The concept that sound reflects and propagates in varied angles is an abstract concept that many students struggle to understand. I review this concept by providing an in-class demonstration that makes this less abstract and something that can be seen with glasses of liquids.
If speed 1 < speed 2, then the incident angle < transmitted angle.
The difference in the stiffness and resulting propagation speeds helps to explain why the straw appears to be “broken” when you look through the side of the glass of water. The angle of transmission is measured against the vertical black line drawn on the glass of water. This helps to illustrate the 30-degree oblique incidence vs. the increased angle of transmission. A real-world example would be the change in imaging of a needle in a fluid-filled structure.
The propagation speed of sound through air is 900 m/sec while the propagation speed of sound through water is 1200 m/sec. To figure out the change in the angle of transmission, we form a ratio that will allow us to arrive at a percentage of change. So, 900/1200 = .75 and, therefore, that ratio of change from air to water in the glass is 100 – 75 = 25%. To figure out the angle, take 30 times .25 = 7.5 degrees. Therefore, 30 + 7.5 = 37.5 degree angle of transmission.
Now, consider a different glass of liquid as part of this demonstration by viewing a glass of Karo syrup.
This time, the glass is filled with Karo syrup, which is stiffer and denser than the water, and the transmitted angle is greater due to the increased ability to travel quickly in the second media.
If speed 1 < speed 2, then the incident angle < transmitted angle.
The propagation speed of sound through air is 900 m/sec while the propagation speed of sound through Karo is 1500 m/sec. To figure out the change in the angle of transmission, we form a ratio that will allow us to arrive at a percentage of change. So, 900/1500 = .60 and, therefore, the ratio of change from air to Karo syrup in the glass is 100 – 60 = 40% gain. To figure out the angle, take 30 times .4 = 12 degrees. 30 + 12 = 42 degree angle of transmission. The real world example for this is noting a speed propagation artifact.
A final demonstration can be a glass that has 1/3 air, 1/3 vinegar, and 1/3 cooking oil. Do not forget to add a straw so that several bends in the straw are noted by viewing through the side of the glass.
Kevin D. Evans, PhD, RT (R) (M) (BD), RDMS, RVS, FSDMS, FAIUM, is Chair and Professor of Radiologic Sciences and Respiratory Therapy at The Ohio State University in Columbus, OH.
If you will be joining us in Orlando for the 2019 AIUM Convention, here are a few things you can do to get the most out of your experience:
Register to attend the 2019 AIUM Convention, the meeting for medical ultrasound, if you haven’t done so already. You have the choice of registering for the whole convention or selecting a 1-day registration, which is available for Sunday, Monday, Tuesday, and Wednesday. Up to 7 CME credits can be earned for each 1-day registration, for a total of up to 28 credits!
GET THE APP
Before and during the convention, use the app to plan your schedule, read about sessions, take notes, learn about exhibitors, and engage with other attendees. To keep on top of all things #AIUM19, download the eventScribe app now:
(1) Download eventScribe
(2) Find our event by searching 2019 AIUM Convention
Then, check out the quick video tutorials on how to get the most out of the app.
Hilton Orlando Bonnet Creek and Waldorf Astoria Orlando are approximately 18 miles from Orlando International Airport (MCO), which offers information on multiple forms oftransportation. The hotels also offer complimentary transportation to Disney® theme parks. For the current shuttle schedule, access the Bonnet Shuttlewebsite, visit the front desk, or call the hotel at 407-597-3600.
Each morning of the main convention, at 6:30 am, join us for a bit of fitness to start your day.
Sunday: Morning Run (meet in the Hilton Lobby)
Monday: Yoga (meet in the Bonnet Creek Pavilion on the Ground Level)
Tuesday: Morning Run (meet in the Hilton Lobby)
Wednesday: Boot Camp (meet in the Bonnet Creek Pavilion on the Ground Level)
New this year: Power Hour Lunch. This year you have the opportunity to attend sessions during lunch. Grab a bite in the Exhibit Hall and keep the learning going!
GET A 1ST LOOK AT NEW PRODUCTS
Visit the Exhibit Hall to see the following new products:
While you’re in the Exhibit Hall, check out MEDNAX in booth 504 to learn about career opportunities for radiologists and maternal-fetal medicine specialists. And stop by the ARDMS (booth 228) to pick up one of their “world-famous” pizza cutters.
GET SOME REST
Need to relax? Need to charge your cell phone? Do both at the new Recharge Lounge, located just outside the Exhibit Hall.
Throughout the convention, we have scattered buttons, each representing 1 of the 20 AIUM specialty-focused communities. Collect all of the communities! If you collect at least 15, you can enter a drawing to win a smartwatch.
If you are feeling a bit peckish, stop by the Exhibit Hall or the Foyer just outside of it to grab some refreshments.
If you’re having problems with tightness in the hip area
and lower back, it might not just be tight muscles, but how your hips are
positioned. Here, we show you a few movements to help fix ANTERIOR PELVIC TILT.
Before we get rolling, let’s explain what anterior pelvic
It’s when your pelvis ends up tilting forward (or anterior;
see image below).
When this happens, it ends up changing the position of your pelvis, hip, and lower back. It also changes the location of your head position, the curve of the spine, and can even lead to knee and ankle problems. This change in the position can cause you to end up having more stress on your hip, back, and knee, which increases the risk of injury and pain.
3 Stretches to Help LIVE PAIN-FREE and Correct Anterior Pelvic Tilt
#1 – 90/90 Hip Flexor Stretch
On a mat, kneel down with the front leg up, with the knee at 90 degrees, the back leg is on the ground, but also bent at 90 degrees. Make sure to tighten up the abdominal area. Then, move your hips forward, maintaining shoulders back. You are looking for a stretch in front of the hip.
You will feel the stretch in the front of your hip and the
thigh. You are looking for a light stretch. You are not trying to rip the
muscle apart. Hold that for about 20 to 30 seconds, twice on each side: first
the right leg, then the left. Alternating back and forth for the two sets.
#2 – Side Lying Quad Stretch
Lying on your side, reach back and grab the foot of the top leg with the same side’s arm as the leg you are bending. As you grab the foot, bring the heel towards the butt. The key here is not to just pull the heel to the butt but bring the thigh back a little bit in order to intensify the stretch in the front of the thigh and the front of the hip. Think – PULL THE HEEL AWAY FROM THE BUTT 6–8 INCHES.
You are looking at holding the light stretch for 20 seconds
and you will do it twice on each side, alternating: Right Leg, then roll to
other side and do Left Leg. Repeat.
#3 – Deep Squat Stretch
Stand up tall with a wider stance then shoulder width. From
that position, squat down with hips below the knees. In the bottom position,
place the elbows between the knees and then push the knees out with the elbows.
You are looking for a stretch in the inner thigh and hips.
This position and pressure will end up changing the position in the lower back and in the pelvis from an anterior tilt to a posterior tilt. Perform this stretch twice with a 20- to 30-second hold for each.
What stretches do you do? How do you improve your posture? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.
Mark “Coach Rozy” Roozen, MEd, CSCS, NSCA-CPT, TSAC-F, FNSCA, is a certified strength and conditioning specialist, a certified personal trainer, and a fellow of the National Strength and Conditioning Association (NSCA).
Doug Wuebben BA, AS, RDCS (Adult and Peds), FASE, is a registered echocardiographer and also a consultant, international presenter, and author of e-books in the areas of ergonomics, exercise and pain, and injury correction for sonographers. He has also been published on the topics of telemedicine and achieving lab accreditation.
Wuebben and Roozen are co-founders of Live Pain Free — The Right Moves. They can be contacted at firstname.lastname@example.org.
disclosure… I wasn’t actually there. Anyone
who knows me knows I am not the “sleeping with yaks, no shower for a month”
kinda girl. I also have no shame in admitting that I had no chance of surviving
the 80+-mile trek 3 miles high amongst the clouds. Fortunately for me, and the
people who inhabit the Zanskar Mountain Range, I had 4 residents who wanted to
spend several months hiking through a mostly impassable mountain trail
providing care to those who live in this spectacular part of the world. Our Lumify’s
passport had already amassed an impressive collection of stamps, but none of
them as remote as the Himalayas. There is no electrical infrastructure in this
region, and all sources of energy come from kerosene, dung briquettes, or solar
power. As Dan and Zac departed for India, we had no idea if this crazy plan to
operate the ultrasound solely off of a portable solar pad was going to work.
Frankly, I was a bit worried that I was adding a few extra pounds to their pack
for no good reason. But, after spending 30 days in one of the most remote
locations on this Earth, the guys returned with some great stories, good
images, and a ton more facial hair.
As I sat
curled up in my leather chair with a supple cabernet, I reviewed the data from
their trip and realized just how awesome this was. There had never before been
medical imaging accessible at this elevation, and its availability had a direct
impact on patient care. We repeated the adventure the following year with a new
set of residents and the same cheap solar pad from Amazon. After some minor
modifications based on our lessons learned from our inaugural year, Marc and
Rob yielded more consistent scan times and reliable use.
believe solar powered POCUS can change the face of austere medicine. All you
need is a solar pad, a portable ultrasound, and the desire and willingness to
leave the comfort of home. Or at least have a few residents up for the
Cheers from Kashmir!
Have you performed ultrasound examinations in remote regions? What was your experience? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community. Visit the Journal of Ultrasound in Medicine online.
Laura Nolting, MD, FACEP, is the Director of Emergency Ultrasound and the Ultrasound Fellowship Director for the Department of Emergency Medicine at Palmetto Health Richland in Columbia, South Carolina.
The subtle sound of a distant explosion rang out. We barely flinched, numb to the sound that was a near-daily occurrence at our remote outpost in war-torn Afghanistan in 2005. Minutes later, a fast-approaching Humvee suggested that this time, something was amiss. The sight of a bloodied soldier draped over the vehicle’s hood provided confirmation.
As we scrambled to prepare our dusty, sparsely equipped treatment tent, casualties poured through the door. A young Afghan man, triaged as minimally injured, lay in front of me, peppered from head to toe with small shrapnel wounds. His wounds were indeed benign-appearing, as his triage category suggested, but penetrating wounds can be deceptive. I struggled to gauge whether his lack of responsiveness to my questions was due to our language barrier, or something more sinister like blunt or penetrating head trauma. His primary survey was otherwise unremarkable…nosignificant external hemorrhage, airway intact without labored breathing. His blood pressure was borderline low, not an uncommon finding in the thin/healthy.
I dusted off the nearby SonoSite 180, now widely considered to be the first portable ultrasound device of its kind. Most of its knobs were still foreign to me, and my inexperienced eyes struggled to interpret the grainy images. His belly and lungs appeared unremarkable, but scanning through his subxiphoid region, the black stripe encircling his heart jumped out at me, inconsistent with my already-anchoring bias of a traumatic brain injury, but consistent with the images I had only seen in Ma and Mateer’s landmark text.
I quickly called the surgeon, whose experience with the device barely surpassed my own. After a quick look at both the machine and text, he commanded his team to prep the operating suite, an equally dusty, adjacent tent. Minutes later, the surgeon’s skillful incision of the patient’s pericardium evacuated the now-tamponading bloody effusion, revealing the tiny piece of shrapnel embedded within the patient’s right ventricular wall and saving the patient’s life.
On that day, the humbling and lifesaving power of point-of-care ultrasound (POCUS) was revealed to me. As a junior clinician with limited trauma experience, I had no formal ultrasound training, mentorship, or experience. Yet this machine, when coupled with only a book, and the desire to learn, allowed me the opportunity to overcome the shortcomings of my physical exam skills, my resource constraints, and my cognitive bias, and the mistriage of another, to ensure a patient received the timely and definitive care he deserved. In the decade or so since, I have been fortunate to serve my patients while under the tutelage of several POCUS experts whose altruistic and thoughtful mentorship allowed me the opportunity to cultivate my passion for this powerful tool, while also imparting the nuances and limitations of POCUS, frequently leading me back to a common question:
“How can we best harness the full power of POCUS?”
There is a rapidly growing body of evidence that suggests that clinicians of various skill levels can effectively employ focused POCUS applications with minimal training. Though not without risk, POCUS is no different from other clinical skills; performed with variable competency regardless of profession, specialty, or scope of practice. Some will evoke the mantra of “a fool with a tool is still a fool,” which may certainly be true, but it is unfair to assume that foolhardiness is necessarily bound by profession, experience, or even breadth/depth of training.
The notion that POCUS can/should only be monolithically employed by a limited number of broadly/extensively trained physicians may be yet another example of the monoculture of thought that continues to plague our healthcare system. Certainly, any diagnostic testing should be performed thoughtfully; but do we limit who can use the stethoscope, or order a CBC, based upon title or his/her knowledge of Bayesian principles, Fagan’s nomogram, or pre/post-test probabilities and test-characteristics? Do all successful clinicians adhere to these principles with each and every test they order? Are there other factors to consider when ordering diagnostic testing, particularly in the resource-constrained areas where POCUS can have the greatest impact?
Until POCUS is adaptably and appropriately employed by all those who provide care, regardless of practice setting and scope, its full benefit and potential, especially to those living in medically underserved areas, cannot be realized. Some will inevitably oppose this concept, citing concerns with expertise, patient safety, documentation, reimbursement, etc. Ironically, it is these same arguments that emergency physicians faced 2 decades ago before successfully overcoming significant resistance to fully integrate POCUS into emergency medicine practice.
POCUS is a rare technological tool; one that is portable, versatile, and liked by both patients and clinicians alike. It can expedite diagnosis and care, improve the accuracy of our physical exam, and help us overcome our own anchoring bias while reducing the risk of procedural error, healthcare cost, and iatrogenic radiation exposure. Though it may not impact a majority of patients, for those it does, that impact is often significant. But the most uniquely promising characteristic of POCUS that we should all embrace is its ability to bring better-informed clinicians of any ilk, back to the bedside where they belong, wherever those in need of care may be.
Do you believe the democratization of point-of-care ultrasound can enhance patient care? Share with us your thoughts or your efforts to do so: comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.
Jonathan Monti, PA-C, RDMS, is an Associate Professor of Emergency Medicine PA Studies at Baylor University and president of the Society of Point-of-Care Ultrasound (SPOCUS). He is currently conducting research on the unconventional employment of ultrasound in the U.S. Armed Forces as an employee of the Henry M. Jackson Foundation for the Advancement of Military Medicine.
Ultrasonography (US) is now used in some
fashion by most specialties, and in graduate medical education, performing a US
examination is now a routine expectation in the fields of emergency medicine,
surgical critical care, diagnostic radiology, pulmonology, and gynecology. The
American Medical Association has confirmed that physician‐performed US is
within the scope of practice of appropriately trained physicians and recommend
that training and education standards be developed by individual medical
In light of its clinical and education utility, it is reasonable to expect that US would be taught during medical school. Some national and international bodies, including the AIUM, have proposed curricula for medical students. While its level of use is variable, several schools have described integrated US into undergraduate medical education. Several studies have shown that students are able to and want to learn point-of-care US (POCUS) in medical school. Let’s review some tips for engaging medical students while teaching POCUS.
1. Hands-on time
Allow the medical student to have hands on the probe as much as possible. Limit lecture time to only that which must be done in lecture format. Make sure group learning time is done in small groups with maximal time for each student to use the probe. Give them time to work through different positions and views to help identify windows and quality images. Use your verbal commands to direct them instead of taking the probe. If you are going to take the probe, put your hand over theirs.
2. Engage the student
Find a use for
ultrasound that is relevant to the student’s specialty of choice. Most
specialties now have some use for ultrasound. IF you cannot identify a use for
ultrasound in the specialty of choice, consider teaching general skills like US-guided
IV insertion. Describe how US was or would have been useful during residency.
3. Make it fun
liberally. Consider having a game or competition (see Sono-games, SonoSlam, or
other similar competitions for potential ideas). Multiple homemade procedural
models have been described and are inexpensive. Medical students, in general,
love practicing procedures and are mostly competitive by nature. There are
several ways for the more experienced student to improve their US skills in a
fun manner. Some ideas include identifying inanimate objects blindly that are
immersed in water, a competition like fastest FAST exam, or making a procedural
4. Short and sweet
engaging by spreading practice out over time. Again, keep lectures as brief and
need-to-know as possible. Most medical students will only need a brief physics
review and do not, for example, need to know the Nyquist limit. They need to
know how to answer focused questions with ultrasound. Students will lose
interest if doing the same exam over many hours. Consider spreading sessions,
especially image review sessions, out to 1 hour or less over several days.
Intersperse different types of ultrasound (e.g., abdominal, cardiac, pulmonary,
vascular) within the same session to keep students engaged.
5. Start early
Expose students to
US early on in medical school. Consider adding it to anatomy or physiology
classes while students are still in their pre-clinical years. If you do not
have the swing to add a formal session to preclinical years, consider having
voluntary “anatomy review” sessions using US. Try to get enough interest to
start an interest group for students that is student-run. This will allow them
to take some of the responsibility for scheduling and promoting events and you
can focus on what you do best, teaching US.
Ultrasonography is coming to medical education and will continue to grow in use. While students going into specialties like radiology and emergency medicine may instantly be engaged in US teaching, consider ways to engage other students. There is a role for US in nearly every specialty.
Sonographers can and should play a key role
in teaching medical students techniques for US. Sonographers perform these
exams every day for many years. They have tricks for obtaining quality images
and many sonographers are also quite good at interpreting exams, as well.
Embrace medical students and engage them
with your passion for ultrasound. Show them how it will be helpful to them in
the future. Take an active role in medical student education and watch the use
of ultrasonography in medical practice continue to grow.
Do you have suggestions for teaching POCUS to medical students? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.
Davis, MD, is an Emergency Medicine Resident at Penn State Milton S. Hershey
Early in my career, I recall my choice to pursue my academicniche in ultrasound and more specifically ultrasound education being questioned. “Why would you do that?” “How are you going to get promoted?” “This is just a fad!”. For a moment I paused wondering if I should heed this advice. Was I making a mistake? I am happy I did not dwell on that moment because I would not be where I am, I would not have gotten promoted, I would not have touched so many learners, met so many amazing people, and helped so many patients.
One of my first patients as a doctor illustrates why I teach ultrasound. I was a brand-new doctor maybe 10 days under my belt. I walked in the room of my patient. They were in clear discomfort, I was nervous. I pushed on their abdomen. Unsure, I walked out to my supervisors and said: “I think I have an acute abdomen in bed 10.” We paged surgery and were ordering other imaging when my now-mentor, Dave Bahner, suggested we do a FAST exam. This was before the ultrasound invasion in medical school and my only exposure to ultrasound was limited and in OB and the trauma bay. He immediately noted significant free fluid and presumed rupture of a neobladder. The patient went promptly to the OR. This opened my eyes and sparked the passion for ultrasound that has fueled my career. I could use this machine to look inside and help patients on the outside.
So why teach ultrasound and who should you teach?
I teach ultrasound because…
It enables me to bring 2-dimensional anatomy to life. One of my greatest joys is showing a new medical student, undergrad, or high school student their own heart beating right in front of them and see the awe in their eyes.
It makes complicated concepts simple. I recall the challenge in medical school of the preclinical years 1 and 2. Understanding systole, diastole, cardiac valves, and flow. On paper, these are complicated and merely rote memorization. Watching these events occur on ultrasound in real time and how they are altered by simple maneuvers such as Valsalva or squatting truly aids in full understanding of the concepts.
Ultrasound is always relevant. One of my favorite courses to teach is ‘The Approach to Undifferentiated Shock’. This is attended by all fourth-year medical students. By the fourth year in medical school, many students are distracted by interviews and matching and have already chosen their respective fields. I love this course because as a teacher, I get one last chance to show them the light, or rather sound, and how it could help them if they encounter a patient in shock. I ask each of them their field of choice and if they see ultrasound having a role in their career. Many will nod affirmatively to appease me but by the end of the course, they are asking if we can teach them more ultrasound before they graduate. Ultrasound helps me connect and let them know how we use ultrasound to understand the causes of shock and how to manage these patients. This ability to break down silos and demonstrate how useful it can be across many specialties that care for patients is one of my favorite aspects of teaching bedside ultrasound.
Ultrasound is such an exciting new tool and developed into a new field. New probes, technology, and applications are always evolving and changing how we use it to care for patients.
Ultrasound education is equally as exciting and dynamic. Because of challenges such as limited curricular time and tight budgets we have gotten creative to teach ultrasound. Ultrasound education has led the way with new concepts such as remote instruction, flipped classroom, near-peer training, learning through modeling, and gaming.
I have been fortunate to be blessed with amazing mentors who have given me amazing opportunities. The ultrasound community is small and welcoming, as well as young, fresh, and innovative. One of the greatest joys of teaching ultrasound has been the relationships I have made. I have found wonderful mentors but also been able to be a mentor. To watch my students turn into fellowship directors, division heads, and national speakers has been one of the greatest rewards. I have seen that hard work, loving what you do, and helping others learn ultrasound is a winning strategy for me and possibly you too.
I make myself endlessly available to my learners and that offer does not end at graduation. More so than any award I have ever gotten, the greatest accomplishments of my career are the notes, emails, and texts saying thank you: ultrasound saved my patient last night. Those clinical wins where a patient benefits from a bedside ultrasound make every late night of lecture prep worth it.
So, why teach ultrasound? Ultrasound is the future of medicine and medical education. Get involved!
Why do you teach ultrasound? What do you value most about teaching the next generation of ultrasound users? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.
Creagh Boulger, MD, RDMS, FACEP, is Assistant Professor, Assistant Director of Ultrasound, and Assistant Fellowship Director of Emergency Ultrasound at Ohio State University Wexner Medical Center.