From a Mental Image to Imaging Function in 3D

I’m an engineer, and I work on developing ultrasound technology. When clinical colleagues describe how they use ultrasound to guide minimally invasive procedures, they will often reach a point in the explanation of the procedure when they say: “then I form a mental image of the anatomy.”

I recently attended a conference in Venice, Italy (the IEEE International Ultrasonics Symposium), where researchers have recently used sonar to map the ancient, now-submerged canal system of Venice, uncovering 2000-year-old roads. If we can traverse 2000-year-old Roman roads with sound, why can’t we do the same for minimally invasive procedures? How can we move beyond mental images to guide minimally invasive procedures with 3D images of both anatomy and functional information?

While more than 40 unique minimally invasive procedures are currently performed routinely, image guidance still relies heavily on forms of imaging that use ionizing radiation—for example, fluoroscopy or X-ray computed tomography (CT). For example, more than 1 million percutaneous coronary interventions are performed each year using fluoroscopy

If the technology that helps us explore underwater ruins or drive on the interstate could be integrated into the instruments that are inserted into the body during minimally invasive procedures, these procedures could then be performed without exposing the patient and staff to radiation. Catheters and guidewires could become devices to guide and monitor the procedure. With the right devices, ultrasound could perform several of these measurements, including 3D anatomical imaging, monitoring blood flow, stiffness, and perhaps even monitoring temperature or pressure. It’s easy to imagine a future in which interventions in cardiovascular diseases—the leading cause of death in the U.S.—are guided by ultrasound or other sensors integrated into the needles, guidewires, and in patches on the outside of the patient’s body.  

It’s an exciting time to work in ultrasound technology development because the spaces in which ultrasound can be applied are being stretched in ways that are not possible with other imaging modalities. However, it’s not quite as simple as adding all the sensors to existing devices. All fundamental physical limits on device performance in small spaces must be addressed. For example, an ultrasound transducer is several times less sensitive when sub-millimeter in size in comparison with transducers typically used for non-invasive imaging. Image quality and frame rates must be sufficiently high even with smaller devices.

Imagine if the catheter gives a 3D image of blood flow dynamics surrounding a stenosis, or the guidewire itself can image a chronic occlusion and allows the interventionalist to route the wire around it. Ultrasound-based monitoring patches on the outside of the patient’s body could be integrated with the sensors integrated into the instruments to provide a comprehensive view of the vitals and the instrument location. While imagination is required to envision the future we want, it would be better if we did not have to imagine the anatomy during the procedure. Partnerships between technology developers and clinical experts can enable a future with 3D ultrasound guidance of minimally invasive procedures.

Brooks Lindsey, PhD, is an Assistant Professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology and Emory University.

Optimize Screening of the Fetal Heart

The keys to optimizing screening of the fetal heart are to understand how the ultrasound machine’s functions and controls can affect your image, utilize the entire maternal abdomen, adjust your image presets, and optimize your angle of insonation. So how do you do all that?

You start with the transducer. Be sure to select a transducer that allows for adequate penetration and optimal resolution. All transducers have different operating frequencies and capabilities; high frequencies produce better detail resolution but, of course, with limited sound penetration. These frequencies can be applied in all trimesters, particularly since the advent of high-resolution transducers, which are helpful when imaging delicate heart structures, such as the valves and vessel walls. If, however, the imaging is subpar with a high-frequency transducer, switch to a low-frequency transducer, which is more useful in your patients with a high body mass, in the late second trimester, in the third trimester, and in the event that there is also polyhydramnios syndrome, even when there is rib shadowing. Keep in mind too, that transvaginal imaging is helpful for evaluating the fetal heart in the first or early second trimester, in the event that there is suspected fetal cardiac abnormality, and even when maternal body habitus causes imaging to be difficult.

For your next step, adjust your image presets to optimize your temporal resolution so that you maintain a high frame rate of greater than 25 frames per second. A few of the technical settings that affect temporal resolution are the frame rate (in Hz), frequency selection, depth & focus, sector angle width, and zoom magnification. The better the temporal resolution, the improved detail resolution. To optimize your image, avoid unnecessary depth and make sure your focus is on the region of interest. A multiple focal zone may be applied to structures that don’t move, such as the placenta, but when looking at the 4-chamber heart, you will need a single focal zone. In addition, adjust your sector angle width. Reducing it increases lateral line density, which improves the image quality. Finally, make small adjustments to your settings, such as applying speckle-reduction imaging, adjusting the dynamic range (more or less gray), and scanning in different tones.

When incorporating color Doppler, the color box, color gain, wall motion filter, velocity scale/pulse repetition frequency (PRF), balance, and angle of insolation can each affect the image. The color box slows the frame rate by a significant degree so the smaller the color box, the higher the frame rate. Set color gain initially on low (ie, less color) and gradually increase it until you have optimized the amount of color. The wall motion filter eliminates signals caused by wall motion and low velocities. The velocity scale is the range of mean velocities or PRF in the region of interest. If it is too low, it can produce aliasing, which could lead to a misdiagnosis; too high and the low-velocity flow will not be displayed. Here is a sample of potential ideal velocity flows:

High-velocity flow (>60–80 cm/sec)Low-velocity flow (<30 cm/sec)
Atrioventricular valvesPulmonary veins
Semilunar valvesBicaval (IVC/SVC)
The great vessels (3VV)Evaluating atrial and ventricular septum
The scale is dependent on factors such as body mass index and fetal positioning within the uterus.

The balance allows you to display how much grayscale and color Doppler information you would like to see. Reducing the balance will show grayscale elements within the color box. And, finally, the angle of insonation is very important to keep in mind as the signal from the transducer should be parallel to the direction of blood flow.

J of Ultrasound Medicine, Volume: 35, Issue: 1, Pages: 183-188, First published: 01 January 2016, DOI: (10.7863/ultra.15.02036)

One of the major challenges in ultrasound imaging is scanning a morbidly obese patient. This is a result of the increased distance between the transducer and fetal anatomy, causing degraded resolution. Some techniques for optimizing your imaging in these cases include scanning above the tissue, when the patient’s bladder is full, through the umbilicus, or when the patient is in the Sim’s position (with the patient on their left side), which allows the extra tissue to fall to the left side. Also, keep in mind that when scanning an obese patient, the color doesn’t always fill in. Lowering the color attenuation can help clarify the image.

So, remember, the key to optimizing your fetal heart imaging is in understanding your machines’ functions and controls and how they can affect your image, utilizing the entire maternal abdomen, adjusting your image presets, and optimizing your angle of insonation!

To learn more and see case scenarios, see the American Institute of Ultrasound in Medicine’s (AIUM’s) on-demand webinar with speaker Mishella Perez, MS, RDMS, RDCS, “Fetal Heart Image Optimization: The Key to Screening”, from which this post was adapted. AIUM members can access the webinar for free.

Interested in learning more about fetal imaging? Check out the following resources from the American Institute of Ultrasound in Medicine (AIUM):

What if Ultraportable Ultrasound Devices Were the Future of Healthcare in Africa?

The improvement and miniaturization of ultrasound devices is a result of the need to make ultrasound devices quickly accessible regardless of location. The right diagnosis at the right time in the right place can take you a step ahead in this race for point-of-care diagnosis.

Developed countries have experienced very significant direct and indirect impacts on the quality of care for patients in acute care and those who are hospitalized. However, if in these countries, ultrasound has made it possible to bypass certain additional examinations (standard radiography, CT, MRI, etc) for certain precise indications despite the latter being nevertheless available, it can be deduced logically that under certain conditions, point-of-care ultrasound (POCUS) would have an even greater impact in settings where other modalities are simply not available.

Indeed, developing countries and areas with limited resources often have in common a lack of diagnostic imaging means: old, non-mobile X-ray machines with little or no function at all and you’ll rarely find CT or MRI, and when you do, it is inefficient except in concentrated, large cities.

Add to this an extremely limited electricity supply, which significantly reduces the effectiveness of the existing means even further. It directly results in the impossibility of full-time operation due to power cuts, and indirectly through breakdowns and the gradual deterioration of the equipment related to variations in electrical voltage.

These various problems make Africa extremely fertile ground for the use of clinical ultrasound (POCUS) with exactly the same benefits as those obtained in other better-developed regions, but better still the absence of other means of diagnosis, which could lead clinical ultrasound to become the “gold standard” for clinical diagnosis in African.

The problem, however, is the availability of the devices, especially the type of device. Indeed, the devices currently present in Africa are either static or relatively portable (more than 10kg), which poses a real problem of mobility for an imaging modality that could otherwise be performed at the patient’s bedside.

Ultraportable devices with their small size, their resistance, their autonomy, and their low energy requirement could be a valuable diagnostic aid in Africa. However, there remains the problem of their availability (most manufacturers limit their network to developed countries) and their cost (due to the low purchasing power of practitioners in developing countries), the very idea of ​​obtaining one at its actual cost is completely illusory.

What if the manufacturers of ultraportables developed strategies to support doctors who want to equip themselves and the educated societies with POCUS, set up conventional classroom-based training courses and E-learning free or at a reduced price for all doctors wishing to learn?

Yannick Ndefo, MD, is a general practitioner in Cameroon and a POCUS ambassador for POCUS Certification Academy.

Interested in learning more about ultrasound in global health? Check out these posts from the Scan:

        Functional Transcranial Doppler Ultrasound

        “Hey Hannah – do you think there is much more to discover in ultrasound technology?” Hannah looked at me and…

        It was about 30 years ago when I asked this question to a fellow graduate student while crossing the Duke quad. I was in the middle of a daunting doctoral program in ultrasound engineering—vanilla delay-and-sum beamforming had been the norm for many years, and we all knew speckle was a fundamental physics limitation. So what more could be done?

        Perhaps it was the Carolina heat, or maybe I was addled from late-night calculations… but my, how short-sighted and naïve I was! Since that time, a host of new technologies and discoveries have proliferated within the ultrasound landscape, with many already making their way into the clinic. And of course, ultrasound has never lost its inherent competitive benefits of safety, mobility, and affordability. The future continues to look bright for our favorite imaging modality.

        Today, I’d like to tell you about one of the more ‘niche’ ultrasound applications – functional transcranial Doppler ultrasound (fTCD). fTCD is an extension of transcranial Doppler ultrasound (TCD). Simply put, TCD is pulsed-wave Doppler of the basal cerebral arteries. Recently, a great clinical introduction to transcranial Doppler (TCD) was given on the Sonography Lounge.

        The “functional” aspect of fTCD refers to monitoring changes in cerebral perfusion during neural activation by a functional task. These tasks could include motor, sensory, or cognitive stimuli. The fTCD response is based on neurovascular coupling – essentially, the link between neural activity and cerebral blood flow. Neurovascular coupling is something we don’t completely understand, but certainly something we can observe. One of the simplest (and most famous) examples is the increase in posterior cerebral artery blood flow velocity in response to a perceived visual change.

        fTCD serves as a natural complement to other perfusion imaging modalities such as fMRI, PET, and fNIRS. The high temporal resolution (~100 Hz), anatomical target (deep branches off the circle of Willis), amenity to motion (robust during movement tasks), and safety couple well with the spatial and temporal extent and limits of these other modalities. Interestingly, because of these advantages, fTCD is being used in psychology and neuroscience research.

        What medical information can fTCD results give us? Clinically, the change in cerebral blood flow might indicate hemispheric lateralization, help monitor intracranial pressure, show potential for stroke recovery due to somatosensory activation, and even predict preclinical Alzheimer’s disease – to name only a few! A wide range of clinical applications makes this easy-to-learn technique a tool with powerful potential.

        By the way, how did Hannah (not her real name) answer my question? She just looked at me and laughed!

        Greg Bashford, PhD, PE, is a Professor and Biomedical Engineer at the University of Nebraska.

        Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community to share your experience.

        Live Outside of Your Comfort Zone: Ultrasound Education

        Earlier this year, I attended a new-to-me scientific meeting—the 21st meeting of the International Society for Therapeutic Ultrasound (ISTU) in the beautiful city of Toronto. As I sat in sessions immersed in topics ranging from immunotherapy of liver tumors with histotripsy, to sonogenetic neuromodulation, to focused ultrasound for alleviating the pain from bone metastases, I was overwhelmed. And I was humbled by the vast swaths of knowledge that were nearly completely foreign to me, despite being a senior academic who does research in the field of biomedical ultrasound. I know less about the immune system than I should, and I don’t quite get the nuances of genetics and the brain—well, let’s just say that I like to use mine, but I am unaware of how it all works. I spent a lot of the meeting learning the background to the background of these areas so that I could understand more and better appreciate all the amazing science.

        It was a pain and totally out of my comfort zone, but it was exhilarating! I learned so much, and I now appreciate the challenges, opportunities, and potential impact of this field much more than I did before. I met the brilliant physicians and scientists who were all more than willing to enlighten me about the details of their work and their up-and-coming innovations. It was refreshing. As I listened, I thought about the big picture and the potential impact of all this work on patient care and where the field will go in the future.

        You may be thinking—why did I choose to attend this meeting? Why did I not go to a conference that was more aligned with my area of research? The answer is simple—I wanted to learn new things. I wanted my students to be exposed to innovative research directions and world experts in a related but distinct area. I wanted to better understand the evidence supporting the research so that I can shape my views with data, not dogma or hearsay. I also contributed a bit by sharing our group’s work on nanobubbles and the lessons we have learned from mostly diagnostic imaging research with these agents that can be applied to therapeutic strategies with focused ultrasound. I am most grateful to the organizers for having the foresight to explore how our research can complement therapeutic ultrasound applications and for inviting me to deliver one of the invited talks. I walked away, ready and inspired to foray into the intimidating world of ultrasound-mediated immunotherapy. Armed with the lay of the land and having met the pioneers of this field, I think the foundations we learned at this meeting will shape the next 5–10 years of our research.

        I want to encourage all of you to expose yourself, your colleagues, and your trainees to new concepts, new science, and new clinical approaches. Be open-minded to change, think, consider the evidence, and make rational, data-driven decisions as you move forward with your clinical practice, research, and day-to-day obligations. Educate yourself in the new research and translational directions in the field. The world of biomedical ultrasound is complex, multidisciplinary, and rich with burgeoning ideas that will someday revolutionize clinical practice. Many recent innovations, like the focused ultrasound treatment of essential tremor, are doing so already.

        Live outside of your comfort zone—it will refresh and energize you, and it will stimulate new ideas that may someday save one patient, or save the world. Of course, it’s fine to do things as you’ve always done and stay where it’s cozy and comfortable, but I promise you will enjoy it if you venture beyond, even a little bit. Enjoy your summer and science on!

        Agata A. Exner, PhD (@AgExner;, is the Henry Paine Willson Professor and Vice Chair in the Department of Radiology at Case Western Reserve University & University Hospitals of Cleveland.

        Can We Use Ultrasound to Pace the Heart?

        In a Heartbeat

        What would it take to get back a heartbeat?

        We hear about cardiovascular diseases (CVDs) all the time, with an estimated 31% of deaths globally1. It’s not uncommon to hear stories about a close friend who was young and had a heart attack. Perhaps your mom or dad had a stroke or even a neighbor who is having heart rhythm issues.

        Every time I think about CVDs, the first thing that comes to my mind is my uncle. He was a healthy man in his 60s, very athletic, he used to swim and participate in marathons all the time. He never smoked, he always had a healthy diet and was active, and bam! One day, he had a stroke. To make the long story short, he ended up having to have a pacemaker implanted. He had a complication due to a pacemaker lead that was dispositioning, which caused a subsequent ischemic stroke.

        Don’t take me wrong, pacemakers can be a good solution. However, complications like broken leads for instance can cause unnecessary “shocks” to the user. Complications that may occur during surgery include allergic reactions, infections, vessel damage, and heart tissue punctures.2 The weakest link in the pacemaker system, most often leading to complications, is the lead. This poses a question: Can we use an alternative source of energy to pace the heart? Can we use ultrasound as an alternative source of energy? Can we use ultrasound to treat CVDs?

        If you would have a choice of another way to “control” the heart, would you do it in a heartbeat?

        Cardiac Pacing

        Looking back, if there was another way to pace my uncle’s heart and bring him back to a normal life, of course I would do it. Pacemakers work only when needed. If your heartbeat is too slow (bradycardia), the pacemaker sends electrical signals to your heart to correct the beat. The same principle is used if your heart is too fast (tachycardia). The pacemaker has a battery, and it works with electric energy. My goal in the last 10 years or so has been to use ultrasound as an alternative source of energy to pace the heart and to treat cardiovascular diseases.

        The first step was to investigate if the ultrasound pulses can increase or decrease the heart rate (HR). Some of my preliminary studies3-5 showed that ultrasound applied to the heart of rats can cause a negative chronotropic effect (or decrease in the heart rate; Figure 1). The ultrasound protocol uses a sequence of different parameters, such as pulse duration (PD), pulse repetition frequency (PRF), etc. The PD is the distance each pulse travels and the pulse repetition frequency is the rate at which the transducer emits the pulses. The pulses must be spaced. This allows enough time between pulses, so the beam has enough time to reach the target and return to the transducer before the next pulse is generated. With a specific sequence, I was able to decrease the heart rate. Voila!

        Figure 1: The top image is the baseline before ultrasound application (HR = 322 BPM), then 3 minutes after ultrasound application (HR = 230 BPM), and 15 minutes after (HR = 223 BPM).

        But what if I can increase the heart rate using ultrasound pulses? In a recent investigation, I was also able to increase the heart rate with a specific sequence of ultrasound pulses (Figure 2).

        Figure 2: HR at various points before, during, or after ultrasound application (points are not linearly spaced). An increase in HR was observed during each increased PRF sequence (1st, 2nd, and 3rd PRF).6

        Is the Future Wireless?

        We are all experiencing changes in gadgets in our daily life, from wireless vacuums to earplugs, chargers, etc. But can we pace the heart without leads? The question remains such as my uncle’s story. He’s still an active guy, but of course he needs to avoid problems like electromagnetic interference (cell phones, metal detectors, etc). Can we have a therapy that uses ultrasound to pace the heart, that is non-invasive, wireless, safe, and feasible? I hope so. Maybe one day I can change this scenario in a heartbeat!


        1. World Health Organization. Fact Sheets: Cardiovascular Disease. Accessed: July 13, 2020. [Online]. Available: https://www.who. int/en/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)

        2. Pakarinen S, Oikarinen L, and Toivonen L. Short-term implantation related complications of cardiac rhythm management device therapy: A retrospective single-centre 1-year survey. Europace 2010; 12:103–108. doi: 10.1093/europace/eup361.

        3. Coiado OC and O’Brien WD. The negative chronotropic effect in rat heart stimulated by ultrasonic pulses: Role of sex and age. J Ultrasound Med 2017; 36:799–808.

        4. Coiado OC and O’Brien WD. The role of the duty factor in ultrasound-mediated cardiac stimulation. J Acoust Soc Am 2014; 136:EL231–EL235.

        5. Coiado OC, Buiochi E, and O’Brien W. Ultrasound-induced heart rate decrease: Role of the vagus nerve. IEEE Trans Ultrason Ferroelectr Freq Control 2015; 62:329–336.

        6. Coiado OC, Yerrabelli RS, Christensen AP, Wozniak M, Lucas A, O’Brien WD Jr. Positive chronotropic effect caused by transthoracic ultrasound in heart of rats. JASA Express Lett 2021; 1:08200.

        Dr. Coiado, PhD, is a Teaching Associate Professor in both the Carle Illinois College of Medicine and the Bioengineering Department at the University of Illinois at Urbana-Champaign. At Carle Illinois College of Medicine, she acts as the Director of Student Research and Discovery Learning. Her research interests focus on cardiovascular studies, acoustics, bioinstrumentation, and education.

        Interested in reading more about vascular ultrasound? Check out these resources:

        Why Should We Use Ultrasound for Nail Evaluation

        Nowadays, with the development of high- and ultra-high-resolution linear transducers, nail ultrasound has gained relevance in the identification of traumatic injuries, tumors, and inflammatory conditions, among others, providing useful information for clinical management, surgical planning, and monitoring disease inflammatory activity and effectivity of the treatment.

        Which technical considerations do we need to keep in mind?

        In all areas of dermatological ultrasound, the evaluation of the nail must be performed with a high-resolution linear transducer, ideally between 15 and 24 MHz, which allows for a perfect anatomical definition of all the components on the nail unit. It is expected to use enough gel between the transducer and the surface of the nail in order to be able to correctly see all the components of the nail (Figure 1), some authors have used other techniques such as immersing the nail in water or the use of pads, but in my practice I consider the first one to be more practical. It is always important to analyze in gray scale, Doppler, Duplex, and color; of course in axial and longitudinal view.

        Figure 1. Adequate technic for nail ultrasound.

        Ultrasound Anatomy of the Nail

        The nail unit is made up of three main components: nail plate, nail bed, and matrix, as seen in Figure 2. Each of these has a precise sonographic definition. We also need to evaluate the periungual area compound for periungual folds. Furthermore, it’s important to include the distal phalanx, the distal interphalangeal joint, and the extensor tendon in the evaluation, mainly for inflammatory diseases such as psoriasis.

        Figure 2A: Gray scale ultrasound longitudinal view of normal anatomy of a nail. Abbreviations: dp, dorsal plate; vp, ventral plate; nb, nail; m, matrix; npf, nail proximalfold.
        Figure 2B: Color Doppler ultrasound longitudinal view of normal vascularization of the nail unit. Abbreviations: nb nail; pnf, proximal nail proximal fold; ipj, interphalangeal joint.

        Why use ultrasound in the nail unit for inflammatory diseases?

        The clinical findings of inflammatory nail diseases such as psoriasis, lichen, scleroderma, arthritis, and lupus may be very similar and difficult to differentiate. The use of biopsy leads to scarring and deformation of the nail. The morphological changes shown on ultrasound for these diseases are very characteristic, and, with adequate clinical correlation, we can avoid the use of biopsy. In psoriasis for example, five sonographic stages are described for the identification of the stage of the disease, and we have the ability to monitor the inflammatory activity by using Doppler evaluation and analyze the distal enthesis of the extensor tendon and synovial proliferation in the interphalangeal space. This is very important to develop early findings of psoriatic arthritis, even in subclinical stages, and this information can be crucial for the prognosis and treatment of patients.

        Why use nail ultrasound in tumors?

        Most nail tumors (73%) are ungular tumors and 27% are periungual. Ultrasound can show the classic appearance of multiple tumors to allow a clear diagnosis and information for surgical planning and treatment. Some studies have shown that ultrasound can change the clinical diagnosis in 35% of cases. For glomus tumors or exostoses, ultrasound can have a specificity of 100% (Figure 3).

        Figure 3A: Ultrasound greyscale, longitudinal view shows well-defined hyperechoic nodule with scalloping of the bone margin of the distal phalanx.
        Figure 3B: Color Duplex ultrasound (longitudinal view) shows hypervascularity within the nodule.

        Why use nail ultrasound for trauma?

        The nail unit is very prone to micro and macro-trauma. Micro-trauma can produce dystrophic changes in the nail plate that can simulate other nail diseases such as onychomycosis or nail psoriasis, retronychia and onychomadesis, being able to differentiate them adequately with ultrasound (Figure 4). In macro-trauma, fragmentation of the plate, hematomas, and even fractures of the distal phalanges can be diagnosed.

        Figure 4A: Gray scale ultrasound longitudinal view. The arrow indicates a big fragment of retronychia with thickening of the proximal nail fold.
        Figure 4B: Gray scale ultrasound longitudinal view with Onychomadesis. There are two fragments of the nail plate.

        As we can see, ultrasound can give us sufficient and very clear information on all the components of the nail unit. Nail ultrasound may be more widely available than other diagnostic tools like MR, it also has more spatial resolution and there is no need for contrast. Of course, ultrasound nail evaluation should be performed following the technical recommendations for Dermatological ultrasound, and the study needs to be performed by a qualified individual with training and knowledge of nail pathology, which can be very challenging. In that scenario, it can be considered the first-line modality to clear up multiple nail pathologies.


        Aluja Jaramillo F, Quiasúa Mejía DC, Martínez Ordúz HM, González Ardila C. Nail unit ultrasound: a complete guide of the nail diseases. J Ultrasound 2017; 20:181–192. doi:10.1007/s40477-017-0253-6

        González CP. Ultrasonido de alta resolución en enfermedades benignas de la piel. Revista De La Asociación Colombiana De Dermatología Y Cirugía Dermatológica 2018; 26:230–239.

        Kromann CB, Wortsman X, Jemec GBE. High-Frequency Ultrasound of the Nail. In: Humbert P, Maibach H, Fanian F, Agache P (eds). Agaches Measuring the Skin. Springer, Cham; 2015.

        Wortsman X, Alfageme F, Roustan G, et al. Guidelines for performing dermatologic ultrasound examinations by the DERMUS Group. J Ultrasound Med 2016; 35:577–580.

        Claudia Gonzalez, MD, is a Radiologist at Rosario University in Bogota, Colombia, is Vice Chair of the Dermatologic Ultrasound AIUM Interest Group, and has a Private Practice for high-resolution dermatological and MSK ultrasound in Bogotá, Colombia.

        Interested in reading more about POCUS medical education? Check out these posts from the Scan:

        Where it Matters Most

        The infant, carried by her father, had been vomiting for several days. The patient’s history was consistent with pyloric stenosis, but there were still other differential diagnoses to consider. The surgeon caring for the patient was trained in Morocco and France. He was an excellent physician who returned to his community in the small coastal country of The Gambia in West Africa. The physician needed diagnostic ultrasound to confirm or refute the presumed diagnosis. He was plagued by indecision at the prospect of performing unnecessary surgery on the infant. The patient had traveled at great cost and distance to arrive at the only tertiary care center in the country. Her family needed help and if they could not find it here, they were out of options.

        At the invitation of the surgeon, I was taking the entire attending physician group from every specialty available through a point-of-care ultrasound (POCUS) course. The course was tailor-made for surgeons, despite having representatives present from internal medicine and pediatrics. It was reasoned that the largest immediate gains would be from trauma care, ultrasound-guided procedures, and confirmation of surgical diagnoses and complications. The amount of blunt trauma and blind procedures including liver biopsies was staggering.

        Each day focused on problem-based and group learning, with gamification and competition built it. The goal was to keep the learners engaged and follow up with deliberate practice every afternoon. The surgeon would bring patients from the hospital who required diagnostics, which were unavailable until now. Patients made the trek up 2 flights of stairs, where we were teaching in the only air-conditioned space. Conditions that would be identified early in high-resource regions are often elusive without the necessary diagnostics. With POCUS, we identified patients with heart failure, pneumonia, bowel obstructions, appendicitis, and complications of pregnancy. We also identified conditions that are less readily seen in high-resource health systems such as rheumatic heart disease and hepatic abscesses.

        Each day focused on problem-based and group learning, with gamification and competition built it. The goal was to keep the learners engaged and follow up with deliberate practice every afternoon. The surgeon would bring patients from the hospital who required diagnostics, which were unavailable until now. Patients made the trek up 2 flights of stairs, where we were teaching in the only air-conditioned space. Conditions that would be identified early in high-resource regions are often elusive without the necessary diagnostics. With POCUS, we identified patients with heart failure, pneumonia, bowel obstructions, appendicitis, and complications of pregnancy. We also identified conditions that are less readily seen in high-resource health systems such as rheumatic heart disease and hepatic abscesses.

        The surgeon confirmed the diagnosis of pyloric stenosis during our POCUS course. He took his patient to the operating theater with confidence and she did well postoperatively. Ultrasound continues to make a lasting impact in The Gambia. Together, we are building a sustainable program that will incorporate POCUS into all graduate medical education. POCUS impacts care wherever it is used by trained professionals, but in my experience, it is the single most important diagnostic tool in low-resource health systems.

        Michael Schick, DO, MA, MIH, FACEP, is an Assistant Professor of Emergency Medicine and Director of International Ultrasound at UC Davis Medical Center.

        Interested in reading more about POCUS medical education? Check out these posts from the Scan:

        One More Reason to Advocate for Contrast-Enhanced Ultrasound in Children: No Current Shortage of Ultrasound Contrast Agents

        Contrast-enhanced ultrasound (CEUS) is a valuable tool to evaluate the pediatric patient as it offers many of the diagnostic benefits of other imaging modalities such as CT or MRI but avoids potential risks including radiation exposure and sedation. Furthermore, CEUS is portable and can be performed at the patient’s bedside, which is particularly important in critically ill children where transportation to the radiology department may be difficult. Currently, in the United States, only one ultrasound contrast agent is FDA-approved for use in pediatric patients for intravesical use for contrast-enhanced voiding urosonography (ceVUS) and for intravenous use for characterization of liver lesions and cardiac indications. However, off-label use has greatly expanded the applications of this technology to the betterment of patients.

        Grayscale (left) and contrast-enhanced (right) ultrasound of the left kidney in a 3-year-old boy incidentally found to have a renal lesion on prior spine MRI. Images demonstrate a predominately cystic complex lesion (circle). On contrast-enhanced images, the cystic components are clearly demonstrated with faint enhancement of thin septations allowing characterization of the lesion as a minimally complex renal cyst (Bosniak type 2F). Normal diffuse homogenous enhancement is seen in the remainder of the left renal parenchyma (arrows). In this case, the use of contrast-enhanced ultrasound for lesion characterization prevented radiation exposure, which would be required for CT, and sedation, which would be required for MRI.

        Multiple studies have shown the feasibility and value of CEUS in a wide variety of applications including evaluation of the neonatal brain in hypoxic-ischemic injury, intraoperative characterization of brain lesions for real-time assessment of resection margins, initial and follow-up evaluations in the setting of solid abdominal organ trauma, quantification of femoral head perfusion before and after developmental hip dysplasia reduction, and intraoperative ceVUS to visualize vesicoureteral reflux and assess the efficacy of bladder bulking agent injections and possible requirement for additional surgical procedures. This is to name just a few!

        Additionally, CEUS has been utilized by Interventional Radiology departments in many troubleshooting situations including evaluation of vascular access/thrombosis, identifying solid tumor components for biopsy, visualizing non-solid abscess contents for accurate drain placement, and lymph node injection for evaluation of the lymphatic drainage pathways. Again, this is a limited list of uses! Essentially, any diagnostic or therapeutic situation that would benefit from real-time bedside evaluation of organs, lesions, vessels (or anything in the human body) could potentially benefit from CEUS.

        Despite the widespread applications of CEUS, few centers regularly employ this technique or only use it in select cases. Concerns about contrast agent side effects, including anaphylaxis, have been consistently demonstrated to be minimal and lower than other contrast agents routinely utilized in imaging studies and the safety of ultrasound contrast agents has been continually proven over time. While appropriate monitoring and preparation for severe reactions is mandatory, this is not dissimilar to safety practices with CT and MRI contrast agents. Speaking of which, current CT contrast shortages and uncertain implications of gadolinium deposition with MRI contrast agents further bolster support for using CEUS as a first-line imaging modality.

        Even after explaining the relatively high benefit-to-risk ratio in this patient population, advocates for CEUS continue to find resistance to broader use. Some obstacles to wider implementation include staff training and requirement of a radiologist during the CEUS, which is currently standard practice. Select institutions offer CEUS training courses for technologists and physicians to familiarize them with technique and workflow management. Like any new procedure, education, experience, and departmental support allow increasing confidence and ease of implementation. Despite adequate technologist and nursing staff familiarity, in this time of ever-growing imaging study volumes and hospital staffing shortages, requiring the physical attendance of a radiologist for a CEUS examination is less than ideal. However, this allows valuable support for the technologist and for the radiologist to communicate directly with the patient and family providing an immeasurable face-to-face interaction that cannot be replicated in the reading room.

        To summarize, CEUS is an incredibly valuable tool in evaluating children with vast clinical applications, the list of which continues to grow over time. If you have a patient and ask yourself “could CEUS add information with high benefit-to-risk ratio,” the answer is often “yes.” But lack of widespread awareness and implementation lead to clinicians never asking that question or even considering the potential benefit of CEUS in pediatric patients. A growing community of Pediatric Diagnostic and Interventional Radiologists would like to change that in the future.

        If you are using CEUS at your institution, what kind of scenarios (standard and unique) have you found CEUS to be helpful? If you are not using CEUS at your institution, what do you see as current obstacles? What would be required or helpful for you to implement in your practice?

        Ryne Didier, MD, is a Pediatric Radiologist at the Children’s Hospital of Philadelphia (@CHOPRadiology). Her clinical and research interests include prenatal imaging and emerging ultrasound imaging techniques and applications.

        Interested in learning more about pediatric ultrasound? Check out the following posts from the Scan:

        I Lost My Stethoscope…on Purpose

        In July of 2016, my medical school gave me my first, only, and likely, last stethoscope. Since its adoption by clinicians, it has become so iconic to the physician identity. I wanted to hear murmurs and rales—and sometimes prank my classmates and yell into the diaphragm. Since the start of my clinical rotations, it has been my constant companion, tucked away in my bag until I drape it behind my neck at the start of shift. I felt naked without it. Not in my bag? Might as well show up to work without my scrub top. But here I am, almost 3 years into residency: it’s somewhere at the bottom of my bag…I think.

        Throughout the years, emergency clinicians have continued to adapt and evolve in parallel to the rapidly expanding medical device industry, such as portable ultrasounds. The term “portable”, when describing ultrasounds, has evolved beyond most of our wildest imaginations. The once bulky, immobile machines that were only seen in the “ultrasound suite or room” are now stowed away in backpacks and physicians’ back pockets. The ubiquitous nature of ultrasound has encouraged even physicians that did not train with it to adapt and learn to utilize it for almost any chief complaint. 

        I posit the adoption of point-of-care ultrasound (POCUS) as part of the routine physical exam in the emergency department. Except in the case of an asthmatic assessment for wheezing, confirmation of breath sounds after rapid sequence induction (RSI), or in a patient with penetrating chest trauma, the stethoscope has become obsolete.

        Transthoracic echocardiograms are often the most interesting studies due to the dynamic nature of the exam and the potential for performing various advanced studies. Everyone gets excited seeing a pericardial effusion and making a determination if the patient has early signs of tamponade or the visualization of a transvenous pacemaker wire’s capturing. However, I am arguing for the complete replacement of the stethoscope with point-of-care ultrasound. So, unless you believe in the existence of an I/VI systolic murmur in the patient’s upper left sternal border, you’re probably already convinced of its utility for the cardiac exam. So, let’s talk lungs.

        A 32-year-old male presented after a mountain bike accident complaining of shoulder and back pain since he had fallen onto the dirt mound after overestimating a jump. He had been diverted from the trauma bay and moved to the back of the department after having been triaged with an Emergency Severity Index (ESI) of 3. I entered the room and introduced myself. He was tachypneic but easily spoke in full sentences. I placed him on the monitor and found this otherwise healthy, active, and fit male was hypoxic to 90% on room air.

        Pneumothorax, right? I just needed to prove it. I set his nasal cannula to 5 liters and continued my physical exam. Breath sounds were normal, trachea was midline, no paradoxical chest wall movement or obvious deformities. On repeat vitals the patient was normotensive, but the pulse oximetry was dipping from 96%, then 94%, then holding at 90%. The nurse immediately called the x-ray technician, however, they were busy with various other trauma patients. My attending brought an ultrasound to the bedside, which revealed no lung sliding on his left. Clearly, he needed a tube thoracostomy performed. Using POCUS, we expedited treatment; the kit was brought to bedside, and by the time the technician had arrived, I had already consented the patient, prepped for the procedure, and anesthetized the site. The tube was placed successfully, and vitals immediately improved. Ultimately, the patient was weaned to 2 liters of oxygen via nasal cannula and admitted to the hospital.

        Fast forward to the fall. It was the middle of my second year, and COVID-19 was rearing its head again. But physicians were wiser this time: we ought not to rush to intubate, lest the patient never come off the ventilator. It was mid-afternoon, and the ED staff was pushing through their post-prandial drowsiness. A 64-year-old male with a history of hypertension and medication noncompliance was rushed to the resuscitation bay in respiratory distress. He was in extremis, fluctuating between 80–85%. We put on a non-rebreather and cranked up the oxygen. Using an Egyptian translator, he responded in 2- to 3-word sentences: he reported a recent COVID-19 exposure in his family in Egypt just before returning to the United States and reported the only symptom of shortness of breath.

        We listened to his lung fields. We all had differing opinions as to what we were hearing. I reported rales, another reported rhonchi, and the first year medical student said, “[The lungs] sound really bad.” I could not appreciate jugular vein distention (JVD) due to body habitus. He had no lower extremity edema. Blood gas demonstrated no acid-base imbalance. COVID screening was pending. The X-ray technician was on the way. The respiratory technician had put him on a bilevel positive airway pressure machine (BiPAP), but he continued to deteriorate, though more slowly. I was pushed to set up for intubation. But I asked to mix a bag of nitroglycerin first while I took the time to perform an ultrasound. While others argued this was COVID pneumonia, I thought it was due to his hypertension or sympathetic crashing acute pulmonary edema (SCAPE). If I intubate, he codes.

        The first blood pressure was taken while I looked at his lungs. B-lines everywhere, systolic greater than 230 and diastolic in the low 100s. While giving myself a pat on the back, I asked the nurse to go ahead and hang the nitroglycerin while keeping him on BiPAP. He stabilized, then headed upstairs to the ICU.

        Still not convinced? One more case. A woman in her 70s with a history of congestive heart failure and paroxysmal atrial fibrillation presented complaining of shortness of breath. She had been taking her medications, including her diuretic, as prescribed. She was hypoxic in the mid-80s. After improving her saturations with a nasal cannula, I looked at her monitor and confirmed with an electrocardiogram (EKG): she was also in atrial fibrillation with rapid ventricular response (RVR) in the 130s. She insisted it was due to her fast heart rate. She had been adamant the last time this happened, she was simply given a medication to slow her heart, which caused complete resolution of her symptoms.

        Next best step? Is it merely rate control then? Is tachycardia the etiology or symptom? I heard rales bilaterally, measured JVD to the angle of her mandible, and noted 3+ pitting edema to her legs. Ultrasound demonstrated a severely depressed ejection fraction with any pericardial effusion. Her inferior vena cava was plethoric. She had diffuse B lines bilaterally with small pleural effusions. The temptation is simply to rate control. Yet, in taking a step back to further assess, I chose, rather, to drop her preload with noninvasive positive pressure ventilation (NIPPV) and IV diuretics.

        In multiple cases, the utilization of POCUS has proven an invaluable tool. I believe it is a vital skill. The emergency physician ought to become comfortable with this tool so readily at our disposal. The next time you feel the need to listen for the difference between rhonchi and rales, pick up a probe to settle the argument.

        Author, Aaron Alindogan, MD, is a second year resident at the Department of Emergency Medicine at UT Health San Antonio. Editor, Ryan Joseph, DO, DTM&H, is an assistant professor of emergency medicine at UT Health San Antonio.