as a proof of concept. The long-term goal is to produce real-time 3D ultrasound images of the cerebral vasculature from a portable unit capable of internet transmission thus enabling interactive 3D imaging, remote diagnosis and earlier therapeutic intervention. We are motivated by the urgency for rapid diagnosis of stroke due to the short time window of effective therapeutic intervention.

Medical ultrasound: imaging of soft tissue strain and elasticity

PubMed Central

Wells, Peter N. T.; Liang, Hai-Dong

2011-01-01

After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques—low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)—are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool. PMID:21680780

Arterial blood pressure estimation using ultrasound: Clinical results on healthy volunteers and a medicated hypertensive volunteer.

PubMed

Zakrzewski, Aaron M; Anthony, Brian W

2017-07-01

This study presents a non-occlusive and non-invasive ultrasound-based technique to measure blood pressure. Most popular clinically-used arterial blood pressure measurement techniques suffer from important weaknesses including being inaccurate, invasive, or occlusive. In the proposed technique, an ultrasound probe is placed on the patient's carotid artery and the contact force between the probe and the tissue is slowly increased while ultrasound images and contact force data are recorded. From this data, the artery is segmented and the segmentation data is sent into an optimization procedure; after post-processing, blood pressure is displayed to the user. This technique was applied to 24 healthy single-visit volunteers, one multi-visit healthy volunteer, and one multi-visit medicated hypertensive volunteer. Compared to the oscillometric cuff, the accuracy and precision of the algorithm-reported systolic pressure is -2.4 ± 10.2 mmHg, and for diastolic pressure is -0.3 ± 8.2 mmHg. This method has the potential to occupy a clinical middle-ground between the arterial catheter and the oscillometric cuff.

A joint watermarking/encryption algorithm for verifying medical image integrity and authenticity in both encrypted and spatial domains.

PubMed

Bouslimi, D; Coatrieux, G; Roux, Ch

2011-01-01

In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to the outcomes of the image integrity and of its origins even though the image is stored encrypted. Experimental results achieved on 8 bits encoded Ultrasound images illustrate the overall performances of the proposed scheme. By making use of the AES block cipher in CBC mode, the proposed solution is compliant with or transparent to the DICOM standard.

Quantitative shear wave optical coherence elastography (SW-OCE) with acoustic radiation force impulses (ARFI) induced by phase array transducer

NASA Astrophysics Data System (ADS)

Song, Shaozhen; Le, Nhan Minh; Wang, Ruikang K.; Huang, Zhihong

2015-03-01

Shear Wave Optical Coherence Elastography (SW-OCE) uses the speed of propagating shear waves to provide a quantitative measurement of localized shear modulus, making it a valuable technique for the elasticity characterization of tissues such as skin and ocular tissue. One of the main challenges in shear wave elastography is to induce a reliable source of shear wave; most of nowadays techniques use external vibrators which have several drawbacks such as limited wave propagation range and/or difficulties in non-invasive scans requiring precisions, accuracy. Thus, we propose linear phase array ultrasound transducer as a remote wave source, combined with the high-speed, 47,000-frame-per-second Shear-wave visualization provided by phase-sensitive OCT. In this study, we observed for the first time shear waves induced by a 128 element linear array ultrasound imaging transducer, while the ultrasound and OCT images (within the OCE detection range) were triggered simultaneously. Acoustic radiation force impulses are induced by emitting 10 MHz tone-bursts of sub-millisecond durations (between 50 μm - 100 μm). Ultrasound beam steering is achieved by programming appropriate phase delay, covering a lateral range of 10 mm and full OCT axial (depth) range in the imaging sample. Tissue-mimicking phantoms with agarose concentration of 0.5% and 1% was used in the SW-OCE measurements as the only imaging samples. The results show extensive improvements over the range of SW-OCE elasticity map; such improvements can also be seen over shear wave velocities in softer and stiffer phantoms, as well as determining the boundary of multiple inclusions with different stiffness. This approach opens up the feasibility to combine medical ultrasound imaging and SW-OCE for high-resolution localized quantitative measurement of tissue biomechanical property.

Study of Tissue Phantoms, Tissues, and Contrast Agent with the Biophotoacoustic Radar and Comparison to Ultrasound Imaging for Deep Subsurface Imaging

NASA Astrophysics Data System (ADS)

Alwi, R.; Telenkov, S.; Mandelis, A.; Gu, F.

2012-11-01

In this study, the imaging capability of our wide-spectrum frequency-domain photoacoustic (FD-PA) imaging alias "photoacoustic radar" methodology for imaging of soft tissues is explored. A practical application of the mathematical correlation processing method with relatively long (1 ms) frequency-modulated optical excitation is demonstrated for reconstruction of the spatial location of the PA sources. Image comparison with ultrasound (US) modality was investigated to see the complementarity between the two techniques. The obtained results with a phased array probe on tissue phantoms and their comparison to US images demonstrated that the FD-PA technique has strong potential for deep subsurface imaging with excellent contrast and high signal-to-noise ratio. FD-PA images of blood vessels in a human wrist and an in vivo subcutaneous tumor in a rat model are presented. As in other imaging modalities, the employment of contrast agents is desirable to improve the capability of medical diagnostics. Therefore, this study also evaluated and characterized the use of Food and Drug Administration (FDA)-approved superparamagnetic iron oxide nanoparticles (SPION) as PA contrast agents.

Utilization of bedside urogenital ultrasound in an austere combat setting: enterovesicular fistula case report.

PubMed

Lunceford, Nicole; Scherl, Robert J; Elliot, Jonathan; Bechtel, Brett F; Auten, Jonathan

2013-03-01

The role of bedside ultrasound by physicians with advanced ultrasound training, such as emergency medicine providers, has been clearly established in the austere setting of combat medicine. This highly mobile, noninvasive, and versatile imaging modality has a role in evaluating battle- and nonbattle-related presentations. This case report describes a U.S. Marine reporting to an austere medical facility with the chief complaint of abdominal pain. An ultrasound of the patient's urinary tract revealed abnormalities that suggested right bladder wall thickening and an echo dense layer of sediment as the potential source of his discomfort. These findings supported patient transfer to a higher echelon of care. Further diagnostic testing revealed Crohn's disease with an associated enterovesicular fistula. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Internal Medicine Residents' Retention of Knowledge and Skills in Bedside Ultrasound.

PubMed

Town, James A; Bergl, Paul A; Narang, Akhil; McConville, John F

2016-10-01

The long-term retention of knowledge and skills in bedside ultrasound by internal medicine residents after ultrasound training is not well understood. We sought to determine whether knowledge and skills acquired from focused training in bedside ultrasound are retained over time, and whether retention is related to independent practice. We conducted a prospective observational trial of 101 internal medicine residents at an academic medical center who participated in a bedside ultrasound workshop followed by 12 months of independent practice. Performance was measured on image-based knowledge and skills assessment using direct observation, both before the workshop and 12 months later. Individual usage data were obtained along with a survey on attitudes toward bedside ultrasound. Participants' mean knowledge assessment score increased from a baseline of 63.7% to 84.5% immediately after training ( P  < .001). At 12 months, mean knowledge score fell to 73.0%, significantly different from both prior assessments ( P  < .001). Despite knowledge decline, the mean skills assessment score improved from a baseline of 30.5% to 50.4% at 12 months ( P  < .001). Residents reporting more ultrasound use (> 25 examinations) had higher scores in baseline knowledge and skills assessments than those with lower usage (< 25 examinations). Change in knowledge and image acquisition skills between assessments was equal in both subgroups. Residents' knowledge of ultrasound improved after brief training but decayed over time, whereas skills showed marginal improvement over the study, with minimal support. Growth and retention of ultrasound abilities were not impacted by usage rates.

Internal Medicine Residents' Retention of Knowledge and Skills in Bedside Ultrasound

PubMed Central

Town, James A.; Bergl, Paul A.; Narang, Akhil; McConville, John F.

2016-01-01

ABSTRACT Background  The long-term retention of knowledge and skills in bedside ultrasound by internal medicine residents after ultrasound training is not well understood. Objective  We sought to determine whether knowledge and skills acquired from focused training in bedside ultrasound are retained over time, and whether retention is related to independent practice. Methods  We conducted a prospective observational trial of 101 internal medicine residents at an academic medical center who participated in a bedside ultrasound workshop followed by 12 months of independent practice. Performance was measured on image-based knowledge and skills assessment using direct observation, both before the workshop and 12 months later. Individual usage data were obtained along with a survey on attitudes toward bedside ultrasound. Results  Participants' mean knowledge assessment score increased from a baseline of 63.7% to 84.5% immediately after training (P < .001). At 12 months, mean knowledge score fell to 73.0%, significantly different from both prior assessments (P < .001). Despite knowledge decline, the mean skills assessment score improved from a baseline of 30.5% to 50.4% at 12 months (P < .001). Residents reporting more ultrasound use (> 25 examinations) had higher scores in baseline knowledge and skills assessments than those with lower usage (< 25 examinations). Change in knowledge and image acquisition skills between assessments was equal in both subgroups. Conclusions  Residents' knowledge of ultrasound improved after brief training but decayed over time, whereas skills showed marginal improvement over the study, with minimal support. Growth and retention of ultrasound abilities were not impacted by usage rates. PMID:27777666

Advanced ultrasound applications in the assessment of renal transplants: contrast-enhanced ultrasound, elastography, and B-flow.

PubMed

Morgan, Tara A; Jha, Priyanka; Poder, Liina; Weinstein, Stefanie

2018-04-09

Ultrasound is routinely used as the first imaging exam for evaluation of renal transplants and can identify most major surgical complications and evaluate vascularity with color Doppler. Ultrasound is limited, however, in the detection of parenchymal disease processes and Doppler evaluation is also prone to technical errors. Multiple new ultrasound applications have been developed and are under ongoing investigation which could add additional diagnostic capability to the routine ultrasound exam with minimal additional time, cost, and patient risk. Contrast-enhanced ultrasound (CEUS) can be used off-label in the transplant kidney, and can assist in detection of infection, trauma, and vascular complications. CEUS also can demonstrate perfusion of the transplant assessed quantitatively with generation of time-intensity curves. Future directions of CEUS include monitoring treatment response and microbubble targeted medication delivery. Elastography is an ultrasound application that can detect changes in tissue elasticity, which is useful to diagnose diffuse parenchymal disease, such as fibrosis, otherwise unrecognizable with ultrasound. Elastography has been successfully applied in other organs including the liver, thyroid, and breast; however, it is still under development for use in the transplant kidney. Unique properties of the transplant kidney including its heterogeneity, anatomic location, and other technical factors present challenges in the development of reference standard measurements. Lastly, B-flow imaging is a flow application derived from B-mode. This application can show the true lumen size of a vessel which is useful to depict vascular anatomy and bypasses some of the pitfalls of color Doppler such as demonstration of slow flow.

Real-time dynamic display of registered 4D cardiac MR and ultrasound images using a GPU

NASA Astrophysics Data System (ADS)

Zhang, Q.; Huang, X.; Eagleson, R.; Guiraudon, G.; Peters, T. M.

2007-03-01

In minimally invasive image-guided surgical interventions, different imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), and real-time three-dimensional (3D) ultrasound (US), can provide complementary, multi-spectral image information. Multimodality dynamic image registration is a well-established approach that permits real-time diagnostic information to be enhanced by placing lower-quality real-time images within a high quality anatomical context. For the guidance of cardiac procedures, it would be valuable to register dynamic MRI or CT with intraoperative US. However, in practice, either the high computational cost prohibits such real-time visualization of volumetric multimodal images in a real-world medical environment, or else the resulting image quality is not satisfactory for accurate guidance during the intervention. Modern graphics processing units (GPUs) provide the programmability, parallelism and increased computational precision to begin to address this problem. In this work, we first outline our research on dynamic 3D cardiac MR and US image acquisition, real-time dual-modality registration and US tracking. Then we describe image processing and optimization techniques for 4D (3D + time) cardiac image real-time rendering. We also present our multimodality 4D medical image visualization engine, which directly runs on a GPU in real-time by exploiting the advantages of the graphics hardware. In addition, techniques such as multiple transfer functions for different imaging modalities, dynamic texture binding, advanced texture sampling and multimodality image compositing are employed to facilitate the real-time display and manipulation of the registered dual-modality dynamic 3D MR and US cardiac datasets.

A New Era in Diagnostic Ultrasound, Superb Microvascular Imaging: Preliminary Results in Pediatric Hepato-Gastrointestinal Disorders.

PubMed

Ohno, Yasuharu; Fujimoto, Tamotsu; Shibata, Yukari

2017-02-01

Introduction  Superb microvascular imaging is a new ultrasound image processing technique that uses advanced clutter suppression to extract flow signals from vessels and which helps us visualize very small vascular structures that were not previously visible without the use of a contrast agent. We herein analyzed the usefulness of superb microvascular imaging in the diagnosis of hepato-gastrointestinal disorders in pediatric patients. Materials and Methods  Fifty-six pediatric patients who underwent a total of 81 superb microvascular imaging examinations with an Aplio 300 ultrasound system (Toshiba Medical Systems, Tokyo, Japan) were enrolled in this study. The subjects underwent conventional ultrasound examinations, including Doppler imaging followed by superb microvascular imaging. The superb microvascular imaging findings and standard imaging were compared. All of the examinations were performed without sedation. Results  The average age of the patients (male, n  = 38; female, n  = 18) was 4 years. The clinical diagnoses included hepatobiliary disorders ( n  = 29), acute appendicitis ( n  = 10), and other intestinal disorders ( n  = 17). The target organs for superb microvascular imaging were the liver, appendix, rectum, intestine, gallbladder, and lymph node. In most of the patients, superb microvascular imaging achieved the excellent visualization of microvascular structures, revealing abnormal vasculature in 21 out of 46 (45.7%) examinations of the liver, 9/9 (100%) examinations of the appendix, 0/11 (0%) examinations of the rectum, 9/11 (81.8%) examinations of the intestine, 0/1 (0%) examinations of the gallbladder, and 3/3 (100%) examinations of the lymph nodes. Superb microvascular imaging was superior to Doppler imaging for depicting the microvascular structures. Conclusions  Superb microvascular imaging is especially useful for depicting the microvascular flow and can aid in the diagnosis and treatment planning for pediatric patients with hepato-gastrointestinal disorders. Georg Thieme Verlag KG Stuttgart · New York.

Plantar fascia segmentation and thickness estimation in ultrasound images.

PubMed

Boussouar, Abdelhafid; Meziane, Farid; Crofts, Gillian

2017-03-01

Ultrasound (US) imaging offers significant potential in diagnosis of plantar fascia (PF) injury and monitoring treatment. In particular US imaging has been shown to be reliable in foot and ankle assessment and offers a real-time effective imaging technique that is able to reliably confirm structural changes, such as thickening, and identify changes in the internal echo structure associated with diseased or damaged tissue. Despite the advantages of US imaging, images are difficult to interpret during medical assessment. This is partly due to the size and position of the PF in relation to the adjacent tissues. It is therefore a requirement to devise a system that allows better and easier interpretation of PF ultrasound images during diagnosis. This study proposes an automatic segmentation approach which for the first time extracts ultrasound data to estimate size across three sections of the PF (rearfoot, midfoot and forefoot). This segmentation method uses artificial neural network module (ANN) in order to classify small overlapping patches as belonging or not-belonging to the region of interest (ROI) of the PF tissue. Features ranking and selection techniques were performed as a post-processing step for features extraction to reduce the dimension and number of the extracted features. The trained ANN classifies the image overlapping patches into PF and non-PF tissue, and then it is used to segment the desired PF region. The PF thickness was calculated using two different methods: distance transformation and area-length calculation algorithms. This new approach is capable of accurately segmenting the PF region, differentiating it from surrounding tissues and estimating its thickness. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

NASA Astrophysics Data System (ADS)

Wood, Bradford J.; Yanof, J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kruecker, J.; Bauer, C.; Seip, R.; Kam, A.; Li, K. C. P.

2006-05-01

To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large animals and humans for HIFU-induced ablation and drug delivery. Integrated CT-guided focused ultrasound holds promise for tissue ablation, enhancing local drug delivery, and CT thermometry for monitoring ablation in near real-time.

Fast and robust multimodal image registration using a local derivative pattern.

PubMed

Jiang, Dongsheng; Shi, Yonghong; Chen, Xinrong; Wang, Manning; Song, Zhijian

2017-02-01

Deformable multimodal image registration, which can benefit radiotherapy and image guided surgery by providing complementary information, remains a challenging task in the medical image analysis field due to the difficulty of defining a proper similarity measure. This article presents a novel, robust and fast binary descriptor, the discriminative local derivative pattern (dLDP), which is able to encode images of different modalities into similar image representations. dLDP calculates a binary string for each voxel according to the pattern of intensity derivatives in its neighborhood. The descriptor similarity is evaluated using the Hamming distance, which can be efficiently computed, instead of conventional L1 or L2 norms. For the first time, we validated the effectiveness and feasibility of the local derivative pattern for multimodal deformable image registration with several multi-modal registration applications. dLDP was compared with three state-of-the-art methods in artificial image and clinical settings. In the experiments of deformable registration between different magnetic resonance imaging (MRI) modalities from BrainWeb, between computed tomography and MRI images from patient data, and between MRI and ultrasound images from BITE database, we show our method outperforms localized mutual information and entropy images in terms of both accuracy and time efficiency. We have further validated dLDP for the deformable registration of preoperative MRI and three-dimensional intraoperative ultrasound images. Our results indicate that dLDP reduces the average mean target registration error from 4.12 mm to 2.30 mm. This accuracy is statistically equivalent to the accuracy of the state-of-the-art methods in the study; however, in terms of computational complexity, our method significantly outperforms other methods and is even comparable to the sum of the absolute difference. The results reveal that dLDP can achieve superior performance regarding both accuracy and time efficiency in general multimodal image registration. In addition, dLDP also indicates the potential for clinical ultrasound guided intervention. © 2016 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Integrated photoacoustic, ultrasound and fluorescence platform for diagnostic medical imaging-proof of concept study with a tissue mimicking phantom.

PubMed

James, Joseph; Murukeshan, Vadakke Matham; Woh, Lye Sun

2014-07-01

The structural and molecular heterogeneities of biological tissues demand the interrogation of the samples with multiple energy sources and provide visualization capabilities at varying spatial resolution and depth scales for obtaining complementary diagnostic information. A novel multi-modal imaging approach that uses optical and acoustic energies to perform photoacoustic, ultrasound and fluorescence imaging at multiple resolution scales from the tissue surface and depth is proposed in this paper. The system comprises of two distinct forms of hardware level integration so as to have an integrated imaging system under a single instrumentation set-up. The experimental studies show that the system is capable of mapping high resolution fluorescence signatures from the surface, optical absorption and acoustic heterogeneities along the depth (>2cm) of the tissue at multi-scale resolution (<1µm to <0.5mm).

Region-of-interest breast images with the Twente Photoacoustic Mammoscope (PAM)

NASA Astrophysics Data System (ADS)

Manohar, Srirang; Vaartjes, Sanne E.; van Hespen, Johan G. C.; Klaase, Joost M.; van den Engh, Frank M.; The, Andy K. H.; Steenbergen, Wiendelt; van Leeuwen, Ton G.

2007-02-01

The Twente Photoacoustic Mammoscope (PAM) is based on generating laser-induced ultrasound from absorbing structures in the breast. The heart of the instrument is a flat PVDF based detector matrix comprising 590 active elements. The exciting source is an Nd:YAG laser operating at 1064 nm with 5 ns pulses. The instrument is built around a hospital bed. A study protocol was designed to explore the feasibility of using the photoacoustic technique as embodied in PAM to detect cancer in the breasts of patients with suspect/symptomatic breasts. The protocol was approved by a Medical Ethics testing committee and the instrument approved for laser and electrical safety. The protocol was executed at the Medisch Spectrum Twente by using the mammoscope to obtain photoacoustic region-of-interest (ROI) images of the suspect/symptomatic breasts. We report on one case and compare the photoacoustic images obtained with x-ray mammograms and ultrasound images.

Nerve Entrapment in Ankle and Foot: Ultrasound Imaging.

PubMed

Chari, Basavaraj; McNally, Eugene

2018-07-01

Peripheral nerve entrapment of the ankle and foot is relatively uncommon and often underdiagnosed because electrophysiologic studies may not contribute to the diagnosis. Anatomy of the peripheral nerves is variable and complex, and along with a comprehensive physical examination, a thorough understanding of the applied anatomy is essential. Several studies have helped identify specific areas in which nerves are commonly compressed. Identified secondary causes of nerve compression include previous trauma, osteophytes, ganglion cysts, edema, accessory muscles, tenosynovitis, vascular lesions, and a primary nerve tumor. Imaging plays a key role in identifying primary and secondary causes of nerve entrapment, specifically ultrasound (US) and magnetic resonance imaging. US is a dynamic imaging modality that is cost effective and offers excellent resolution. Symptoms of nerve entrapment may mimic other common foot and ankle conditions such as plantar fasciitis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A 30-MHz piezo-composite ultrasound array for medical imaging applications.

PubMed

Ritter, Timothy A; Shrout, Thomas R; Tutwiler, Rick; Shung, K Kirk

2002-02-01

Ultrasound imaging at frequencies above 20 MHz is capable of achieving improved resolution in clinical applications requiring limited penetration depth. High frequency arrays that allow real-time imaging are desired for these applications but are not yet currently available. In this work, a method for fabricating fine-scale 2-2 composites suitable for 30-MHz linear array transducers was successfully demonstrated. High thickness coupling, low mechanical loss, and moderate electrical loss were achieved. This piezo-composite was incorporated into a 30-MHz array that included acoustic matching, an elevation focusing lens, electrical matching, and an air-filled kerf between elements. Bandwidths near 60%, 15-dB insertion loss, and crosstalk less than -30 dB were measured. Images of both a phantom and an ex vivo human eye were acquired using a synthetic aperture reconstruction method, resulting in measured lateral and axial resolutions of approximately 100 microm.

Interventional robotic systems: Applications and technology state-of-the-art

PubMed Central

CLEARY, KEVIN; MELZER, ANDREAS; WATSON, VANCE; KRONREIF, GERNOT; STOIANOVICI, DAN

2011-01-01

Many different robotic systems have been developed for invasive medical procedures. In this article we will focus on robotic systems for image-guided interventions such as biopsy of suspicious lesions, interstitial tumor treatment, or needle placement for spinal blocks and neurolysis. Medical robotics is a young and evolving field and the ultimate role of these systems has yet to be determined. This paper presents four interventional robotics systems designed to work with MRI, CT, fluoroscopy, and ultrasound imaging devices. The details of each system are given along with any phantom, animal, or human trials. The systems include the AcuBot for active needle insertion under CT or fluoroscopy, the B-Rob systems for needle placement using CT or ultrasound, the INNOMOTION for MRI and CT interventions, and the MRBot for MRI procedures. Following these descriptions, the technology issues of image compatibility, registration, patient movement and respiration, force feedback, and control mode are briefly discussed. It is our belief that robotic systems will be an important part of future interventions, but more research and clinical trials are needed. The possibility of performing new clinical procedures that the human cannot achieve remains an ultimate goal for medical robotics. Engineers and physicians should work together to create and validate these systems for the benefits of patients everywhere. PMID:16754193

Current developments and clinical applications of bubble technology in Japan: a report from 85th Annual Scientific Meeting of The Japan Society of Ultrasonic in Medicine, Tokyo, 25-27 May, 2012.

PubMed

Achmad, Arifudin; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

2013-06-01

The potentials of bubble technology in ultrasound has been investigated thoroughly in the last decade. Japan has entered as one of the leaders in bubble technology in ultrasound since Sonazoid (Daiichi Sankyo & GE Healthcare) was marketed in 2007. The 85th Annual Scientific Meeting of The Japan Society of Ultrasonics in Medicine held in Tokyo from May 25 to 27, 2012 is where researchers and clinicians from all over Japan presented recent advances and new developments in ultrasound in both the medical and the engineering aspects of this science. Even though bubble technology was originally developed simply to improve the conventional ultrasound imaging, recent discoveries have opened up powerful emerging applications. Bubble technology is the particular topic to be reviewed in this report, including its mechanical advances for molecular imaging, drug/gene delivery device and sonoporation up to its current clinical application for liver cancers and other liver, gastrointestinal, kidney and breast diseases.

Palpation imaging using a haptic system for virtual reality applications in medicine.

PubMed

Khaled, W; Reichling, S; Bruhns, O T; Boese, H; Baumann, M; Monkman, G; Egersdoerfer, S; Klein, D; Tunayar, A; Freimuth, H; Lorenz, A; Pessavento, A; Ermert, H

2004-01-01

In the field of medical diagnosis, there is a strong need to determine mechanical properties of biological tissue, which are of histological and pathological relevance. Malignant tumors are significantly stiffer than surrounding healthy tissue. One of the established diagnosis procedures is the palpation of body organs and tissue. Palpation is used to measure swelling, detect bone fracture, find and measure pulse, or to locate changes in the pathological state of tissue and organs. Current medical practice routinely uses sophisticated diagnostic tests through magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) imaging. However, they cannot provide direct measure of tissue elasticity. Last year we presented the concept of the first haptic sensor actuator system to visualize and reconstruct mechanical properties of tissue using ultrasonic elastography and a haptic display with electrorheological fluids. We developed a real time strain imaging system for tumor diagnosis. It allows biopsies simultaneously to conventional ultrasound B-Mode and strain imaging investigations. We deduce the relative mechanical properties by using finite element simulations and numerical solution models solving the inverse problem. Various modifications on the haptic sensor actuator system have been investigated. This haptic system has the potential of inducing real time substantial forces, using a compact lightweight mechanism which can be applied to numerous areas including intraoperative navigation, telemedicine, teaching and telecommunication.

Cancer during Pregnancy

MedlinePlus

... radiation. When possible, women may use a lead shield that covers the abdomen during CT scans. CT scans of the abdomen or pelvis should be done only if absolutely necessary and after discussion with the medical team. Other tests. Magnetic resonance imaging (MRI) , ultrasound , and biopsy are generally ...

NASA biomedical Applications Team Advisory Center for Medical Technology and Systems

NASA Technical Reports Server (NTRS)

Siedband, M. P.

1981-01-01

Projects carried out by the UW-BATeam are reported. The following subjects were investigated: clinical opthalmic ultrasound improvements, magnetic cell sorters, hyperthermia treatment for cancer, joystick driving control for the handicapped, qualitative coronary artery imaging (MIPS), and speech autocuers.

Automatic segmentation and measurements of gestational sac using static B-mode ultrasound images

NASA Astrophysics Data System (ADS)

Ibrahim, Dheyaa Ahmed; Al-Assam, Hisham; Du, Hongbo; Farren, Jessica; Al-karawi, Dhurgham; Bourne, Tom; Jassim, Sabah

2016-05-01

Ultrasound imagery has been widely used for medical diagnoses. Ultrasound scanning is safe and non-invasive, and hence used throughout pregnancy for monitoring growth. In the first trimester, an important measurement is that of the Gestation Sac (GS). The task of measuring the GS size from an ultrasound image is done manually by a Gynecologist. This paper presents a new approach to automatically segment a GS from a static B-mode image by exploiting its geometric features for early identification of miscarriage cases. To accurately locate the GS in the image, the proposed solution uses wavelet transform to suppress the speckle noise by eliminating the high-frequency sub-bands and prepare an enhanced image. This is followed by a segmentation step that isolates the GS through the several stages. First, the mean value is used as a threshold to binarise the image, followed by filtering unwanted objects based on their circularity, size and mean of greyscale. The mean value of each object is then used to further select candidate objects. A Region Growing technique is applied as a post-processing to finally identify the GS. We evaluated the effectiveness of the proposed solution by firstly comparing the automatic size measurements of the segmented GS against the manual measurements, and then integrating the proposed segmentation solution into a classification framework for identifying miscarriage cases and pregnancy of unknown viability (PUV). Both test results demonstrate that the proposed method is effective in segmentation the GS and classifying the outcomes with high level accuracy (sensitivity (miscarriage) of 100% and specificity (PUV) of 99.87%).

Multimodal US-gamma imaging using collaborative robotics for cancer staging biopsies.

PubMed

Esposito, Marco; Busam, Benjamin; Hennersperger, Christoph; Rackerseder, Julia; Navab, Nassir; Frisch, Benjamin

2016-09-01

The staging of female breast cancer requires detailed information about the level of cancer spread through the lymphatic system. Common practice to obtain this information for patients with early-stage cancer is sentinel lymph node (SLN) biopsy, where LNs are radioactively identified for surgical removal and subsequent histological analysis. Punch needle biopsy is a less invasive approach but suffers from the lack of combined anatomical and nuclear information. We present and evaluate a system that introduces live collaborative robotic 2D gamma imaging in addition to live 2D ultrasound to identify SLNs in the surrounding anatomy. The system consists of a robotic arm equipped with both a gamma camera and a stereoscopic tracking system that monitors the position of an ultrasound probe operated by the physician. The arm cooperatively places the gamma camera parallel to the ultrasound imaging plane to provide live multimodal visualization and guidance. We validate the system by evaluating the target registration errors between fused nuclear and US image data in a phantom consisting of two spheres, one of which is filled with radioactivity. Medical experts perform punch biopsies on agar-gelatine phantoms with complex configurations of hot and cold lesions to provide a qualitative and quantitative evaluation of the system. The average point registration error for the overlay is [Formula: see text] mm. The time of the entire procedure was reduced by 36 %, with 80v of the biopsies being successful. The users' feedback was very positive, and the system was deemed to be very intuitive, with handling similar to classic US-guided needle biopsy. We present and evaluate the first medical collaborative robotic imaging system. Feedback from potential users for SLN punch needle biopsy is encouraging. Ongoing work investigates the clinical feasibility with more complex and realistic phantoms.

Estimation and tracking of AP-diameter of the inferior vena cava in ultrasound images using a novel active circle algorithm.

PubMed

Karami, Ebrahim; Shehata, Mohamed S; Smith, Andrew

2018-05-04

Medical research suggests that the anterior-posterior (AP)-diameter of the inferior vena cava (IVC) and its associated temporal variation as imaged by bedside ultrasound is useful in guiding fluid resuscitation of the critically-ill patient. Unfortunately, indistinct edges and gaps in vessel walls are frequently present which impede accurate estimation of the IVC AP-diameter for both human operators and segmentation algorithms. The majority of research involving use of the IVC to guide fluid resuscitation involves manual measurement of the maximum and minimum AP-diameter as it varies over time. This effort proposes using a time-varying circle fitted inside the typically ellipsoid IVC as an efficient, consistent and novel approach to tracking and approximating the AP-diameter even in the context of poor image quality. In this active-circle algorithm, a novel evolution functional is proposed and shown to be a useful tool for ultrasound image processing. The proposed algorithm is compared with an expert manual measurement, and state-of-the-art relevant algorithms. It is shown that the algorithm outperforms other techniques and performs very close to manual measurement. Copyright © 2018 Elsevier Ltd. All rights reserved.

Noninvasive Test Detects Cardiovascular Disease

NASA Technical Reports Server (NTRS)

2007-01-01

At NASA's Jet Propulsion Laboratory (JPL), NASA-developed Video Imaging Communication and Retrieval (VICAR) software laid the groundwork for analyzing images of all kinds. A project seeking to use imaging technology for health care diagnosis began when the imaging team considered using the VICAR software to analyze X-ray images of soft tissue. With marginal success using X-rays, the team applied the same methodology to ultrasound imagery, which was already digitally formatted. The new approach proved successful for assessing amounts of plaque build-up and arterial wall thickness, direct predictors of heart disease, and the result was a noninvasive diagnostic system with the ability to accurately predict heart health. Medical Technologies International Inc. (MTI) further developed and then submitted the technology to a vigorous review process at the FDA, which cleared the software for public use. The software, patented under the name Prowin, is being used in MTI's patented ArterioVision, a carotid intima-media thickness (CIMT) test that uses ultrasound image-capturing and analysis software to noninvasively identify the risk for the major cause of heart attack and strokes: atherosclerosis. ArterioVision provides a direct measurement of atherosclerosis by safely and painlessly measuring the thickness of the first two layers of the carotid artery wall using an ultrasound procedure and advanced image-analysis software. The technology is now in use in all 50 states and in many countries throughout the world.

The ultrasound brain helmet: early human feasibility study of multiple simultaneous 3D scans of cerebral vasculature

NASA Astrophysics Data System (ADS)

Lindsey, Brooks D.; Ivancevich, Nikolas M.; Whitman, John; Light, Edward; Fronheiser, Matthew; Nicoletto, Heather A.; Laskowitz, Daniel T.; Smith, Stephen W.

2009-02-01

We describe early stage experiments to test the feasibility of an ultrasound brain helmet to produce multiple simultaneous real-time 3D scans of the cerebral vasculature from temporal and suboccipital acoustic windows of the skull. The transducer hardware and software of the Volumetrics Medical Imaging real-time 3D scanner were modified to support dual 2.5 MHz matrix arrays of 256 transmit elements and 128 receive elements which produce two simultaneous 64° pyramidal scans. The real-time display format consists of two coronal B-mode images merged into a 128° sector, two simultaneous parasagittal images merged into a 128° × 64° C-mode plane, and a simultaneous 64° axial image. Real-time 3D color Doppler images acquired in initial clinical studies after contrast injection demonstrate flow in several representative blood vessels. An offline Doppler rendering of data from two transducers simultaneously scanning via the temporal windows provides an early visualization of the flow in vessels on both sides of the brain. The long-term goal is to produce real-time 3D ultrasound images of the cerebral vasculature from a portable unit capable of internet transmission, thus enabling interactive 3D imaging, remote diagnosis and earlier therapeutic intervention. We are motivated by the urgency for rapid diagnosis of stroke due to the short time window of effective therapeutic intervention.

Optimization of contrast-to-tissue ratio by adaptation of transmitted ternary signal in ultrasound pulse inversion imaging.

PubMed

Ménigot, Sébastien; Girault, Jean-Marc

2013-01-01

Ultrasound contrast imaging has provided more accurate medical diagnoses thanks to the development of innovating modalities like the pulse inversion imaging. However, this latter modality that improves the contrast-to-tissue ratio (CTR) is not optimal, since the frequency is manually chosen jointly with the probe. However, an optimal choice of this command is possible, but it requires precise information about the transducer and the medium which can be experimentally difficult to obtain, even inaccessible. It turns out that the optimization can become more complex by taking into account the kind of generators, since the generators of electrical signals in a conventional ultrasound scanner can be unipolar, bipolar, or tripolar. Our aim was to seek the ternary command which maximized the CTR. By combining a genetic algorithm and a closed loop, the system automatically proposed the optimal ternary command. In simulation, the gain compared with the usual ternary signal could reach about 3.9 dB. Another interesting finding was that, in contrast to what is generally accepted, the optimal command was not a fixed-frequency signal but had harmonic components.

WE-E-9A-01: Ultrasound Elasticity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emelianov, S; Hall, T; Bouchard, R

2014-06-15

Principles and techniques of ultrasound-based elasticity imaging will be presented, including quasistatic strain imaging, shear wave elasticity imaging, and their implementations in available systems. Deeper exploration of quasistatic methods, including elastic relaxation, and their applications, advantages, artifacts and limitations will be discussed. Transient elastography based on progressive and standing shear waves will be explained in more depth, along with applications, advantages, artifacts and limitations, as will measurement of complex elastic moduli. Comparisons will be made between ultrasound radiation force techniques, MR elastography, and the simple A mode plus mechanical plunger technique. Progress in efforts, such as that by the Quantitativemore » Imaging Biomarkers Alliance, to reduce the differences in the elastic modulus reported by different commercial systems will be explained. Dr. Hall is on an Advisory Board for Siemens Ultrasound and has a research collaboration with them, including joint funding by R01CA140271 for nonlinear elasticity imaging. Learning Objectives: Be reminded of the long history of palpation of tissue elasticity for critical medical diagnosis and the relatively recent advances to be able to image tissue strain in response to an applied force. Understand the differences between shear wave speed elasticity measurement and imaging and understand the factors affecting measurement and image frame repletion rates. Understand shear wave propagation effects that can affect measurements, such as essentially lack of propagation in fluids and boundary effects, so important in thin layers. Know characteristics of available elasticity imaging phantoms, their uses and limitations. Understand thermal and cavitational limitations affecting radiation force-based shear wave imaging. Have learning and references adequate to for you to use in teaching elasticity imaging to residents and technologists. Be able to explain how elasticity measurement and imaging can contribute to diagnosis of breast and prostate cancer, staging of liver fibrosis, age estimation of deep veinous fhrombosis, confirmation of thermal lesions in the liver after RF ablation.« less

Implementation of a 4-Year Point-of-Care Ultrasound Curriculum in a Liaison Committee on Medical Education-Accredited US Medical School.

PubMed

Wilson, Sean P; Mefford, Jason M; Lahham, Shadi; Lotfipour, Shahram; Subeh, Mohammad; Maldonado, Gracie; Spann, Sophie; Fox, John C

2017-02-01

The established benefits of point-of-care ultrasound have given rise to multiple new and innovative curriculums to incorporate ultrasound teaching into medical education. This study sought to measure the educational success of a comprehensive and integrated 4-year point-of-care ultrasound curriculum. We integrated a curriculum consisting of traditional didactics combined with asynchronous learning modules and hands-on practice on live models with skilled sonographers into all 4 years of education at a Liaison Committee on Medical Education-accredited US Medical School. Each graduating student was administered an exit examination with 48 questions that corresponded to ultrasound milestones. Ninety-five percent (n = 84) of fourth-year medical students completed the exit examination. The mean score was 79.5% (SD, 10.2%), with mean scores on the ultrasound physics and anatomy subsections being 77.1% (SD, 11.0%) and 85.9% (SD, 21.0%), respectively. A comprehensive 4-year point-of-care ultrasound curriculum integrated into medical school may successfully equip graduating medical students with a fundamental understanding of ultrasound physics, anatomy, and disease recognition. © 2016 by the American Institute of Ultrasound in Medicine.

Acoustic Waves in Medical Imaging and Diagnostics

PubMed Central

Sarvazyan, Armen P.; Urban, Matthew W.; Greenleaf, James F.

2013-01-01

Up until about two decades ago acoustic imaging and ultrasound imaging were synonymous. The term “ultrasonography,” or its abbreviated version “sonography” meant an imaging modality based on the use of ultrasonic compressional bulk waves. Since the 1990s numerous acoustic imaging modalities started to emerge based on the use of a different mode of acoustic wave: shear waves. It was demonstrated that imaging with these waves can provide very useful and very different information about the biological tissue being examined. We will discuss physical basis for the differences between these two basic modes of acoustic waves used in medical imaging and analyze the advantages associated with shear acoustic imaging. A comprehensive analysis of the range of acoustic wavelengths, velocities, and frequencies that have been used in different imaging applications will be presented. We will discuss the potential for future shear wave imaging applications. PMID:23643056

Validation of On-Orbit Methodology for the Assessment of Cardiac Function and Changes in the Circulating Volume Using Ultrasound and "Braslet-M" Occlusion Cuffs

NASA Technical Reports Server (NTRS)

Bogomolov, V. V.; Duncan, J. M.; Alferova, I. V.; Dulchavsky, S. A.; Ebert, D.; Hamilton, D. R.; Matveev, V. P.; Sargsyan, A. E.

2008-01-01

Recent advances in remotely guided imaging techniques on ISS allow the acquisition of high quality ultrasound data using crewmember operators with no medical background and minimal training. However, ongoing efforts are required to develop and validate methodology for complex imaging protocols to ensure their repeatability, efficiency, and suitability for use aboard the ISS. This Station Developmental Test Objective (SDTO) tests a cardiovascular evaluation methodology that takes advantage of the ISS Ultrasound capability, the Braslet-M device, and modified respiratory maneuvers (Valsalva and Mueller), to broaden the spectrum of anatomical and functional information on human cardiovascular system during long-duration space missions. The proposed methodology optimizes and combines new and previously demonstrated methods, and is expected to benefit medically indicated assessments, operational research protocols, and data collections for science. Braslet-M is a current Russian operational countermeasure that compresses the upper thigh to impede the venous return from lower extremities. The goal of the SDTO is to establish and validate a repeatable ultrasound-based methodology for the assessment of a number of cardiovascular criteria in microgravity. Braslet-M device is used as a means to acutely alter volume distribution while focused ultrasound measurements are performed. Modified respiratory maneuvers are done upon volume manipulations to record commensurate changes in anatomical and functional parameters. The overall cardiovascular effects of the Braslet-M device are not completely understood, and although not a primary objective of this SDTO, this effort will provide pilot data regarding the suitability of Braslet-M for its intended purpose, effects, and the indications for its use.

Optical Micromachined Ultrasound Transducers (OMUT)-- A New Approach for High Frequency Ultrasound Imaging

NASA Astrophysics Data System (ADS)

Tadayon, Mohammad Amin

Piezoelectric technology is the backbone of most medical ultrasound imaging arrays, however, in scaling the technology to sizes required for high frequency operation (> 20 MHz), it encounters substantial difficulties in fabrication and signal transduction efficiency. These limitations particularly affect the design of intravascular ultrasound (IVUS) imaging probes whose operating frequency can approach 60 MHz. Optical technology has been proposed and investigated for several decades as an alternative approach for high frequency ultrasound transducers. However, to apply this promising technology in guiding clinical operations such as in interventional cardiology, brain surgery, and laparoscopic surgery further raise in the sensitivity is required. Here, in order to achieve the required sensitivity for an intravascular ultrasound imaging probe, we introduce design changes making use of alternative receiver mechanisms. First, we present an air cavity detector that makes use of a polymer membrane for increased mechanical deflection. We have also significantly raised the thin film detector sensitivity by improving its optical characteristics. This can be achieved by inducing a refractive index feature inside the Fabry-Perot resonator that simply creates a waveguide between the two mirrors. This approach eliminates the loss in energy due to diffraction in the cavity, and therefore the Q-factor is only limited by mirror loss and absorption. To demonstrate this optical improvements, a waveguide Fabry-Perot resonator has been fabricated consisting of two dielectric Bragg reflectors with a layer of photosensitive polymer between them. The measured finesse of the fabricated resonator was 692, and the Q-factor was 55000. The fabrication process of this device has been modified to fabricate an ultrasonically testable waveguide Fabry-Perot resonator. By applying this method, we have achieved a noise equivalent pressure of 178 Pa over a bandwidth of 28 MHz or 0.03 Pa/Hz1/2 which is approximately 20-fold better than a similar device without a waveguide. The finesse of the tested Fabry-Perot resonator was around 200. This result is 5 times higher than the finesse measured in the same device outside the waveguide region. In future, our developed technology can be integrated on the tip of an optical fiber bundle and applied for intravascular ultrasound imaging.

Real-time ultrasound-tagging to track the 2D motion of the common carotid artery wall in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zahnd, Guillaume, E-mail: g.zahnd@erasmusmc.nl; Salles, Sébastien; Liebgott, Hervé

2015-02-15

Purpose: Tracking the motion of biological tissues represents an important issue in the field of medical ultrasound imaging. However, the longitudinal component of the motion (i.e., perpendicular to the beam axis) remains more challenging to extract due to the rather coarse resolution cell of ultrasound scanners along this direction. The aim of this study is to introduce a real-time beamforming strategy dedicated to acquire tagged images featuring a distinct pattern in the objective to ease the tracking. Methods: Under the conditions of the Fraunhofer approximation, a specific apodization function was applied to the received raw channel data, in real-time duringmore » image acquisition, in order to introduce a periodic oscillations pattern along the longitudinal direction of the radio frequency signal. Analytic signals were then extracted from the tagged images, and subpixel motion tracking of the intima–media complex was subsequently performed offline, by means of a previously introduced bidimensional analytic phase-based estimator. Results: The authors’ framework was applied in vivo on the common carotid artery from 20 young healthy volunteers and 6 elderly patients with high atherosclerosis risk. Cine-loops of tagged images were acquired during three cardiac cycles. Evaluated against reference trajectories manually generated by three experienced analysts, the mean absolute tracking error was 98 ± 84 μm and 55 ± 44 μm in the longitudinal and axial directions, respectively. These errors corresponded to 28% ± 23% and 13% ± 9% of the longitudinal and axial amplitude of the assessed motion, respectively. Conclusions: The proposed framework enables tagged ultrasound images of in vivo tissues to be acquired in real-time. Such unconventional beamforming strategy contributes to improve tracking accuracy and could potentially benefit to the interpretation and diagnosis of biomedical images.« less

Efficient Sample Delay Calculation for 2-D and 3-D Ultrasound Imaging.

PubMed

Ibrahim, Aya; Hager, Pascal A; Bartolini, Andrea; Angiolini, Federico; Arditi, Marcel; Thiran, Jean-Philippe; Benini, Luca; De Micheli, Giovanni

2017-08-01

Ultrasound imaging is a reference medical diagnostic technique, thanks to its blend of versatility, effectiveness, and moderate cost. The core computation of all ultrasound imaging methods is based on simple formulae, except for those required to calculate acoustic propagation delays with high precision and throughput. Unfortunately, advanced three-dimensional (3-D) systems require the calculation or storage of billions of such delay values per frame, which is a challenge. In 2-D systems, this requirement can be four orders of magnitude lower, but efficient computation is still crucial in view of low-power implementations that can be battery-operated, enabling usage in numerous additional scenarios. In this paper, we explore two smart designs of the delay generation function. To quantify their hardware cost, we implement them on FPGA and study their footprint and performance. We evaluate how these architectures scale to different ultrasound applications, from a low-power 2-D system to a next-generation 3-D machine. When using numerical approximations, we demonstrate the ability to generate delay values with sufficient throughput to support 10 000-channel 3-D imaging at up to 30 fps while using 63% of a Virtex 7 FPGA, requiring 24 MB of external memory accessed at about 32 GB/s bandwidth. Alternatively, with similar FPGA occupation, we show an exact calculation method that reaches 24 fps on 1225-channel 3-D imaging and does not require external memory at all. Both designs can be scaled to use a negligible amount of resources for 2-D imaging in low-power applications and for ultrafast 2-D imaging at hundreds of frames per second.

Quality assurance in ultrasound screening for hepatocellular carcinoma using a standardized phantom and standard clinical images: a 3-year national investigation in Korea.

PubMed

Choi, Joon-Il; Jung, Seung Eun; Kim, Pyo Nyun; Cha, Sang Hoon; Jun, Jae Kwan; Lee, Hoo-Yeon; Park, Eun-Cheol

2014-06-01

The purpose of this study was to investigate the quality of ultrasound (US) imaging for hepatocellular carcinoma screening. The investigation was performed at all medical institutes participating in the National Cancer Screening Program in Korea. For assessment of personnel, we inquired who was performing the US screenings. For phantom image evaluation, the dead zone, vertical and horizontal measurements, axial and lateral resolution, sensitivity, and gray scale/dynamic range were evaluated. For clinical image evaluation, US images of patients were evaluated in terms of the standard images, technical information, overall image quality, appropriateness of depth, foci, annotations, and the presence of any artifacts. Failure rates for phantom and clinical image evaluations at general hospitals, smaller hospitals, and private clinics were 20.9%, 24.5%, 24.1% and 5.5%, and 14.8% and 9.5%, respectively. No statistically significant difference was observed in the failure rates for the phantom images among groups of different years of manufacture. For the clinical image evaluation, the results of radiologists were significantly better than those of other professional groups (P = .0001 and .0004 versus nonradiology physicians and nonphysicians, respectively). The failure rate was also higher when the storage format was analog versus digital (P < .001). Approximately 20% of US scanners failed the phantom image evaluation. The year of scanner manufacture was not significantly associated with the results of the phantom image evaluation. The quality of the clinical images obtained by radiologists was the best. © 2014 by the American Institute of Ultrasound in Medicine.

Co-robotic ultrasound imaging: a cooperative force control approach

NASA Astrophysics Data System (ADS)

Finocchi, Rodolfo; Aalamifar, Fereshteh; Fang, Ting Yun; Taylor, Russell H.; Boctor, Emad M.

2017-03-01

Ultrasound (US) imaging remains one of the most commonly used imaging modalities in medical practice. However, due to the physical effort required to perform US imaging tasks, 63-91% of ultrasonographers develop musculoskeletal disorders throughout their careers. The goal of this work is to provide ultrasonographers with a system that facilitates and reduces strain in US image acquisition. To this end, we propose a system for admittance force robot control that uses the six-degree-of-freedom UR5 industrial robot. A six-axis force sensor is used to measure the forces and torques applied by the sonographer on the probe. As the sonographer pushes against the US probe, the robot complies with these forces, following the user's desired path. A one-axis load cell is used to measure contact forces between the patient and the probe in real time. When imaging, the robot augments the axial forces applied by the user, lessening the physical effort required. User studies showed an overall decrease in hand tremor while imaging at high forces, improvements in image stability, and a decrease in difficulty and strenuousness.

Image-guided interventional procedures in the dog and cat.

PubMed

Vignoli, Massimo; Saunders, Jimmy H

2011-03-01

Medical imaging is essential for the diagnostic workup of many soft tissue and bone lesions in dogs and cats, but imaging modalities do not always allow the clinician to differentiate inflammatory or infectious conditions from neoplastic disorders. This review describes interventional procedures in dogs and cats for collection of samples for cytological or histopathological examinations under imaging guidance. It describes the indications and procedures for imaging-guided sampling, including ultrasound (US), computed tomography (CT), magnetic resonance imaging and fluoroscopy. US and CT are currently the modalities of choice in interventional imaging. Copyright © 2009 Elsevier Ltd. All rights reserved.

Ethical analysis of non-medical fetal ultrasound.

PubMed

Leung, John Lai Yin; Pang, Samantha Mei Che

2009-09-01

Obstetric ultrasound is the well-recognized prenatal test used to visualize and determine the condition of a pregnant woman and her fetus. Apart from the clinical application, some businesses have started promoting the use of fetal ultrasound machines for nonmedical reasons. Non-medical fetal ultrasound (also known as 'keepsake' ultrasound) is defined as using ultrasound to view, take a picture, or determine the sex of a fetus without a medical indication. Notwithstanding the guidelines and warnings regarding ultrasound safety issued by governments and professional bodies, the absence of scientifically proven physical harm to fetuses from this procedure seems to provide these businesses with grounds for rapid expansion. However, this argument is too simplistic because current epidemiological evidence is not synchronous with advancing ultrasound technology. As non-medical fetal ultrasound has aroused very significant public attention, a thorough ethical analysis of this topic is essential. Using a multifaceted approach, we analyse the ethical perspective of non-medical fetal ultrasound in terms of the expectant mother, the fetus and health professionals. After applying four major theories of ethics and principles (the precautionary principle; theories of consequentialism and impartiality; duty-based theory; and rights-based theories), we conclude that obstetric ultrasound practice is ethically justifiable only if the indication for its use is based on medical evidence. Non-medical fetal ultrasound can be considered ethically unjustifiable. Nevertheless, the ethical analysis of this issue is time dependent owing to rapid advancements in ultrasound technology and the safety issue. The role of health professionals in ensuring that obstetric ultrasound is an ethically justifiable practice is also discussed.

Is it time to include point-of-care ultrasound in general surgery training? A review to stimulate discussion.

PubMed

Mollenkopf, Maximilian; Tait, Noel

2013-12-01

Point-of-care ultrasound scanning or POCUS is a focused ultrasound (US) scan, performed by non-imaging clinicians during physical examination, an invasive procedure or surgery. As this technology becomes cheaper, smaller and easier to use, its scope for use by surgeons grows, a trend that may generate a gap between use and training. Opportunities for enhanced general surgery skill sets may be reduced unless consideration is given to inclusion of POCUS in general surgery training. To stimulate discussion regarding inclusion of POCUS in the general surgery curriculum; to resource this discussion with an overview of current trends and issues around POCUS; and to discuss concerns and controversies that may arise if POCUS was adopted into general surgery training. A literature search was performed using PUBMED, MEDLINE, Google and Google Scholar, using the terms 'ultrasound', 'point-of-care-ultrasound', 'bedside ultrasound', 'portable ultrasound' and 'hand-held ultrasound'. Literature, references and non-literature resources found were reviewed for relevance to US education in general surgery. Increasingly, medical students are graduating with basic POCUS skills. Specialty-specific uses of POCUS are proliferating. Training and assessment resources are not keeping up, in accessibility or standardization. A learned surgical college led training and accreditation process would require aligned education in anatomy and US technology and collaboration with the specialist imaging community to ensure appropriate standards are clarified and met. Research is also required into how general surgery trainees can best achieve and maintain POCUS competence. © 2013 Royal Australasian College of Surgeons.

Reversible Watermarking Surviving JPEG Compression.

PubMed

Zain, J; Clarke, M

2005-01-01

This paper will discuss the properties of watermarking medical images. We will also discuss the possibility of such images being compressed by JPEG and give an overview of JPEG compression. We will then propose a watermarking scheme that is reversible and robust to JPEG compression. The purpose is to verify the integrity and authenticity of medical images. We used 800x600x8 bits ultrasound (US) images in our experiment. SHA-256 of the image is then embedded in the Least significant bits (LSB) of an 8x8 block in the Region of Non Interest (RONI). The image is then compressed using JPEG and decompressed using Photoshop 6.0. If the image has not been altered, the watermark extracted will match the hash (SHA256) of the original image. The result shown that the embedded watermark is robust to JPEG compression up to image quality 60 (~91% compressed).

A perspective on high-frequency ultrasound for medical applications

NASA Astrophysics Data System (ADS)

Mamou, Jonathan; Aristizába, Orlando; Silverman, Ronald H.; Ketterling, Jeffrey A.

2010-01-01

High-frequency ultrasound (HFU, >15 MHz) is a rapidly developing field. HFU is currently used and investigated for ophthalmologic, dermatologic, intravascular, and small-animal imaging. HFU offers a non-invasive means to investigate tissue at the microscopic level with resolutions often better than 100 μm. However, fine resolution is only obtained over the limited depth-of-field (˜1 mm) of single-element spherically-focused transducers typically used for HFU applications. Another limitation is penetration depth because most biological tissues have large attenuation at high frequencies. In this study, two 5-element annular arrays with center frequencies of 17 and 34 MHz were fabricated and methods were developed to obtain images with increased penetration depth and depth-of-field. These methods were used in ophthalmologic and small-animal imaging studies. Improved blood sensitivity was obtained when a phantom mimicking a vitreous hemorrhage was imaged. Central-nervous systems of 12.5-day-old mouse embryos were imaged in utero and in three dimensions for the first time.

Sensitivity of simulated transcranial ultrasound fields to acoustic medium property maps

NASA Astrophysics Data System (ADS)

Robertson, James; Martin, Eleanor; Cox, Ben; Treeby, Bradley E.

2017-04-01

High intensity transcranial focused ultrasound is an FDA approved treatment for essential tremor, while low-intensity applications such as neurostimulation and opening the blood brain barrier are under active research. Simulations of transcranial ultrasound propagation are used both for focusing through the skull, and predicting intracranial fields. Maps of the skull acoustic properties are necessary for accurate simulations, and can be derived from medical images using a variety of methods. The skull maps range from segmented, homogeneous models, to fully heterogeneous models derived from medical image intensity. In the present work, the impact of uncertainties in the skull properties is examined using a model of transcranial propagation from a single element focused transducer. The impact of changes in bone layer geometry and the sound speed, density, and acoustic absorption values is quantified through a numerical sensitivity analysis. Sound speed is shown to be the most influential acoustic property, and must be defined with less than 4% error to obtain acceptable accuracy in simulated focus pressure, position, and volume. Changes in the skull thickness of as little as 0.1 mm can cause an error in peak intracranial pressure of greater than 5%, while smoothing with a 1 \\text{m}{{\\text{m}}3} kernel to imitate the effect of obtaining skull maps from low resolution images causes an increase of over 50% in peak pressure. The numerical results are confirmed experimentally through comparison with sonications made through 3D printed and resin cast skull bone phantoms.

MITK-OpenIGTLink for combining open-source toolkits in real-time computer-assisted interventions.

PubMed

Klemm, Martin; Kirchner, Thomas; Gröhl, Janek; Cheray, Dominique; Nolden, Marco; Seitel, Alexander; Hoppe, Harald; Maier-Hein, Lena; Franz, Alfred M

2017-03-01

Due to rapid developments in the research areas of medical imaging, medical image processing and robotics, computer-assisted interventions (CAI) are becoming an integral part of modern patient care. From a software engineering point of view, these systems are highly complex and research can benefit greatly from reusing software components. This is supported by a number of open-source toolkits for medical imaging and CAI such as the medical imaging interaction toolkit (MITK), the public software library for ultrasound imaging research (PLUS) and 3D Slicer. An independent inter-toolkit communication such as the open image-guided therapy link (OpenIGTLink) can be used to combine the advantages of these toolkits and enable an easier realization of a clinical CAI workflow. MITK-OpenIGTLink is presented as a network interface within MITK that allows easy to use, asynchronous two-way messaging between MITK and clinical devices or other toolkits. Performance and interoperability tests with MITK-OpenIGTLink were carried out considering the whole CAI workflow from data acquisition over processing to visualization. We present how MITK-OpenIGTLink can be applied in different usage scenarios. In performance tests, tracking data were transmitted with a frame rate of up to 1000 Hz and a latency of 2.81 ms. Transmission of images with typical ultrasound (US) and greyscale high-definition (HD) resolutions of [Formula: see text] and [Formula: see text] is possible at up to 512 and 128 Hz, respectively. With the integration of OpenIGTLink into MITK, this protocol is now supported by all established open-source toolkits in the field. This eases interoperability between MITK and toolkits such as PLUS or 3D Slicer and facilitates cross-toolkit research collaborations. MITK and its submodule MITK-OpenIGTLink are provided open source under a BSD-style licence ( http://mitk.org ).

WE-H-209-00: Carson/Zagzebski Distinguished Lectureship: Image Guided Ultrasound Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Focused ultrasound has been shown to be the only method that allows noninvasive thermal coagulation of tissues and recently this potential has been explored for image-guided drug delivery. In this presentation, the advances in ultrasound phased array technology for energy delivery, exposure monitoring and control will be discussed. Experimental results from novel multi-frequency transmit/receive arrays will be presented. In addition, the feasibility of fully electronically focused and steered high power arrays with many thousands of transducer elements will be discussed. Finally, some of the recent clinical and preclinical results for the treatment of brain disease will be reviewed. Learning Objectives:more » Introduce FUS therapy principles and modern techniques Discuss use of FUS for drug delivery Cover the technology required to deliver FUS and monitor therapy Present clinical examples of the uses of these techniques This research was supported by funding from The Canada Research Chair Program, Grants from CIHR and NIH (no. EB003268).; K. Hynynen, Canada Foundation for Innovation; Canadian Institutes of Health Research; Focused Ultrasound Surgery Foundation; Canada Research Chair Program; Natural Sciences and Engineering Research Council of Canada; Ontario Research Fund; National Institutes of Health; Canadian Cancer Society Research Institute; The Weston Brain Institute; Harmonic Medical; Focused Ultrasound Instruments.« less

Robot-assisted ultrasound imaging: overview and development of a parallel telerobotic system.

PubMed

Monfaredi, Reza; Wilson, Emmanuel; Azizi Koutenaei, Bamshad; Labrecque, Brendan; Leroy, Kristen; Goldie, James; Louis, Eric; Swerdlow, Daniel; Cleary, Kevin

2015-02-01

Ultrasound imaging is frequently used in medicine. The quality of ultrasound images is often dependent on the skill of the sonographer. Several researchers have proposed robotic systems to aid in ultrasound image acquisition. In this paper we first provide a short overview of robot-assisted ultrasound imaging (US). We categorize robot-assisted US imaging systems into three approaches: autonomous US imaging, teleoperated US imaging, and human-robot cooperation. For each approach several systems are introduced and briefly discussed. We then describe a compact six degree of freedom parallel mechanism telerobotic system for ultrasound imaging developed by our research team. The long-term goal of this work is to enable remote ultrasound scanning through teleoperation. This parallel mechanism allows for both translation and rotation of an ultrasound probe mounted on the top plate along with force control. Our experimental results confirmed good mechanical system performance with a positioning error of < 1 mm. Phantom experiments by a radiologist showed promising results with good image quality.

MLESAC Based Localization of Needle Insertion Using 2D Ultrasound Images

NASA Astrophysics Data System (ADS)

Xu, Fei; Gao, Dedong; Wang, Shan; Zhanwen, A.

2018-04-01

In the 2D ultrasound image of ultrasound-guided percutaneous needle insertions, it is difficult to determine the positions of needle axis and tip because of the existence of artifacts and other noises. In this work the speckle is regarded as the noise of an ultrasound image, and a novel algorithm is presented to detect the needle in a 2D ultrasound image. Firstly, the wavelet soft thresholding technique based on BayesShrink rule is used to denoise the speckle of ultrasound image. Secondly, we add Otsu’s thresholding method and morphologic operations to pre-process the ultrasound image. Finally, the localization of the needle is identified and positioned in the 2D ultrasound image based on the maximum likelihood estimation sample consensus (MLESAC) algorithm. The experimental results show that it is valid for estimating the position of needle axis and tip in the ultrasound images with the proposed algorithm. The research work is hopeful to be used in the path planning and robot-assisted needle insertion procedures.

Medical Ultrasound Video Coding with H.265/HEVC Based on ROI Extraction

PubMed Central

Wu, Yueying; Liu, Pengyu; Gao, Yuan; Jia, Kebin

2016-01-01

High-efficiency video compression technology is of primary importance to the storage and transmission of digital medical video in modern medical communication systems. To further improve the compression performance of medical ultrasound video, two innovative technologies based on diagnostic region-of-interest (ROI) extraction using the high efficiency video coding (H.265/HEVC) standard are presented in this paper. First, an effective ROI extraction algorithm based on image textural features is proposed to strengthen the applicability of ROI detection results in the H.265/HEVC quad-tree coding structure. Second, a hierarchical coding method based on transform coefficient adjustment and a quantization parameter (QP) selection process is designed to implement the otherness encoding for ROIs and non-ROIs. Experimental results demonstrate that the proposed optimization strategy significantly improves the coding performance by achieving a BD-BR reduction of 13.52% and a BD-PSNR gain of 1.16 dB on average compared to H.265/HEVC (HM15.0). The proposed medical video coding algorithm is expected to satisfy low bit-rate compression requirements for modern medical communication systems. PMID:27814367

Medical Ultrasound Video Coding with H.265/HEVC Based on ROI Extraction.

PubMed

Wu, Yueying; Liu, Pengyu; Gao, Yuan; Jia, Kebin

2016-01-01

High-efficiency video compression technology is of primary importance to the storage and transmission of digital medical video in modern medical communication systems. To further improve the compression performance of medical ultrasound video, two innovative technologies based on diagnostic region-of-interest (ROI) extraction using the high efficiency video coding (H.265/HEVC) standard are presented in this paper. First, an effective ROI extraction algorithm based on image textural features is proposed to strengthen the applicability of ROI detection results in the H.265/HEVC quad-tree coding structure. Second, a hierarchical coding method based on transform coefficient adjustment and a quantization parameter (QP) selection process is designed to implement the otherness encoding for ROIs and non-ROIs. Experimental results demonstrate that the proposed optimization strategy significantly improves the coding performance by achieving a BD-BR reduction of 13.52% and a BD-PSNR gain of 1.16 dB on average compared to H.265/HEVC (HM15.0). The proposed medical video coding algorithm is expected to satisfy low bit-rate compression requirements for modern medical communication systems.

Early Detection of Ovarian Cancer by Molecular Targeted Ultrasound Imaging Together with Serum Markers of Tumor-Associated Nuclear Change and Angiogenesis

DTIC Science & Technology

2014-03-01

Pincas; Rush University Medical Center, Pathology, Obstetrics and Gynecology Basu, Sanjib; Rush University Medical Center, Preventive Medicine ...and Jacques S Abramowicz 2, 5 Departments of 1 Pharmacology, 2 Obstetrics and Gynecology, 3 Pathology, 5 Preventive Medicine (Biostatistics...Animal Sciences, University of Illinois at Urbana-Champaign, Urbana (Dr Bahr Obstetrics and Gynecology, Wayne State University School of Medicine

Method and system to synchronize acoustic therapy with ultrasound imaging

NASA Technical Reports Server (NTRS)

Hossack, James (Inventor); Owen, Neil (Inventor); Bailey, Michael R. (Inventor)

2009-01-01

Interference in ultrasound imaging when used in connection with high intensity focused ultrasound (HIFU) is avoided by employing a synchronization signal to control the HIFU signal. Unless the timing of the HIFU transducer is controlled, its output will substantially overwhelm the signal produced by ultrasound imaging system and obscure the image it produces. The synchronization signal employed to control the HIFU transducer is obtained without requiring modification of the ultrasound imaging system. Signals corresponding to scattered ultrasound imaging waves are collected using either the HIFU transducer or a dedicated receiver. A synchronization processor manipulates the scattered ultrasound imaging signals to achieve the synchronization signal, which is then used to control the HIFU bursts so as to substantially reduce or eliminate HIFU interference in the ultrasound image. The synchronization processor can alternatively be implemented using a computing device or an application-specific circuit.

Descriptive Cadaveric Study Comparing the Accuracy of Ultrasound Versus Fluoroscopic Guidance for First Sacral Transforaminal Injections: A Comparison Study.

PubMed

Thompson, Bradley F; Pingree, Matthew J; Qu, Wenchun; Murthy, Naveen S; Lachman, Nirusha; Hurdle, Mark Friedrich

2018-04-01

Ultrasound is rarely used for guiding lumbosacral epidural steroid injections due to its technical limitations. For example, sonographic imaging lacks the ability to confirm epidural spread and identify vascular uptake. The perceived risk that these limitations pose to human subjects has precluded any large scale clinical trials to date. To compare the accuracy of ultrasound versus fluoroscopic guidance for first sacral transforaminal epidural injections. Cadaveric comparative study using dichotomous outcomes. A fluoroscopy suite and anatomic laboratory at an academic medical center. Four unembalmed adult human cadavers with no history of spinal surgery. Eight sites were injected twice by one interventionalist, using fluoroscopic and ultrasound guidance. In the fluoroscopy arm, contrast spread was assessed using computed tomography. In the ultrasound arm, latex spread was assessed using gross anatomic dissection. Any visible evidence of epidural spread constituted a positive result. Comparison of the success of obtaining epidural contrast flow was the primary outcome measure. Secondary outcome measures included average duration, rate of intravascular uptake, and quantity of intravascular uptake. All injections performed in both the ultrasound arm and the fluoroscopy arm had positive epidural spread. The average duration was 3.03 minutes with fluoroscopy and 4.76 minutes with ultrasound. The rate of intravascular uptake was 37.5% with fluoroscopy and 50% with ultrasound. Within the ultrasound arm, greater intravascular spread and duration variability were recorded. Although ultrasonography can provide reliable image guidance for cannulating the first sacral foramen in cadavers, it would have limited clinical utility due to its inability to visualize relevant neurovascular structures deep to the osseus roof and exclude intravascular uptake. IV. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Co-registered photoacoustic, thermoacoustic, and ultrasound mouse imaging

NASA Astrophysics Data System (ADS)

Reinecke, Daniel R.; Kruger, Robert A.; Lam, Richard B.; DelRio, Stephen P.

2010-02-01

We have constructed and tested a prototype test bed that allows us to form 3D photoacoustic CT images using near-infrared (NIR) irradiation (700 - 900 nm), 3D thermoacoustic CT images using microwave irradiation (434 MHz), and 3D ultrasound images from a commercial ultrasound scanner. The device utilizes a vertically oriented, curved array to capture the photoacoustic and thermoacoustic data. In addition, an 8-MHz linear array fixed in a horizontal position provides the ultrasound data. The photoacoustic and thermoacoustic data sets are co-registered exactly because they use the same detector. The ultrasound data set requires only simple corrections to co-register its images. The photoacoustic, thermoacoustic, and ultrasound images of mouse anatomy reveal complementary anatomic information as they exploit different contrast mechanisms. The thermoacoustic images differentiate between muscle, fat and bone. The photoacoustic images reveal the hemoglobin distribution, which is localized predominantly in the vascular space. The ultrasound images provide detailed information about the bony structures. Superposition of all three images onto a co-registered hybrid image shows the potential of a trimodal photoacoustic-thermoacoustic-ultrasound small-animal imaging system.

Ultrasound in medical education: listening to the echoes of the past to shape a vision for the future.

PubMed

Lane, N; Lahham, S; Joseph, L; Bahner, D P; Fox, J C

2015-10-01

Ultrasound in medical education has seen a tremendous growth over the last 10-20 years but ultrasound technology has been around for hundreds of years and sound has an even longer scientific history. The development of using sound and ultrasound to understand our body and our surroundings has been a rich part of human history. From the development of materials to produce piezoelectric conductors, ultrasound has been used and improved in many industries and medical specialties. As diagnostic medical ultrasound has improved its resolution and become more portable, various specialties from radiology, cardiology, obstetrics and more recently emergency, critical care and proceduralists have found the added benefits of using ultrasound to safely help patients. The past advancements in technology have established the scaffold for the possibilities of diagnostic ultrasound's use in the present and future. A few medical educators have integrated ultrasound into medical school while a wealth of content exists online for learning ultrasound. Twenty-first century learners prefer blended learning where material can be reviewed online and personalize the education on their own time frame. This material combined with hands-on experience and mentorship can be used to develop learners' aptitude in ultrasound. As educators embrace this ultrasound technology and integrate it throughout the medical education journey, collaboration across specialties will synthesize a clear path forward when needs and resources are paired with vision and a strategic plan.

[Rational imaging in locally advanced prostate cancer].

PubMed

Beissert, M; Lorenz, R; Gerharz, E W

2008-11-01

Prostate cancer is one of the principal medical problems facing the male population in developed countries with an increasing need for sophisticated imaging techniques and risk-adapted treatment options. This article presents an overview of the current imaging procedures in the diagnosis of locally advanced prostate cancer. Apart from conventional gray-scale transrectal ultrasound (TRUS) as the most frequently used primary imaging modality we describe computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). CT and MRI not only allow assessment of prostate anatomy but also a specific evaluation of the pelvic region. Color-coded and contrast-enhanced ultrasound, real-time elastography, dynamic contrast enhancement in MR imaging, diffusion imaging, and MR spectroscopy may lead to a clinically relevant improvement in the diagnosis of prostate cancer. While bone scintigraphy with (99m)Tc-bisphosphonates is still the method of choice in the evaluation of bone metastasis, whole-body MRI and PET using (18)F-NaF, (18)F-FDG, (11)C-choline, (11)C-acetate, and (18)F-choline as tracers achieve higher sensitivities.

Picture archiving and communication system--Part one: Filmless radiology and distance radiology.

PubMed

De Backer, A I; Mortelé, K J; De Keulenaer, B L

2004-01-01

Picture archiving and communication system (PACS) is a collection of technologies used to carry out digital medical imaging. PACS is used to digitally acquire medical images from the various modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and digital projection radiography. The image data and pertinent information are transmitted to other and possibly remote locations over networks, where they may be displayed on computer workstations for soft copy viewing in multiple locations, thus permitting simultaneous consultations and almost instant reporting from radiologists at a distance. Data are secured and archived on digital media such as optical disks or tape, and may be automatically retrieved as necessary. Close integration with the hospital information system (HIS)--radiology information system (RIS) is critical for system functionality. Medical image management systems are maturing, providing access outside of the radiology department to images throughout the hospital via the Ethernet, at different hospitals, or from a home workstation if teleradiology has been implemented.

Non-stationary blind deconvolution of medical ultrasound scans

NASA Astrophysics Data System (ADS)

Michailovich, Oleg V.

2017-03-01

In linear approximation, the formation of a radio-frequency (RF) ultrasound image can be described based on a standard convolution model in which the image is obtained as a result of convolution of the point spread function (PSF) of the ultrasound scanner in use with a tissue reflectivity function (TRF). Due to the band-limited nature of the PSF, the RF images can only be acquired at a finite spatial resolution, which is often insufficient for proper representation of the diagnostic information contained in the TRF. One particular way to alleviate this problem is by means of image deconvolution, which is usually performed in a "blind" mode, when both PSF and TRF are estimated at the same time. Despite its proven effectiveness, blind deconvolution (BD) still suffers from a number of drawbacks, chief among which stems from its dependence on a stationary convolution model, which is incapable of accounting for the spatial variability of the PSF. As a result, virtually all existing BD algorithms are applied to localized segments of RF images. In this work, we introduce a novel method for non-stationary BD, which is capable of recovering the TRF concurrently with the spatially variable PSF. Particularly, our approach is based on semigroup theory which allows one to describe the effect of such a PSF in terms of the action of a properly defined linear semigroup. The approach leads to a tractable optimization problem, which can be solved using standard numerical methods. The effectiveness of the proposed solution is supported by experiments with in vivo ultrasound data.

The benefits and limitations of using ultrasonography to supplement anatomical understanding.

PubMed

Sweetman, Greg M; Crawford, Gail; Hird, Kathryn; Fear, Mark W

2013-01-01

Anatomical understanding is critical to medical education. With reduced teaching time and limited cadaver availability, it is important to investigate how best to utilize in vivo imaging to supplement anatomical understanding and better prepare medical graduates for the proliferation of point-of-care imaging in the future. To investigate whether using short sessions of in vivo imaging using ultrasonography could benefit students' anatomical knowledge and clinical application, we conducted a 2-hour session on abdominal anatomy using ultrasonography in small groups of five to six students, for both first- and second-year student cohorts. Individual feedback was collected to assess student perceptions. To measure retention and understanding, a short examination containing ultrasound images and questions and performance of a clinical skill (gastrointestinal' tract examination) were assessed. Ultrasonography sessions were highly valued by the students, with 90% of the students reporting their understanding was improved, and over 70% reporting increased confidence in their anatomical knowledge. However, the assessments showed no appreciable impact on skills or understanding related to abdominal anatomy and examination. We conclude that the risk associated with limited exposure increasing confidence without increasing skills remains real and that in vivo imaging is not effective when used as a short adjunct teaching tool. The widespread use of ultrasonography means finding the best way to incorporate ultrasound into medical education remains important. To this end, we are currently implementing an extended program including echocardiography and multiple anatomical sessions that will determine if frequency and repetition of use can positively impact on student performance and understanding. Copyright © 2012 American Association of Anatomists.

Ultrasound Imaging System Video

NASA Technical Reports Server (NTRS)

2002-01-01

In this video, astronaut Peggy Whitson uses the Human Research Facility (HRF) Ultrasound Imaging System in the Destiny Laboratory of the International Space Station (ISS) to image her own heart. The Ultrasound Imaging System provides three-dimension image enlargement of the heart and other organs, muscles, and blood vessels. It is capable of high resolution imaging in a wide range of applications, both research and diagnostic, such as Echocardiography (ultrasound of the heart), abdominal, vascular, gynecological, muscle, tendon, and transcranial ultrasound.

Using radioactive drugs could lead to better imaging of prostate cancer | Center for Cancer Research

Cancer.gov

Medical imaging (x-ray, ultrasound, MRI, CT, PET scan) is a noninvasive way to view the internal structures of the body. However, these tools are not ideal for detecting cancer that has spread, or metastasized, because the precise location of these cancer cells is unknown. Researchers are now testing an experimental radiotracer called 18F-DCFPyL to help find sites of cancer in

Varying ultrasound power level to distinguish surgical instruments and tissue.

PubMed

Ren, Hongliang; Anuraj, Banani; Dupont, Pierre E

2018-03-01

We investigate a new framework of surgical instrument detection based on power-varying ultrasound images with simple and efficient pixel-wise intensity processing. Without using complicated feature extraction methods, we identified the instrument with an estimated optimal power level and by comparing pixel values of varying transducer power level images. The proposed framework exploits the physics of ultrasound imaging system by varying the transducer power level to effectively distinguish metallic surgical instruments from tissue. This power-varying image-guidance is motivated from our observations that ultrasound imaging at different power levels exhibit different contrast enhancement capabilities between tissue and instruments in ultrasound-guided robotic beating-heart surgery. Using lower transducer power levels (ranging from 40 to 75% of the rated lowest ultrasound power levels of the two tested ultrasound scanners) can effectively suppress the strong imaging artifacts from metallic instruments and thus, can be utilized together with the images from normal transducer power levels to enhance the separability between instrument and tissue, improving intraoperative instrument tracking accuracy from the acquired noisy ultrasound volumetric images. We performed experiments in phantoms and ex vivo hearts in water tank environments. The proposed multi-level power-varying ultrasound imaging approach can identify robotic instruments of high acoustic impedance from low-signal-to-noise-ratio ultrasound images by power adjustments.

Generation of acoustic self-bending and bottle beams by phase engineering

NASA Astrophysics Data System (ADS)

Zhang, Peng; Li, Tongcang; Zhu, Jie; Zhu, Xuefeng; Yang, Sui; Wang, Yuan; Yin, Xiaobo; Zhang, Xiang

2014-07-01

Directing acoustic waves along curved paths is critical for applications such as ultrasound imaging, surgery and acoustic cloaking. Metamaterials can direct waves by spatially varying the material properties through which the wave propagates. However, this approach is not always feasible, particularly for acoustic applications. Here we demonstrate the generation of acoustic bottle beams in homogeneous space without using metamaterials. Instead, the sound energy flows through a three-dimensional curved shell in air leaving a close-to-zero pressure region in the middle, exhibiting the capability of circumventing obstacles. By designing the initial phase, we develop a general recipe for creating self-bending wave packets, which can set acoustic beams propagating along arbitrary prescribed convex trajectories. The measured acoustic pulling force experienced by a rigid ball placed inside such a beam confirms the pressure field of the bottle. The demonstrated acoustic bottle and self-bending beams have potential applications in medical ultrasound imaging, therapeutic ultrasound, as well as acoustic levitations and isolations.

[Interpretation of ultrasound findings in otorhinolaryngology. Salivary glands, paraganglioma, angioma, esophagus, hypopharynx, extra cranial vessels and temporomandibular joint].

PubMed

Bozzato, A

2015-06-01

The second part of this continuing medical education article focuses on sonographic assessment of the salivary glands, cervical paraganglioma, angioma, esophagus, extra cranial blood vessels and the temporomandibular joint. The currently available minimally invasive therapeutic options (e. g. sialendoscopy, lithotripsy, therapeutic duct lavage and extracapsular dissection) for salivary gland disease presuppose a precise imaging modality. Modern ultrasound is able to meet this challenge, making additional imaging a rare necessity. Regions of the neck with a difficult topography (esophagus and hypopharynx) can often be successfully portrayed sonographically. Furthermore, ultrasound enables functional evaluation of swallowing in the cervical parts of the esophagus in dysphagia patients. In addition to the branchial cleft anomalies and lymph nodes discussed in part 1, paraganglioma, angiomatosis and neurogenic tumors are important differential diagnoses of solid lesions of the neck. Finally, venous and arterial alterations of the extracranial vessels of the neck relevant to clinical routine are depicted, as are pathological conditions of the temporomandibular joint relevant to the otorhinolaryngologist.

Evaluations of UltraiQ software for objective ultrasound image quality assessment using images from a commercial scanner.

PubMed

Long, Zaiyang; Tradup, Donald J; Stekel, Scott F; Gorny, Krzysztof R; Hangiandreou, Nicholas J

2018-03-01

We evaluated a commercially available software package that uses B-mode images to semi-automatically measure quantitative metrics of ultrasound image quality, such as contrast response, depth of penetration (DOP), and spatial resolution (lateral, axial, and elevational). Since measurement of elevational resolution is not a part of the software package, we achieved it by acquiring phantom images with transducers tilted at 45 degrees relative to the phantom. Each measurement was assessed in terms of measurement stability, sensitivity, repeatability, and semi-automated measurement success rate. All assessments were performed on a GE Logiq E9 ultrasound system with linear (9L or 11L), curved (C1-5), and sector (S1-5) transducers, using a CIRS model 040GSE phantom. In stability tests, the measurements of contrast, DOP, and spatial resolution remained within a ±10% variation threshold in 90%, 100%, and 69% of cases, respectively. In sensitivity tests, contrast, DOP, and spatial resolution measurements followed the expected behavior in 100%, 100%, and 72% of cases, respectively. In repeatability testing, intra- and inter-individual coefficients of variations were equal to or less than 3.2%, 1.3%, and 4.4% for contrast, DOP, and spatial resolution (lateral and axial), respectively. The coefficients of variation corresponding to the elevational resolution test were all within 9.5%. Overall, in our assessment, the evaluated package performed well for objective and quantitative assessment of the above-mentioned image qualities under well-controlled acquisition conditions. We are finding it to be useful for various clinical ultrasound applications including performance comparison between scanners from different vendors. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Evaluation of image compression for computer-aided diagnosis of breast tumors in 3D sonography

NASA Astrophysics Data System (ADS)

Chen, We-Min; Huang, Yu-Len; Tao, Chi-Chuan; Chen, Dar-Ren; Moon, Woo-Kyung

2006-03-01

Medical imaging examinations form the basis for physicians diagnosing diseases, as evidenced by the increasing use of digital medical images for picture archiving and communications systems (PACS). However, with enlarged medical image databases and rapid growth of patients' case reports, PACS requires image compression to accelerate the image transmission rate and conserve disk space for diminishing implementation costs. For this purpose, JPEG and JPEG2000 have been accepted as legal formats for the digital imaging and communications in medicine (DICOM). The high compression ratio is felt to be useful for medical imagery. Therefore, this study evaluates the compression ratios of JPEG and JPEG2000 standards for computer-aided diagnosis (CAD) of breast tumors in 3-D medical ultrasound (US) images. The 3-D US data sets with various compression ratios are compressed using the two efficacious image compression standards. The reconstructed data sets are then diagnosed by a previous proposed CAD system. The diagnostic accuracy is measured based on receiver operating characteristic (ROC) analysis. Namely, the ROC curves are used to compare the diagnostic performance of two or more reconstructed images. Analysis results ensure a comparison of the compression ratios by using JPEG and JPEG2000 for 3-D US images. Results of this study provide the possible bit rates using JPEG and JPEG2000 for 3-D breast US images.

Using Ultrasound to Teach Medical Students Cardiac Physiology

ERIC Educational Resources Information Center

Bell, Floyd E., III; Wilson, L. Britt; Hoppmann, Richard A.

2015-01-01

Ultrasound is being incorporated more into undergraduate medical education. Studies have shown that medical students have positive perceptions about the value of ultrasound in teaching courses like anatomy and physiology. The purpose of the present study was to provide objective evidence of whether ultrasound helps students learn cardiac…

WE-A-18C-01: Emerging and Innovative Ultrasound Technology in Diagnosis and Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emelianov, S; Oraevsky, A; Stafford, R

The application of new ultrasound-based technologies in medicine has expanded in recent years. One area of rapid growth has been the combination of ultrasound with other methods of image generation and imaging modalities to produce hybrid approaches for diagnostic imaging and noninvasive therapeutic intervention. The presentations associated with this session will provide an overview of two emerging technologies that are currently being developed and implemented to enhance ultrasound-related diagnostic imaging and therapy: the utilization of optically-induced ultrasound imaging (optoacoustic / photoacoustic imaging) and the use of magnetic resonance imaging to guide the use of high-intensity focused ultrasound for therapeutic applications.more » Learning Objectives: Develop a general understanding of the underlying technologies associated with optoacoustic / photoacoustic tomography and MRguided high-intensity focused ultrasound. Develop an understanding of the current methods of these new ultrasound-based technologies in preclinical research and clinical applications.« less

TH-A-18A-01: Innovation in Clinical Breast Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, B; Yang, K; Yaffe, M

Several novel modalities have been or are on the verge of being introduced into the breast imaging clinic. These include tomosynthesis imaging, dedicated breast CT, contrast-enhanced digital mammography, and automated breast ultrasound, all of which are covered in this course. Tomosynthesis and dedicated breast CT address the problem of tissue superimposition that limits mammography screening performance, by improved or full resolution of the 3D breast morphology. Contrast-enhanced digital mammography provides functional information that allows for visualization of tumor angiogenesis. 3D breast ultrasound has high sensitivity for tumor detection in dense breasts, but the imaging exam was traditionally performed by radiologists.more » In automated breast ultrasound, the scan is performed in an automated fashion, making for a more practical imaging tool, that is now used as an adjunct to digital mammography in breast cancer screening. This course will provide medical physicists with an in-depth understanding of the imaging physics of each of these four novel imaging techniques, as well as the rationale and implementation of QC procedures. Further, basic clinical applications and work flow issues will be discussed. Learning Objectives: To be able to describe the underlying physical and physiological principles of each imaging technique, and to understand the corresponding imaging acquisition process. To be able to describe the critical system components and their performance requirements. To understand the rationale and implementation of quality control procedures, as well as regulatory requirements for systems with FDA approval. To learn about clinical applications and understand risks and benefits/strength and weakness of each modality in terms of clinical breast imaging.« less

Shape complexes: the intersection of label orderings and star convexity constraints in continuous max-flow medical image segmentation

PubMed Central

Baxter, John S. H.; Inoue, Jiro; Drangova, Maria; Peters, Terry M.

2016-01-01

Abstract. Optimization-based segmentation approaches deriving from discrete graph-cuts and continuous max-flow have become increasingly nuanced, allowing for topological and geometric constraints on the resulting segmentation while retaining global optimality. However, these two considerations, topological and geometric, have yet to be combined in a unified manner. The concept of “shape complexes,” which combine geodesic star convexity with extendable continuous max-flow solvers, is presented. These shape complexes allow more complicated shapes to be created through the use of multiple labels and super-labels, with geodesic star convexity governed by a topological ordering. These problems can be optimized using extendable continuous max-flow solvers. Previous approaches required computationally expensive coordinate system warping, which are ill-defined and ambiguous in the general case. These shape complexes are demonstrated in a set of synthetic images as well as vessel segmentation in ultrasound, valve segmentation in ultrasound, and atrial wall segmentation from contrast-enhanced CT. Shape complexes represent an extendable tool alongside other continuous max-flow methods that may be suitable for a wide range of medical image segmentation problems. PMID:28018937

Superficial Ultrasound Shear Wave Speed Measurements in Soft and Hard Elasticity Phantoms: Repeatability and Reproducibility Using Two Different Ultrasound Systems

PubMed Central

Dillman, Jonathan R.; Chen, Shigao; Davenport, Matthew S.; Zhao, Heng; Urban, Matthew W.; Song, Pengfei; Watcharotone, Kuanwong; Carson, Paul L.

2014-01-01

Background There is a paucity of data available regarding the repeatability and reproducibility of superficial shear wave speed (SWS) measurements at imaging depths relevant to the pediatric population. Purpose To assess the repeatability and reproducibility of superficial shear wave speed (SWS) measurements acquired from elasticity phantoms at varying imaging depths using three different imaging methods, two different ultrasound systems, and multiple operators. Methods and Materials Soft and hard elasticity phantoms manufactured by Computerized Imaging Reference Systems, Inc. (Norfolk, VA) were utilized for our investigation. Institution #1 used an Acuson S3000 ultrasound system (Siemens Medical Solutions USA, Inc.) and three different shear wave imaging method/transducer combinations, while institution #2 used an Aixplorer ultrasound system (Supersonic Imagine) and two different transducers. Ten stiffness measurements were acquired from each phantom at three depths (1.0, 2.5, and 4.0 cm) by four operators at each institution. Student’s t-test was used to compare SWS measurements between imaging techniques, while SWS measurement agreement was assessed with two-way random effects single measure intra-class correlation coefficients and coefficients of variation. Mixed model regression analysis determined the effect of predictor variables on SWS measurements. Results For the soft phantom, the average of mean SWS measurements across the various imaging methods and depths was 0.84 ± 0.04 m/s (mean ± standard deviation) for the Acuson S3000 system and 0.90 ± 0.02 m/s for the Aixplorer system (p=0.003). For the hard phantom, the average of mean SWS measurements across the various imaging methods and depths was 2.14 ± 0.08 m/s for the Acuson S3000 system and 2.07 ± 0.03 m/s Aixplorer system (p>0.05). The coefficients of variation were low (0.5–6.8%), and inter-operator agreement was near-perfect (ICCs ≥0.99). Shear wave imaging method and imaging depth significantly affected measured SWS (p<0.0001). Conclusions Superficial SWS measurements in elasticity phantoms demonstrate minimal variability across imaging method/transducer combinations, imaging depths, and between operators. The exact clinical significance of this variability is uncertain and may vary by organ and specific disease state. PMID:25249389

3D ultrasound imaging in image-guided intervention.

PubMed

Fenster, Aaron; Bax, Jeff; Neshat, Hamid; Cool, Derek; Kakani, Nirmal; Romagnoli, Cesare

2014-01-01

Ultrasound imaging is used extensively in diagnosis and image-guidance for interventions of human diseases. However, conventional 2D ultrasound suffers from limitations since it can only provide 2D images of 3-dimensional structures in the body. Thus, measurement of organ size is variable, and guidance of interventions is limited, as the physician is required to mentally reconstruct the 3-dimensional anatomy using 2D views. Over the past 20 years, a number of 3-dimensional ultrasound imaging approaches have been developed. We have developed an approach that is based on a mechanical mechanism to move any conventional ultrasound transducer while 2D images are collected rapidly and reconstructed into a 3D image. In this presentation, 3D ultrasound imaging approaches will be described for use in image-guided interventions.

Compact CdZnTe-based gamma camera for prostate cancer imaging

NASA Astrophysics Data System (ADS)

Cui, Yonggang; Lall, Terry; Tsui, Benjamin; Yu, Jianhua; Mahler, George; Bolotnikov, Aleksey; Vaska, Paul; De Geronimo, Gianluigi; O'Connor, Paul; Meinken, George; Joyal, John; Barrett, John; Camarda, Giuseppe; Hossain, Anwar; Kim, Ki Hyun; Yang, Ge; Pomper, Marty; Cho, Steve; Weisman, Ken; Seo, Youngho; Babich, John; LaFrance, Norman; James, Ralph B.

2011-06-01

In this paper, we discuss the design of a compact gamma camera for high-resolution prostate cancer imaging using Cadmium Zinc Telluride (CdZnTe or CZT) radiation detectors. Prostate cancer is a common disease in men. Nowadays, a blood test measuring the level of prostate specific antigen (PSA) is widely used for screening for the disease in males over 50, followed by (ultrasound) imaging-guided biopsy. However, PSA tests have a high falsepositive rate and ultrasound-guided biopsy has a high likelihood of missing small cancerous tissues. Commercial methods of nuclear medical imaging, e.g. PET and SPECT, can functionally image the organs, and potentially find cancer tissues at early stages, but their applications in diagnosing prostate cancer has been limited by the smallness of the prostate gland and the long working distance between the organ and the detectors comprising these imaging systems. CZT is a semiconductor material with wide band-gap and relatively high electron mobility, and thus can operate at room temperature without additional cooling. CZT detectors are photon-electron direct-conversion devices, thus offering high energy-resolution in detecting gamma rays, enabling energy-resolved imaging, and reducing the background of Compton-scattering events. In addition, CZT material has high stopping power for gamma rays; for medical imaging, a few-mm-thick CZT material provides adequate detection efficiency for many SPECT radiotracers. Because of these advantages, CZT detectors are becoming popular for several SPECT medical-imaging applications. Most recently, we designed a compact gamma camera using CZT detectors coupled to an application-specific-integratedcircuit (ASIC). This camera functions as a trans-rectal probe to image the prostate gland from a distance of only 1-5 cm, thus offering higher detection efficiency and higher spatial resolution. Hence, it potentially can detect prostate cancers at their early stages. The performance tests of this camera have been completed. The results show better than 6-mm resolution at a distance of 1 cm. Details of the test results are discussed in this paper.

Virtual Ultrasound Guidance for Inexperienced Operators

NASA Technical Reports Server (NTRS)

Caine, Timothy; Martin, David

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit in which the time delay inherent with communication will make remote guidance impractical. The Virtual Ultrasound Guidance system is a combination of hardware and software. The hardware portion includes, but is not limited to, video glasses that allow hands-free, full-screen viewing. The glasses also allow the operator a substantial field of view below the glasses to view and operate the ultrasound system. The software is a comprehensive video program designed to guide an inexperienced operator through a detailed ultrasound or echocardiographic study without extensive training or guidance from the ground. The program contains a detailed description using video and audio to demonstrate equipment controls, ergonomics of scanning, study protocol, and scanning guidance, including recovery from sub-optimal images. The components used in the initial validation of the system include an Apple iPod Classic third-generation as the video source, and Myvue video glasses. Initially, the program prompts the operator to power-up the ultrasound and position the patient. The operator would put on the video glasses and attach them to the video source. After turning on both devices and the ultrasound system, the audio-video guidance would then instruct on patient positioning and scanning techniques. A detailed scanning protocol follows with descriptions and reference video of each view along with advice on technique. The program also instructs the operator regarding the types of images to store and how to overcome pitfalls in scanning. Images can be forwarded to the ground or other site when convenient. Following study completion, the video glasses, video source, and ultrasound system are powered down and stored. Virtually any equipment that can play back video can be used to play back the program. This includes a DVD player, personal computer, and some MP3 players.

Towards enabling ultrasound guidance in cervical cancer high-dose-rate brachytherapy

NASA Astrophysics Data System (ADS)

Wong, Adrian; Sojoudia, Samira; Gaudet, Marc; Yap, Wan Wan; Chang, Silvia D.; Abolmaesumi, Purang; Aquino-Parsons, Christina; Moradi, Mehdi

2014-03-01

MRI and Computed Tomography (CT) are used in image-based solutions for guiding High Dose Rate (HDR) brachytherapy treatment of cervical cancer. MRI is costly and CT exposes the patients to ionizing radiation. Ultrasound, on the other hand, is affordable and safe. The long-term goal of our work is to enable the use of multiparametric ultrasound imaging in image-guided HDR for cervical cancer. In this paper, we report the development of enabling technology for ultrasound guidance and tissue typing. We report a system to obtain the 3D freehand transabdominal ultrasound RF signals and B-mode images of the uterus, and a method for registration of ultrasound to MRI. MRI and 3D ultrasound images of the female pelvis were registered by contouring the uterus in the two modalities, creating a surface model, followed by rigid and B-spline deformable registration. The resulting transformation was used to map the location of the tumor from the T2-weighted MRI to ultrasound images and to determine cancerous and normal areas in ultrasound. B-mode images show a contrast for cancer vs. normal tissue. Our study shows the potential and the challenges of ultrasound imaging in guiding cervical cancer treatments.

Settling the 'Score' with Heart Disease

NASA Technical Reports Server (NTRS)

2004-01-01

Technology and medicine forged a bond in 1986 when a group of dedicated NASA scientists, University of Southern California (USC) medical professors, and a Dutch cardiologist joined forces to prevent heart attacks, using ultrasound images of astronauts blood-flow patterns and the supercomputer depended upon to orchestrate the "Star Wars" Strategic Defense Initiative.

Automated ultrasound edge-tracking software comparable to established semi-automated reference software for carotid intima-media thickness analysis.

PubMed

Shenouda, Ninette; Proudfoot, Nicole A; Currie, Katharine D; Timmons, Brian W; MacDonald, Maureen J

2018-05-01

Many commercial ultrasound systems are now including automated analysis packages for the determination of carotid intima-media thickness (cIMT); however, details regarding their algorithms and methodology are not published. Few studies have compared their accuracy and reliability with previously established automated software, and those that have were in asymptomatic adults. Therefore, this study compared cIMT measures from a fully automated ultrasound edge-tracking software (EchoPAC PC, Version 110.0.2; GE Medical Systems, Horten, Norway) to an established semi-automated reference software (Artery Measurement System (AMS) II, Version 1.141; Gothenburg, Sweden) in 30 healthy preschool children (ages 3-5 years) and 27 adults with coronary artery disease (CAD; ages 48-81 years). For both groups, Bland-Altman plots revealed good agreement with a negligible mean cIMT difference of -0·03 mm. Software differences were statistically, but not clinically, significant for preschool images (P = 0·001) and were not significant for CAD images (P = 0·09). Intra- and interoperator repeatability was high and comparable between software for preschool images (ICC, 0·90-0·96; CV, 1·3-2·5%), but slightly higher with the automated ultrasound than the semi-automated reference software for CAD images (ICC, 0·98-0·99; CV, 1·4-2·0% versus ICC, 0·84-0·89; CV, 5·6-6·8%). These findings suggest that the automated ultrasound software produces valid cIMT values in healthy preschool children and adults with CAD. Automated ultrasound software may be useful for ensuring consistency among multisite research initiatives or large cohort studies involving repeated cIMT measures, particularly in adults with documented CAD. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Comparison of radiography and ultrasonography for the diagnosis of osteochondritis dissecans in the equine femoropatellar joint.

PubMed

Bourzac, C; Alexander, K; Rossier, Y; Laverty, S

2009-09-01

Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FPjoint. To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. The medical records of all horses diagnosed with FP OCD between 1995 and 2006 were assessed. Inclusion criteria included availability of both radiographic and ultrasonographic images. Lesion characteristics were evaluated in each trochlear ridge and trochlear groove. For assessment of the accuracy (sensitivity and specificity) of both imaging techniques in the diagnosis of OCD, only cases with an arthroscopic or necropsy examination were studied. Twenty-one horses were included. OCD lesions were diagnosed by radiography (30/32 joints) and ultrasound (32/32 joints). The lateral trochlear ridge (LTR, 91%) and the medial trochlear ridge (MTR, 17%) were involved on radiography. The localisation on ultrasound examination was similar (97% LTR, 25% MTR). All but one lesion seen on radiography were also detected with ultrasound; 2 LTR and 3 MTR lesions, not seen on radiography were diagnosed by ultrasound and confirmed at arthroscopy or necropsy. The specificity was 100% regardless of the site and imaging procedure except for the distal third of the MTR (94% for ultrasound). The sensitivity varied, depending on lesion site. Ultrasonography is a valuable diagnostic tool to diagnose OCD lesions in the FP joint and more sensitive than radiography for lesions affecting the MTR of the distal femur. Ultrasound should be considered as a useful adjunct to radiography for diagnosing equine FP OCD, especially in cases of high clinical suspicion but equivocal radiographic findings. Images can be generated immediately when digital radiography is not available, permitting an immediate on-site diagnosis.

Speckle reduction in echocardiography by temporal compounding and anisotropic diffusion filtering

NASA Astrophysics Data System (ADS)

Giraldo-Guzmán, Jader; Porto-Solano, Oscar; Cadena-Bonfanti, Alberto; Contreras-Ortiz, Sonia H.

2015-01-01

Echocardiography is a medical imaging technique based on ultrasound signals that is used to evaluate heart anatomy and physiology. Echocardiographic images are affected by speckle, a type of multiplicative noise that obscures details of the structures, and reduces the overall image quality. This paper shows an approach to enhance echocardiography using two processing techniques: temporal compounding and anisotropic diffusion filtering. We used twenty echocardiographic videos that include one or three cardiac cycles to test the algorithms. Two images from each cycle were aligned in space and averaged to obtain the compound images. These images were then processed using anisotropic diffusion filters to further improve their quality. Resultant images were evaluated using quality metrics and visual assessment by two medical doctors. The average total improvement on signal-to-noise ratio was up to 100.29% for videos with three cycles, and up to 32.57% for videos with one cycle.

Automatic dynamic range adjustment for ultrasound B-mode imaging.

PubMed

Lee, Yeonhwa; Kang, Jinbum; Yoo, Yangmo

2015-02-01

In medical ultrasound imaging, dynamic range (DR) is defined as the difference between the maximum and minimum values of the displayed signal to display and it is one of the most essential parameters that determine its image quality. Typically, DR is given with a fixed value and adjusted manually by operators, which leads to low clinical productivity and high user dependency. Furthermore, in 3D ultrasound imaging, DR values are unable to be adjusted during 3D data acquisition. A histogram matching method, which equalizes the histogram of an input image based on that from a reference image, can be applied to determine the DR value. However, it could be lead to an over contrasted image. In this paper, a new Automatic Dynamic Range Adjustment (ADRA) method is presented that adaptively adjusts the DR value by manipulating input images similar to a reference image. The proposed ADRA method uses the distance ratio between the log average and each extreme value of a reference image. To evaluate the performance of the ADRA method, the similarity between the reference and input images was measured by computing a correlation coefficient (CC). In in vivo experiments, the CC values were increased by applying the ADRA method from 0.6872 to 0.9870 and from 0.9274 to 0.9939 for kidney and liver data, respectively, compared to the fixed DR case. In addition, the proposed ADRA method showed to outperform the histogram matching method with in vivo liver and kidney data. When using 3D abdominal data with 70 frames, while the CC value from the ADRA method is slightly increased (i.e., 0.6%), the proposed method showed improved image quality in the c-plane compared to its fixed counterpart, which suffered from a shadow artifact. These results indicate that the proposed method can enhance image quality in 2D and 3D ultrasound B-mode imaging by improving the similarity between the reference and input images while eliminating unnecessary manual interaction by the user. Copyright © 2014 Elsevier B.V. All rights reserved.

Block selective redaction for minimizing loss during de-identification of burned in text in irreversibly compressed JPEG medical images.

PubMed

Clunie, David A; Gebow, Dan

2015-01-01

Deidentification of medical images requires attention to both header information as well as the pixel data itself, in which burned-in text may be present. If the pixel data to be deidentified is stored in a compressed form, traditionally it is decompressed, identifying text is redacted, and if necessary, pixel data are recompressed. Decompression without recompression may result in images of excessive or intractable size. Recompression with an irreversible scheme is undesirable because it may cause additional loss in the diagnostically relevant regions of the images. The irreversible (lossy) JPEG compression scheme works on small blocks of the image independently, hence, redaction can selectively be confined only to those blocks containing identifying text, leaving all other blocks unchanged. An open source implementation of selective redaction and a demonstration of its applicability to multiframe color ultrasound images is described. The process can be applied either to standalone JPEG images or JPEG bit streams encapsulated in other formats, which in the case of medical images, is usually DICOM.

Development of educational image databases and e-books for medical physics training.

PubMed

Tabakov, S; Roberts, V C; Jonsson, B-A; Ljungberg, M; Lewis, C A; Wirestam, R; Strand, S-E; Lamm, I-L; Milano, F; Simmons, A; Deane, C; Goss, D; Aitken, V; Noel, A; Giraud, J-Y; Sherriff, S; Smith, P; Clarke, G; Almqvist, M; Jansson, T

2005-09-01

Medical physics education and training requires the use of extensive imaging material and specific explanations. These requirements provide an excellent background for application of e-Learning. The EU projects Consortia EMERALD and EMIT developed five volumes of such materials, now used in 65 countries. EMERALD developed e-Learning materials in three areas of medical physics (X-ray diagnostic radiology, nuclear medicine and radiotherapy). EMIT developed e-Learning materials in two further areas: ultrasound and magnetic resonance imaging. This paper describes the development of these e-Learning materials (consisting of e-books and educational image databases). The e-books include tasks helping studying of various equipment and methods. The text of these PDF e-books is hyperlinked with respective images. The e-books are used through the readers' own Internet browser. Each Image Database (IDB) includes a browser, which displays hundreds of images of equipment, block diagrams and graphs, image quality examples, artefacts, etc. Both the e-books and IDB are engraved on five separate CD-ROMs. Demo of these materials can be taken from www.emerald2.net.

Towards an Optimal Interest Point Detector for Measurements in Ultrasound Images

NASA Astrophysics Data System (ADS)

Zukal, Martin; Beneš, Radek; Číka, Petr; Říha, Kamil

2013-12-01

This paper focuses on the comparison of different interest point detectors and their utilization for measurements in ultrasound (US) images. Certain medical examinations are based on speckle tracking which strongly relies on features that can be reliably tracked frame to frame. Only significant features (interest points) resistant to noise and brightness changes within US images are suitable for accurate long-lasting tracking. We compare three interest point detectors - Harris-Laplace, Difference of Gaussian (DoG) and Fast Hessian - and identify the most suitable one for use in US images on the basis of an objective criterion. Repeatability rate is assumed to be an objective quality measure for comparison. We have measured repeatability in images corrupted by different types of noise (speckle noise, Gaussian noise) and for changes in brightness. The Harris-Laplace detector outperformed its competitors and seems to be a sound option when choosing a suitable interest point detector for US images. However, it has to be noted that Fast Hessian and DoG detectors achieved better results in terms of processing speed.

A pilot study of comprehensive ultrasound education at the Wayne State University School of Medicine: a pioneer year review.

PubMed

Rao, Sishir; van Holsbeeck, Lodewijk; Musial, Joseph L; Parker, Alton; Bouffard, J Antonio; Bridge, Patrick; Jackson, Matt; Dulchavsky, Scott A

2008-05-01

Ultrasound is a versatile diagnostic modality used in a variety of medical fields. Wayne State University School of Medicine (WSUSOM) is one of the first medical schools in the United States to integrate an ultrasound curriculum through both basic science courses and clinical clerkships. In 2006, 25 portable ultrasound units were donated to WSUSOM. First-year medical students were provided an ultrasound curriculum consisting of 6 organ-system sessions that addressed the basics of ultrasound techniques, anatomy, and procedural skills. After the last session, students were administered 2 anonymous and voluntary evaluations. The first assessed their overall experience with the ultrasound curriculum, and the second assessed their technical skills in applying ultrasound techniques. Eighty-three percent of students agreed or strongly agreed that their experience with ultrasound education was positive. On the summative evaluation, nearly 91% of students agreed or strongly agreed that they would benefit from continued ultrasound education throughout their 4 years of medical school. Student performance on the technical assessment was also very positive, with mean class performance of 87%. As residency programs adopt ultrasound training, medical school faculty should consider incorporating ultrasound education into their curriculum. Portable ultrasound has the potential to be used in many different settings, including rural practice sites and sporting events. The WSUSOM committee's pilot ultrasound curriculum will continue to use student feedback to enhance the ultrasound experience, helping students prepare for challenges that they will face in the future.

High-frequency ultrasound for monitoring changes in liver tissue during preservation

NASA Astrophysics Data System (ADS)

Vlad, Roxana M.; Czarnota, Gregory J.; Giles, Anoja; Sherar, Michael D.; Hunt, John W.; Kolios, Michael C.

2005-01-01

Currently the only method to assess liver preservation injury is based on liver appearance and donor medical history. Previous work has shown that high-frequency ultrasound could detect ischemic cell death due to changes in cell morphology. In this study, we use high-frequency ultrasound integrated backscatter to assess liver damage in experimental models of liver ischemia. Ultimately, our goal is to predict organ suitability for transplantation using high-frequency imaging and spectral analysis techniques. To examine the effects of liver ischemia at different temperatures, livers from Wistar rats were surgically excised, immersed in phosphate buffer saline and stored at 4 and 20 °C for 24 h. To mimic organ preservation, livers were excised, flushed with University of Wisconsin (UW) solution and stored at 4 °C for 24 h. Preservation injury was simulated by either not flushing livers with UW solution or, before scanning, allowing livers to reach room temperature. Ultrasound images and corresponding radiofrequency data were collected over the ischemic period. No significant increase in integrated backscatter (~2.5 dBr) was measured for the livers prepared using standard preservation conditions. For all other ischemia models, the integrated backscatter increased by 4-9 dBr demonstrating kinetics dependent on storage conditions. The results provide a possible framework for using high-frequency imaging to non-invasively assess liver preservation injury.

Virtual Sonography Through the Internet: Volume Compression Issues

PubMed Central

Vilarchao-Cavia, Joseba; Troyano-Luque, Juan-Mario; Clavijo, Matilde

2001-01-01

Background Three-dimensional ultrasound images allow virtual sonography even at a distance. However, the size of final 3-D files limits their transmission through slow networks such as the Internet. Objective To analyze compression techniques that transform ultrasound images into small 3-D volumes that can be transmitted through the Internet without loss of relevant medical information. Methods Samples were selected from ultrasound examinations performed during, 1999-2000, in the Obstetrics and Gynecology Department at the University Hospital in La Laguna, Canary Islands, Spain. The conventional ultrasound video output was recorded at 25 fps (frames per second) on a PC, producing 100- to 120-MB files (for from 500 to 550 frames). Processing to obtain 3-D images progressively reduced file size. Results The original frames passed through different compression stages: selecting the region of interest, rendering techniques, and compression for storage. Final 3-D volumes reached 1:25 compression rates (1.5- to 2-MB files). Those volumes need 7 to 8 minutes to be transmitted through the Internet at a mean data throughput of 6.6 Kbytes per second. At the receiving site, virtual sonography is possible using orthogonal projections or oblique cuts. Conclusions Modern volume-rendering techniques allowed distant virtual sonography through the Internet. This is the result of their efficient data compression that maintains its attractiveness as a main criterion for distant diagnosis. PMID:11720963

Real-time simulation of ultrasound refraction phenomena using ray-trace based wavefront construction method.

PubMed

Szostek, Kamil; Piórkowski, Adam

2016-10-01

Ultrasound (US) imaging is one of the most popular techniques used in clinical diagnosis, mainly due to lack of adverse effects on patients and the simplicity of US equipment. However, the characteristics of the medium cause US imaging to imprecisely reconstruct examined tissues. The artifacts are the results of wave phenomena, i.e. diffraction or refraction, and should be recognized during examination to avoid misinterpretation of an US image. Currently, US training is based on teaching materials and simulators and ultrasound simulation has become an active research area in medical computer science. Many US simulators are limited by the complexity of the wave phenomena, leading to intensive sophisticated computation that makes it difficult for systems to operate in real time. To achieve the required frame rate, the vast majority of simulators reduce the problem of wave diffraction and refraction. The following paper proposes a solution for an ultrasound simulator based on methods known in geophysics. To improve simulation quality, a wavefront construction method was adapted which takes into account the refraction phenomena. This technique uses ray tracing and velocity averaging to construct wavefronts in the simulation. Instead of a geological medium, real CT scans are applied. This approach can produce more realistic projections of pathological findings and is also capable of providing real-time simulation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Synthetic aperture imaging in ultrasound calibration

NASA Astrophysics Data System (ADS)

Ameri, Golafsoun; Baxter, John S. H.; McLeod, A. Jonathan; Jayaranthe, Uditha L.; Chen, Elvis C. S.; Peters, Terry M.

2014-03-01

Ultrasound calibration allows for ultrasound images to be incorporated into a variety of interventional applica­ tions. Traditional Z- bar calibration procedures rely on wired phantoms with an a priori known geometry. The line fiducials produce small, localized echoes which are then segmented from an array of ultrasound images from different tracked probe positions. In conventional B-mode ultrasound, the wires at greater depths appear blurred and are difficult to segment accurately, limiting the accuracy of ultrasound calibration. This paper presents a novel ultrasound calibration procedure that takes advantage of synthetic aperture imaging to reconstruct high resolution ultrasound images at arbitrary depths. In these images, line fiducials are much more readily and accu­ rately segmented, leading to decreased calibration error. The proposed calibration technique is compared to one based on B-mode ultrasound. The fiducial localization error was improved from 0.21mm in conventional B-mode images to 0.15mm in synthetic aperture images corresponding to an improvement of 29%. This resulted in an overall reduction of calibration error from a target registration error of 2.00mm to 1.78mm, an improvement of 11%. Synthetic aperture images display greatly improved segmentation capabilities due to their improved resolution and interpretability resulting in improved calibration.

Hybrid Pixel-Based Method for Cardiac Ultrasound Fusion Based on Integration of PCA and DWT.

PubMed

Mazaheri, Samaneh; Sulaiman, Puteri Suhaiza; Wirza, Rahmita; Dimon, Mohd Zamrin; Khalid, Fatimah; Moosavi Tayebi, Rohollah

2015-01-01

Medical image fusion is the procedure of combining several images from one or multiple imaging modalities. In spite of numerous attempts in direction of automation ventricle segmentation and tracking in echocardiography, due to low quality images with missing anatomical details or speckle noises and restricted field of view, this problem is a challenging task. This paper presents a fusion method which particularly intends to increase the segment-ability of echocardiography features such as endocardial and improving the image contrast. In addition, it tries to expand the field of view, decreasing impact of noise and artifacts and enhancing the signal to noise ratio of the echo images. The proposed algorithm weights the image information regarding an integration feature between all the overlapping images, by using a combination of principal component analysis and discrete wavelet transform. For evaluation, a comparison has been done between results of some well-known techniques and the proposed method. Also, different metrics are implemented to evaluate the performance of proposed algorithm. It has been concluded that the presented pixel-based method based on the integration of PCA and DWT has the best result for the segment-ability of cardiac ultrasound images and better performance in all metrics.

Advanced ultrasound training for fourth-year medical students: a novel training program at The Ohio State University College of Medicine.

PubMed

Bahner, David P; Royall, Nelson A

2013-02-01

Ultrasound training and education in medical schools is rare, and the foci of current ultrasound curricula are limited. There is a significant need for advanced ultrasound training models in medical school curricula to reduce educational burdens for physician residency programs and improve overall physician competency.The authors describe and evaluate the advanced ultrasound training program developed at The Ohio State University College of Medicine (OSU COM). The OSU COM program is a longitudinal advanced ultrasound curriculum for fourth-year medical students pursuing specialties that require frequent use of focused ultrasound. One hundred fifty student participants have completed the yearlong program to date. Participants engage in didactic lectures, journal club sessions, hands-on training, teaching and patient-modeling activities, and complete a final project. Experienced Ohio State University Medical Center faculty are recruited from specialties that frequently use ultrasound (e.g., emergency medicine, internal medicine, obstetrics-gynecology). A multimodal instructional assessment approach ensures that ultrasound training yields experience with cognitive, behavioral, and constructive learning components. The authors discuss the benefits of the program as well as its challenges and future directions.The advanced ultrasound training program at OSU COM demonstrates a novel approach to providing ultrasound training for medical students, offering a feasible model for meeting training guidelines without increasing the educational requirements for residency programs.

Ultrasound in space

NASA Technical Reports Server (NTRS)

Martin, David S.; South, Donna A.; Garcia, Kathleen M.; Arbeille, Philippe

2003-01-01

Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

Imaging findings in 14 domestic ferrets (Mustela putorius furo) with lymphoma.

PubMed

Suran, Jantra Ngosuwan; Wyre, Nicole Rene

2013-01-01

Lymphoma is the most common malignant neoplasia in domestic ferrets, Mustela putorius furo. However, imaging findings in ferrets with lymphoma have primarily been described in single case reports. The purpose of this retrospective study was to describe imaging findings in a group of ferrets with confirmed lymphoma. Medical records were searched between 2002 and 2012. A total of 14 ferrets were included. Radiographs (n = 12), ultrasound (n = 14), computed tomography (CT; n = 1), and magnetic resonance imaging (MRI; n = 1) images were available for review. Median age at the time of diagnosis was 5.2 years (range 3.25-7.6 years). Clinical signs were predominantly nonspecific (8/14). The time between the first imaging study and lymphoma diagnosis was 1 day or less in most ferrets (12). Imaging lesions were predominantly detected in the abdomen, and most frequently included intra-abdominal lymphadenopathy (12/14), splenomegaly (8/14), and peritoneal effusion (11/14). Lymphadenopathy and mass lesions were typically hypoechoic on ultrasound. Mild peritoneal effusion was the only detected abnormality in two ferrets. Mild pleural effusion was the most common thoracic abnormality (3/12). Expansile lytic lesions were present in the vertebrae of two ferrets with T3-L3 myelopathy and the femur in a ferret with lameness. Hyperattenuating, enhancing masses with secondary spinal cord compression were associated with vertebral lysis in CT images of one ferret. The MRI study in one ferret with myelopathy was inconclusive. Findings indicated that imaging characteristics of lymphoma in ferrets are similar to those previously reported in dogs, cats, and humans. © 2013 Veterinary Radiology & Ultrasound.

TU-A-210-00: HIFU Therapies - A Primer

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2015-06-15

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis inmore » 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.« less

TU-A-210-01: HIFU Physics and Delivery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eames, M.

2015-06-15

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis inmore » 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.« less

Accelerated Training at Mach 20: A Brief Communication Submitted from the International Space Station

NASA Technical Reports Server (NTRS)

Foale, C. Michael; Kaleri, Alexander Y.; Sargsyan, Ashot E.; Hamilton, Douglas R.; Melton, Shannon; Martin, David; Dulchavsky, Scott A.

2004-01-01

The performance of complex tasks on the International Space Station (ISS) requires significant preflight crew training commitments and frequent skill and knowledge refreshment. This report documents a recently developed just-in-time training methodology, which integrates preflight hardware familiarization and procedure training with an on-orbit CD-ROM-based skill enhancement. This just-in-time concept was used to support real-time remote expert guidance to complete medical examinations using the ISS Human Research Facility (HRF). An American and Russian ISS crewmember received 2-hours of hands on ultrasound training 8 months prior to the on-orbit ultrasound exam. A CD-ROM-based Onboard Proficiency Enhancement (OPE) interactive multimedia program consisting of memory enhancing tutorials, and skill testing exercises, was completed by the crewmember six days prior to the on-orbit ultrasound exam. The crewmember was then remotely guided through a thoracic, vascular, and echocardiographic examination by ultrasound imaging experts. Results of the CD ROM based OPE session were used to modify the instructions during a complete 35 minute real-time thoracic, cardiac, and carotid/jugular ultrasound study. Following commands from the ground-based expert, the crewmember acquired all target views and images without difficulty. The anatomical content and fidelity of ultrasound video were excellent and adequate for clinical decision-making. Complex ultrasound experiments with expert guidance were performed with high accuracy following limited pre-flight training and CD-ROM-based in-flight review, despite a 2-second communication latency. In-flight application of multimedia proficiency enhancement software, coupled with real-time remote expert guidance, can facilitate the performance of complex demanding tasks.

Noncontact ultrasound imaging applied to cortical bone phantoms

PubMed Central

Bulman, J. B.; Ganezer, K. S.; Halcrow, P. W.; Neeson, Ian

2012-01-01

Purpose: The purpose of this paper was to take the first steps toward applying noncontact ultrasound (NCU) to the tasks of monitoring osteoporosis and quantitative ultrasound imaging (QUS) of cortical bone. The authors also focused on the advantages of NCU, such as its lack of reliance on a technologist to apply transducers and a layer of acoustical coupling gel, the ability of the transducers to operate autonomously as specified by preprogrammed software, and the likely reduction in statistical and systematic errors associated with the variability in the pressure applied by the clinician to the transmitting transducer that NCU might provide. The authors also undertook this study in order to find additional applications of NCU beyond its past limited usage in assessing the severity of third degree burns. Methods: A noncontact ultrasound imaging system using a pair of specially designed broadband, 1.5 MHz noncontact piezoelectric transducers and cortical bone phantoms, were used to determine bone mineral density (BMD), speed of sound (SOS), integrated response (IR), and ultrasonic transmittance. Air gaps of greater than 3 cm, two transmission and two reflection paths, and a digital signal processor were also used in the collection of data from phantoms of nominal mass densities that varied from 1.17 to 2.25 g/cm3 and in bone mineral density from 0 to 1.7 g/cm3. Results: Good correlations between known BMD and measured SOS, IR, and transmittance were obtained for all 17 phantoms, and methods for quantifying and minimizing sources of systematic errors were outlined. The BMD of the phantom sets extended through most of the in vivo range found in cortical bone. A total of 16–20 repeated measurements of the SOS, thickness, and IR for the phantom set that were conducted over a period of several months showed a small variation in the range of measurements of ±1%–2%. These NCU data were shown to be in agreement with similar results using contact ultrasound to be within 1%–2%. Transmittance images of cortical bone phantoms showed differences in the nominal overall BMD values of the phantoms that were large enough to be distinguished by a visual examination. A list of possible sources of errors in quantitative NCU was also included in this study. Conclusions: The results of this paper suggest that NCU might find additional applications in medical imaging, beyond its original and only previous usage in assessing third degree burns. The fact that the authors’ phantom measurements using conventional, gel coupled ultrasound are in agreement with those obtained with NCU demonstrates that in spite of large additional levels of attenuation of up to 150 dB and new error sources, NCU could have comparable levels of accuracy to those of conventional quantitative ultrasound, while providing the medical and patient comfort-related advantages of not involving direct contact. PMID:22755697

Double-Stage Delay Multiply and Sum Beamforming Algorithm Applied to Ultrasound Medical Imaging.

PubMed

Mozaffarzadeh, Moein; Sadeghi, Masume; Mahloojifar, Ali; Orooji, Mahdi

2018-03-01

In ultrasound (US) imaging, delay and sum (DAS) is the most common beamformer, but it leads to low-quality images. Delay multiply and sum (DMAS) was introduced to address this problem. However, the reconstructed images using DMAS still suffer from the level of side lobes and low noise suppression. Here, a novel beamforming algorithm is introduced based on expansion of the DMAS formula. We found that there is a DAS algebra inside the expansion, and we proposed use of the DMAS instead of the DAS algebra. The introduced method, namely double-stage DMAS (DS-DMAS), is evaluated numerically and experimentally. The quantitative results indicate that DS-DMAS results in an approximately 25% lower level of side lobes compared with DMAS. Moreover, the introduced method leads to 23%, 22% and 43% improvement in signal-to-noise ratio, full width at half-maximum and contrast ratio, respectively, compared with the DMAS beamformer. Copyright © 2018. Published by Elsevier Inc.

Novel medical imaging technologies for disease diagnosis and treatment

NASA Astrophysics Data System (ADS)

Olego, Diego

2009-03-01

New clinical approaches for disease diagnosis, treatment and monitoring will rely on the ability of simultaneously obtaining anatomical, functional and biological information. Medical imaging technologies in combination with targeted contrast agents play a key role in delivering with ever increasing temporal and spatial resolution structural and functional information about conditions and pathologies in cardiology, oncology and neurology fields among others. This presentation will review the clinical motivations and physics challenges in on-going developments of new medical imaging techniques and the associated contrast agents. Examples to be discussed are: *The enrichment of computer tomography with spectral sensitivity for the diagnosis of vulnerable sclerotic plaque. *Time of flight positron emission tomography for improved resolution in metabolic characterization of pathologies. *Magnetic particle imaging -a novel imaging modality based on in-vivo measurement of the local concentration of iron oxide nano-particles - for blood perfusion measurement with better sensitivity, spatial resolution and 3D real time acquisition. *Focused ultrasound for therapy delivery.

HoDOr: histogram of differential orientations for rigid landmark tracking in medical images

NASA Astrophysics Data System (ADS)

Tiwari, Abhishek; Patwardhan, Kedar Anil

2018-03-01

Feature extraction plays a pivotal role in pattern recognition and matching. An ideal feature should be invariant to image transformations such as translation, rotation, scaling, etc. In this work, we present a novel rotation-invariant feature, which is based on Histogram of Oriented Gradients (HOG). We compare performance of the proposed approach with the HOG feature on 2D phantom data, as well as 3D medical imaging data. We have used traditional histogram comparison measures such as Bhattacharyya distance and Normalized Correlation Coefficient (NCC) to assess efficacy of the proposed approach under effects of image rotation. In our experiments, the proposed feature performs 40%, 20%, and 28% better than the HOG feature on phantom (2D), Computed Tomography (CT-3D), and Ultrasound (US-3D) data for image matching, and landmark tracking tasks respectively.

Utility of 3-dimensional ultrasound imaging to evaluate carotid artery stenosis: comparison with magnetic resonance angiography.

PubMed

Igase, Keiji; Kumon, Yoshiaki; Matsubara, Ichiro; Arai, Masamori; Goishi, Junji; Watanabe, Hideaki; Ohnishi, Takanori; Sadamoto, Kazuhiko

2015-01-01

We evaluated the utility of 3-dimensional (3-D) ultrasound imaging for assessment of carotid artery stenosis, as compared with similar assessment via magnetic resonance angiography (MRA). Subjects comprised 58 patients with carotid stenosis who underwent both 3-D ultrasound imaging and MRA. We studied whether abnormal findings detected by ultrasound imaging could be diagnosed using MRA. Ultrasound images were generated using Voluson 730 Expert and Voluson E8. The degree of stenosis was mild in 17, moderate in 16, and severe in 25 patients, according to ultrasound imaging. Stenosis could not be recognized using MRA in 4 of 17 patients diagnosed with mild stenosis using ultrasound imaging. Ultrasound imaging showed ulceration in 13 patients and mobile plaque in 6 patients. When assessing these patients, MRA showed ulceration in only 2 of 13 patients and did not detect mobile plaque in any of these 6 patients. Static 3-D B mode images demonstrated distributions of plaque, ulceration, and mobile plaque, and static 3-D flow images showed flow configuration as a total structure. Real-time 3-D B mode images demonstrated plaque and vessel movement. Carotid artery stenting was not selected for patients diagnosed with ulceration or mobile plaque. Ultrasound imaging was necessary to detect mild stenosis, ulcerated plaque, or mobile plaque in comparison with MRA, and 3-D ultrasound imaging was useful to recognize carotid stenosis and flow pattern as a total structure by static and real-time 3-D demonstration. This information may contribute to surgical planning. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Time reversal and phase coherent music techniques for super-resolution ultrasound imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Lianjie; Labyed, Yassin

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements. A modified TR-MUSIC imaging algorithm is used to account for ultrasound scattering from both density and compressibility contrasts. The phase response of ultrasound transducer elements is accounted for in a PC-MUSIC system.

Externally Delivered Focused Ultrasound for Renal Denervation.

PubMed

Neuzil, Petr; Ormiston, John; Brinton, Todd J; Starek, Zdenek; Esler, Murray; Dawood, Omar; Anderson, Thomas L; Gertner, Michael; Whitbourne, Rob; Schmieder, Roland E

2016-06-27

The aim of this study was to assess clinical safety and efficacy outcomes of renal denervation executed by an externally delivered, completely noninvasive focused therapeutic ultrasound device. Renal denervation has emerged as a potential treatment approach for resistant hypertension. Sixty-nine subjects received renal denervation with externally delivered focused ultrasound via the Kona Medical Surround Sound System. This approach was investigated across 3 consecutive studies to optimize targeting, tracking, and dosing. In the third study, treatments were performed in a completely noninvasive way using duplex ultrasound image guidance to target the therapy. Short- and long-term safety and efficacy were evaluated through use of clinical assessments, magnetic resonance imaging scans prior to and 3 and 24 weeks after renal denervation, and, in cases in which a targeting catheter was used to facilitate targeting, fluoroscopic angiography with contrast. All patients tolerated renal denervation using externally delivered focused ultrasound. Office blood pressure (BP) decreased by 24.6 ± 27.6/9.0 ± 15.0 mm Hg (from baseline BP of 180.0 ± 18.5/97.7 ± 13.7 mm Hg) in 69 patients after 6 months and 23.8 ± 24.1/10.3 ± 13.1 mm Hg in 64 patients with complete 1-year follow-up. The response rate (BP decrease >10 mm Hg) was 75% after 6 months and 77% after 1 year. The most common adverse event was post-treatment back pain, which was reported in 32 of 69 patients and resolved within 72 h in most cases. No intervention-related adverse events involving motor or sensory deficits were reported. Renal function was not altered, and vascular safety was established by magnetic resonance imaging (all patients), fluoroscopic angiography (n = 48), and optical coherence tomography (n = 5). Using externally delivered focused ultrasound and noninvasive duplex ultrasound, image-guided targeting was associated with substantial BP reduction without any major safety signals. Further randomized, sham-controlled trials will be needed to validate this unique approach. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Multi-ray medical ultrasound simulation without explicit speckle modelling.

PubMed

Tuzer, Mert; Yazıcı, Abdulkadir; Türkay, Rüştü; Boyman, Michael; Acar, Burak

2018-05-04

To develop a medical ultrasound (US) simulation method using T1-weighted magnetic resonance images (MRI) as the input that offers a compromise between low-cost ray-based and high-cost realistic wave-based simulations. The proposed method uses a novel multi-ray image formation approach with a virtual phased array transducer probe. A domain model is built from input MR images. Multiple virtual acoustic rays are emerged from each element of the linear transducer array. Reflected and transmitted acoustic energy at discrete points along each ray is computed independently. Simulated US images are computed by fusion of the reflected energy along multiple rays from multiple transducers, while phase delays due to differences in distances to transducers are taken into account. A preliminary implementation using GPUs is presented. Preliminary results show that the multi-ray approach is capable of generating view point-dependent realistic US images with an inherent Rician distributed speckle pattern automatically. The proposed simulator can reproduce the shadowing artefacts and demonstrates frequency dependence apt for practical training purposes. We also have presented preliminary results towards the utilization of the method for real-time simulations. The proposed method offers a low-cost near-real-time wave-like simulation of realistic US images from input MR data. It can further be improved to cover the pathological findings using an improved domain model, without any algorithmic updates. Such a domain model would require lesion segmentation or manual embedding of virtual pathologies for training purposes.

High Resolution X-Ray Phase Contrast Imaging With Acoustic Tissue-Selective Contrast Enhancement

DTIC Science & Technology

2006-06-01

1999). 17. Sarvazyan, A. P. Shear Wave Elasticity Imaging: A New Ultrasonic Technology of Medical Diagnostics. Ultrasound in Medicine and Biology 24... elastography 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a...Body Figure 2 shows the results of a set of experiments involving a simulated breast . The phantom (purchased from CIR, Inc.) was designed to

Registration of 3D fetal neurosonography and MRI☆

PubMed Central

Kuklisova-Murgasova, Maria; Cifor, Amalia; Napolitano, Raffaele; Papageorghiou, Aris; Quaghebeur, Gerardine; Rutherford, Mary A.; Hajnal, Joseph V.; Noble, J. Alison; Schnabel, Julia A.

2013-01-01

We propose a method for registration of 3D fetal brain ultrasound with a reconstructed magnetic resonance fetal brain volume. This method, for the first time, allows the alignment of models of the fetal brain built from magnetic resonance images with 3D fetal brain ultrasound, opening possibilities to develop new, prior information based image analysis methods for 3D fetal neurosonography. The reconstructed magnetic resonance volume is first segmented using a probabilistic atlas and a pseudo ultrasound image volume is simulated from the segmentation. This pseudo ultrasound image is then affinely aligned with clinical ultrasound fetal brain volumes using a robust block-matching approach that can deal with intensity artefacts and missing features in the ultrasound images. A qualitative and quantitative evaluation demonstrates good performance of the method for our application, in comparison with other tested approaches. The intensity average of 27 ultrasound images co-aligned with the pseudo ultrasound template shows good correlation with anatomy of the fetal brain as seen in the reconstructed magnetic resonance image. PMID:23969169

Risk of cesarean delivery when second-trimester ultrasound dating disagrees with definite last menstrual period.

PubMed

Grewal, Jagteshwar; Zhang, Jun; Mikolajczyk, Rafael T; Ford, Jessie

2010-08-01

Estimates of gestational age based on early second-trimester ultrasound often differ from that based on the last menstrual period (LMP) even when a woman is certain about her LMP. Discrepancies in these gestational age estimates may be associated with an increased risk of cesarean section and low birth weight. We analyzed 7228 singleton, low-risk, white women from The Routine Antenatal Diagnostic Imaging with Ultrasound trial. The women were recruited at less than 14 weeks of gestation and received ultrasound exams between 15 and 22 weeks. Our results indicate that among nulliparous women, the risk of cesarean section increased from 10% when the ultrasound-based gestational age exceeded the LMP-based estimate by 4 days to 60% when the discrepancy increased to 21 days. Moreover, for each additional day the ultrasound-based estimate exceeded the LMP-based estimate, birth weight was higher by 9.6 g. Our findings indicate that a positive discrepancy (i.e., ultrasound-based estimate exceeds LMP-based estimate) in gestational age is associated with an increased risk of cesarean section. A negative discrepancy, by contrast, may reflect early intrauterine growth restriction and an increased risk of low birth weight. Copyright Thieme Medical Publishers.

Hot topics in biomedical ultrasound: ultrasound therapy and its integration with ultrasonic imaging

NASA Astrophysics Data System (ADS)

Everbach, E. Carr

2005-09-01

Since the development of biomedical ultrasound imaging from sonar after WWII, there has been a clear divide between ultrasonic imaging and ultrasound therapy. While imaging techniques are designed to cause as little change as possible in the tissues through which ultrasound propagates, ultrasound therapy typically relies upon heating or acoustic cavitation to produce a desirable therapeutic effect. Concerns over the increasingly high acoustic outputs of diagnostic ultrasound scanners prompted the adoption of the Mechanical Index (MI) and Thermal Index (TI) in the early 1990s. Therapeutic applications of ultrasound, meanwhile, have evolved from deep tissue heating in sports medicine to include targeted drug delivery, tumor and plaque ablation, cauterization via high intensity focused ultrasound (HIFU), and accelerated dissolution of blood clots. The integration of ultrasonic imaging and therapy in one device is just beginning, but the promise of improved patient outcomes is balanced by regulatory and practical impediments.

Real-time photoacoustic and ultrasound dual-modality imaging system facilitated with graphics processing unit and code parallel optimization.

PubMed

Yuan, Jie; Xu, Guan; Yu, Yao; Zhou, Yu; Carson, Paul L; Wang, Xueding; Liu, Xiaojun

2013-08-01

Photoacoustic tomography (PAT) offers structural and functional imaging of living biological tissue with highly sensitive optical absorption contrast and excellent spatial resolution comparable to medical ultrasound (US) imaging. We report the development of a fully integrated PAT and US dual-modality imaging system, which performs signal scanning, image reconstruction, and display for both photoacoustic (PA) and US imaging all in a truly real-time manner. The back-projection (BP) algorithm for PA image reconstruction is optimized to reduce the computational cost and facilitate parallel computation on a state of the art graphics processing unit (GPU) card. For the first time, PAT and US imaging of the same object can be conducted simultaneously and continuously, at a real-time frame rate, presently limited by the laser repetition rate of 10 Hz. Noninvasive PAT and US imaging of human peripheral joints in vivo were achieved, demonstrating the satisfactory image quality realized with this system. Another experiment, simultaneous PAT and US imaging of contrast agent flowing through an artificial vessel, was conducted to verify the performance of this system for imaging fast biological events. The GPU-based image reconstruction software code for this dual-modality system is open source and available for download from http://sourceforge.net/projects/patrealtime.

Has 4D transperineal ultrasound additional value over 2D transperineal ultrasound for diagnosing obstructed defaecation syndrome?

PubMed

van Gruting, I M A; Kluivers, K; Sultan, A H; De Bin, R; Stankiewicz, A; Blake, H; Thakar, R

2018-06-08

To establish the diagnostic test accuracy of both two-dimensional (2D) and four-dimensional (4D) transperineal ultrasound, to assess if 4D ultrasound imaging provides additional value in the diagnosis of posterior pelvic floor disorders in women with obstructed defaecation syndrome. In this prospective cohort study, 121 consecutive women with obstructed defaecation syndrome were recruited. Symptoms of obstructed defaecation and signs of pelvic organ prolapse were assessed using validated methods. All women underwent both 2D transperineal ultrasound (Pro-focus, 8802 transducer, BK-medical) and 4D transperineal ultrasound (Voluson i, RAB4-8-RS transducer, GE). Imaging analysis was performed by two blinded observers. Pelvic floor disorders were dichotomised into presence or absence according pre-defined cut-off values. In the absence of a reference standard a composite reference standard was created from a combination of results of evacuation proctogram, magnetic resonance imaging and endovaginal ultrasound. Primary outcome measures were diagnostic test characteristics of 2D and 4D transperineal ultrasound for diagnosis or rectocele, enterocele, intussusception and anismus. Secondary outcome measures were interobserver agreement, agreement between the two techniques and correlation of signs and symptoms to imaging findings. For diagnosis of all four posterior pelvic floor disorders there was no difference in sensitivity and specificity between 2D and 4D TPUS (p= 0.131 - 1.000). A good agreement between 2D and 4D TPUS was found for the diagnosis of rectocele (ĸ 0.675) and a moderate agreement for diagnosis of enterocele, intussusception and anismus (ĸ 0.465 - 0.545). There was no difference in rectocele depth measurements between both TPUS techniques (19.9 mm vs 19.0 mm, p=0.802). Inter-observer agreement was comparable for both techniques, however 2D TPUS had an excellent interobserver agreement for diagnosis of enterocele and rectocele depth measurements. Diagnosis of rectocele and enterocele on both 2D and 4D TPUS correlated well with presence of posterior vaginal wall prolapse on clinical examination (OR 1.89 - 2.72). In this group of ODS patients, the imaging findings on both techniques did not correlate with severity of symptoms of ODS (OR 0.82 - 1.08). There is no evidence of a superiority of 4D ultrasound acquisition to dynamic 2D ultrasound acquisition for the diagnosis of posterior pelvic floor disorders. Both 2D and 4D TPUS could be used interchangeably to screen women with symptoms of obstructed defaecation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Analysis of the impact of digital watermarking on computer-aided diagnosis in medical imaging.

PubMed

Garcia-Hernandez, Jose Juan; Gomez-Flores, Wilfrido; Rubio-Loyola, Javier

2016-01-01

Medical images (MI) are relevant sources of information for detecting and diagnosing a large number of illnesses and abnormalities. Due to their importance, this study is focused on breast ultrasound (BUS), which is the main adjunct for mammography to detect common breast lesions among women worldwide. On the other hand, aiming to enhance data security, image fidelity, authenticity, and content verification in e-health environments, MI watermarking has been widely used, whose main goal is to embed patient meta-data into MI so that the resulting image keeps its original quality. In this sense, this paper deals with the comparison of two watermarking approaches, namely spread spectrum based on the discrete cosine transform (SS-DCT) and the high-capacity data-hiding (HCDH) algorithm, so that the watermarked BUS images are guaranteed to be adequate for a computer-aided diagnosis (CADx) system, whose two principal outcomes are lesion segmentation and classification. Experimental results show that HCDH algorithm is highly recommended for watermarking medical images, maintaining the image quality and without introducing distortion into the output of CADx. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

Ultrasound Molecular Imaging: Moving Towards Clinical Translation

PubMed Central

Abou-Elkacem, Lotfi; Bachawal, Sunitha V.; Willmann, Jürgen K.

2015-01-01

Ultrasound is a widely available, cost-effective, real-time, non-invasive and safe imaging modality widely used in the clinic for anatomical and functional imaging. With the introduction of novel molecularly-targeted ultrasound contrast agents, another dimension of ultrasound has become a reality: diagnosing and monitoring pathological processes at the molecular level. Most commonly used ultrasound molecular imaging contrast agents are micron sized, gas-containing microbubbles functionalized to recognize and attach to molecules expressed on inflamed or angiogenic vascular endothelial cells. There are several potential clinical applications currently being explored including earlier detection, molecular profiling, and monitoring of cancer, as well as visualization of ischemic memory in transient myocardial ischemia, monitoring of disease activity in inflammatory bowel disease, and assessment of arteriosclerosis. Recently, a first clinical grade ultrasound contrast agent (BR55), targeted at a molecule expressed in neoangiogenesis (vascular endothelial growth factor receptor type 2; VEGFR2) has been introduced and safety and feasibility of VEGFR2-targeted ultrasound imaging is being explored in first inhuman clinical trials in various cancer types. This review describes the design of ultrasound molecular imaging contrast agents, imaging techniques, and potential future clinical applications of ultrasound molecular imaging. PMID:25851932

Ultrasound molecular imaging: Moving toward clinical translation.

PubMed

Abou-Elkacem, Lotfi; Bachawal, Sunitha V; Willmann, Jürgen K

2015-09-01

Ultrasound is a widely available, cost-effective, real-time, non-invasive and safe imaging modality widely used in the clinic for anatomical and functional imaging. With the introduction of novel molecularly-targeted ultrasound contrast agents, another dimension of ultrasound has become a reality: diagnosing and monitoring pathological processes at the molecular level. Most commonly used ultrasound molecular imaging contrast agents are micron sized, gas-containing microbubbles functionalized to recognize and attach to molecules expressed on inflamed or angiogenic vascular endothelial cells. There are several potential clinical applications currently being explored including earlier detection, molecular profiling, and monitoring of cancer, as well as visualization of ischemic memory in transient myocardial ischemia, monitoring of disease activity in inflammatory bowel disease, and assessment of arteriosclerosis. Recently, a first clinical grade ultrasound contrast agent (BR55), targeted at a molecule expressed in neoangiogenesis (vascular endothelial growth factor receptor type 2; VEGFR2) has been introduced and safety and feasibility of VEGFR2-targeted ultrasound imaging is being explored in first inhuman clinical trials in various cancer types. This review describes the design of ultrasound molecular imaging contrast agents, imaging techniques, and potential future clinical applications of ultrasound molecular imaging. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Novel Use of Ultrasound to Teach Reproductive System Physical Examination Skills and Pelvic Anatomy.

PubMed

Parikh, Tejal; Czuzak, Maria; Bui, Naomi; Wildner, Corinna; Koch, Bryna; Leko, Elizabeth; Rappaport, William; Adhikari, Srikar; Gordon, Paul; Gura, Mike; Ellis, Susan

2018-03-01

To determine whether integration of ultrasound (US) into a reproductive system examination clinical skills lab can increase confidence in palpating key reproductive structures during testicular and bimanual pelvic examinations, reduce anxiety about conducting testicular and bimanual pelvic examinations, and improve performance on multiple-choice questions based on structure identification using US images. Second-year medical students enrolled in the Life Cycle preclinical course participated in this cross-sectional study. A single learning activity was developed to pair the teaching of the reproductive system physical examination with the use of US in the clinical skills lab. The evaluation of the teaching session consisted of a pre-post analysis of student self-reported knowledge, confidence, and anxiety. The response rate for the pre survey was 82% (n = 96), and the rate for the post survey was 79% (n = 93). Students' confidence in their ability to identify reproductive system structures on US images increased from pre to post survey. Their confidence in their ability to palpate the epididymis, uterus, and ovary during a physical examination improved, and their anxiety about conducting testicular and bimanual pelvic examinations decreased. Student satisfaction with the session was high. Students' performance on multiple-choice questions based on structure identification using US images was at 96% or higher. Our study findings support the integration of US into a reproductive system examination clinical skills lab. Medical students acquire competency and confidence in reproductive system physical examination skills with US integration. © 2017 by the American Institute of Ultrasound in Medicine.

Evaluating the extent of cell death in 3D high frequency ultrasound by registration with whole-mount tumor histopathology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlad, Roxana M.; Kolios, Michael C.; Moseley, Joanne L.

Purpose: High frequency ultrasound imaging, 10-30 MHz, has the capability to assess tumor response to radiotherapy in mouse tumors as early as 24 h after treatment administration. The advantage of this technique is that the image contrast is generated by changes in the physical properties of dying cells. Therefore, a subject can be imaged before and multiple times during the treatment without the requirement of injecting specialized contrast agents. This study is motivated by a need to provide metrics of comparison between the volume and localization of cell death, assessed from histology, with the volume and localization of cell deathmore » surrogate, assessed as regions with increased echogeneity from ultrasound images. Methods: The mice were exposed to radiation doses of 2, 4, and 8 Gy. Ultrasound images were collected from each tumor before and 24 h after exposure to radiation using a broadband 25 MHz center frequency transducer. After radiotherapy, tumors exhibited hyperechoic regions in ultrasound images that corresponded to areas of cell death in histology. The ultrasound and histological images were rigidly registered. The tumors and regions of cell death were manually outlined on histological images. Similarly, the tumors and hyperechoic regions were outlined on the ultrasound images. Each set of contours was converted to a volumetric mesh in order to compare the volumes and the localization of cell death in histological and ultrasound images. Results: A shrinkage factor of 17{+-}2% was calculated from the difference in the tumor volumes evaluated from histological and ultrasound images. This was used to correct the tumor and cell death volumes assessed from histology. After this correction, the average absolute difference between the volume of cell death assessed from ultrasound and histological images was 11{+-}14% and the volume overlap was 70{+-}12%. Conclusions: The method provided metrics of comparison between the volume of cell death assessed from histology and that assessed from ultrasound images. It was applied here to evaluate the capability of ultrasound imaging to assess early tumor response to radiotherapy in mouse tumors. Similarly, it can be applied in the future to evaluate the capability of ultrasound imaging to assess early tumor response to other modalities of cancer treatment. The study contributes to an understanding of the capabilities and limitation of ultrasound imaging at noninvasively detecting cell death. This provides a foundation for future developments regarding the use of ultrasound in preclinical and clinical applications to adapt treatments based on tumor response to cancer therapy.« less

The Effects of Oxygen on Ultrasound-Induced Blood-Brain Barrier Disruption in Mice.

PubMed

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2017-02-01

Numerous researchers are investigating the use of microbubble-enhanced ultrasound to disrupt the blood-brain barrier (BBB) and deliver drugs to the brain. This study investigated the impact of using oxygen as a carrier gas for anesthesia on microbubble activity and BBB disruption. Targets in mice were sonicated in combination with administration of Optison microbubbles (100 μL/kg) under isoflurane anesthesia with either oxygen or medical air. A 690-kHz focused ultrasound transducer applied 10-ms bursts at peak pressure amplitudes of 0.46-0.54 MPa (n = 2) or 0.34-0.36 MPa (n = 5). After sonication of two locations in one hemisphere, the carrier gas for the anesthesia was changed and the sonications were repeated in the contralateral hemisphere. The BBB disruption, measured via contrast-enhanced magnetic resonance imaging, was significantly greater (p < 0.001) with medical air than with oxygen. Harmonic emissions were also greater with air (p < 0.001), while the decay rate of the harmonic emissions was 1.5 times faster with oxygen. A good correlation (R 2 , 0.46) was observed between the harmonic emissions strength and magnetic resonance imaging signal enhancement. At 0.46-0.54 MPa, both the occurrence and strength of wideband emissions were greater with medical air. However, at lower peak pressure amplitudes of 0.34-0.36 MPa, the strength and probability for wideband emissions were higher with oxygen. Little or no effects were observed in histology at 0.34-0.36 MPa. These findings show that use of oxygen as a carrier gas can result in a substantial diminution of BBB disruption. These results should be taken into account when comparing studies from different researchers and in translating this method to humans. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

8A.03: CONTINUOUS MONITORING OF HEMODYNAMICS IN THE SHORT ARM HUMAN CENTRIFUGE: A FEASIBILITY STUDY.

PubMed

Londono, F; Uytterhaegen, B; Kassel, R; Vanraemdonck, R; Beck, A; Comet, B; Runge, A; Segers, P

2015-06-01

The aim was to test the technical feasibility of a set up combining tonometry and ultrasound, designated as Continuous Physiological and Medical Monitoring (CPMM), for cardiovascular assessment on humans and to evaluate the ability to assess physiological changes induced by artificial gravity in the short arm human centrifuge (SAHC, Verhaert, Belgium) for detecting and preventing potential disorders induced by weightlessness. The project was developed under an European Space Agency (ESA) contract (4000101988/10/NL/EM) and with its support, by the company Verhaert in consortium with the Institute for Space Medicine and Physiology (MEDES) and Ghent University. Measurements were performed at MEDES facilities in 4 young (presumably) healthy volunteers (3 males). For two volunteers, the protocol was divided in three periods: acceleration, steady rotation velocity and deceleration, obtaining carotid pulsed wave (PW)-Mode ultrasound sequences. For another volunteer (female), carotid PW-Mode ultrasound images and brachial and radial tonometry signals were acquired at baseline and during steady rotation. For the fourth volunteer, carotid and femoral PW-Mode ultrasound images and brachial, radial and carotid tonometry signals were acquired at baseline and during an initial (velocity1) and a following faster (velocity2) rotation velocity (see figure on the following page). Carotid PW-Mode ultrasound imaging was obtained in all 4 volunteers during different steps of the protocol. Femoral ultrasound imaging presented more difficulties related mainly to the placement of the probe after baseline, even if in one case results were feasible. Tonometry was, generally, a bigger challenge due to the intrinsic sensitivity of the method. Overall, radial artery tonometry provided the best results, while brachial artery results were acceptable only in one occasion. Carotid tonometry was measured only for one subject with suitable results for processing. Tonometry measurements were feasible under a spin velocity limit, while PW-Mode ultrasound images were more robust and stable. Although general conclusions must be supported by a larger sample, suitable signals and locations were identified and a user friendly and mobile set-up was tested successfully and it is available for further research to identified and assess mechanisms and reflexes acting in physiological adaptation to various gravity conditions.(Figure is included in full-text article.).

[Abdominal ultrasound abnormalities incidentally discovered in patients with asymptomatic HIV in Lome (Togo)].

PubMed

Sonhaye, L; Tchaou, M; Amadou, A; Gbande, P; Assih, K; Djibril, M; Adjenou, K; Redah, D; N'Dakéna, K

2014-01-01

Few studies have examined ultrasound imaging of abdominal manifestations of HIV-AIDS, although these rank second only to its pleuropulmonary manifestations. Thus, this study sought to determine the features of abdominal ultrasound in HIV infection. This prospective, descriptive and analytical study took place in the radiology department of the University Hospital Campus Lomé and covered the three-year period of 2009-2011. It included all patients older than 15 years with positive HIV serology. During the study period, 566 patients met the inclusion criteria. Ultrasound examination showed the liver appeared normal in 153 patients (27.0%), but homogeneously hyperechoic and thus suggestive of hepatic steatosis in 107 (18.9%). The bile duct was dilatated in 12 patients or 2.1%. An anomaly in the corticomedullary differentiation in normal-sized kidneys was noted in 28.1% (159 patients). Diffuse homogeneous hypertrophy of the pancreas was found in 3 patients (0.53%). Splenomegaly was noted in 387 patients (68.4%); the echopattern of the spleen was diffusely micronodular in 6 patients (1.1%). Deep adenopathies were found in 29 patients (5.1%) and ascites in 46 patients (8.1%). Abdominal ultrasound is a medical imaging technique available in developing countries, less expensive than others, which can be considered an alternative to computed tomography (CT) in the countries of sub-Saharan Africa for the exploration of the abdominal manifestations of HIV.

Quantitative contrast-enhanced ultrasound imaging: a review of sources of variability

PubMed Central

Tang, M.-X.; Mulvana, H.; Gauthier, T.; Lim, A. K. P.; Cosgrove, D. O.; Eckersley, R. J.; Stride, E.

2011-01-01

Ultrasound provides a valuable tool for medical diagnosis offering real-time imaging with excellent spatial resolution and low cost. The advent of microbubble contrast agents has provided the additional ability to obtain essential quantitative information relating to tissue vascularity, tissue perfusion and even endothelial wall function. This technique has shown great promise for diagnosis and monitoring in a wide range of clinical conditions such as cardiovascular diseases and cancer, with considerable potential benefits in terms of patient care. A key challenge of this technique, however, is the existence of significant variations in the imaging results, and the lack of understanding regarding their origin. The aim of this paper is to review the potential sources of variability in the quantification of tissue perfusion based on microbubble contrast-enhanced ultrasound images. These are divided into the following three categories: (i) factors relating to the scanner setting, which include transmission power, transmission focal depth, dynamic range, signal gain and transmission frequency, (ii) factors relating to the patient, which include body physical differences, physiological interaction of body with bubbles, propagation and attenuation through tissue, and tissue motion, and (iii) factors relating to the microbubbles, which include the type of bubbles and their stability, preparation and injection and dosage. It has been shown that the factors in all the three categories can significantly affect the imaging results and contribute to the variations observed. How these factors influence quantitative imaging is explained and possible methods for reducing such variations are discussed. PMID:22866229

Towards Dynamic Contrast Specific Ultrasound Tomography

NASA Astrophysics Data System (ADS)

Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-10-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography.

PubMed

Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

2016-10-05

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography

PubMed Central

Demi, Libertario; Van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-01-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast. PMID:27703251

MO-DE-210-03: Ultrasound imaging is an attractive method for image guided radiation treatment (IGRT), by itself or to complement other imaging modalities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, K.

Ultrasound imaging is an attractive method for image guided radiation treatment (IGRT), by itself or to complement other imaging modalities. It is inexpensive, portable and provides good soft tissue contrast. For challenging soft tissue targets such as pancreatic cancer, ultrasound imaging can be used in combination with pre-treatment MRI and/or CT to transfer important anatomical features for target localization at time of treatment. The non-invasive and non-ionizing nature of ultrasound imaging is particularly powerful for intra-fraction localization and monitoring. Recognizing these advantages, efforts are being made to incorporate novel robotic approaches to position and manipulate the ultrasound probe during irradiation.more » These recent enabling developments hold potential to bring ultrasound imaging to a new level of IGRT applications. However, many challenges, not limited to image registration, robotic deployment, probe interference and image acquisition rate, need to be addressed to realize the full potential of IGRT with ultrasound imaging. Learning Objectives: Understand the benefits and limitations in using ultrasound to augment MRI and/or CT for motion monitoring during radiation therapy delivery. Understanding passive and active robotic approaches to implement ultrasound imaging for intra-fraction monitoring. Understand issues of probe interference with radiotherapy treatment. Understand the critical clinical workflow for effective and reproducible IGRT using ultrasound guidance. The work of X.L. is supported in part by Elekta; J.W. and K.D. is supported in part by a NIH grant R01 CA161613 and by Elekta; D.H. is support in part by a NIH grant R41 CA174089.« less

Development of an in vitro diaphragm motion reproduction system.

PubMed

Liao, Ai-Ho; Chuang, Ho-Chiao; Shih, Ming-Chih; Hsu, Hsiao-Yu; Tien, Der-Chi; Kuo, Chia-Chun; Jeng, Shiu-Chen; Chiou, Jeng-Fong

2017-07-01

This study developed an in vitro diaphragm motion reproduction system (IVDMRS) based on noninvasive and real-time ultrasound imaging to track the internal displacement of the human diaphragm and diaphragm phantoms with a respiration simulation system (RSS). An ultrasound image tracking algorithm (UITA) was used to retrieve the displacement data of the tracking target and reproduce the diaphragm motion in real time using a red laser to irradiate the diaphragm phantom in vitro. This study also recorded the respiration patterns in 10 volunteers. Both simulated and the respiration patterns in 10 human volunteers signals were input to the RSS for conducting experiments involving the reproduction of diaphragm motion in vitro using the IVDMRS. The reproduction accuracy of the IVDMRS was calculated and analyzed. The results indicate that the respiration frequency substantially affects the correlation between ultrasound and kV images, as well as the reproduction accuracy of the IVDMRS due to the system delay time (0.35s) of ultrasound imaging and signal transmission. The utilization of a phase lead compensator (PLC) reduced the error caused by this delay, thereby improving the reproduction accuracy of the IVDMRS by 14.09-46.98%. Applying the IVDMRS in clinical treatments will allow medical staff to monitor the target displacements in real time by observing the movement of the laser beam. If the target displacement moves outside the planning target volume (PTV), the treatment can be immediately stopped to ensure that healthy tissues do not receive high doses of radiation. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Monitoring for Renal Stone Recurrence in Astronauts With History of Stone

NASA Technical Reports Server (NTRS)

Reyes, David P.; Sargsyan, Ashot; Locke, James; Davis, Jeffrey

2014-01-01

After an initial stone episode persons are at increased risk for future stone formation. A systematic approach is required to monitor the efficacy of treatment and preventive measures, and to assess the risk of developing new stones. This is important for persons working in critical jobs or austere environments, such as astronauts. A literature review of the current standards of care for renal stone monitoring and imaging was done. Military and civil aviation standards were also reviewed, as well as the medical precedents from the space program. Additionally, a new, more effective, renal stone ultrasound protocol has been developed. Using this work, a monitoring algorithm was proposed that takes into consideration the unique mission and operational environment of spaceflight. The approach to imaging persons with history of renal stones varies widely in the literature. Imaging is often done yearly or biannually, which may be too long for mission critical personnel. In the proposed algorithm astronauts with a history of renal stone, who may be under consideration for assignment, are imaged by a detailed, physiciandriven, ultrasound protocol. Unassigned personnel are monitored by yearly ultrasound and urine studies. Any positive ultrasound study is then followed by low-dose renal computed tomography scan. Other criteria are also established. The proposed algorithm provides a balanced approach between efficacy and reduced radiation exposure for the monitoring of astronauts with a renal stone history. This may eventually allow a transition from a risk-averse, to a risk-modifying approach that can enable continued service of individuals with history of renal stone that have adequately controlled risk factors.

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers.

PubMed

Bo, Xiao-Wan; Xu, Hui-Xiong; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-11-01

To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging is better than both conventional ultrasound and ultrasound-CECT/CEMRI fusion imaging for lesion visualization and improves the operator confidence, thus it should be recommended to be used as a routine in ultrasound-guided percutaneous RFA procedures for liver cancer.

Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers

PubMed Central

Bo, Xiao-Wan; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

2016-01-01

Objective: To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. Methods: 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. Results: On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p < 0.001 in comparison with conventional ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p < 0.001 in comparison with ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Conclusion: Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging is better than both conventional ultrasound and ultrasound-CECT/CEMRI fusion imaging for lesion visualization and improves the operator confidence, thus it should be recommended to be used as a routine in ultrasound-guided percutaneous RFA procedures for liver cancer. PMID:27626506

What resources are used in emergency departments in rural sub-Saharan Africa? A retrospective analysis of patient care in a district-level hospital in Uganda.

PubMed

Bitter, Cindy Carol; Rice, Brian; Periyanayagam, Usha; Dreifuss, Bradley; Hammerstedt, Heather; Nelson, Sara W; Bisanzo, Mark; Maling, Samuel; Chamberlain, Stacey

2018-02-24

To determine the most commonly used resources (provider procedural skills, medications, laboratory studies and imaging) needed to care for patients. A single emergency department (ED) of a district-level hospital in rural Uganda. 26 710 patient visits. Procedures were performed for 65.6% of patients, predominantly intravenous cannulation, wound care, bladder catheterisation and orthopaedic procedures. Medications were administered to 87.6% of patients, most often pain medications, antibiotics, intravenous fluids, antimalarials, nutritional supplements and vaccinations. Laboratory testing was used for 85% of patients, predominantly malaria smears, rapid glucose testing, HIV assays, blood counts, urinalyses and blood type. Radiology testing was performed for 17.3% of patients, including X-rays, point-of-care ultrasound and formal ultrasound. This study describes the skills and resources needed to care for a large prospective cohort of patients seen in a district hospital ED in rural sub-Saharan Africa. It demonstrates that the vast majority of patients were treated with a small formulary of critical medications and limited access to laboratories and imaging, but providers require a broad set of decision-making and procedural skills. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

NiftyNet: a deep-learning platform for medical imaging.

PubMed

Gibson, Eli; Li, Wenqi; Sudre, Carole; Fidon, Lucas; Shakir, Dzhoshkun I; Wang, Guotai; Eaton-Rosen, Zach; Gray, Robert; Doel, Tom; Hu, Yipeng; Whyntie, Tom; Nachev, Parashkev; Modat, Marc; Barratt, Dean C; Ourselin, Sébastien; Cardoso, M Jorge; Vercauteren, Tom

2018-05-01

Medical image analysis and computer-assisted intervention problems are increasingly being addressed with deep-learning-based solutions. Established deep-learning platforms are flexible but do not provide specific functionality for medical image analysis and adapting them for this domain of application requires substantial implementation effort. Consequently, there has been substantial duplication of effort and incompatible infrastructure developed across many research groups. This work presents the open-source NiftyNet platform for deep learning in medical imaging. The ambition of NiftyNet is to accelerate and simplify the development of these solutions, and to provide a common mechanism for disseminating research outputs for the community to use, adapt and build upon. The NiftyNet infrastructure provides a modular deep-learning pipeline for a range of medical imaging applications including segmentation, regression, image generation and representation learning applications. Components of the NiftyNet pipeline including data loading, data augmentation, network architectures, loss functions and evaluation metrics are tailored to, and take advantage of, the idiosyncracies of medical image analysis and computer-assisted intervention. NiftyNet is built on the TensorFlow framework and supports features such as TensorBoard visualization of 2D and 3D images and computational graphs by default. We present three illustrative medical image analysis applications built using NiftyNet infrastructure: (1) segmentation of multiple abdominal organs from computed tomography; (2) image regression to predict computed tomography attenuation maps from brain magnetic resonance images; and (3) generation of simulated ultrasound images for specified anatomical poses. The NiftyNet infrastructure enables researchers to rapidly develop and distribute deep learning solutions for segmentation, regression, image generation and representation learning applications, or extend the platform to new applications. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

PubMed

Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

2017-04-01

Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

Downstream Imaging Utilization After Emergency Department Ultrasound Interpreted by Radiologists Versus Nonradiologists: A Medicare Claims-Based Study.

PubMed

Allen, Bibb; Carrol, L Van; Hughes, Danny R; Hemingway, Jennifer; Duszak, Richard; Rosenkrantz, Andrew B

2017-04-01

To study differences in imaging utilization downstream to initial emergency department (ED) ultrasound examinations interpreted by radiologists versus nonradiologists. Using 5% Medicare Research Identifiable Files from 2009 to 2014, we identified episodes where the place of service was "emergency room hospital" and the patient also underwent an ultrasound examination. We determined whether the initial ultrasound was interpreted by a radiologist or nonradiologist and then summed all additional imaging events occurring within 7, 14, and 30 days of each initial ED ultrasound. For each year and each study window, we calculated the mean number of downstream imaging procedures by specialty group. Of 200,357 ED ultrasound events, 163,569 (81.6%) were interpreted by radiologists and 36,788 (18.4%) by nonradiologists. Across all study years, ED patients undergoing ultrasound examinations interpreted by nonradiologists underwent 1.08, 1.22, and 1.34 additional diagnostic imaging studies at 7, 14, and 30 days, respectively (P < .01) compared with when the initial ultrasound examination was interpreted by a radiologist. From 2010 to 2014, the volume of downstream imaging for both radiologists and nonradiologists significantly decreased, with each year resulting in 0.08 fewer imaging examinations (P < .001) 14 days after the ED ultrasound event. Despite that decline, differences in downstream imaging between radiologists and nonradiologists persisted over time. Downstream imaging after an initial ED ultrasound is significantly reduced when the ultrasound examination is interpreted by a radiologist rather than a nonradiologist. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Musculoskeletal ultrasound and other imaging modalities in rheumatoid arthritis.

PubMed

Ohrndorf, Sarah; Werner, Stephanie G; Finzel, Stephanie; Backhaus, Marina

2013-05-01

This review refers to the use of musculoskeletal ultrasound in patients with rheumatoid arthritis (RA) both in clinical practice and research. Furthermore, other novel sensitive imaging modalities (high resolution peripheral quantitative computed tomography and fluorescence optical imaging) are introduced in this article. Recently published ultrasound studies presented power Doppler activity by ultrasound highly predictive for later radiographic erosions in patients with RA. Another study presented synovitis detected by ultrasound being predictive of subsequent structural radiographic destruction irrespective of the ultrasound modality (grayscale ultrasound/power Doppler ultrasound). Further studies are currently under way which prove ultrasound findings as imaging biomarkers in the destructive process of RA. Other introduced novel imaging modalities are in the validation process to prove their impact and significance in inflammatory joint diseases. The introduced imaging modalities show different sensitivities and specificities as well as strength and weakness belonging to the assessment of inflammation, differentiation of the involved structures and radiological progression. The review tries to give an answer regarding how to best integrate them into daily clinical practice with the aim to improve the diagnostic algorithms, the daily patient care and, furthermore, the disease's outcome.

Standards of ultrasound imaging of the adrenal glands

PubMed Central

Jakubowski, Wiesław S.; Dobruch-Sobczak, Katarzyna; Kasperlik-Załuska, Anna A.

2015-01-01

Adrenal glands are paired endocrine glands located over the upper renal poles. Adrenal pathologies have various clinical presentations. They can coexist with the hyperfunction of individual cortical zones or the medulla, insufficiency of the adrenal cortex or retained normal hormonal function. The most common adrenal masses are tumors incidentally detected in imaging examinations (ultrasound, tomography, magnetic resonance imaging), referred to as incidentalomas. They include a range of histopathological entities but cortical adenomas without hormonal hyperfunction are the most common. Each abdominal ultrasound scan of a child or adult should include the assessment of the suprarenal areas. If a previously non-reported, incidental solid focal lesion exceeding 1 cm (incidentaloma) is detected in the suprarenal area, computed tomography or magnetic resonance imaging should be conducted to confirm its presence and for differentiation and the tumor functional status should be determined. Ultrasound imaging is also used to monitor adrenal incidentaloma that is not eligible for a surgery. The paper presents recommendations concerning the performance and assessment of ultrasound examinations of the adrenal glands and their pathological lesions. The article includes new ultrasound techniques, such as tissue harmonic imaging, spatial compound imaging, three-dimensional ultrasound, elastography, contrast-enhanced ultrasound and parametric imaging. The guidelines presented above are consistent with the recommendations of the Polish Ultrasound Society. PMID:26807295

Dual-mode transducers for ultrasound imaging and thermal therapy.

PubMed

Owen, N R; Chapelon, J Y; Bouchoux, G; Berriet, R; Fleury, G; Lafon, C

2010-02-01

Medical imaging is a vital component of high intensity focused ultrasound (HIFU) therapy, which is gaining clinical acceptance for tissue ablation and cancer therapy. Imaging is necessary to plan and guide the application of therapeutic ultrasound, and to monitor the effects it induces in tissue. Because they can transmit high intensity continuous wave ultrasound for treatment and pulsed ultrasound for imaging, dual-mode transducers aim to improve the guidance and monitoring stages. Their primary advantage is implicit registration between the imaging and treatment axes, and so they can help ensure before treatment that the therapeutic beam is correctly aligned with the planned treatment volume. During treatment, imaging signals can be processed in real-time to assess acoustic properties of the tissue that are related to thermal ablation. Piezocomposite materials are favorable for dual-mode transducers because of their improved bandwidth, which in turn improves imaging performance while maintaining high efficiency for treatment. Here we present our experiences with three dual-mode transducers for interstitial applications. The first was an 11-MHz monoelement designed for use in the bile duct. It had a 25x7.5 mm(2) aperture that was cylindrically focused to 10mm. The applicator motion was step-wise rotational for imaging and therapy over a 360 degrees, or smaller, sector. The second transducer had 5-elements, each measuring 3.0x3.8 mm(2) for a total aperture of 3.0x20 mm(2). It operated at 5.6 MHz, was cylindrically focused to 14 mm, and was integrated with a servo-controlled oscillating probe designed for sector imaging and directive therapy in the liver. The last transducer was a 5-MHz, 64-element linear array designed for beam-formed imaging and therapy. The aperture was 3.0x18 mm(2) with a pitch of 0.280 mm. Characterization results included conversion efficiencies above 50%, pulse-echo bandwidths above 50%, surface intensities up to 30 W/cm(2), and axial imaging resolutions to 0.2 mm. The second transducer was evaluated in vivo using porcine liver, where coagulation necrosis was induced up to a depth of 20 mm in 120 s. B-mode and M-mode images displayed a hypoechoic region that agreed well with lesion depth observed by gross histology. These feasibility studies demonstrate that the dual-mode transducers had imaging performance that was sufficient to aid the guidance and monitoring of treatment, and could sustain high intensities to induce coagulation necrosis in vivo.

Diagnostic and interventional musculoskeletal ultrasound: part 1. Fundamentals.

PubMed

Smith, Jay; Finnoff, Jonathan T

2009-01-01

Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Technological advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applications in the evaluation and treatment of patients with neurologic and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared with other available imaging modalities, (2) describe how ultrasound machines produce images using sound waves, (3) discuss the steps necessary to acquire and optimize an ultrasound image, (4) understand the different ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones, and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound in musculoskeletal practice. Part 1 of this 2-part article reviews the fundamentals of clinical ultrasonographic imaging, including relevant physics, equipment, training, image optimization, and scanning principles for diagnostic and interventional purposes.

Ultrasound Guidance and Monitoring of Laser-Based Fat Removal

PubMed Central

Shah, Jignesh; Thomsen, Sharon; Milner, Thomas E.; Emelianov, Stanislav Y.

2009-01-01

Background and Objectives We report on a study to investigate feasibility of utilizing ultrasound imaging to guide laser removal of subcutaneous fat. Ultrasound imaging can be used to identify the tissue composition and to monitor the temperature increase in response to laser irradiation. Study Design/Materials and Methods Laser heating was performed on ex vivo porcine subcutaneous fat through the overlying skin using a continuous wave laser operating at 1,210 nm optical wavelength. Ultrasound images were recorded using a 10 MHz linear array-based ultrasound imaging system. Results Ultrasound imaging was utilized to differentiate between water-based and lipid-based regions within the porcine tissue and to identify the dermis-fat junction. Temperature maps during the laser exposure in the skin and fatty tissue layers were computed. Conclusions Results of our study demonstrate the potential of using ultrasound imaging to guide laser fat removal. PMID:19065554

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey

PubMed Central

Zhang, Fan; Li, Xuelong

2018-01-01

The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system. PMID:29687000

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey.

PubMed

Huang, Qinghua; Zhang, Fan; Li, Xuelong

2018-01-01

The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

Using radioactive drugs could lead to better imaging of prostate cancer | Center for Cancer Research

Cancer.gov

Medical imaging (x-ray, ultrasound, MRI, CT, PET scan) is a noninvasive way to view the internal structures of the body. However, these tools are not ideal for detecting cancer that has spread, or metastasized, because the precise location of these cancer cells is unknown. Researchers are now testing an experimental radiotracer called 18F-DCFPyL to help find sites of cancer in the body.  Learn more...

Ultra-high Speed Optical Imaging of Ultrasound-activated Microbubbles in Mesenteric Microvessels

NASA Astrophysics Data System (ADS)

Chen, Hong

Ultrasound contrast agent microbubbles have gained widespread applications in diagnostic and therapeutic ultrasound. Animal studies of bioeffects induced by ultrasound-activated microbubbles have demonstrated that microbubbles can cause microvessel damage. Much scientific attention has been attracted to such microvascular bioeffects, not only because of the related safety concerns, but also because of the potential useful applications of microbubbles in the intravascular delivery of drugs and genetic materials into target tissues. A significant challenge in using microbubbles in medical ultrasound is the lack of knowledge about how the microbubbles behave in blood vessels when exposed to ultrasound and how their interactions with ultrasound cause vascular damage. Although extensive studies were performed in the past to study the dynamics of microbubbles, most of those studies were performed in vitro and did not directly address the clinical environment in which microbubbles are injected into blood vessels. In this thesis work, a synchronized optical-acoustic system was set up for ultrahigh speed imaging of insonated microbubbles in microvessels. The recorded images revealed the formation of microjets penetrating the microbubbles, as well as vessel distention (motion outward against the surrounding tissue) and vessel invagination (motion inward toward the lumen) caused by the expansion and collapse of the microbubbles, respectively. Contrary to current paradigms which propose that microbubbles damage vessels either by distending them or by forming liquid jets impinging on them, microbubbles translation and jetting were in the direction away from the nearest vessel wall; furthermore, invagination typically exceeded distention in arterioles and venules. Vessel invagination was found to be associated with vascular damage. These studies suggest that vessel invagination may be a newly discovered potential mechanism for vascular damage by ultrasound-activated microbubbles. The dynamics of bubble-vessel interactions are coupled intimately with the viscoelastic properties of the microvessels. To probe these properties, a method based on the relaxation times of the invaginated microvessels was used to estimate the relaxation time constants of the microvessels. It was found that the time constants were on microsecond time scales, which provided insight into the unique and unknown viscoelastic properties of the microvessels.

American Institute of Ultrasound in Medicine

MedlinePlus

... Ultrasound Pediatric Ultrasound Point-of-Care Ultrasound Sonography Therapeutic Ultrasound Ultrasound in Global Health Ultrasound in Medical Education CME Center CME Tracker Annual Convention Journal Tests ...

Diaphragm breathing movement measurement using ultrasound and radiographic imaging: a concurrent validity.

PubMed

Noh, Dong K; Lee, Jae J; You, Joshua H

2014-01-01

Recent ultrasound imaging evidence asserts that the diaphragm is an important multifunctional muscle to control breathing as well as stabilize the core and posture in humans. However, the validity and accuracy of ultrasound for the measurement of dynamic diaphragm movements during breathing and functional core activities have not been determined. The specific aim of this study was to validate the accuracy of ultrasound imaging measurements of diaphragm movements by concurrently comparing these measurements to the gold standard of radiographic imaging measurements. A total of 14 asymptomatic adults (9 males, 5 females; mean age =28.4 ± 3.0 years) were recruited to participate in the study. Ultrasound and radiographic images were used concurrently to determine diaphragm movement (inspiration, expiration, and excursion) during tidal breathing. Pearson correlation analysis showed strong correlations, ranging from r=0.78 to r=0.83, between ultrasound and radiographic imaging measurements of the diaphragm during inhalation, exhalation, and excursion. These findings suggest that ultrasound imaging measurement is useful to accurately evaluate diaphragm movements during tidal breathing. Clinically, ultrasound imaging measurements can be used to diagnose and treat diaphragm movement impairments in individuals with neuromuscular disorders including spinal cord injuries, stroke, and multiple sclerosis.

Automated assessment of joint synovitis activity from medical ultrasound and power doppler examinations using image processing and machine learning methods.

PubMed

Cupek, Rafal; Ziębiński, Adam

2016-01-01

Rheumatoid arthritis is the most common rheumatic disease with arthritis, and causes substantial functional disability in approximately 50% patients after 10 years. Accurate measurement of the disease activity is crucial to provide an adequate treatment and care to the patients. The aim of this study is focused on a computer aided diagnostic system that supports an assessment of synovitis severity. This paper focus on a computer aided diagnostic system that was developed within joint Polish-Norwegian research project related to the automated assessment of the severity of synovitis. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Synovitis is estimated by ultrasound examiner using the scoring system graded from 0 to 3. Activity score is estimated on the basis of the examiner's experience or standardized ultrasound atlases. The method needs trained medical personnel and the result can be affected by a human error. The porotype of a computer-aided diagnostic system and algorithms essential for an analysis of ultrasonic images of finger joints are main scientific output of the MEDUSA project. Medusa Evaluation System prototype uses bone, skin, joint and synovitis area detectors for mutual structural model based evaluation of synovitis. Finally, several algorithms that support the semi-automatic or automatic detection of the bone region were prepared as well as a system that uses the statistical data processing approach in order to automatically localize the regions of interest. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Activity score is estimated on the basis of the examiner's experience and the result can be affected by a human error. In this paper we presented the MEDUSA project which is focused on a computer aided diagnostic system that supports an assessment of synovitis severity.

Smart Ultrasound Remote Guidance Experiment (SURGE)- Concept of Operations Evaluation for Using Remote Guidance Ultrasound for Planetary Space Flight

NASA Technical Reports Server (NTRS)

Hurst, Victor, IV; Peterson, Sean; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Douglas; Ham, David; Amponsah, David; Dulchavsky, Scott

2010-01-01

Introduction Use of remote guidance (RG) techniques aboard the International Space Station (ISS) has enabled astronauts to collect diagnostic-level ultrasound images. Exploration class missions will require this cohort of (typically) non-formally trained sonographers to operate with greater autonomy given the longer communication delays (2 seconds for ISS vs. >6 seconds for missions beyond the Moon) and communication blackouts. To determine the feasibility and training requirements for autonomous ultrasound image collection by non-expert ultrasound operators, ultrasound images were collected from a similar cohort using three different image collection protocols: RG only, RG with a computer-based learning tool (LT), and autonomous image collection with LT. The groups were assessed for both image quality and time to collect the images. Methods Subjects were randomized into three groups: RG only, RG with LT, and autonomous with LT. Each subject received 10 minutes of standardized training before the experiment. The subjects were tasked with making the following ultrasound assessments: 1) bone fracture and 2) focused assessment with sonography in trauma (FAST) to assess a patient s abdomen. Human factors-related questionnaire data were collected immediately after the assessments. Results The autonomous group did not out-perform the two groups that received RG. The mean time for the autonomous group to collect images was less than the RG groups, however the mean image quality for the autonomous group was less compared to both RG groups. Discussion Remote guidance continues to produce higher quality ultrasound images than autonomous ultrasound operation. This is likely due to near-instant feedback on image quality from the remote guider. Expansion in communication time delays, however, diminishes the capability to provide this feedback, thus requiring more autonomous ultrasound operation. The LT has the potential to be an excellent training and coaching component for autonomous ultrasound image collection during exploration missions.

WE-EF-210-07: Development of a Minimally Invasive Photo Acoustic Imaging System for Early Prostate Cancer Detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sano, M; Yousefi, S; Xing, L

Purpose: The objective of this work is to design, implement and characterize a catheter-based ultrasound/photoacoustic imaging probe for early-diagnosis of prostate cancer and to aid in image-guided radiation therapy. Methods: The need to image across 6–10cm of tissue to image the whole prostate gland limits the resolution achievable with a transrectal ultrasound approach. In contrast, the urethra bisects the prostate gland, providing a minimally invasive pathway for deploying a high resolution ultrasound transducer. Utilizing a high-frequency (20MHz) ultrasound/photoacoustic probe, high-resolution structural and molecular imaging of the prostate tissue is possible. A custom 3D printed probe containing a high-frequency single-element ultrasoundmore » transducer is utilized. The diameter of the probe is designed to fit inside a Foley catheter and the probe is rotated around the central axis to achieve a circular B-scan. A custom ultrasound amplifier and receiver was set up to trigger the ultrasound pulse transmission and record the reflected signal. The reconstructed images were compared to images generated by traditional 5 MHz ultrasound transducers. Results: The preliminary results using the high-frequency ultrasound probe show that it is possible to resolve finely detailed information in a prostate tissue phantom that was not achievable with previous low-frequency ultrasound systems. Preliminary ultrasound imaging was performed on tissue mimicking phantom and sensitivity and signal-to-noise ratio of the catheter was measured. Conclusion: In order to achieve non-invasive, high-resolution, structural and molecular imaging for early-diagnosis and image-guided radiation therapy of the prostate tissue, a transurethral catheter was designed. Structural/molecular imaging using ultrasound/photoacoustic of the prostate tissue will allow for localization of hyper vascularized areas for early-stage prostate cancer diagnosis.« less

Ultrasonography for diagnosis, monitoring and treatment of tenosynovitis in patients with rheumatoid arthritis.

PubMed

Danielsen, Mads Ammitzbøll

2018-03-01

Rheumatod arthritis is a chronic systemic autoimmune disease, characterized by inflammation in joints and tendon sheaths, which frequently leads to permanent and serious disability due to joint destruction, but also tendon and ligament ruptures. Clinical management of rheumatoid arthritis has traditionally been supported by biochemical and radiographic findings. However, imaging modalities like ultrasound and magnetic resonance imaging (MRI) have improved the possibility for better management of rheumatoid arthritis patients, due to higher sensitivity and specificity for detecting ongoing inflammation, this thesis is focusing on tenosynovitis as recent studies have shown that inflammation in tendon sheaths, i.e. tenosynovitis, is a very common manifestation of rheumatoid arthritis and may often be mistaken for synovitis. Furthermore, presence of ultrasonographic tenosynovitis may predict clinical flare and erosive progression. 
The main aim of this PhD thesis was to further develop and validate ultrasound as a tool for diagnosis, monitoring and treatment of tenosynovitis. This was investigated in four studies: 
Study I: 3D Doppler Ultrasound findings in healthy wrist and finger tendon sheaths - Can feeding vessels lead to misinterpretation in Doppler-detected tenosynovitis? 
Study II: Image fusion of Ultrasound and MRI and B-flow evaluation of tenosynovitis - A pilot study on new imaging techniques in rheumatoid arthritis patients. 
Study III: Validity and sensitivity to change of the semi-quantitative Outcome Measures in Rheumatology Clinical Trials (OMERACT) ultrasound scoring system for tenosynovitis in patients with rheumatoid arthritis and for the quantitative scoring system, pixel index. 
Study IV: Intramuscular versus ultrasound guided intratenosynovial glucocorticoid injection for tenosynovitis in patients with rheumatoid arthritis - A randomised, double-blind, controlled study with ultrasound and clinical follow up at 4 and 12 weeks. 
From the studies presented in the PhD thesis the following was concluded:
 Doppler findings in or in close proximity to the tendon sheaths were common in wrists and fingers in healthy participants. These feeding vessels may be a source of misinterpretation, i.e .wrong diagnosis of a low degree of tenosynovitis, not only due to their presence but also because they may be interpreted as being inside the tendon sheath due to blooming and reverberations artefacts.
 Ultrasound and MRI had high agreement using image fusion for assessment of tenosynovitis when MRI partial volume artefacts were taken into account. In contrast, the agreement between B-flow and ultrasound was poor, since the quality of the b-flow images and the flow sensitivity were low.
 The OMERACT ultrasound scoring system for tenosynovitis had an excellent intra- and interreader agreement between trained investigators and a high ability to detect change over time, similarly, the quantitative tenosynovitis assessment by pixel index had a very good intrareader agreement and moderate to good interreader agreement, but only a moderate ability to detect change over time. The ultrasound scores had a high responsiveness, indicating that the OMERACT ultrasound scoring system was useful for diagnosing and monitoring tenosynovitis in rheumatoid arthritis patients in clinical trials and practice. For treatment of tenosynovitis in rheumatoid arthritis patients, remission (ultrasound tenosynovitis grey scale score ≤1 and Doppler score = 0) was achieved significantly more frequently in the ultrasound guided intratenosynovial glucocorticoid injection group than in the intramuscular glucocorticoid injection group, both at 4 and 12 week follow-ups. Furthermore, tenosynovitis responded significantly better clinically and by ultrasound assessment when treated with ultrasound guided intratenosynovial glucocorticoid injection com-pared to intramuscular glucocorticoid injection, both at 4 and 12 week follow-ups. Articles published in the Danish Medical Journal are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Windowed time-reversal music technique for super-resolution ultrasound imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Lianjie; Labyed, Yassin

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements.

Cognitive load imposed by knobology may adversely affect learners' perception of utility in using ultrasonography to learn physical examination skills, but not anatomy.

PubMed

Jamniczky, Heather A; McLaughlin, Kevin; Kaminska, Malgorzata E; Raman, Maitreyi; Somayaji, Ranjani; Wright, Bruce; Ma, Irene W Y

2015-01-01

Ultrasonography is increasingly used for teaching anatomy and physical examination skills but its effect on cognitive load is unknown. This study aimed to determine ultrasound's perceived utility for learning, and to investigate the effect of cognitive load on its perceived utility. Consenting first-year medical students (n = 137) completed ultrasound training that includes a didactic component and four ultrasound-guided anatomy and physical examination teaching sessions. Learners then completed a survey on comfort with physical examination techniques (three items; alpha = 0.77), perceived utility of ultrasound in learning (two items; alpha = 0.89), and cognitive load on ultrasound use [measured with a validated nine-point scale (10 items; alpha = 0.88)]. Learners found ultrasound useful for learning for both anatomy and physical examination (mean 4.2 ± 0.9 and 4.4 ± 0.8, respectively; where 1 = very useless and 5 = very useful). Principal components analysis on the cognitive load survey revealed two factors, "image interpretation" and "basic knobology," which accounted for 60.3% of total variance. Weighted factor scores were not associated with perceived utility in learning anatomy (beta = 0.01, P = 0.62 for "image interpretation" and beta = -0.04, P = 0.33 for "basic knobology"). However, factor score on "knobology" was inversely associated with perceived utility for learning physical examination (beta = -0.06; P = 0.03). While a basic introduction to ultrasound may suffice for teaching anatomy, more training may be required for teaching physical examination. Prior to teaching physical examination skills with ultrasonography, we recommend ensuring that learners have sufficient knobology skills. © 2014 American Association of Anatomists.

Assessment of a Novel Point-of-Care Ultrasound Curriculum's Effect on Competency Measures in Family Medicine Graduate Medical Education.

PubMed

Bornemann, Paul

2017-06-01

Point-of-care ultrasound has been shown to decrease the use of expensive diagnostic studies and improve quality outcome measures. Currently, there is a large desire for training in family medicine residencies, but very few programs have established curricula. We sought to develop a family medicine residency curriculum and evaluate it with tools we developed. We wanted our curriculum to be easy to adopt by other residency programs, even if they did not have many well-trained ultrasound faculty. We developed a curriculum in the form of a 4-week rotation in a family medicine residency program. It consisted of self-study videos, hands-on training, and image review. We followed residents in postgraduate years 1 to 3 over a 12-month period. We developed tools, including a knowledge exam, to test image interpretation and clinical decision making, an observed structured clinical exam to assess scanning skills, and a survey to assess perceptions of point-of-care ultrasound in family medicine. The assessments were administered before and after each resident's rotation. Seventeen residents completed the rotation. The average knowledge test score improved significantly, from 62 to 84%. The average observed structured clinical exam scores also improved significantly, from 41 to 85%. The average perception survey scores improved slightly from 4.4 to 4.6. We developed a point-of-care ultrasound curriculum for family medicine residency programs that improves measures of resident attitude, skills, and knowledge. This curriculum can be adopted by residency programs with few faculty members who are experienced in ultrasound. © 2017 by the American Institute of Ultrasound in Medicine.

A new method of cardiographic image segmentation based on grammar

NASA Astrophysics Data System (ADS)

Hamdi, Salah; Ben Abdallah, Asma; Bedoui, Mohamed H.; Alimi, Adel M.

2011-10-01

The measurement of the most common ultrasound parameters, such as aortic area, mitral area and left ventricle (LV) volume, requires the delineation of the organ in order to estimate the area. In terms of medical image processing this translates into the need to segment the image and define the contours as accurately as possible. The aim of this work is to segment an image and make an automated area estimation based on grammar. The entity "language" will be projected to the entity "image" to perform structural analysis and parsing of the image. We will show how the idea of segmentation and grammar-based area estimation is applied to real problems of cardio-graphic image processing.

Establishing an Ultrasound Curriculum in Undergraduate Medical Education: How Much Time Does It Take?

PubMed

Siegel-Richman, Yonaton; Kendall, John

2018-03-01

Over the years, the use of ultrasound in the medical profession has become a common occurrence. As a result, many medical schools are considering an ultrasound curriculum for first- and second-year medical students. The question posed by many of these programs is how much time and effort are required to establish such a curriculum. We at the University of Colorado School of Medicine sought to quantify the resources and time required. We conducted a cohort study that analyzed the time spent teaching, as well as the types of instructors (eg, faculty, resident, and peer student) that contributed to our ultrasound curriculum. The study population consisted of instructors who participated in the curriculum during the 2014-2015 academic year. We analyzed the amount of time that facilitators spent teaching and tabulated these data using their specialty. Our data revealed that within an academic year, a combined total of 484 hours were spent teaching ultrasound to first- and second-year medical students combined. A total of 6 days were required to teach ultrasound to first-year medical students, and a total of 5 days were required for second-year medical students. It required 1 instructor for every 8 students, and most the faculty who volunteered time were from the field of emergency medicine, followed by family medicine and radiology. We describe the number of hours and instructors required to implement an ultrasound curriculum for undergraduate medical education. © 2017 by the American Institute of Ultrasound in Medicine.

[Contrast-enhanced ultrasound (CEUS) and image fusion for procedures of liver interventions].

PubMed

Jung, E M; Clevert, D A

2018-06-01

Contrast-enhanced ultrasound (CEUS) is becoming increasingly important for the detection and characterization of malignant liver lesions and allows percutaneous treatment when surgery is not possible. Contrast-enhanced ultrasound image fusion with computed tomography (CT) and magnetic resonance imaging (MRI) opens up further options for the targeted investigation of a modified tumor treatment. Ultrasound image fusion offers the potential for real-time imaging and can be combined with other cross-sectional imaging techniques as well as CEUS. With the implementation of ultrasound contrast agents and image fusion, ultrasound has been improved in the detection and characterization of liver lesions in comparison to other cross-sectional imaging techniques. In addition, this method can also be used for intervention procedures. The success rate of fusion-guided biopsies or CEUS-guided tumor ablation lies between 80 and 100% in the literature. Ultrasound-guided image fusion using CT or MRI data, in combination with CEUS, can facilitate diagnosis and therapy follow-up after liver interventions. In addition to the primary applications of image fusion in the diagnosis and treatment of liver lesions, further useful indications can be integrated into daily work. These include, for example, intraoperative and vascular applications as well applications in other organ systems.

A Dual-Modality System for Both Multi-Color Ultrasound-Switchable Fluorescence and Ultrasound Imaging

PubMed Central

Kandukuri, Jayanth; Yu, Shuai; Cheng, Bingbing; Bandi, Venugopal; D’Souza, Francis; Nguyen, Kytai T.; Hong, Yi; Yuan, Baohong

2017-01-01

Simultaneous imaging of multiple targets (SIMT) in opaque biological tissues is an important goal for molecular imaging in the future. Multi-color fluorescence imaging in deep tissues is a promising technology to reach this goal. In this work, we developed a dual-modality imaging system by combining our recently developed ultrasound-switchable fluorescence (USF) imaging technology with the conventional ultrasound (US) B-mode imaging. This dual-modality system can simultaneously image tissue acoustic structure information and multi-color fluorophores in centimeter-deep tissue with comparable spatial resolutions. To conduct USF imaging on the same plane (i.e., x-z plane) as US imaging, we adopted two 90°-crossed ultrasound transducers with an overlapped focal region, while the US transducer (the third one) was positioned at the center of these two USF transducers. Thus, the axial resolution of USF is close to the lateral resolution, which allows a point-by-point USF scanning on the same plane as the US imaging. Both multi-color USF and ultrasound imaging of a tissue phantom were demonstrated. PMID:28165390

High-frequency ultrasound imaging for breast cancer biopsy guidance

PubMed Central

Cummins, Thomas; Yoon, Changhan; Choi, Hojong; Eliahoo, Payam; Kim, Hyung Ham; Yamashita, Mary W.; Hovanessian-Larsen, Linda J.; Lang, Julie E.; Sener, Stephen F.; Vallone, John; Martin, Sue E.; Kirk Shung, K.

2015-01-01

Abstract. Image-guided core needle biopsy is the current gold standard for breast cancer diagnosis. Microcalcifications, an important radiographic finding on mammography suggestive of early breast cancer such as ductal carcinoma in situ, are usually biopsied under stereotactic guidance. This procedure, however, is uncomfortable for patients and requires the use of ionizing radiation. It would be preferable to biopsy microcalcifications under ultrasound guidance since it is a faster procedure, more comfortable for the patient, and requires no radiation. However, microcalcifications cannot reliably be detected with the current standard ultrasound imaging systems. This study is motivated by the clinical need for real-time high-resolution ultrasound imaging of microcalcifications, so that biopsies can be accurately performed under ultrasound guidance. We have investigated how high-frequency ultrasound imaging can enable visualization of microstructures in ex vivo breast tissue biopsy samples. We generated B-mode images of breast tissue and applied the Nakagami filtering technique to help refine image output so that microcalcifications could be better assessed during ultrasound-guided core biopsies. We describe the preliminary clinical results of high-frequency ultrasound imaging of ex vivo breast biopsy tissue with microcalcifications and without Nakagami filtering and the correlation of these images with the pathology examination by hematoxylin and eosin stain and whole slide digital scanning. PMID:26693167

Two- and three-dimensional ultrasound imaging to facilitate detection and targeting of taut bands in myofascial pain syndrome.

PubMed

Shankar, Hariharan; Reddy, Sapna

2012-07-01

Ultrasound imaging has gained acceptance in pain management interventions. Features of myofascial pain syndrome have been explored using ultrasound imaging and elastography. There is a paucity of reports showing the benefit clinically. This report provides three-dimensional features of taut bands and highlights the advantages of using two-dimensional ultrasound imaging to improve targeting of taut bands in deeper locations. Fifty-eight-year-old man with pain and decreased range of motion of the right shoulder was referred for further management of pain above the scapula after having failed conservative management for myofascial pain syndrome. Three-dimensional ultrasound images provided evidence of aberrancy in the architecture of the muscle fascicles around the taut bands compared to the adjacent normal muscle tissue during serial sectioning of the accrued image. On two-dimensional ultrasound imaging over the palpated taut band, areas of hyperechogenicity were visualized in the trapezius and supraspinatus muscles. Subsequently, the patient received ultrasound-guided real-time lidocaine injections to the trigger points with successful resolution of symptoms. This is a successful demonstration of utility of ultrasound imaging of taut bands in the management of myofascial pain syndrome. Utility of this imaging modality in myofascial pain syndrome requires further clinical validation. Wiley Periodicals, Inc.

Feasibility of remote real-time guidance of a cardiac examination performed by novices using a pocket-sized ultrasound device.

PubMed

Mai, Tuan V; Ahn, David T; Phillips, Colin T; Agan, Donna L; Kimura, Bruce J

2013-01-01

Background. The potential of pocket-sized ultrasound devices (PUDs) to improve global healthcare delivery is limited by the lack of a suitable imaging protocol and trained users. Therefore, we investigated the feasibility of performing a brief, evidence-based cardiac limited ultrasound exam (CLUE) through wireless guidance of novice users. Methods. Three trainees applied PUDs on 27 subjects while directed by an off-site cardiologist to obtain a CLUE to screen for LV systolic dysfunction (LVSD), LA enlargement (LAE), ultrasound lung comets (ULC+), and elevated CVP (eCVP). Real-time remote audiovisual guidance and interpretation by the cardiologist were performed using the iPhone 4/iPod (FaceTime, Apple, Inc.) attached to the PUD and transmitted data wirelessly. Accuracy and technical quality of transmitted images were compared to on-site, gold-standard echo thresholds. Results. Novice versus sonographer imaging yielded technically adequate views in 122/135 (90%) versus 130/135 (96%) (P < 0.05). CLUE's combined SN, SP, and ACC were 0.67, 0.96, and 0.90. Technical adequacy (%) and accuracy for each abnormality (n) were LVSD (85%, 0.93, n = 5), LAE (89%, 0.74, n = 16), ULC+ (100%, 0.94, n = 5), and eCVP (78%, 0.91, n = 1). Conclusion. A novice can perform the CLUE using PUD when wirelessly guided by an expert. This method could facilitate PUD use for off-site bedside medical decision making and triaging of patients.

Nonlinear oscillation and interfacial stability of an encapsulated microbubble under dual-frequency ultrasound

NASA Astrophysics Data System (ADS)

Calvisi, Michael; Liu, Yunqiao; Wang, Qianxi

2016-11-01

Encapsulated microbubbles (EMBs) are widely used in medical ultrasound imaging as contrast-enhanced agents. However, the potential damaging effects of violent, collapsing EMBs to cells and tissues in clinical practice have remained a concern. Dual-frequency ultrasound is a promising technique for improving the efficacy and safety of sonography. The EMB system modeled consists of the external liquid, membrane, and internal gases. The microbubble dynamics are simulated using a simple nonlinear interactive theory, considering the compressibility of the internal gas, viscosity of the liquid flow, and elasticity of the membrane. The radial oscillation and interfacial stability of an EMB under single and dual-frequency excitations are compared. The simulation results show that the dual-frequency technique produces larger backscatter pressure at higher harmonics of the primary driving frequency. This enriched acoustic spectrum can enhance blood-tissue contrast and improve sonographic image quality. The results further show that the acoustic pressure threshold associated with the onset of shape instability is greater for dual-frequency driving. This suggests that the dual-frequency technique stabilizes the EMB, thereby improving the efficacy and safety of contrast-enhanced agents.

Efficacy of computer-based video and simulation in ultrasound-guided regional anesthesia training.

PubMed

Woodworth, Glenn E; Chen, Elliza M; Horn, Jean-Louis E; Aziz, Michael F

2014-05-01

To determine the effectiveness of a short educational video and simulation on improvement of ultrasound (US) image acquisition and interpretation skills. Prospective, randomized study. University medical center. 28 anesthesia residents and community anesthesiologists with varied ultrasound experience were randomized to teaching video with interactive simulation or sham video groups. Participants were assessed preintervention and postintervention on their ability to identify the sciatic nerve and other anatomic structures on static US images, as well as their ability to locate the sciatic nerve with US on live models. Pretest written test scores correlated with reported US block experience (Kendall tau rank r = 0.47) and with live US scanning scores (r = 0.64). The teaching video and simulation significantly improved scores on the written examination (P < 0.001); however, they did not significantly improve live US scanning skills. A short educational video with interactive simulation significantly improved knowledge of US anatomy, but failed to improve hands-on performance of US scanning to localize the nerve. Copyright © 2014 Elsevier Inc. All rights reserved.

The hydrodynamic and ultrasound-induced forces on microbubbles under high Reynolds number flow representative of the human systemic circulation

NASA Astrophysics Data System (ADS)

Clark, Alicia; Aliseda, Alberto

2016-11-01

Ultrasound contrast agents (UCAs) are micron-sized bubbles that are used in conjunction with ultrasound (US) in medical applications such as thrombolysis and targeted intravenous drug delivery. Previous work has shown that the Bjerknes force, due to the phase difference between the incoming US pressure wave and the bubble volume oscillations, can be used to manipulate the trajectories of microbubbles. Our work explores the behavior of microbubbles in medium sized blood vessels under both uniform and pulsatile flows at a range of physiologically relevant Reynolds and Womersley numbers. High speed images were taken of the microbubbles in an in-vitro flow loop that replicates physiological flow conditions. During the imaging, the microbubbles were insonified at different diagnostic ultrasound settings (varying center frequency, PRF, etc.). An in-house Lagrangian particle tracking code was then used to determine the trajectories of the microbubbles and, thus, a dynamic model for the microbubbles including the Bjerknes forces acting on them, as well as drag, lift, and added mass. Preliminary work has also explored the behavior of the microbubbles in a patient-specific model of a carotid artery bifurcation to demonstrate the feasibility of preferential steering of microbubbles towards the intracranial circulation with US.

Ultrasound - Breast

MedlinePlus

... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... perform an ultrasound-guided biopsy . Because ultrasound provides real-time images, it is often used to guide biopsy ...

Standard plane localization in ultrasound by radial component model and selective search.

PubMed

Ni, Dong; Yang, Xin; Chen, Xin; Chin, Chien-Ting; Chen, Siping; Heng, Pheng Ann; Li, Shengli; Qin, Jing; Wang, Tianfu

2014-11-01

Acquisition of the standard plane is crucial for medical ultrasound diagnosis. However, this process requires substantial experience and a thorough knowledge of human anatomy. Therefore it is very challenging for novices and even time consuming for experienced examiners. We proposed a hierarchical, supervised learning framework for automatically detecting the standard plane from consecutive 2-D ultrasound images. We tested this technique by developing a system that localizes the fetal abdominal standard plane from ultrasound video by detecting three key anatomical structures: the stomach bubble, umbilical vein and spine. We first proposed a novel radial component-based model to describe the geometric constraints of these key anatomical structures. We then introduced a novel selective search method which exploits the vessel probability algorithm to produce probable locations for the spine and umbilical vein. Next, using component classifiers trained by random forests, we detected the key anatomical structures at their probable locations within the regions constrained by the radial component-based model. Finally, a second-level classifier combined the results from the component detection to identify an ultrasound image as either a "fetal abdominal standard plane" or a "non- fetal abdominal standard plane." Experimental results on 223 fetal abdomen videos showed that the detection accuracy of our method was as high as 85.6% and significantly outperformed both the full abdomen and the separate anatomy detection methods without geometric constraints. The experimental results demonstrated that our system shows great promise for application to clinical practice. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Development of a control algorithm for the ultrasound scanning robot (NCCUSR) using ultrasound image and force feedback.

PubMed

Kim, Yeoun Jae; Seo, Jong Hyun; Kim, Hong Rae; Kim, Kwang Gi

2017-06-01

Clinicians who frequently perform ultrasound scanning procedures often suffer from musculoskeletal disorders, arthritis, and myalgias. To minimize their occurrence and to assist clinicians, ultrasound scanning robots have been developed worldwide. Although, to date, there is still no commercially available ultrasound scanning robot, many control methods have been suggested and researched. These control algorithms are either image based or force based. If the ultrasound scanning robot control algorithm was a combination of the two algorithms, it could benefit from the advantage of each one. However, there are no existing control methods for ultrasound scanning robots that combine force control and image analysis. Therefore, in this work, a control algorithm is developed for an ultrasound scanning robot using force feedback and ultrasound image analysis. A manipulator-type ultrasound scanning robot named 'NCCUSR' is developed and a control algorithm for this robot is suggested and verified. First, conventional hybrid position-force control is implemented for the robot and the hybrid position-force control algorithm is combined with ultrasound image analysis to fully control the robot. The control method is verified using a thyroid phantom. It was found that the proposed algorithm can be applied to control the ultrasound scanning robot and experimental outcomes suggest that the images acquired using the proposed control method can yield a rating score that is equivalent to images acquired directly by the clinicians. The proposed control method can be applied to control the ultrasound scanning robot. However, more work must be completed to verify the proposed control method in order to become clinically feasible. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Image Guidance Technologies for Interventional Pain Procedures: Ultrasound, Fluoroscopy, and CT.

PubMed

Wang, Dajie

2018-01-26

Chronic pain is a common medical condition. Patients who suffer uncontrolled chronic pain may require interventions including spinal injections and various nerve blocks. Interventional procedures have evolved and improved over time since epidural injection was first introduced for low back pain and sciatica in 1901. One of the major contributors in the improvement of these interventions is the advancement of imaging guidance technologies. The utilization of image guidance has dramatically improved the accuracy and safety of these interventions. The first image guidance technology adopted by pain specialists was fluoroscopy. This was followed by CT and ultrasound. Fluoroscopy can be used to visualize bony structures of the spine. It is still the most commonly used guidance technology in spinal injections. In the recent years, ultrasound guidance has been increasingly adopted by interventionists to perform various injections. Because its ability to visualize soft tissue, vessels, and nerves, this guidance technology appears to be a better option than fluoroscopy for interventions including SGB and celiac plexus blocks, when visualization of the vessels may prevent intravascular injection. The current evidence indicates the efficacies of these interventions are similar between ultrasound guidance and fluoroscopy guidance for SGB and celiac plexus blocks. For facet injections and interlaminar epidural steroid injections, it is important to visualize bony structures in order to perform these procedures accurately and safely. It is worth noting that facet joint injections can be done under ultrasound guidance with equivalent efficacy to fluoroscopic guidance. However, obese patients may present challenge for ultrasound guidance due to its poor visualization of deep anatomical structures. Regarding transforaminal epidural steroid injections, there are limited evidence to support that ultrasound guidance technology has equivalent efficacy and less complications comparing to fluoroscopy. However, further studies are required to prove the efficacy of ultrasound-guided transforaminal epidural injections. SI joint is unique due to its multiplanar orientation, irregular joint gap, partial ankylosis, and thick dorsal and interosseous ligament. Therefore, it can be difficult to access the joint space with fluoroscopic guidance and ultrasound guidance. CT scan, with its cross-sectional images, can identify posterior joint gap, is most likely the best guidance technology for this intervention. Intercostal nerves lie in the subcostal grove close to the plural space. Significant risk of pneumothorax is associated with intercostal blocks. Ultrasound can provide visualization of ribs and pleura. Therefore, it may improve the accuracy of the injection and reduce the risk of pneumothorax. At present time, most pain specialists are familiar with fluoroscopic guidance techniques, and fluoroscopic machines are readily available in the pain clinics. In the contrast, CT guidance can only be performed in specially equipped facilities. Ultrasound machine is generally portable and inexpensive in comparison to CT scanner and fluoroscopic machine. As pain specialists continue to improve their patient care, ultrasound and CT guidance will undoubtedly be incorporated more into the pain management practice. This review is based on a paucity of clinical evidence to compare these guidance technologies; clearly, more clinical studies is needed to further elucidate the pro and cons of each guidance method for various pain management interventions.

Contrast-Enhanced Ultrasound as a New Investigative Tool in Diagnostic Imaging of Muscle Injuries-A Pilot Study Evaluating Conventional Ultrasound, CEUS, and Findings in MRI.

PubMed

Hotfiel, Thilo; Heiss, Rafael; Swoboda, Bernd; Kellermann, Marion; Gelse, Kolja; Grim, Casper; Strobel, Deike; Wildner, Dane

2018-07-01

To emphasize the diagnostic value of contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries with different degrees of severity by comparing findings to established imaging modalities such as conventional ultrasound and magnetic resonance imaging (MRI). Case series. Institutional study. Conventional ultrasound and CEUS were performed in the Department of Internal Medicine. Magnetic resonance imaging was carried out in the Department of Radiology within the Magnetom Avanto 1.5T and Magnetom Skyra fit 3T (Siemens Healthineers, Erlangen, Germany) and in the Institution of Imaging Diagnostics and Therapy (Magnetom Avanto 1.5T; Siemens, Erlangen, Germany). Fifteen patients who underwent an acute muscle injury were recruited. The appearance and detectable size of muscle injuries were compared between each imaging modality. The injuries were assessed by 3 independent observers and blinded between imaging modalities. All 15 injuries were identified on MRI and CEUS, whereas 10 injuries showed abnormalities in conventional ultrasound. The determination and measurement revealed significant differences between conventional ultrasound and CEUS depending on injury severity. Contrast-enhanced ultrasound revealed an impairment of microcirculation in grade I lesions (corresponding to intramuscular edema observed in MRI), which was not detectable using conventional ultrasound. Our results indicate that performing CEUS seems to be a sensitive additional diagnostic modality in the early assessment of muscle injuries. Our results highlight the advantages of CEUS in the imaging of low-grade lesions when compared with conventional ultrasound, as this was the more accurate modality for identifying intramuscular edema.

Intelligent estimation of noise and blur variances using ANN for the restoration of ultrasound images.

PubMed

Uddin, Muhammad Shahin; Halder, Kalyan Kumar; Tahtali, Murat; Lambert, Andrew J; Pickering, Mark R; Marchese, Margaret; Stuart, Iain

2016-11-01

Ultrasound (US) imaging is a widely used clinical diagnostic tool in medical imaging techniques. It is a comparatively safe, economical, painless, portable, and noninvasive real-time tool compared to the other imaging modalities. However, the image quality of US imaging is severely affected by the presence of speckle noise and blur during the acquisition process. In order to ensure a high-quality clinical diagnosis, US images must be restored by reducing their speckle noise and blur. In general, speckle noise is modeled as a multiplicative noise following a Rayleigh distribution and blur as a Gaussian function. Hereto, we propose an intelligent estimator based on artificial neural networks (ANNs) to estimate the variances of noise and blur, which, in turn, are used to obtain an image without discernible distortions. A set of statistical features computed from the image and its complex wavelet sub-bands are used as input to the ANN. In the proposed method, we solve the inverse Rayleigh function numerically for speckle reduction and use the Richardson-Lucy algorithm for de-blurring. The performance of this method is compared with that of the traditional methods by applying them to a synthetic, physical phantom and clinical data, which confirms better restoration results by the proposed method.

Hybrid Pixel-Based Method for Cardiac Ultrasound Fusion Based on Integration of PCA and DWT

PubMed Central

Sulaiman, Puteri Suhaiza; Wirza, Rahmita; Dimon, Mohd Zamrin; Khalid, Fatimah; Moosavi Tayebi, Rohollah

2015-01-01

Medical image fusion is the procedure of combining several images from one or multiple imaging modalities. In spite of numerous attempts in direction of automation ventricle segmentation and tracking in echocardiography, due to low quality images with missing anatomical details or speckle noises and restricted field of view, this problem is a challenging task. This paper presents a fusion method which particularly intends to increase the segment-ability of echocardiography features such as endocardial and improving the image contrast. In addition, it tries to expand the field of view, decreasing impact of noise and artifacts and enhancing the signal to noise ratio of the echo images. The proposed algorithm weights the image information regarding an integration feature between all the overlapping images, by using a combination of principal component analysis and discrete wavelet transform. For evaluation, a comparison has been done between results of some well-known techniques and the proposed method. Also, different metrics are implemented to evaluate the performance of proposed algorithm. It has been concluded that the presented pixel-based method based on the integration of PCA and DWT has the best result for the segment-ability of cardiac ultrasound images and better performance in all metrics. PMID:26089965

Intrauterine photoacoustic and ultrasound imaging probe

NASA Astrophysics Data System (ADS)

Miranda, Christopher; Barkley, Joel; Smith, Barbara S.

2018-04-01

Intrauterine photoacoustic and ultrasound imaging are probe-based imaging modalities with translational potential for use in detecting endometrial diseases. This deep-tissue imaging probe design allows for the retrofitting of commercially available endometrial sampling curettes. The imaging probe presented here has a 2.92-mm diameter and approximate length of 26 cm, which allows for entry into the human endometrial cavity, making it possible to use photoacoustic imaging and high-resolution ultrasound to characterize the uterus. We demonstrate the imaging probes' ability to provide structural information of an excised pig uterus using ultrasound imaging and detect photoacoustic signals at a radial depth of 1 cm.

Extracting cardiac myofiber orientations from high frequency ultrasound images

NASA Astrophysics Data System (ADS)

Qin, Xulei; Cong, Zhibin; Jiang, Rong; Shen, Ming; Wagner, Mary B.; Kirshbom, Paul; Fei, Baowei

2013-03-01

Cardiac myofiber plays an important role in stress mechanism during heart beating periods. The orientation of myofibers decides the effects of the stress distribution and the whole heart deformation. It is important to image and quantitatively extract these orientations for understanding the cardiac physiological and pathological mechanism and for diagnosis of chronic diseases. Ultrasound has been wildly used in cardiac diagnosis because of its ability of performing dynamic and noninvasive imaging and because of its low cost. An extraction method is proposed to automatically detect the cardiac myofiber orientations from high frequency ultrasound images. First, heart walls containing myofibers are imaged by B-mode high frequency (<20 MHz) ultrasound imaging. Second, myofiber orientations are extracted from ultrasound images using the proposed method that combines a nonlinear anisotropic diffusion filter, Canny edge detector, Hough transform, and K-means clustering. This method is validated by the results of ultrasound data from phantoms and pig hearts.

Motion Detection in Ultrasound Image-Sequences Using Tensor Voting

NASA Astrophysics Data System (ADS)

Inba, Masafumi; Yanagida, Hirotaka; Tamura, Yasutaka

2008-05-01

Motion detection in ultrasound image sequences using tensor voting is described. We have been developing an ultrasound imaging system adopting a combination of coded excitation and synthetic aperture focusing techniques. In our method, frame rate of the system at distance of 150 mm reaches 5000 frame/s. Sparse array and short duration coded ultrasound signals are used for high-speed data acquisition. However, many artifacts appear in the reconstructed image sequences because of the incompleteness of the transmitted code. To reduce the artifacts, we have examined the application of tensor voting to the imaging method which adopts both coded excitation and synthetic aperture techniques. In this study, the basis of applying tensor voting and the motion detection method to ultrasound images is derived. It was confirmed that velocity detection and feature enhancement are possible using tensor voting in the time and space of simulated ultrasound three-dimensional image sequences.

Development of the Fetal Vermis: New Biometry Reference Data and Comparison of 3 Diagnostic Modalities-3D Ultrasound, 2D Ultrasound, and MR Imaging.

PubMed

Katorza, E; Bertucci, E; Perlman, S; Taschini, S; Ber, R; Gilboa, Y; Mazza, V; Achiron, R

2016-07-01

Normal biometry of the fetal posterior fossa rules out most major anomalies of the cerebellum and vermis. Our aim was to provide new reference data of the fetal vermis in 4 biometric parameters by using 3 imaging modalities, 2D ultrasound, 3D ultrasound, and MR imaging, and to assess the relation among these modalities. A retrospective study was conducted between June 2011 and June 2013. Three different imaging modalities were used to measure vermis biometry: 2D ultrasound, 3D ultrasound, and MR imaging. The vermian parameters evaluated were the maximum superoinferior diameter, maximum anteroposterior diameter, the perimeter, and the surface area. Statistical analysis was performed to calculate centiles for gestational age and to assess the agreement among the 3 imaging modalities. The number of fetuses in the study group was 193, 172, and 151 for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. The mean and median gestational ages were 29.1 weeks, 29.5 weeks (range, 21-35 weeks); 28.2 weeks, 29.05 weeks (range, 21-35 weeks); and 32.1 weeks, 32.6 weeks (range, 27-35 weeks) for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. In all 3 modalities, the biometric measurements of the vermis have shown a linear growth with gestational age. For all 4 biometric parameters, the lowest results were those measured by MR imaging, while the highest results were measured by 3D ultrasound. The inter- and intraobserver agreement was excellent for all measures and all imaging modalities. Limits of agreement were considered acceptable for clinical purposes for all parameters, with excellent or substantial agreement defined by the intraclass correlation coefficient. Imaging technique-specific reference data should be used for the assessment of the fetal vermis in pregnancy. © 2016 by American Journal of Neuroradiology.

Hybrid MRI-Ultrasound acquisitions, and scannerless real-time imaging.

PubMed

Preiswerk, Frank; Toews, Matthew; Cheng, Cheng-Chieh; Chiou, Jr-Yuan George; Mei, Chang-Sheng; Schaefer, Lena F; Hoge, W Scott; Schwartz, Benjamin M; Panych, Lawrence P; Madore, Bruno

2017-09-01

To combine MRI, ultrasound, and computer science methodologies toward generating MRI contrast at the high frame rates of ultrasound, inside and even outside the MRI bore. A small transducer, held onto the abdomen with an adhesive bandage, collected ultrasound signals during MRI. Based on these ultrasound signals and their correlations with MRI, a machine-learning algorithm created synthetic MR images at frame rates up to 100 per second. In one particular implementation, volunteers were taken out of the MRI bore with the ultrasound sensor still in place, and MR images were generated on the basis of ultrasound signal and learned correlations alone in a "scannerless" manner. Hybrid ultrasound-MRI data were acquired in eight separate imaging sessions. Locations of liver features, in synthetic images, were compared with those from acquired images: The mean error was 1.0 pixel (2.1 mm), with best case 0.4 and worst case 4.1 pixels (in the presence of heavy coughing). For results from outside the bore, qualitative validation involved optically tracked ultrasound imaging with/without coughing. The proposed setup can generate an accurate stream of high-speed MR images, up to 100 frames per second, inside or even outside the MR bore. Magn Reson Med 78:897-908, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Evaluation of Imaging Parameters of Ultrasound Scanners: Baseline for Future Testing

PubMed Central

Pasicz, Katarzyna; Grabska, Iwona; Skrzyński, Witold; Ślusarczyk-Kacprzyk, Wioletta; Bulski, Wojciech

2017-01-01

Summary Background Regular quality control is required in Poland only for those methods of medical imaging which involve the use of ionizing radiation but not for ultrasonography. It is known that the quality of ultrasound images may be affected by the wearing down or malfunctioning of equipment. Material/Methods An evaluation of image quality was carried out for 22 ultrasound scanners equipped with 46 transducers. The CIRS Phantom model 040GSE was used. A set of tests was established which could be carried out with the phantom, including: depth of penetration, dead zone, distance measurement accuracy, resolution, uniformity, and visibility of structures. Results While the dead zone was 0 mm for 89% of transducers, it was 3 mm for the oldest transducer. The distances measured agreed with the actual distances by 1 mm or less in most cases, with the largest difference of 2.6 mm. The resolution in the axial direction for linear transducers did not exceed 1 mm, but it reached even 5 mm for some of the convex and sector transducers, especially at higher depths and in the lateral direction. For 29% of transducers, some distortions of anechoic structures were observed. Artifacts were detected for several transducers. Conclusions The results will serve as a baseline for future testing. Several cases of suboptimal image quality were identified along with differences in performance between similar transducers. The results could be used to decide on the applicability of a given scanner or transducer for a particular kind of examination. PMID:29657644

Using the ATL HDI 1000 to collect demodulated RF data for monitoring HIFU lesion formation

NASA Astrophysics Data System (ADS)

Anand, Ajay; Kaczkowski, Peter J.; Daigle, Ron E.; Huang, Lingyun; Paun, Marla; Beach, Kirk W.; Crum, Lawrence A.

2003-05-01

The ability to accurately track and monitor the progress of lesion formation during HIFU (High Intensity Focused Ultrasound) therapy is important for the success of HIFU-based treatment protocols. To aid in the development of algorithms for accurately targeting and monitoring formation of HIFU induced lesions, we have developed a software system to perform RF data acquisition during HIFU therapy using a commercially available clinical ultrasound scanner (ATL HDI 1000, Philips Medical Systems, Bothell, WA). The HDI 1000 scanner functions on a software dominant architecture, permitting straightforward external control of its operation and relatively easy access to quadrature demodulated RF data. A PC running a custom developed program sends control signals to the HIFU module via GPIB and to the HDI 1000 via Telnet, alternately interleaving HIFU exposures and RF frame acquisitions. The system was tested during experiments in which HIFU lesions were created in excised animal tissue. No crosstalk between the HIFU beam and the ultrasound imager was detected, thus demonstrating synchronization. Newly developed acquisition modes allow greater user control in setting the image geometry and scanline density, and enables high frame rate acquisition. This system facilitates rapid development of signal-processing based HIFU therapy monitoring algorithms and their implementation in image-guided thermal therapy systems. In addition, the HDI 1000 system can be easily customized for use with other emerging imaging modalities that require access to the RF data such as elastographic methods and new Doppler-based imaging and tissue characterization techniques.

EFSUMB Statement on Medical Student Education in Ultrasound [long version

PubMed Central

Cantisani, V.; Dietrich, C. F.; Badea, R.; Dudea, S.; Prosch, H.; Cerezo, E.; Nuernberg, D.; Serra, A. L.; Sidhu, P. S.; Radzina, M.; Piscaglia, F.; Bachmann Nielsen, M.; Ewertsen, C.; Săftoiu, A.; Calliada, F.; Gilja, O. H.

2016-01-01

The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) recommends that ultrasound should be used systematically as an easy accessible and instructive educational tool in the curriculum of modern medical schools. Medical students should acquire theoretical knowledge of the modality and hands-on training should be implemented and adhere to evidence-based principles. In this paper we report EFSUMB policy statements on medical student education in ultrasound that in a short version is already published in Ultraschall in der Medizin 1. PMID:27689163

Renal Cysts

MedlinePlus

... inside the renal cysts. Your doctor may use ultrasound imaging to monitor renal cysts for any changes over ... Related Articles and Media Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Magnetic Resonance Imaging (MRI) - Body Ultrasound - Pelvis Children's (Pediatric) Nuclear Medicine ...

Breast ultrasound tomography with two parallel transducer arrays: preliminary clinical results

NASA Astrophysics Data System (ADS)

Huang, Lianjie; Shin, Junseob; Chen, Ting; Lin, Youzuo; Intrator, Miranda; Hanson, Kenneth; Epstein, Katherine; Sandoval, Daniel; Williamson, Michael

2015-03-01

Ultrasound tomography has great potential to provide quantitative estimations of physical properties of breast tumors for accurate characterization of breast cancer. We design and manufacture a new synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays. The distance of these two transducer arrays is adjustable for scanning breasts with different sizes. The ultrasound transducer arrays are translated vertically to scan the entire breast slice by slice and acquires ultrasound transmission and reflection data for whole-breast ultrasound imaging and tomographic reconstructions. We use the system to acquire patient data at the University of New Mexico Hospital for clinical studies. We present some preliminary imaging results of in vivo patient ultrasound data. Our preliminary clinical imaging results show promising of our breast ultrasound tomography system with two parallel transducer arrays for breast cancer imaging and characterization.

Basic physics of ultrasound imaging.

PubMed

Aldrich, John E

2007-05-01

The appearance of ultrasound images depends critically on the physical interactions of sound with the tissues in the body. The basic principles of ultrasound imaging and the physical reasons for many common artifacts are described.

Ultrasound of the Thyroid Gland

MedlinePlus

... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... has substantially grown over time Because ultrasound provides real-time images, images that are renewed continuously, it also ...

Advances in Medical Analytics Solutions for Autonomous Medical Operations on Long-Duration Missions

NASA Technical Reports Server (NTRS)

Thompson, David E.; Lindsey, Antonia Edward

2017-01-01

A review will be presented on the progress made under STMDGame Changing Development Program Funding towards the development of a Medical Decision Support System for augmenting crew capabilities during long-duration missions, such as Mars Transit. To create an MDSS, initial work requires acquiring images and developing models that analyze and assess the features in such medical biosensor images that support medical assessment of pathologies. For FY17, the project has focused on ultrasound images towards cardiac pathologies: namely, evaluation and assessment of pericardial effusion identification and discrimination from related pneumothorax and even bladder-induced infections that cause inflammation around the heart. This identification is substantially changed due to uncertainty due to conditions of fluid behavior under space-microgravity. This talk will present and discuss the work-to-date in this Project, recognizing conditions under which various machine learning technologies, deep-learning via convolutional neural nets, and statistical learning methods for feature identification and classification can be employed and conditioned to graphical format in preparation for attachment to an inference engine that eventually creates decision support recommendations to remote crew in a triage setting.

MRI-powered biomedical devices.

PubMed

Hovet, Sierra; Ren, Hongliang; Xu, Sheng; Wood, Bradford; Tokuda, Junichi; Tse, Zion Tsz Ho

2017-11-16

Magnetic resonance imaging (MRI) is beneficial for imaging-guided procedures because it provides higher resolution images and better soft tissue contrast than computed tomography (CT), ultrasound, and X-ray. MRI can be used to streamline diagnostics and treatment because it does not require patients to be repositioned between scans of different areas of the body. It is even possible to use MRI to visualize, power, and control medical devices inside the human body to access remote locations and perform minimally invasive procedures. Therefore, MR conditional medical devices have the potential to improve a wide variety of medical procedures; this potential is explored in terms of practical considerations pertaining to clinical applications and the MRI environment. Recent advancements in this field are introduced with a review of clinically relevant research in the areas of interventional tools, endovascular microbots, and closed-loop controlled MRI robots. Challenges related to technology and clinical feasibility are discussed, including MRI based propulsion and control, navigation of medical devices through the human body, clinical adoptability, and regulatory issues. The development of MRI-powered medical devices is an emerging field, but the potential clinical impact of these devices is promising.

Medical imaging and computers in the diagnosis of breast cancer

NASA Astrophysics Data System (ADS)

Giger, Maryellen L.

2014-09-01

Computer-aided diagnosis (CAD) and quantitative image analysis (QIA) methods (i.e., computerized methods of analyzing digital breast images: mammograms, ultrasound, and magnetic resonance images) can yield novel image-based tumor and parenchyma characteristics (i.e., signatures that may ultimately contribute to the design of patient-specific breast cancer management plans). The role of QIA/CAD has been expanding beyond screening programs towards applications in risk assessment, diagnosis, prognosis, and response to therapy as well as in data mining to discover relationships of image-based lesion characteristics with genomics and other phenotypes; thus, as they apply to disease states. These various computer-based applications are demonstrated through research examples from the Giger Lab.

Evidence-based pain management: is the concept of integrative medicine applicable?

PubMed Central

2012-01-01

This article is dedicated to the concept of predictive, preventive, and personalized (integrative) medicine beneficial and applicable to advance pain management, overviews recent insights, and discusses novel minimally invasive tools, performed under ultrasound guidance, enhanced by model-guided approach in the field of musculoskeletal pain and neuromuscular diseases. The complexity of pain emergence and regression demands intellectual-, image-guided techniques personally specified to the patient. For personalized approach, the combination of the modalities of ultrasound, EMG, MRI, PET, and SPECT gives new opportunities to experimental and clinical studies. Neuromuscular imaging should be crucial for emergence of studies concerning advanced neuroimaging technologies to predict movement disorders, postural imbalance with integrated application of imaging, and functional modalities for rehabilitation and pain management. Scientific results should initiate evidence-based preventive movement programs in sport medicine rehabilitation. Traditional medicine and mathematical analytical approaches and education challenges are discussed in this review. The physiological management of exactly assessed pathological condition, particularly in movement disorders, requires participative medical approach to gain harmonized and sustainable effect. PMID:23088743

Recent technological advancements in cardiac ultrasound imaging.

PubMed

Dave, Jaydev K; Mc Donald, Maureen E; Mehrotra, Praveen; Kohut, Andrew R; Eisenbrey, John R; Forsberg, Flemming

2018-03-01

About 92.1 million Americans suffer from at least one type of cardiovascular disease. Worldwide, cardiovascular diseases are the number one cause of death (about 31% of all global deaths). Recent technological advancements in cardiac ultrasound imaging are expected to aid in the clinical diagnosis of many cardiovascular diseases. This article provides an overview of such recent technological advancements, specifically focusing on tissue Doppler imaging, strain imaging, contrast echocardiography, 3D echocardiography, point-of-care echocardiography, 3D volumetric flow assessments, and elastography. With these advancements ultrasound imaging is rapidly changing the domain of cardiac imaging. The advantages offered by ultrasound imaging include real-time imaging, imaging at patient bed-side, cost-effectiveness and ionizing-radiation-free imaging. Along with these advantages, the steps taken towards standardization of ultrasound based quantitative markers, reviewed here, will play a major role in addressing the healthcare burden associated with cardiovascular diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced Ultrasound Visualization of Bracytherapy Seeds by a Novel Magnetically Induced Motion Imaging Method

DTIC Science & Technology

2008-04-01

We report our progress in developing Magnetically Induced Motion Imaging (MIMI) for unambiguous identification and localization brachytherapy seeds ...in ultrasound images. Coupled finite element and ultrasound imaging simulations have been performed to demonstrate that seeds are detectable with MIMI

Prospects for telediagnosis using ultrasound.

PubMed

Dewey, C F; Thomas, J D; Kunt, M; Hunter, I W

1996-01-01

Ultrasound imaging is currently used as a primary diagnostic tool in cardiology, abdominal disorders, pulmonary medicine, trauma, and obstetrics. Because of its relatively low capital and operating costs as well as its growth potential, it represents one of the major diagnostic modalities of future health care. However, the use of ultrasonography as a mobile and powerful modality is controlled by the availability of a highly skilled technician to acquire the images and an experienced physician to interpret them. This paper discusses the technology required to increase the availability of a diagnosing physician by employing telerobotics. With this technology, the physician can guide the motion of the transducer by the technician from a remote location. Thus, the physician controls the examination and renders the diagnosis. It is shown that communication lines at 1.5 Mbits/s (T-1 speed) can, with appropriate compression, support both real-time viewing of the ultrasound images and telerobotic manipulation of the transducer. The incremental costs of telediagnosis for an examination are estimated to be a small fraction of the base charges and significantly less than the expense of bringing a physician to a remote location or transporting a patient to a regional medical center. Telediagnosis can, in addition, provide benefits from immediate interpretation and consultation that cannot be duplicated using store-and-forward scenarios.

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

PubMed

Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

2013-04-01

There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P < 0.001 for each). On review by expert radiologists, the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (κ = 0.34). Expert review of MRCPs did not identify any additional cases of pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

Automatic segmentation method of pelvic floor levator hiatus in ultrasound using a self-normalizing neural network

PubMed Central

Dietz, Hans Peter; D’hooge, Jan; Barratt, Dean; Deprest, Jan

2018-01-01

Abstract. Segmentation of the levator hiatus in ultrasound allows the extraction of biometrics, which are of importance for pelvic floor disorder assessment. We present a fully automatic method using a convolutional neural network (CNN) to outline the levator hiatus in a two-dimensional image extracted from a three-dimensional ultrasound volume. In particular, our method uses a recently developed scaled exponential linear unit (SELU) as a nonlinear self-normalizing activation function, which for the first time has been applied in medical imaging with CNN. SELU has important advantages such as being parameter-free and mini-batch independent, which may help to overcome memory constraints during training. A dataset with 91 images from 35 patients during Valsalva, contraction, and rest, all labeled by three operators, is used for training and evaluation in a leave-one-patient-out cross validation. Results show a median Dice similarity coefficient of 0.90 with an interquartile range of 0.08, with equivalent performance to the three operators (with a Williams’ index of 1.03), and outperforming a U-Net architecture without the need for batch normalization. We conclude that the proposed fully automatic method achieved equivalent accuracy in segmenting the pelvic floor levator hiatus compared to a previous semiautomatic approach. PMID:29340289

Automatic segmentation method of pelvic floor levator hiatus in ultrasound using a self-normalizing neural network.

PubMed

Bonmati, Ester; Hu, Yipeng; Sindhwani, Nikhil; Dietz, Hans Peter; D'hooge, Jan; Barratt, Dean; Deprest, Jan; Vercauteren, Tom

2018-04-01

Segmentation of the levator hiatus in ultrasound allows the extraction of biometrics, which are of importance for pelvic floor disorder assessment. We present a fully automatic method using a convolutional neural network (CNN) to outline the levator hiatus in a two-dimensional image extracted from a three-dimensional ultrasound volume. In particular, our method uses a recently developed scaled exponential linear unit (SELU) as a nonlinear self-normalizing activation function, which for the first time has been applied in medical imaging with CNN. SELU has important advantages such as being parameter-free and mini-batch independent, which may help to overcome memory constraints during training. A dataset with 91 images from 35 patients during Valsalva, contraction, and rest, all labeled by three operators, is used for training and evaluation in a leave-one-patient-out cross validation. Results show a median Dice similarity coefficient of 0.90 with an interquartile range of 0.08, with equivalent performance to the three operators (with a Williams' index of 1.03), and outperforming a U-Net architecture without the need for batch normalization. We conclude that the proposed fully automatic method achieved equivalent accuracy in segmenting the pelvic floor levator hiatus compared to a previous semiautomatic approach.

Ultrasound: Bladder (For Parents)

MedlinePlus

... the computer screen. A technician (sonographer) trained in ultrasound imaging will spread a clear, warm gel on the ... specially trained in reading and interpreting X-ray, ultrasound, and other imaging studies) will interpret the ultrasound results and then ...

Ultrasound: Pelvis (For Parents)

MedlinePlus

... the computer screen. A technician (sonographer) trained in ultrasound imaging will spread a clear, warm gel on the ... specially trained in reading and interpreting X-ray, ultrasound, and other imaging studies) will interpret the ultrasound results and then ...

Rendering an archive in three dimensions

NASA Astrophysics Data System (ADS)

Leiman, David A.; Twose, Claire; Lee, Teresa Y. H.; Fletcher, Alex; Yoo, Terry S.

2003-05-01

We examine the requirements for a publicly accessible, online collection of three-dimensional biomedical image data, including those yielded by radiological processes such as MRI, ultrasound and others. Intended as a repository and distribution mechanism for such medical data, we created the National Online Volumetric Archive (NOVA) as a case study aimed at identifying the multiple issues involved in realizing a large-scale digital archive. In the paper we discuss such factors as the current legal and health information privacy policy affecting the collection of human medical images, retrieval and management of information and technical implementation. This project culminated in the launching of a website that includes downloadable datasets and a prototype data submission system.

Feasibility of ultrasound imaging of osteochondral defects in the ankle: a clinical pilot study.

PubMed

Kok, A C; Terra, M P; Muller, S; Askeland, C; van Dijk, C N; Kerkhoffs, G M M J; Tuijthof, G J M

2014-10-01

Talar osteochondral defects (OCDs) are imaged using magnetic resonance imaging (MRI) or computed tomography (CT). For extensive follow-up, ultrasound might be a fast, non-invasive alternative that images both bone and cartilage. In this study the potential of ultrasound, as compared with CT, in the imaging and grading of OCDs is explored. On the basis of prior CT scans, nine ankles of patients without OCDs and nine ankles of patients with anterocentral OCDs were selected and classified using the Loomer CT classification. A blinded expert skeletal radiologist imaged all ankles with ultrasound and recorded the presence of OCDs. Similarly to CT, ultrasound revealed typical morphologic OCD features, for example, cortex irregularities and loose fragments. Cartilage disruptions, Loomer grades IV (displaced fragment) and V (cyst with fibrous roof), were visible as well. This study encourages further research on the use of ultrasound as a follow-up imaging modality for OCDs located anteriorly or centrally on the talar dome. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Three-dimensional printed ultrasound and photoacoustic training phantoms for vasculature access (Conference Presentation)

NASA Astrophysics Data System (ADS)

Nikitichev, Daniil I.; Xia, Wenfeng; West, Simeon J.; Desjardins, Adrien E.; Ourselin, Sebastien; Vercauteren, Tom

2017-03-01

Ultrasound (US) imaging is widely used to guide vascular access procedures such as arterial and venous cannulation. As needle visualisation with US imaging can be very challenging, it is easy to misplace the needle in the patient and it can be life threating. Photoacoustic (PA) imaging is well suited to image medical needles and catheters that are commonly used for vascular access. To improve the success rate, a certain level of proficiency is required that can be gained through extensive practice on phantoms. Unfortunately, commercial training phantoms are expensive and custom-made phantoms usually do not replicate the anatomy very well. Thus, there is a great demand for more realistic and affordable ultrasound and photoacoustic imaging phantoms for vasculature access procedures training. Three-dimensional (3D) printing can help create models that replicate complex anatomical geometries. However, the available 3D printed materials do not possess realistic tissue properties. Alternatively, tissue-mimicking materials can be employed using casting and 3D printed moulds but this approach is limited to the creation of realistic outer shapes with no replication of complex internal structures. In this study, we developed a realistic vasculature access phantom using a combination of mineral oil based materials as background tissue and a non-toxic, water dissolvable filament material to create complex vascular structure using 3D printing. US and PA images of the phantoms comprising the complex vasculature network were acquired. The results show that 3D printing can facilitate the fabrication of anatomically realistic training phantoms, with designs that can be customized and shared electronically.

Novel ultrasound-responsive chitosan/perfluorohexane nanodroplets for image-guided smart delivery of an anticancer agent: Curcumin.

PubMed

Baghbani, Fatemeh; Chegeni, Mahdieh; Moztarzadeh, Fathollah; Hadian-Ghazvini, Samaneh; Raz, Majid

2017-05-01

Ultrasound-responsive nanodroplets are a class of new emerging smart drug delivery systems which provide image-guided nano-therapy of various diseases, especially cancers. Here, we developed multifunctional smart curcumin-loaded chitosan/perfluorohexane nanodroplets for contrast-ultrasound imaging and on-demand drug delivery. The nanodroplets were synthesized via nanoemulsion process. The optimal formulation with the size of 101.2nm and 77.8% curcumin entrapment was chosen for release study and cytotoxicity evaluation. Sonication at the frequency of 1MHz, 2W/cm 2 for 4min triggered the release of 63.5% of curcumin from optimal formulation (Cur-NDs-2). Ultrasound aided release study indicated that the concentration of perfluorohexane and the degree of acoustic droplet vaporization play important role in ultrasound-active drug release. B-mode ultrasound imaging confirmed strong ultrasound contrast of chitosan nanodroplets even at low concentrations via droplet to bubble transition. Finally, cytotoxicity of the ultrasound-responsive nanodroplets in the presence of ultrasound was evaluated in-vitro on 4T1 human breast cancer cells. Cell growth inhibitory effects of curcumin-loaded nanodroplets significantly increased by ultrasound exposure. According to the obtained results, these ultrasound responsive curcumin-loaded chitosan/perfluorohexane nanodroplets have a great potential for imaged-guided cancer therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Point-of-care ultrasound (POCUS): unnecessary gadgetry or evidence-based medicine?

PubMed

Smallwood, Nicholas; Dachsel, Martin

2018-06-01

Over the last decade there has been increasing interest and enthusiasm in point-of-care ultrasound (POCUS) as an aide to traditional examination techniques in assessing acutely unwell adult patients. However, it currently remains the domain of a relatively small handful of physicians within the UK. There are numerous reasons for this, notably a lack of training pathways and supervisors but also a lack of understanding of the evidence base behind this imaging modality. This review article aims to explore some of the evidence base behind POCUS for a number of medical pathologies, and where possible compare it to evidenced traditional examination techniques. We discuss the issues around training in bedside ultrasound and recommend a push to integrate POCUS training into internal medicine curricula and support trainers to comprehensively deliver this. © Royal College of Physicians 2018. All rights reserved.