Using two-dimensional ultrasound imaging to examine venous pressure

Guided wave elastography of jugular veins: Theory, method and in vivo experiment

Testing the mechanical properties of veins is important for diagnosing some cardiovascular diseases such as deep venous thrombosis. Additionally, it plays a crucial role in designing body protective products such as head protective gear, where simulations are necessary to predict the mechanical responses of bridging veins during head impacts. The data on venous mechanical properties reported in the literature have mainly been obtained from ex vivo experiments, and inferring the material parameters of veins in vivo is challenging. Here, we address this issue by proposing a guided wave elastography method in which guided waves are generated in the jugular veins with focused acoustic radiation force and tracked by an ultrafast ultrasound imaging system. Then, a mechanical model considering the effects of the perivascular soft tissues and prestresses in the veins was applied to analyze the wave motions in the jugular veins. Our model enables the development of an inverse method to infer the elastic properties of the veins from measured guided waves. Phantom experiments were performed to validate the theory, and in vivo experiments were carried out to demonstrate the usefulness of the inverse method in practice.

Ultrasound imaging in teaching cardiovascular physiology: disruption and challenge to foster learning

This work extends previously described applications of ultrasound technology in illustrating cardiovascular phenomena to investigation of learning effectiveness. To this end, learning in ultrasound-enhanced classes was assessed by quantifying the improvement in single best answer (SBA) exams conducted before and after an ultrasound practical class. This improvement was then compared to that seen in the same SBA exams conducted in matched groups that undertook similar classes conducted without ultrasound equipment. The SBA exams were designed to include questions that directly related to the phenomena being investigated in the practical classes as well as other "filler" questions to disguise the intent of the exam and ensure that standards of physiology knowledge were similar between the two groups. Any small statistically significant gains in performance observed between the two groups were confounded by differences in baseline (pretest) performance between the groups. These results contradict our previous work, which showed that self-reported measures of learning increased after ultrasound classes. It may be optimistic to expect improvements in deep learning and test performance immediately after even the most effective educational intervention. Direct measurement of the phenomena that bring about deep, long-term learning in classes remains problematic. Notwithstanding this, there is much evidence for the value of enhancing physiology learning by providing varying contexts in the physical, semantic, and cognitive domains. Ultrasound technology is a cheap and effective means of providing such context in physiology practical classes.NEW & NOTEWORTHY This work compares learning in cardiovascular physiology classes enhanced by using cheap ultrasound equipment with learning in comparable control classes without ultrasound. Performance improvement in single best answer tests between pre- and postclass tests were compared for the ultrasound and control classes, with little difference shown between the two classes. We question whether it is appropriate to measure deep learning after 2-h classes or whether other, phenomenological, qualitative measures of educational effectiveness would be better.

Snapshot of ultrasound imaging in basic anatomy and physiology teaching in the United Kingdom and Republic of Ireland: perceptions, obstacles, and solutions

We have used ultrasound imaging and technology as a tool for nonclinical teaching of basic physiological concepts for several years and are aware anecdotally that only a few others in the United Kingdom and Republic of Ireland (UK/ROI) are also using ultrasound with this intention in physiology and anatomy teaching. To better understand what areas ultrasound is used for by others, along with what barriers might exist to its use, we reached out to colleagues in UK/ROI institutions instructing on anatomy and physiology courses by asking them to complete a survey regarding their experiences. Relatively few institutions (9%) reported using the technology in this way but covered physiology and anatomy teaching in most major body systems. The perception of responding educators overall is that, overwhelmingly, ultrasound offers a useful addition to the teaching of physiology and anatomy and is very popular with students. Barriers to its implementation were identified, including unfamiliarity with equipment and potential uses. Lack of funding for equipment and staff, issues with class sizes, and lack of curriculum time were also identified. Despite these potential impediments, most nonusers were interested in finding out about the uses of ultrasound as a teaching tool. We conclude that the teaching community would benefit from wider dissemination of local practices.NEW & NOTEWORTHY We surveyed UK and Republic of Ireland institutions to establish the extent of ultrasound use in teaching undergraduate modules with significant anatomy or physiology content. Responses indicate that although ultrasound is used for a wide variety of systems, only a small proportion of courses use ultrasound for teaching. There is widespread interest in its use, with the main barriers being unfamiliarity with potential uses and the technology. We endorse further dissemination of this teaching practice.

Brachial artery blood flow by vascular ultrasound in education

There is extensive and increasing use of ultrasound in medical care and scientific research, so it is important that the technique, indication, and interpretation of ultrasound investigations are included in medical and biological education. Applications of ultrasound in medical care and education employ not only noninvasive imaging of structure but also the evaluation of organ function. Vascular ultrasound is one such application that has been hitherto relatively neglected in physiology education. The techniques of vascular ultrasound and the physiological regulation of human limb blood flow are reviewed to inform students and curriculum designers. Emphasis is placed on the value of converting velocity measurement by ultrasound to volumetric flow and on the mechanisms involved in rapidly changing flows with interventions. Live collection of real data by ultrasound can show macrovascular and microvascular features of vascular physiology. Macrovascular features include imaging and flow velocity profiles. Microvascular perfusion studies show conductance changes with interventions such as exercise and ischemia. Vascular ultrasound offers exciting opportunities for undergraduate research projects using human subjects. The literature is interesting and, though complex, offers excellent educational experience, with scope for the development of critical thinking and meaningful original research.NEW & NOTEWORTHY Ultrasound imaging has emergent prominence in clinical investigation and education. Vascular ultrasound also evaluates function. Simple methods are described that enable the application of basic ultrasound principles to the measurement of velocity and, importantly, to calculate absolute volumetric blood flow. These methods should be useful in undergraduate and graduate education, with application in clinical practice and research.

Adaptation of an anatomy graduate course in ultrasound imaging from in-person to live, remote instruction during the Covid-19 pandemic

Health concerns during the Covid-19 pandemic required the adaptation of a lecture-laboratory course in ultrasound imaging for graduate students from an in-person to a live, remote learning format. The adaptation of in-person lectures to live, remote delivery was achieved by using videoconferencing. The adaptation of in-person laboratory sessions to live, remote instruction was achieved in the first half of the course by providing a hand-held ultrasound instrument to each student who performed self-scanning at their remote locations, while the instructor provided live instruction using videoconferencing. In the second half of the course, the students transitioned to using cart-based, hospital-type instruments and self-scanning in the ultrasound laboratory on campus. The aim of this study was to measure the success of this adaptation to the course by comparing assessment scores of students in the live, remote course with assessment scores of students in the in-person course offered in the previous year. There were no statistically significant differences in the assessment scores of students in the two courses. The adaptation of a course in ultrasound imaging from an in-person to a live, remote learning format during the Covid-19 pandemic described here suggests that contrary to the prevailing view, ultrasound imaging can be taught to students without in-person instruction. The adapted course can serve as a model for teaching ultrasound where instructors and learners are physically separated by constraints other than health concerns during a pandemic.