Ultrasound in Orthopedic Practice

Point-of-care ultrasound brings great value to patient care in orthopedic practice, especially for soft tissue problems. It offers safe, cost-effective, and real-time evaluation for soft tissue pathologies and helps narrow down the differential diagnosis.Pic1

There are a variety of soft tissue lesions in orthopedic practice with a classic clinical presentation that may not necessitate ultrasound examination for confirmation of diagnosis, for example, ganglion cyst. However, there is value in performing an ultrasound scan for these common soft tissue lesions.

Ganglion cyst on the dorsum of the wrist or radial-volar aspect of the wrist are confirmed based on clinical examination and presentation. Adding ultrasound examination can help differentiate classic ganglion cyst from some rare findings like Lipoma, anomalous muscles, or soft tissue tumors. Ultrasound examination may also be helpful in finding the source of the ganglion cyst or the stalk of the ganglion cyst. This can help pre-surgical planning if resection of the ganglion cyst is desired by the patient and recommended by the surgeon, because arthroscopic or traditional surgical approach may be needed based on the location of the stalk or neck of the cyst.

Images 1 and 2 show examples of two different patients with a similar presentation of slow-growing mass on the digit. Image 1 from patient 1 shows a solid tumor overlying the flexor tendons of the digit, where the mass was palpated. Image 2 from patient 2, shows a cystic mass overlying the tendons of the digit. In both of the cases, masses were painless and slow growing with minimal to no discomfort. Ultrasound is a great tool in differentiating solid vs cystic lesions and can help avoid attempted aspiration of a solid mass when the mass is presented in an area of classic ganglion cyst’s usual presentation.

Another soft tissue problem, where ultrasound is a superior imaging tool is tendon pathology. Ultrasound can help differentiate tendinosis, tenosynovitis, or tendon tears.

In tenosynovitis, tendon by itself shows normal echotexture and uniform appearance but the tenosynovium that surrounds the tendon gets inflamed and appears as hypoechoic halo around the tendon, for example, in image 3, tendons of the first dorsal compartment of the wrist show uniform thickness and fibrillar echotexture, however there is hypoechoic swelling around the tendons, this is an example of tenosynovitis of first dorsal compartment of the wrist.

In tendinosis, tendon loses its fibrillar pattern and appears swollen and may show vascularity on color ultrasound, which is suggestive of neoangiogenesis or angiofibroblastic proliferation. For example, in Image 4, the tendons of the first dorsal compartment of the wrist show focal enlargement, hypoechoic swelling, and loss of normal fibrillar echotexture and tendon appears disorganized with evidence of increased vascularity on color ultrasound. This is an example of tendinopathy or tendinosis.

Focal tendon tears appear as anechoic or hypoechoic focal defects in tendon substance. Image 5 shows a partial tear of the triceps tendon from the olecranon process. The partial tear appears as a focal hypoechoic defect in the tendon, which is confirmed in the long and short axis scan of the tendon.

In full-thickness tears, the tendon is seen retracted proximally with no fiber attachment at the tendon footprint. Image 6 shows an example of a full thickness complete tear of the supraspinatus tendon from its bony attachment at the greater tubercle. The tendon has retracted proximally and the retracted stump is not visible on ultrasound examination.

Image 6

Point-of-care ultrasound adds significant value to clinical examination in an orthopedic setting. It enhances the understanding of a patient’s problem, increases confidence in the care provided, and high patient satisfaction is reported.

In what unexpected ways do you find ultrasound to be useful? Do you have additional tips for using ultrasound in orthopedics?  Comment below or let us know on Twitter: @AIUM_Ultrasound.

Mohini Rawat, DPT, MS, ECS, OCS, RMSK, is program director of Fellowship in Musculoskeletal Ultrasonography at Hands On Diagnostics and owner of Acumen Diagnostics. She is ABPTS Board-Certified in Clinical Electrophysiology; ABPTS Board-Certified in Orthopedics; registered in Musculoskeletal Sonography, APCA; and has an added Point-of-Care MSK Soft Tissue Clinical Certificate.

Training Beyond Discipline – Developing Devotion in Ultrasound

Mathews Benji KA point-of-care ultrasound (POCUS) revolution is unfolding before our eyes, forever changing the way we interact with patients. It started with a revolution in specialties such as emergency medicine and critical care, and now it has entered into my sphere with internal medicine and hospital medicine. I see this whenever I’m on clinical service. A 3rd year medical student talks about diffuse B-lines as we stop antibiotics and start diuretics on a patient with pulmonary edema; a 3rd year resident asks to look at a patient’s kidney with ultrasound as we manage undifferentiated acute kidney injury; nursing staff curiously looking on as a patient is shown their weak heart as goals of care are discussed.

At the same time, we in internal medicine and hospital medicine are living in a medical world filled with many challenges towards implementation of POCUS. Though there are many devices in the emergency rooms and some in the critical care wards, there are not many in the inpatient wards nor in the clinics. Though numerous workshops and courses abound in POCUS, many attendees do not continue to use this skillset after training. Those that received initial training find it too challenging to discipline themselves to continue to scan.

It is that latter sentiment that caught my attention this last year. The concept of discipline and viewing POCUS through its lens. A quote by Luciano Pavarotti comes to mind,

“People think I’m disciplined. It is not discipline. It is devotion. There is a great difference.”

I’ve often heard the sentiments:

“It is so hard to learn POCUS, how do you find the time for it on a busy clinical service to get images?”

“I find it hard to set aside time during my non-clinical work days as other work and life piles up.”

I’m not sure about you, but the word discipline does not often carry an inspirational tone to it. There is a sense of drudgery, lack of passion surrounding the word. As an ultrasound director, that is the farthest from what I want my learners to experience with POCUS.

When I looked up the word discipline in the Oxford Dictionary there it was as well:

dis·ci·pline
noun
1.
the practice of training people to obey rules or a code of behavior, using punishment to correct disobedience.
“a lack of proper parental and school discipline”

2.
a branch of knowledge, typically one studied in higher education.
“sociology is a fairly new discipline”

Is it #1 that we were aiming for? Or at the very least, is that what people are sensing? Hopefully, we’re not using punishment to correct disobedience. The Pavorotti quote struck a chord in me. As a contrast to discipline, we have devotion.

The word “devotion” is defined by Oxford Dictionary as follows:

de·vo·tion
noun
1.  love, loyalty, or enthusiasm for a person, activity, or cause.
“Eleanor’s devotion to her husband”
synonyms: loyalty, faithfulness, fidelity, constancy, commitment, adherence, allegiance, dedication; More

•  religious worship or observance.
“the order’s aim was to live a life of devotion”
synonyms: devoutness, piety, religiousness, spirituality, godliness, holiness, sanctity
“a life of devotion”

•  prayers or religious observances.
plural noun: devotions
synonyms: religious worship, worship, religious observance

Devotion does have some concepts borne from religion or worship but that doesn’t make it an irrelevant word for the POCUS learner or teacher. The first definition of love, loyalty, or enthusiasm captures the essence of what most of us are hoping POCUS to be for our learners. As my good friend and POCUS enthusiast, Dr. Gordy Johnson, from Portland, Oregon, says, we need to remember “our first kiss.” What was the moment that grasped us with POCUS?

Don’t get me wrong, I’m not completely opposed to the word discipline, but it moves beyond that if we’re going to develop fully devoted clinicians in the realm of bedside ultrasound. Those that are equipped with the cognitive elements know when POCUS should be used, why it should be used, how to acquire images, and then how to clinically integrate it.

This post was originally intended as a follow-up of the AIUM webinar on the Comprehensive Hospitalist Assessment & Mentorship with Portfolios (CHAMP) Ultrasound Program with hopes to continue the conversation surrounding what makes for an effective training program. The program involved online modules, an in-person course with assessments, portfolio development, refresher training, and final assessments. The key lesson we have learned is that longitudinal training with deliberate practice of POCUS skills with individualized performance feedback is critical for skill acquisition. However, the intangible pieces of how people continued to scan was developing an enthusiasm and love surrounding ultrasound by seeing its impact in the marketplace. As they were continuing to scan, their patients, their students, the many nursing staff were partnering in a stronger way with this diagnostic powerhouse in their hands.

With all this, I cannot help but be optimistic when I see the commitment of many in the POCUS movement already. I would urge all of us to evaluate how we develop devotion in ultrasound, how to tap into the dynamism of the POCUS movement coming up the pipeline with our medical students and residents. They have the potential to disrupt inertia and be an impactful force to integrate POCUS more into internal medicine and hospital medicine.

If you are an ultrasound educator, how do you inspire devotion? What are some of your best practices surrounding training in POCUS? Which do you think is most important: discipline or devotion? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Benji K. Mathews, MD, FACP, SFHM, is the Ultrasound Director of the Department of Hospital Medicine at HealthPartners in St. Paul, Minnesota.

Pre-eclampsia, Growth Restriction, and a Placenta Bank

Our Maternal-Fetal Medicine fellow was talking about a delivery that occurred while I was away. The fetus was growth-restricted and developed worsening indices on Doppler ultrasound of the umbilical arteries. What was initially an increased Systolic/Diastolic ratio became first absent and then reversed end-diastolic flow. As this occurred over several weeks, the patient herself had worsening blood pressures and symptoms related to her pre-eclampsia and the fetal tracing became more concerning. She was ultimately delivered and her tiny and premature baby was now in the care of the neonatologists.201500581_Hill-7

The fellow’s presentation focused on the ultrasound findings and the surveillance of pregnancies that become complicated in this way. What was known was the best current management in this case. The unknown was why this had happened in the first place. I was about to interrupt the presentation when our fellow, knowing what I was going to ask, looked over at me and said “Yes, I did collect the placenta.”

Pre-eclampsia is a common condition and growth restriction, by definition, occurs in 10% of pregnancies. The conditions are highly related. We have risk factors for both, but we seldom know the cause. Our treatments seem crude to a bench researcher; try to control the condition as long as you can, and if either patient or her fetus becomes too sick, deliver the pregnancy.

As an obstetrics and gynecology resident, I was fascinated by developmental programming in these fetuses and sent in a grant application to the American Institute of Ultrasound in Medicine requesting seed funding to look at the hormonal associations with growth restriction. Their contribution to my research was a turning point for me. I had always thought of myself as a clinical researcher and this was my first exploration of translational research. During my fellowship in Maternal-Fetal Medicine, I collected ultrasound data on growth restricted pregnancies and sampled placentas and cord blood from the pregnancies when they delivered. What I had thought would be a one-off project became a jumping off point for continued exploration into placental biology.

Five years later, I have established a placenta bank at the University of Arizona. What was a small study focusing on just one condition has inspired the creation of a bigger project. Our residents and fellows now contribute to the bank and have the ability to answer their own questions with the samples already collected. The bank is a resource to all of us and has fostered collaborations with the University of Arizona Biorepository and the department of Animal and Comparative Biomedical Sciences. My initial work focused on changes in leptin, renin, and C-reactive protein in cord blood, but as I learned more, the objective changed to include RNA analysis of the placental tissue. We noted that the structural protein expression was different in the growth-restricted pregnancies. This has led to the proposal of a whole different model regarding the causation of preeclampsia and growth restriction.

We will wait and see how this baby does in the neonatal intensive care unit. As we go about our conservative management until the risk becomes too great to continue, it is a comfort to know we are looking for reasons; if we understand possible mechanisms better, there is the potential to mitigate or reverse the development of fetal and maternal morbidities.

How has ultrasound shaped your career? Has an ultrasound study led you down an unexpected path? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Meghan Hill, MBBS, is Assistant Professor at The University of Arizona College of Medicine, Department of Obstetrics & Gynecology.

Storing Blood as a Dry Powder

Did you know that blood can only be stored for up to 6 weeks when refrigerated? Because synthetic blood is not available in the clinic, blood supplies must be continually replenished from healthy donors. Even if there is a surge in blood donations at one point in time, 6 weeks later there could be shortages if continued donations do not meet the current demand. Blood can be frozen for a decade or more but significant challenges in processing blood for frozen storage limit this option to specific situations such as for rare blood types or military use. The freezing process currently utilizes high concentrations of glycerol to protect red blood cells during frozen storage but this compound must be removed prior to transfusion, and the de-glycerolization process is very sensitive and time-consuming. Therefore, most hospitals and medical centers utilize refrigeration for blood storage.

What if, instead of refrigerating or freezing blood, there was a method to freeze-dry blood for long-term storage as a dry powder, similar to the process used for astronaut food? This could enable long-term blood storage at room temperature, and when the blood is needed for transfusion the cells could be quickly reconstituted simply by adding sterile water. Not only would this offer another option for long-term storage, it would be particularly useful in situations where refrigeration or freezing is not available, such as in some remote medical centers or for the military in far-forward settings. In addition, this method could enable stockpiles of strategic blood reserves in order to maintain an adequate blood supply during disasters such as hurricanes, which disrupt blood donations.

Blood cells dried

Electron microscopy image of red blood cells after drying/rehydration following ultrasound-mediated loading with preservative compounds.

The idea of turning blood into a dry powder and then rehydrating it for transfusion may sound like science fiction, but could it become a reality? Can nature provide clues to help us solve this problem? There are many cases in history where significant scientific breakthroughs were achieved by studying nature. For example, the Wright brothers studied the characteristics of birds’ wings during flight to discover an effective design for airplane wings. Also, Alessandro Volta invented the battery after carefully studying the electric organ in torpedo fish. In the context of cell preservation, it has been found that some organisms can survive complete desiccation for long periods of time. For example, tardigrades and brine shrimp (“water bears” and “sea monkeys”) can be dried out and remain in a state that approaches “suspended animation” for decades, but when they are rehydrated they return to normal physiological function and can even reproduce. This led us to ask the question, if these complex multicellular animals can survive desiccation, why not individual red blood cells? Scientists have found that these organisms produce protective compounds, including certain sugars and proteins, which prevent damage to their membranes during drying and rehydration.

Unfortunately, human cells do not have the transporters in their membranes that enable internalization of the protective compounds found in organisms that can survive desiccation. Therefore, an active loading method is required. We realized that the process of ultrasound-mediated drug delivery via sonoporation could potentially be applied to solve this problem and enable delivery of protective compounds into human red blood cells. In the past, most ultrasound research has either ignored red blood cells or attempted to minimize sonoporation in these cells. But what if we could intentionally sonoporate red blood cells outside of the body in order to actively load them with protective compounds so that they could be stored as a dry powder at room temperature until needed for transfusion?

Our initial efforts to load red blood cells with protective compounds for storage as a dry powder have been promising. We prepared solutions containing red blood cells, preservative compounds, and microbubbles followed by treatment with B-mode ultrasound for ~60 seconds. After ultrasound treatment, the cells were freeze-dried and stored as a dried powder at room temperature (21–23 °C) for 6 weeks or longer. Cells were rehydrated with water and we measured up to 30% recovery of viable red blood cells. In addition, we performed electron microscopy imaging of the rehydrated red blood cells and observed evidence of normal biconcave-discoid shape. Our next steps involve testing the rehydrated cells in an animal model of acute hemorrhage in order to assess the function and safety of the red blood cells in vivo after dry storage at room temperature.

Research studies are currently ongoing and much more work remains to be done before clinical translation is possible, but if it is successful this approach could have a significant impact on blood supply, particularly in locations where refrigeration and freezing are not available. In addition, this approach could potentially enable dry storage of other cell products. As I consider the possibilities of this approach, I wonder if there are other things that we can learn from nature that could also transform medical practice.

Have you learned something else from nature that has been incorporated into your medical practice? Do you have any ideas that could potentially transform medical practice? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Jonathan Kopechek is an Assistant Professor of Bioengineering at the University of Louisville. His Twitter handle is @ProfKope.

Real-time Ultrasound in Physical Therapy

In the past 20 years, there are very few pieces of equipment I can say unequivocally changed how I practice as a physical therapist (PT); without question, real-time ultrasound (RTUS) is one. A sports/orthopedic colleague introduced RTUS to my practice 8 years ago. As a pelvic PT, I thought it would be a nice adjunct to my current practice with biofeedback, exercise, and manual techniques. I was wrong. It was a game changer. What initially started out as an exercise in interpreting black & white ink-blot-like images has evolved into so much more.Lisa-Damico-Portraits-Carrie-Pagliano-0413-LOW-RES

For those unfamiliar with pelvic floor physical therapy, typical pelvic floor assessment, without RTUS, includes an external assessment of the perineal region. Frequently, internal digital assessment is used to identify pelvic floor muscle strength, endurance, coordination, tender points, and presence of pelvic organ prolapse. Biofeedback assessment can give a general sense of local muscle activity, via either internal or external electrodes. Absent from this data collection, however, is the ability to assess function. What is the effect of pelvic floor activity on the bladder? What specific muscles in the pelvis and abdomen are activating and when? What do you do when a patient is unable to tolerate an internal assessment? RTUS addresses all of these questions. Via a transabdominal approach, I am able to assess the function of pelvic, abdominal, hip, and back musculature in the context of breath and movement. I am able to make an assessment without an internal approach, which may be threatening or uncomfortable for patients with pelvic pain. I am able to determine the function of the pelvic floor and its effect on the bladder and urethra as well.

My practice includes RTUS primarily for evaluation of movement of the pelvic floor, abdominals, hip, and spine. The primary goal is to find and address neuromuscular dysfunction in the context of urinary/fecal incontinence, pelvic pain, diastasis recti, and pelvic girdle pain. Beyond helping me identify inefficient movement strategies, coordination variances, and relevant dysfunction, RTUS has been an enormous help in educating my patients about their own bodies and how they function. I never anticipated how much a little black and white image would help patients make this connection! For example, many people have no idea where their pelvic floor is, much less what its relationship is to their bladder, pelvis, or breath. With just a quick look at the screen and a little orientation, RTUS can give patients a window into the simple yet complex connections within their own bodies.

The most striking patient activity with RTUS is using imaging to show the relationship between breath and the pelvic/abdominal region. Patients who are visual learners especially find this an invaluable tool. I use focused exhalation (cued blowing through a straw), vocalization, and varying volumes and octaves to get automatic activation of transverse abdominal and pelvic floor musculature. Patients see, in real time, the effect of their breathing (or breath-holding) strategies have on activation of muscles in the pelvic region. Patients no longer have to try to cognitively process how to turn these muscles on or off (which is laborious and practically impossible to be consistent), but rely on something as simple as breath to assist in activating or relaxing their muscles.

As you can see, RTUS provides both patients and clinicians a window into the pelvic region, providing additional insight into the patient’s function and dysfunction. Having AIUM recognize physical therapists in the AIUM Practice Parameter for the Performance of Selected Ultrasound-Guided Procedures is an outstanding step toward including PTs in this area of practice. I’ve been privileged to work alongside physical therapists working in the area of RTUS education, facilitated diagnostics and real-time needle tracking within our profession. I’m excited that the area of pelvic physical therapy is being included in using RTUS in progressive physical therapy practice. I am looking forward to more integration of RTUS in physical therapy patient care as well as physical therapy education! The more physical therapists have knowledge and skill using this unique tool, the more comprehensive care and outcomes PTs can provide!

Have you included real-time ultrasound in your physical therapy practice? If so, how has it impacted your practice? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Carrie Pagliano, PT, DPT, MTC, is a Board Certified Women’s Health & Orthopaedic Clinical Specialist and is owner of Carrie Pagliano PT, LLC, in Arlington, VA.

Determining Umbilical Cord Blood Flow

Umbilical cord blood flow is among the most highly desired parameters for monitoring fetal well-being. This is because cord blood flow directly reflects placental volume flow, which is considered to be as important in the fetus as cardiac output and lung perfusion are in adults.1 Yet, presently employed noninvasive methods, such as umbilical artery Doppler waveform analyses, use surrogate flow evaluation parameters, such as systolic/diastolic ratios, which do not directly reflect placental-fetal blood flow.2,3 Volume flow estimation overcomes this by measuring true flow, and it has been shown that volume flow changes in the umbilical vein occur before umbilical artery flow indices become abnormal.4

Yet, the present volume flow measurement method has severe problems limiting its utility. These include technical difficulties in flow measurement in umbilical cords and faulty assumptions employed in the measurement. The present method using spectral Doppler is

                 Q = V × A                    (1),

where Q is volume flow, V is the mean velocity through the Doppler sample volume, and A is the cross-sectional area of the vessel of interest. This formula assumes that the 2D flow profile is cylindrically symmetric with a circular cross-section, and the line of the Doppler sampling cuts perfectly through the center of the sampled vessel. The velocity estimates require angle correction, and if the vessel is tortuous, as in umbilical cords, the sampling position placement and angle correction are hard to perform. Multiple investigators have warned that small errors in volume flow components can result in large errors in the calculation of volume flow.5-7

A new, easy-to-perform volume flow method overcomes almost all of the limitations of the standard technique. The new method is angle independent, flow profile independent, and vessel geometry independent. It works as follows:

Volume flow is defined as the total flux across any surface, S, intersecting the vessel. This is written as

Eq2

where Q is again volume flow, V is the local velocity through each area element dA, and “” is the dot product which projects the local velocity V onto the normal vector for each area element. This is known as Gauss’s theorem. The intersecting surface, known as the “C” surface, is very simple to obtain using 3D ultrasound (Figure8). In order to validate this method, we obtained an AIUM EER-funded research grant.

Fig

Figure: (A) Four-panel view of a single 3D color flow acquisition of the umbilical cord. The four views are as follows: upper-left is axial-lateral, upper-right is axial-elevational, bottom-left is elevational-lateral (ie, the c-surface), and bottom-right is a rendered 3D reconstruction. Arteries are shown in blue and the vein is shown in red. The schematic in (B) illustrates the orientation of the probe and the corresponding c-surface in the elevational-lateral imaging plane. The vessel colors in (B) match the directionality in (A). The entire umbilical cord passes through the c-surface but only the cross-sections of the umbilical arteries and umbilical vein are illustrated in (B). The two arteries are separated in power Doppler (not shown). (Printed with permission from Pinter et al. J Ultrasound Med. 2012;31(12):1927-34. © 2016 by the American Institute of Ultrasound in Medicine)

We had 2 specific aims: 1) Test the reproducibility of the volume flow measurement, and 2) evaluate the relationship of volume flow to clinical outcome in a high-risk patient population.

In the first aim, we performed studies on 35 subjects between the gestational ages of 22–37 weeks, 26 high risk and 9 normal.9 We attempted to measure umbilical cord blood flow at 3 sites in the cord in each subject, and we averaged 28.3 ± 3.3 (mean ± standard deviation) samples per site. We used a GE LOGIQ E9 ultrasound system with a 2.0–8.0 MHz bandwidth convex array transducer to acquire multiple volume 3D color and power mode data sets. Since we were measuring mean blood flow, we assessed variability using relative standard error (standard error /mean) (RSE). The average RSE for blood flow at each cord position was ±5.6% while the average RSE among the measurements in each subject was ±12.1%.

For the second aim, we compared the volume flow measurements in 5 subjects that developed preeclampsia with the 9 normal subjects. Even with these small numbers, we detected a significant difference between the mean depth-corrected, weight-normalized umbilical vein blood volume flows in the two groups (P = .035). Further, blood flow abnormalities were detected either at the same time or preceded the hypertensive disorder in 4 of the 5 subjects. This is consistent with our prior publication where blood flow changes preceded the onset of pre-eclamptic symptoms in a study subject.8

With the introduction of 2D array transducers, umbilical cord volume flow estimates can be performed in seconds and given the valuable information provided by this method, umbilical cord volume flow will hopefully become a standard component of fetal examinations.

References:

  1. Tchirikov M, Rybadowski C, Huneke B, Schoder V, Schroder HJ. Umbilical vein blood volume flow rate and umbilical artery pulsatility as ‘venous-arterial index’ in the prediction of neonatal compromise. Ultrasound Obstet Gynecol. 2002;20:580-5.
  2. Newnham JP, Patterson LL, James IR, Diepeveen DA, Reid SE. An evaluation of the efficacy of Doppler flow velocity waveform analysis as a screening test in pregnancy. Am J Obstet Gynecol. 1990;162:403-10.
  3. Acharya G, Wilsgaard T, Bernsten GKR, Maltau JM, Kiserud T. Doppler-derived umbilical artery absolute velocities and their relationship to fetoplacental volume blood flow: a longitudinal study. Ultrasound Obstet Gynecol. 2005;25:444-53.
  4. Rigano S, Bozzo M, Ferrazzi E, Bellotti M, Battaglia FC, Galan HL. Early and persistent reduction in umbilical vein blood flow in the growth-restricted fetus: a longitudinal study. Am J Obstet Gynecol. 2001;185:834-8.
  5. Evans DH. On the measurement of the mean velocity of blood flow over the cardiac cycle using Doppler ultrasound. Ultrasound Med Biol. 1985;11(5):735-41.
  6. Gill R. Measurement of blood flow by ultrasound: accuracy and sources of error. Ultrasound Med Biol. 1985;11:625-41.
  7. Lees C, Albaiges G, Deane C, Parra M, Nicolaides KH. Assessment of umbilical arterial and venous flow using color Doppler. Ultrasound Obstet Gynecol. 1999;14:250-5.
  8. Pinter SZ, Rubin JM, Kripfgans OD, Treadwell MC, Romero VC, Richards MS, Zhang M, Hall AL, Fowlkes JB. Three-dimensional sonographic measurement of blood volume flow in the umbilical cord. J Ultrasound Med. 2012;31(12):1927-34.
  9. Pinter SZ, Kripfgans OD, Treadwell MC, Kneitel AW, Fowlkes JB, Rubin JM. Evaluation of umbilical vein blood volume flow in preeclampsia by angle-independent 3D sonography [published online ahead of print December 15, 2017]. J Ultrasound Med. doi:10.1002/jum.14507.

How do you determine umbilical cord blood flow? What problems have you encountered using the traditional method? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Jonathan Rubin, MD, PhD, FAIUM, is Professor Emeritus of Radiology at University of Michigan.

Sonographers and Contrast-Enhanced Ultrasound

Now that contrast-enhanced ultrasound (CEUS) has been approved in the United States for several abdominal applications in adults and pediatrics, I decided to take a deeper look into the sonographer’s role in CEUS. Traditionally, sonographers perform ultrasound examinations based on a protocol, construct a preliminary ultrasound findings worksheet, and perhaps discuss the findings with a radiologist. And now CEUS has transformed traditional ultrasound and gives physicians and sonographers additional diagnostic information related to the presence and patterns of contrast enhancement.DSC00125

Based on sonographers’ traditional scope of practice, some questions came to mind. What is the training process for sonographers to learn CEUS? How should CEUS images be obtained and stored? How should CEUS findings be communicated?

I envision CEUS training for sonographers broken down into stages, where they begin by learning the basics and eventually transition to where they can perform and record the studies independently. The first stage for sonographers is the ‘CEUS learning curve.’ In this stage, sonographers become familiar with basic CEUS concepts, eg, understanding physics of contrast agents and contrast-specific image acquisition modes, CEUS protocols, and typical patterns of contrast enhancement seen in various organs. In addition, an important part of the training is recognizing contrast reactions, and learning IV placement, documentation and billing related to CEUS.

The next stage involves sonographers performing more patient care and gaining scanning responsibilities. Sonographers place the IV and prepare the contrast agent. The scope of sonographer responsibilities does not generally include contrast injection (although it is reasonable since CT, MR, nuclear medicine, and echocardiography technologists routinely place IV lines and inject contrast). It should be noted that CEUS examination usually requires an additional person (physician, nurse, or another sonographer) to assist with contrast injection while the sonographer performs the ultrasound examination. In the beginning of sonographer training, it is very beneficial to have a radiologist present in the room to guide scanning and appropriate image recording.

In the third stage, a well-trained sonographer is more independent. At the completion of the examination, the sonographer will either send clips or still images to a physician to document the CEUS findings and discuss the procedure. Ideally, a worksheet is filled out, comparable to what is done today with “regular” ultrasound.

The majority of CEUS examinations are performed based on pre-determined protocols, usually requiring a 30–60-sec cineloop to document contrast wash-in and arterial phase enhancement. After that continuous scanning should be terminated and replaced with intermittent acquisition of short 5–10-sec cineloops obtained every 30–60 sec to document late phase contrast enhancement. These short clips have the advantage of limiting stored data while providing the interpreting physician with real-time imaging information. Detailed information on liver imaging CEUS protocols could be found in the recently published technical guidelines of the ACR CEUS LI-RADS committee.[i] Some new users might acquire long 2–3-minute cineloops instead, producing massive amounts of CEUS data. As a result, studies can slow down a PACS system if departments are not equipped to deal with large amounts of data. In addition, prolonged continuous insonation of large areas of vascular tissue could result in significant ultrasound contrast agent degradation limiting our ability to detect late wash-out, a critical diagnostic parameter required to diagnose well-differentiated HCC. Any solution requires identifying and capturing critical moments, which will be determined by a sonographer’s expertise. Exactly how sonographers can ensure CEUS will successfully capture the most important images is a critical question that must be answered and standardized.

Ideally, leading academic institutions should provide CEUS training for physicians and sonographers. I have seen and attended CEUS continuing medical education courses and they are a great way for physicians and sonographers to learn CEUS imaging. CEUS is a step forward for sonographers and will potentially transform our scope of practice. The technology will advance the importance of sonographers and diagnostic ultrasound, and importantly it will improve the care of our patients.

Acknowledgements:
Dr. Laurence Needleman, MD
Dr. Andrej Lyshchik, MD
Dr. John Eisenbrey, PhD
Joanna Imle, RDMS, RVT

[i] Lyshchik A, Kono Y, Dietrich CF, Jang HJ, Kim TK, Piscaglia F, Vezeridis A, Willmann JK, Wilson SR. Contrast-enhanced ultrasound of the liver: technical and lexicon recommendations from the ACR CEUS LI-RADS working group. Abdom Radiol (NY). 2017 Nov 18. doi: 10.1007/s00261-017-1392-0. [Epub ahead of print]

Has CEUS helped your sonography career? How do you envision CEUS being incorporated in your work? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Corinne Wessner BS, RDMS, RVT is the Research Sonographer for Thomas Jefferson University Hospital in Philadelphia, Pennsylvania. Corinne has an interest in contrast-enhanced ultrasound, ultrasound research, medical education, and sonographer advocacy.