The Expanding Scope and Diagnostic Capabilities of Vascular Ultrasound

Peripheral Vascular Disease (PVD) in the United States affects approximately 8 million to 12 million patients a year; some experts in the field believe this number may be underestimated. The disease is associated with significant cardiovascular morbidity and mortality, with a high rate of fatal and non-fatal cardiovascular events, such as myocardial infarction, stroke, renal failure, limb amputations, abdominal aortic aneurysms, pulmonary embolus, and progressive ischemic end-organ dysfunction. The reduction in quality of life from global vasculopathy in many patients can thus be significant.

George Berdejo

George Berdejo, BA, RVT, FSVU

Prompt and accurate diagnosis of these disease processes is of utmost importance and high-quality vascular ultrasound plays an essential role. In fact, vascular ultrasound and the role of the vascular ultrasound professional has evolved and expanded rapidly and is at the core of modern vascular disease care in the United States and is emerging around the world.

Vascular ultrasound can be seen at the intersection of imaging, physiology, physiopathology, interventional medicine, and surgery and is utilized widely by healthcare providers from many specialties, including but not limited to vascular technologists and other subspecialty sonographers, vascular surgeons, vascular interventional radiologists, vascular medicine physicians, cardiologists, radiologists, and other vascular specialists with an interest in vascular disease.

At the core of any thriving vascular surgery practice is high-quality vascular ultrasound imaging. Duplex vascular ultrasound (DU) is used to evaluate all of the major vascular beds outside of the heart. The use of duplex ultrasonography for the study of vascular disease is firmly established but is also rapidly expanding. Thanks to continued improvements in the performance of ultrasound devices, vascular ultrasound can be used to perform a greater range of assessments in a noninvasive manner in some cases excluding the need for more invasive, expensive, contrast-based imaging modalities.

The recent proliferation of “less and minimally invasive” endovascular options currently available and offered to patients with various vascular disease processes has mandated better, less invasive, preferably noninvasive methods, to diagnose the disease that is being treated. Advances in technology have increased the diagnostic capabilities of vascular ultrasound and its role not only in diagnosis but also in planning and performing interventions and in patient follow-up and surveillance after intervention. Indeed, vascular ultrasound has become the standard “go-to” diagnostic imaging technique prior to most vascular interventions and has certainly emerged as the imaging technique of choice for following patients after most vascular interventions.

Endograft Evaluation. Duplex vascular ultrasound has emerged as the standard of care for surveillance after endovascular repair of abdominal aortic aneurysms. A major complication of this procedure is endoleak (persistent or recurrent flow within and pressurization of the residual aneurysm sac). This results in persistent risk of aneurysm rupture and potential death. Ultrasound assessment allows imaging and Doppler interrogation of deep structures and low-flow detection capabilities needed in patients with low-volume/low-velocity endoleak. Duplex vascular ultrasound, in good hands, has supplanted computed tomographic angiography as the primary surveillance technique in these patients. In addition, DU allows for the ability to resolve the deep structures of the abdomen to measure aneurysm sac size.

Hemodialysis Access Mapping and Surveillance. Higher frequency, better resolution, smaller footprint transducers that are currently available provide the high-resolution images that are needed to assess the veins and arteries of the upper extremity in order to plan the optimal access sites and also to provide the surveillance often needed postoperatively in order to maximize the life of the access and the quality of life for the dialysis patient.

Lower Extremity Vein Reflux Testing. Chronic venous insufficiency (CVI) is a condition that occurs when the venous wall and/or valves in the leg veins are not working effectively, making it difficult for blood to return to the heart from the legs. An estimated 40 percent of people in the United States have CVI. The seriousness of CVI, along with the complexities of treatment, increase as the disease progresses. Duplex ultrasound is integral in the evaluation, treatment and follow-up of these patients. Absent the appropriate equipment, the initial duplex reflux scan is among the most physically challenging, labor-intensive scans performed in vascular ultrasound. These exams account for 20%–25% of all the ultrasound scans performed in our practice.

Lower Extremity Arterial Mapping. Our philosophy regarding the practical evaluation of patients with known peripheral arterial disease who require intervention includes the use of duplex ultrasound as the primary first-line imaging modality precluding the use of more expensive, invasive, and nephrotoxic diagnostic arteriography in most patients.

Vascular ultrasound is now being used by increasing numbers of specialists who are employing both traditional and newer cutting-edge methods and techniques to improve patient care and management and who are dedicated to the delivery of quality care to their patients.

The future is bright for both vascular ultrasound and the vascular sonography professional!

 

Do you have any tips for performing vascular ultrasound? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community to share your experience.

 

 

George Berdejo, BA, RVT, FSVU, is Director of Vascular Ultrasound Outpatient Services at White Plains Hospital in White Plains, New York. He is the Chair of the AVIDsymposium (www.AVIDsymposium.org) and is the current Chair of the Cardiovascular Community of the AIUM.

Novice to Competence to Understanding Our Role as POCUS Educators

Nights at the VA medical ICU could get lonely sometimes. When the hubbub of the day had drawn down and the critical care fellows had gone home, the work in the ICUs slowed.Headshot_kevin piro

I figured that I would make use of the time that had seemingly stopped. I grabbed the ultrasound and went to scan and chat with a friendly gentleman whom I had admitted the previous night. It became readily apparent that I was still a struggling learner at this point in my training. There was something that looked like cardiac motion, but not resembling anything like the diagrams and videos I had looked at on my own. It was an uncomfortable place to be.

I imagine that is where a lot of people get frustrated and stop, especially when they don’t have someone to encourage and nurture their continued practice. I had a different luxury. Just a few weeks prior, I had received an inquiry about participating in a new general medicine POCUS fellowship at Oregon Health & Science University, and I was instantly sold on its potential. Here was a chance to carve out a new path and to invest in a skill that offered me a skillset that could improve my patient care. And I knew that I would have the benefit of POCUS experts literally holding my hand as I learned the skill. What a luxury!

So, I kept scanning in the ICU prior to my fellowship. You know what I found? Patients are much more forgiving than we might imagine them to be. Most understand that hospitals are frequently places of learning and like to be engaged in the process and, as I stumbled through my next few exams, I was reminded of my Dad’s words of encouragement, “the only difference between you and an expert is that they have done it once or twice.” So I kept at it. I was terrible the next times too. But, it got easier and I felt less intimated with each scan I performed. By the time I hit fellowship, I was already moving in the right direction.

When I started my POCUS fellowship, I was fortunate to work with all sorts of supportive colleagues that allowed me to continue to grow. Where I had struggled to build a foundation on my own, colleagues collected from internists, sonographers, and EM physicians provided me with the scaffolding. They provided me with lessons. “Remember, air is the enemy of ultrasound” and “ultrasound does not give you permission to turn your brain off. It is a problem-solving tool.” They entertained clinical application questions. They gave back when I leaned in. These colleagues were an amazing support network and would help me construct the mosaic that I teach from now.

A few months into the fellowship, I could complete a competent exam comfortably. It came together one day for me when I completed a Cardiovascular Limited Ultrasound Exam (CLUE) on a pleasantly demented older man, who had shortness of breath likely representing heart failure. As I looked at his lungs, taking stock of the bilateral B-lines and pleural effusions that confirmed his diagnosis, I discussed and showed the findings with his daughter.

“This makes so much sense now!” she remarked. The lightbulb went on for her as I democratized her father’s clinical information. The lightbulb came on for me too as I had a sense of satisfaction of both feeling confident in my diagnosis, but also being better able to teach and engage a family in their medical care. My transformation from novice to competency was mostly complete.

Now, a little more than 2 years removed from my fellowship, I have a little more perspective on the road from novice to competency, not only from my personal experience but also from my opportunity to network with an amazing group of enthusiastic (IM) POCUS educators.

These educators are largely trained by their own curiosity, their attendance at POCUS CME courses, or by latching onto experts from peripheral medical departments. In essence, these educators are pulling themselves up by their own bootstraps in a time when there is a distinct scarcity of POCUS educators within Internal Medicine, which can leave the supposed “all-knowledgeable” physician in an uncomfortable place of vulnerability. They have shared the angst that POCUS is a particularly challenging skill to learn due to its humbling nature – we may not know how badly we were hearing murmurs as medical students, but I bet most learners can guess by looking at a picture how poorly they are doing when they are scanning. It was a feeling I shared back in the ICU as a resident, but our experiences diverged when I had mentors who invested in me learning this valuable skill.

But, these physicians who learned POCUS independently are now at the next, even harder, part. As new leaders, we must reach behind us and pull up the trainees, whether that be by creating the next POCUS fellowship, starting or improving a residency POCUS program, or simply training your fellow colleague. We are tasked with making new learners feel supported and encouraged, and to make this technology accessible in fields where POCUS is not the standard of care. We need to foster these learners’ growth so that they can arrive at their own lightbulb moment and so they keep scanning on the ICUs in the effort to improve the care they deliver.

 

What was your defining moment in your decision to go into ultrasound? Have you had a unique learning experience? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community to share your experience.

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Kevin M. Piro, MD, participated in and helped build a point-of-care ultrasound fellowship at Oregon Health & Science University (OHSU), becoming only the second general medicine-focused ultrasound fellowship in the nation. Dr Piro is now a hospitalist at OHSU.

Pioneering Ultrasound Units

If you think your ultrasound machine is out-dated, imagine if you still had to use these from as long ago as the 1940s. 

1940s

Ultrasonic Locator
Dr G. D. Ludwig, a pioneer in medical ultrasound, concentrated on the use of ultrasound to detect gallstones and other foreign bodies embedded in tissues. During his service at the Naval Medical Medical Research Institute in Bethesda, Maryland, Dr Ludwig developed this approach that is similar to the detection of flaws in metal. This is A-mode in its operation and was Dr Ludwig’s first ultrasonic scanning equipment.

Locator

 

1950s

Ultrasonic Cardioscope
Designed and built by the University of Colorado Experimental Unit, the Cardioscope was intended for cardiac work.

Ultrasonic Cardioscope

 

1960s

Sperry Reflectoscope Pulser / Receive Unit 10N
This is an example of the first instrument to use an electronic interval counter to make axial length measurements of the eye. Individual gates for the anterior segment, lens, and vitreous compartment provided accurate measurement at 10 and 15 MHz of the axial length of the eye. This concept was the forerunner of all optical axis measurements of the eye, which are required for calculation of the appropriate intraocular lens implant power after cataract extraction. This instrument, which includes A-mode and M-mode, was developed by Dr D. Jackson Coleman and Dr Benson Carlin at the Department of Ophthalmology, Columbia Presbyterian Medical Center.

Sperry Reflectoscope Pulser

 

Sonoray Model No. 12 Ultrasonic Animal Tester (Branson Instruments, Inc.)
This is an intensity-modulated B-mode unit designed exclusively for animal evaluations. The instrument is housed in a rugged aluminum case with a detachable cover that contains the cables and transducer during transportation. The movable transducer holder on a fixed-curve guide was a forerunner of mechanical B-scan ultrasonic equipment.

Sonoray Animal Tester

 

Smith-Kline Fetal Doptone
In 1966, pharmaceutical manufacturer Smith Kline and French Laboratories of Philadelphia built and marketed a Doppler instrument called the Doptone, which was used to detect and monitor fetal blood flow and the heart rate. This instrument used the continuous wave Doppler prototype that was developed at the University of Washington. 

Smith Kline Fetal Doptone

 

Smith-Kline Ekoline 20
Working in collaboration with Branson Instruments of Stamford, Connecticut, Smith-Kline introduced the Ekoline 20, an A-mode and B-mode instrument for echoencephalography, in 1963. When B-mode was converted to M-mode in 1965, the Ekoline 20 became the dominant instrument for echocardiography as well as was the first instrument available for many start-up clinical diagnostic ultrasound laboratories. The A-mode was used in ophthalmology and neurology to determine brain midlines.

Ekoline 20

 

University of Colorado Experimental System
Developed by Douglas Howry and his team at the University of Colorado Medical Center, this compound immersion scanner included a large water-filled tank. The transducer moved back and forth along a 4-inch path while the carriage on which the transducer was mounted moved in a circle around the tank, producing secondary motion necessary for compound scanning. 

Compound immersion scannerCompound immersion scanner tub

 

1970s

Cromemco Z-2 Computer System (Bioengineering at the University of Washington)
This color-Doppler prototype, introduced in 1977, was the computer used for early color Doppler experiments. Z2 “microcomputers” were used for a variety of data acquisition and analysis applications, including planning combat missions for the United States Air Force and modeling braking profiles for the San Francisco Bay Area Rapid Transit (BART) system during actual operation.

Cromemco Z-2 Computer System

 

ADR-Model 2130
ADR of Tempe, Arizona, began delivering ultrasound components to major equipment manufacturers in 1973. Linear array real-time scanners, which began to be manufactured in the mid-1970s, provided greater resolution and more applications. Grayscale, with at least 10 shades of gray, allowed closely related soft tissues to be better differentiated. This 2-dimensional (2D) imaging machine was widely used in obstetrics and other internal medicine applications. It was marketed as an electronic linear array, which was faster and more repeatable without the need for a water bath as the transducer was placed right on the skin.

ADR Model 2130

 

Sonometrics Systems Inc, NY BR-400V
The first commercially available ophthalmic B-scanner, this system provided both linear and sector B-scans of the eye. The patient was examined in a water bath created around the eye by use of a sterile plastic ophthalmic drape with a central opening. Both A-scan and B-scan evaluations were possible with manual alignment of the transducer in the water bath. The instrument was developed at the Department of Ophthalmology, Columbia Presbyterian Medical Center by Dr D. Jackson Coleman, working with Frederic L. Lizzi and Louis Katz at the Riverside Research Institute.

Sonometrics Systems Inc, NY BR-400V

 

Unirad GZD Model 849
Unirad’s static B-scanner, allowing black-and-white anatomic imaging, was used with a scan arm and had similar controls as those used today, including processing, attenuation compensation, and gain.

Unirad GZD Model 849

 

1980s

American Flight Echocardiograph
This American Flight Echocardiograph (AFE) is a 43-pound off-the-shelf version of an ATL 400 medical ultrasonic imaging system, which was then modified for space shuttle compatibility by engineers at the Johnson Space Center to study the adaptations of the cardiovascular system in weightlessness. Its first journey to space was on the space shuttle Discovery in 1985 and its last on the Endeavour in 1992. The AFE generated a 2D cross-sectional image of the heart and other soft tissues and displayed it in video format at 30 frames per second. Below, Dr Fred Kremkau explains more about it.

 

To check out even more old ultrasound machines, visit the American Institute of Ultrasound in Medicine’s (AIUM’s) An Exhibit of Historical Ultrasound Equipment.

 

How old is the ultrasound machine you use now? What older ultrasound equipment have you used? Did it spark your desire to work with ultrasound? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.

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The AIUM is a multi-disciplinary network of nearly 10,000 professionals who are committed to advancing the safe and effective use of ultrasound in medicine.

Ultrasound in the Age of Telehealth, Telemonitoring, Telemedicine, Robots, and Kimonos

Today, there is online access to almost everything; groceries, a video chat with your grandmother across the globe, step-by-step instructions on how to fix your lawnmower, and a virtual doctor to help with pain in your abdomen. The healthcare applications of the internet have exploded in recent years with digital health and telemedicine assuming one of the highest growth areas for start-up entrepreneurs. The expansion of telehealth resources (IT infrastructure/capabilities) has allowed telemedicine to extend to isolated, inaccessible, remote spaces (maybe even your living room). And telehealth has gone beyond just a video chat with incorporation of sensing technologies including cameras, digital stethoscopes, and ultrasound.
Kat and Scott

Ultrasound imaging in austere locations is not just about access to an ultrasound system; it requires both the ultrasound operator, and the interpreter, to have specific knowledge, competency, and ultimately accountability about the quality of the examination, and the diagnosis it helps to provide. Our NASA-sponsored research team has shown that novice ultrasound operators can acquire diagnostic quality ultrasound images after a short training period with remote tele-ultrasound guidance in a space medicine environment. The astronaut operators were able to perform terrestrial standard abdominal, cardiovascular, and musculoskeletal ultrasound examinations with modest remote guidance oversight; zero gravity specific exams of the eyes, spine, and sinus were also completed. Importantly, the astronaut crewmembers quickly became more autonomous during their 6-month mission in space and were able to self-direct image acquisition.

But a major challenge with tele-ultrasound is operator training. William R. Buras, Sr, Director, Life Sciences at Tietronix Software Inc, and his team are making an augmented reality user interface for ultrasound scanning using a wearable heads-up display with imbedded guidance to improve ultrasound competency. This innovative Houston team is being funded by a NASA grant.

Unfortunately, when it gets to real-world practicality, neither the ultrasound machine nor the examination is intuitive. A team in Canada led by Dr Andy Kirkpatrick are working on a sustainable ultrasound solution using both remote ultrasound system operation and telemonitoring. They investigated the ability of non-trained firefighters to perform ultrasound in Edmonton being guided from Calgary. “We found that by using just-in-time–training with motivated firefighters, the remote examiner guiding the firefighters was 97% correct in determining the presence of a simulated hemo-peritoneum. Ironically, while this trial design also attempted to examine the utility of remote ultrasound knobology control, the firefighters were so good at the task that the remote knobology control became less of a relevant problem” said Dr Kirkpatrick.

To reduce the challenges of novice ultrasound operators, at team in France, led by Dr Phillipe Arbelle, linked a robot-coupled ultrasound device with a remote operator. The distant clinician can move the ultrasound probe with a joystick to acquire the ultrasound images. His concept has been implemented in a French ultrasound device, SonoScanner, that the European Space Agency will begin investigating on the International Space Station.

Similar work in robotic ultrasound is being done in Australia, where a team is building a robotic ultrasound machine that can perform abdominal ultrasound.

Have you seen the guy in a kimono buying a car? Online resourcing is indeed pants-optional. But if you plan on telemonitoring be suitably dressed.

Alien

What other areas have come a long way when it comes to ultrasound? What areas are poised to be next? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Kathleen M Rosendahl-Garcia, BS, RDMS, RVT, RDCS, is a NASA contractor working for KBRWyle and is a senior scientist and clinical sonographer in the Space Medicine division working under the Human Health and Performance Contract. Scott Dulchavsky, MD, PhD, is the Roy D. McClure Chairman of Surgery and Surgeon-in-Chief at Henry Ford Hospital in Detroit, and Professor of Surgery, Molecular Biology and Genetics at the Wayne State University School of Medicine. He is also a principal investigator for NASA and heads a project teaching astronauts how to use medical ultrasound in space.

Why I Love Credentials

My name is Mike. I am many things, including a veteran, a business man, a coach, and a sonographer. And while the “things” I am change over time, one thing has remained the same: I am a student! This is thompsonmost evidenced by the 8 professional credentials I currently hold.

I have found that after being in the field of ultrasound for more than 2 decades, credentialing and continuing education can distinguish the enthusiastic sonographer from the merely competent one. With the introduction of more focused credentials such as musculoskeletal, breast, pediatric, phlebology, and advanced cardiac subspecialties, sonographers can now stand out from the crowd in terms of awareness and competency while at the same time being on the cutting-edge of the latest techniques and literature.

Acquiring a new credential, or even just studying for the registry examination, requires you to learn valuable new knowledge that may impact the way you treat and diagnose patients. For example, while I was preparing for the RPhS registry, multiple sources recommended a pneumatic compression device to augment venous flow while a patient is standing as an alternative to the patient performing the Valsalva maneuver in order to induce and record venous reflux. For me, this method has helped me better evaluate for this condition with less strain on the patient while eliminating communication barriers that may exist. If I hadn’t been preparing for that exam, I probably would never have learned this technique.

While some credentials are necessary for certain jobs, multiple credentials prove to existing and future employers that you take your profession seriously and you don’t settle for the minimum standard. I am not saying you need to get multiple credentials. If your professional interest does not reach beyond one credential, that is fine, but few ultrasound labs today only perform only one specialty. Echocardiography labs and vascular labs are growing together as cardiovascular labs, and many departments are requiring a more comprehensive knowledge in ultrasound. Credentialing yourself to the highest degree may get you the new job you pursue or secure the one you have. While increased pay is always a motive, sometimes the satisfaction of being able to set yourself apart from others in the field can be just as rewarding.

Some sonographers have the position that if the credential doesn’t come with a pay raise, it’s not worth it. With reimbursement cuts and higher credentialing standards being proposed by private and government payors, my opinion is that keeping your job is a pay raise.

Why do you hold the credentials you have? What are your go-to resources? What book would you like to see written? Share your thoughts and ideas here and on Twitter: @AIUM_Ultrasound.

Mike Thompson, MPH, RDMS, RDCS, RVT, RPhS, RVS, RCS, RCCS, is Owner of Diagnostic Resources in Perry, Georgia.

 

How to Obtain Focused Cardiac Ultrasound Images

My first exposure to handheld ultrasound was as a first-year medical student. I was assigned to a cardiology clinic with an attending that pioneered handheld ultrasound examinations. Watching him move from patient to patient and use ultrasound to simultaneously diagnose and teach inspired me to learn how to use ultrasound and incorporate it into my practice.

cardiac_pic2

Parasternal long axis demonstrating a dilated left ventricle.

As a budding cardiologist, examining and triaging patients with handheld ultrasound is a part of my daily work. Although handheld ultrasound and the stethoscope differ vastly in their technology, at the bedside, both are limited by the user’s interpretation of the examination findings. I have found when using handheld ultrasound, as with the stethoscope, perhaps the most important tool is “between the ears.”

The “Introduction to Focused Cardiac Ultrasound” set of lectures provide an overview to focused cardiac ultrasound views and a guide to obtain them. The main goal is to develop an understanding of the scope of focused cardiac ultrasound and to “get the heart on the screen” when scanning. The first lecture focuses on the parasternal long axis and subcostal views of the heart. In practice these views will often be the most helpful and accessible. The second lecture reviews the parasternal and subcostal views and introduces the apical views of the heart. Each lecture includes sample diagnoses.

My rationale for reviewing all the basic views of the heart is to provide a broad survey of all the windows and probe orientations. When a formal cardiac echo is ordered, these are the views and windows obtained by the sonographer. In practice with handheld ultrasound, one or two of these views can be utilized to answer the question at hand. Based on patient positioning and body habitus, however, certain windows may provide a better view of the heart.

My hope in sharing all the views in the second lecture is to not overwhelm the learner but rather provide a strong foundation in understanding the anatomical relationships of the ventricles and atria in the body and see how one window builds off the next. The views in this lecture are directly applicable to structured bedside ultrasound examinations, such as the “CLUE examination.”

At our home institution, we utilize these lectures in a continuously rolling small-group lecture series for our medical students and house staff. The cardiology fellow leads the lecture and the hands-on scanning portion, rotating every third week on the step-down cardiology unit. Overall the feedback has been positive with many of the trainees spreading the skills to other rotations. We are happy to share this resource and welcome feedback.

What resources are invaluable to you? What tools do you use to continually learn? Where do you find the information you need? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Colin Phillips, MD, is Fellow, Division of Cardiovascular Disease at Beth Israel Deaconess Medical Center.