Life is not always easy, sometimes you just have to manage with what you have. To work with limited resources is one of the skills you acquire once you are a primary care physician and particularly in Africa.
This is also true concerning point-of-care ultrasound (POCUS); it is possible to do more with less. If you really understand how it works, you can find new ways to use your tools to get the correct diagnosis.
Now, I want to share with you the case of a 53-year-old male patient whose major complaint was joint pains, particularly in the left wrist and knee. Upon physical examination, the joints were warm, swollen, and painful. I hypothesized that the diagnosis was a primary gout episode but in my health facility I don’t have a uric acid test that I would ordinarily use for confirmation of the diagnosis. I then performed a POCUS examination to confirm the diagnosis by looking for the double contour cartilage line, which is a sign of gout in joints due to uric acid deposit at the surface of bone cartilage. I didn’t have a linear high-frequency probe, so I used an endocavitary probe just as you can see in the pictures.
Ultrasound images of the knee showing the double contour sign indicative of gout.
POCUS can greatly increase healthcare in low-income countries. Usually, the healthcare gap between upper-income and low-income countries is huge but, with POCUS, the same technics can be applied to both, with the same results, if ultrasound devices are available.
However, the problem remains that there is a lack of healthcare professionals who are skilled enough to use it and teach others. The problem is no longer an absence of devices but is now due to an absence of knowledge of how to use them.
Fortunately, due to COVID-19 lockdowns, we know almost everything that can be taught online. Therefore, it is time for us to think about establishing a new way to teach, learn, and practice ultrasound. Many ultrasound societies, such as the AIUM, ISUOG, and EDE, have started to share free POCUS education on their websites. Free online courses should be encouraged since they will lead us to the democratization of ultrasound, particularly in low-resource settings.
Yannick Ndefo, MD, is a general practitioner at St Thomas hospital in Douala, Cameroon.
Interested in learning more? Check out the following posts from the Scan:
As specialists in General Internal Medicine, we are excited to see the benefits of incorporating point-of-care ultrasound (POCUS) when assessing medical patients with complex, multi-system disorders. For example, in a patient with heart failure with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) who presents with dyspnea and is found to have diffuse wheezing on auscultation, a number of possible diagnoses exist. Using basic POCUS techniques, findings of asymmetric B-lines, focal pleural irregularity, cardiac findings that seem unchanged from baseline, and a small, collapsible inferior vena cava, increase our suspicion that an infectious precipitant exacerbating the patient’s COPD is the presumptive diagnosis, rather than a primary cardiac cause.
When applied appropriately, POCUS provides real-time data previously not readily available at the bedside. This data can narrow the differential diagnosis [1] and guide intervention. Such benefits of using POCUS to assess medical patients are increasingly known [2–4]. Although new and advanced applications often predominate in the spotlight, basic applications can add a significant amount of information to assist in the care of our patients [5]. The important role that POCUS can play in evaluating medical patients has recently been recognized by the American College of Physicians and Society of Hospital Medicine [6, 7].
As medical educators, we are equally excited about how POCUS can revolutionize bedside teaching—we have seen this tool provide learners with the opportunity to inspect and then confirm the exact location and height of the jugular vein, see then feel a pulsatile liver secondary to severe tricuspid regurgitation, and percuss then visualize a sonographic Castell’s sign [8]. These “aha” moments when our learners see these maneuvers brought to life are incredibly rewarding. However, the excitement that POCUS brings sometimes needs to be balanced by caution.
Despite POCUS being relatively easy to learn, there are multiple pitfalls. The need to apply minimal criteria when acquiring and interpreting images cannot be understated. Just as important as (if not more important than) correctly identifying a positive finding is the ability to recognize when a scan does not meet minimal criteria. Communicating and teaching these limitations to new POCUS users is of paramount importance. Beyond image acquisition and interpretation, achieving competence in clinical integration requires time, repetitive practice, and feedback. As POCUS educators, we frequently see learners flock to advanced applications, such as advanced hemodynamics and detailed cardiac valvular assessments, without necessarily first mastering the basics. Our experience has been that the yield for many of these advanced applications is not high, but the cognitive load in learning them—especially before mastering the basics—is.
Our approach to using and teaching POCUS is to ensure that we ourselves maintain an appropriate amount of curiosity and humility. We continue to spend time tweaking image acquisition techniques and increasing our understanding of the appropriate uses and limitations of POCUS. This includes expanding our knowledge of the many reasons for false positives and negatives, ensuring our ability to recognize technically limited studies, and maintaining a commitment to finding, applying, and developing the evidence-base to support the use of POCUS for internal medicine. Balancing the tension between experimenting with advanced applications and mastering basic POCUS is sometimes challenging. The steep learning curve of basic POCUS can fool many into thinking mastery has been achieved when there are additional pitfalls to learn.
While we do not wish to dampen learner enthusiasm for high-level applications, we believe there are ways to build learner enthusiasm around basic POCUS. First, we ensure that learners are challenged with cases where clinical integration is complex and nuanced. Emphasis on patient safety and outcomes can help emphasize the need to master basic applications. Second, as educators, we should model a commitment to lifelong learning. Regularly identifying then closing learning gaps can help avoid the illusion that POCUS mastery has been achieved, when in actuality, even basic POCUS applications need to be continually refined and thoughtfully integrated in each unique clinical scenario. This, in addition to encouraging higher-level learners to take a deep dive into high-level applications to appreciate the challenges of these advanced scans, can help maintain while also balancing the excitement of integrating POCUS into the care of complex medical patients.
REFERENCES
Buhumaid RE, et al. Integrating point-of-care ultrasound in the ED evaluation of patients presenting with chest pain and shortness of breath. Am J Emerg Med 2019; 37(2):298–303.
Filopei J, et al. Impact of pocket ultrasound use by internal medicine housestaff in the diagnosis of dyspnea. J Hosp Med 2014; 9(9):594–597.
Razi R, et al. Bedside hand-carried ultrasound by internal medicine residents versus traditional clinical assessment for the identification of systolic dysfunction in patients admitted with decompensated heart failure. J Am Soc Echocardiogr 2011; 24(12): 1319–1324.
Mozzini C, et al. Lung ultrasound in internal medicine efficiently drives the management of patients with heart failure and speeds up the discharge time. Intern Emerg Med 2018; 13(1):27–33.
Zanobetti M, et al. Point-of-care ultrasonography for evaluation of acute dyspnea in the ED. Chest 2017; 151(6): 1295–1301.
Soni NJ, et al. Point-of-Care ultrasound for hospitalists: A position statement of the Society of Hospital Medicine. J Hosp Med 2019; 14: E1–E6.
Qaseem A, et al. Appropriate use of point-of-care ultrasonography in patients with acute dyspnea in emergency department or inpatient settings: A clinical guideline from the American College of Physicians [published online ahead of print April 27, 2021]. Ann Intern Med. doi: 10.7326/M20-7844.
Cessford T, et al. Comparing physical examination with sonographic versions of the same examination techniques for splenomegaly. J Ultrasound Med 2018; 37(7): 1621–1629.
Janeve Desy, MD, MEHP, RDMS, and Michael H. Walsh, MD, work in the Department of Medicine at the University of Calgary; Irene W. Y. Ma, MD, PhD, RDMS, RDCS, works in the Department of Medicine and Department of Community Health Sciences at the University of Calgary.
Want to learn more about POCUS for General Internal Medicine? Check out the following resources from the American Institute of Ultrasound in Medicine (AIUM):
The utility of point-of-care ultrasound (POCUS) is readily apparent in a busy Emergency Department (ED) or Intensive Care Unit. Now, as healthcare in the U.S. changes and decentralizes, widespread POCUS in primary care is poised to show its value to medical systems in a way that will eclipse its impressive origins in hospitals. However, there are many reasons primary care ultrasound hasn’t taken off…yet. Among them is that effectively incorporating POCUS into a clinic can be hard work with many upfront challenges. The following is some advice on overcoming these challenges, focusing on 3 areas.
Determine your desired scope of practice and manage expectations
Get really good at POCUS
Optimize your clinic POCUS workflow
1. Determine your desired scope of practice and manage expectations
Learning to use ultrasound is very similar to learning a musical instrument—you don’t jump in with Chopin, you start off by playing Chopsticks or practicing chords. When determining their intended POCUS scope of practice, outpatient clinicians need to consider that the things they are most interested in doing right away might be some of the more technically demanding or challenging things to learn. Here are some good examples of common outpatient POCUS goals and more appropriate starting points for beginners:
Body Region
Aspirational POCUS Application
Appropriate POCUS Starting Point
Abdominal
Gallstones, Cirrhosis, Appendicitis
Ascites
Cardiac
LVH, Pulmonary Hypertension
Pericardial Effusion
Pulmonary
Pneumonia
Pleural Effusions and Pulmonary Edema
Musculoskeletal
Rotator Cuff Tears
Knee Effusion
Furthermore, even if you appropriately start small and easy, chances are you will at some point perceive that you are terrible. This is normal and experienced by many POCUS experts when they first started. Keep at it, and ensure you have a marathoner’s mindset; remember it’s no quick sprint and requires a stepwise approach. You can learn more about a specific approach to teaching and a framework for growing a POCUS skillset for generalists (PEARLS) by watching the AIUM webinar, “PEARLS: A Physical Exam with Pocket Sized Ultrasound for Routine Use,” here: https://youtu.be/ywuIeoEfG1I
2. Get really good at POCUS
Easy as that, right? Unfortunately, learning POCUS in the clinic is HARDER than learning POCUS in the hospital setting. The time constraints are just as bad as in the ED and, generally, the pathology is much less frequent and more subtle when present. Obtaining cardiac windows in the patient who can’t get out of their wheelchair or rollator let alone climb up to the exam table is not an uncommon circumstance. So how do you get really good under these circumstances? Three key interconnected principles dominate the philosophy we try to instill in our learners as part of our training:
Scan Routinely
Practice Deliberately
Track Your Experience (Build Your Portfolio)
Scan Routinely is probably the most controversial of these, and for me, also the most important. The routine performance of “educational” scans during residency, fellowship, or other training period is the bedrock for successful training and is generally accepted in the POCUS community. This allows one to practice deliberately and pursue a path towards mastery.
The number 1 biggest mistake I see in the early plateaued POCUS learner is they are only performing scans if they feel it is clinically indicated or they have a specific clinical question they expect POCUS to help them answer. If you are not routinely using POCUS you will likely not achieve or maintain the experience where your POCUS skillset will be clinically useful to you.
My threshold for incorporating ultrasound into my evaluation of patients is probably much lower than other POCUS users, and my experience has been that this has helped me tremendously. This experience has supported the perspective that POCUS should be viewed as a vital clinical skill to be perpetually maintained and improved upon, not a separate and distinct diagnostic test to be brought out only when patients fit into narrow predefined boxes.
Finally, even if you do not incorporate images into the EMR or bill for your exams (and there are many reasons why you should not do this early on), you should routinely save your images and build a portfolio. Committing your interpretations to a log, on paper or electronically, allows you to attain vital feedback through your longitudinal experience and patient follow-up. It also allows you to more easily seek expert mentorship, teach others, and can serve as inspiration if your motivation or progress seems to drop off.
3. Optimize your clinic POCUS workflow
Like many aspects of clinic, part of optimizing your POCUS workflow involves training your staff. In many ways, it helps to treat the POCUS device like the clinic EKG machine. If you know you will likely include POCUS because of the chief complaint (eg, dyspnea, flank pain, or lower extremity swelling) have staff put the patient in the most suitable room and ensure they are properly undressed/draped in advance. Train staff to be comfortable handling the device, cleaning it, and setting it up in the room with patient information entered in (if applicable). If you unexpectedly determine POCUS is needed during an encounter but setup is suboptimal, see another patient while the patient and room are prepared. Also, consider restructuring how you examine patients. Often time constraints do not permit the traditional order of history -> traditional examination -> ultrasound examination, and you will be more efficient by incorporating ultrasound sooner and blending history and pertinent traditional exam maneuvers along the way.
Finally, when first starting off, when incorporating routine scanning into your workflow, keep a narrow focus and a set time limit (<5 minutes). Don’t be shy about using an alarm on your phone to keep yourself honest. You may need to focus on obtaining a single high-quality view, and then add additional views as you’re able while still staying under time. Taking 20 minutes to perform POCUS in the middle of a packed clinic is another common mistake that can torpedo a workday and create negative associations that increase reluctance to practice and utilize POCUS.
Once you obtain some basic skills at POCUS and have a good clinic workflow, you’ll quickly get a few early saves and successes that enhance your dedication and propel you forward. Before long, you will wonder how you ever did without it!
Mike Wagner, MD, FACP, FAIUM, during a remote/virtual teaching session.
Mike Wagner, MD, FACP, FAIUM, is an Associate Professor of Medicine at the University of South Carolina School of Medicine in Greenville.
For nearly two decades, ultrasound has had to struggle to gain equal footing in the eyes of imagers who have had much longer experience in cross-sectional imaging. With some exceptions, ultrasound was seen as a second-tier modality due to concerns about its sensitivity and specificity for many diagnoses. As the technology has improved, the quality of ultrasound imaging has risen to a level on par with CT and MRI for many more of the diagnoses throughout the body. As a result, even imagers with a strong bias toward CT/MRI are now forced to consider ultrasound more frequently in their current practice.
Factors that favor the consideration of ultrasound for initial imaging include its lack of ionizing radiation, portability, widespread access, and relative low costs. Considering these advantages, it is no wonder that healthcare policy thought leaders would be looking to ultrasound as a first-line imaging option when possible.
One of these interested groups is the government. The Center for Medicare & Medicaid Services (CMS) continues to focus on value-based aspects of medical imaging to provide high-quality clinical diagnoses and improved patient outcomes. As a result, the 2014 Protecting Access to Medicare Act (PAMA) legislation includes language that encourages physicians to consider studies that may be less costly or more beneficial to patients when they are choosing imaging for their Medicare patients, and it was PAMA that first defined ultrasound as a Non-Advanced Diagnostic Imaging Study (NADIS), along with radiography and fluoroscopy.
For those of you like me who bristle every time there is an obvious or glaring slight against ultrasound in favor of CT/MR, it was at first hard not to react with disbelief. However, in this rare case, it serves to benefit the sonography community. Because of ultrasound’s NADIS designation, there are reduced hurdles to ordering ultrasound versus “advanced imaging”, depending on the local clinical decision support mechanism (CDSM).
How does this affect ultrasound in a direct concrete way? The implications are significant. As one example, the American College of Radiology (ACR) Appropriateness Criteria (AC) Committee has evaluated the literature and generated appropriateness categorization for over 1900 clinical scenarios for CDSM distribution in over 700 medical institutions for decision support.
In these recommendations, the AC guidelines instruct that when ultrasound (US) can provide sufficient clinical information to manage the patient or achieve a similar patient outcome compared to an ADIS, the US procedure should be rated more appropriate than the ADIS procedure.
As ultrasound is actively recommended to ordering physicians when it is the most appropriate study, internal bias toward CT/MRI should decrease over time. I do not suggest and would not want ultrasound to be recommended when it is not the best choice; only that it should be recommended when it is. These changes are likely to help move us toward this ideal. I foresee a continued strong presence of ultrasound within the imaging toolbox for physicians for years to come.
DCF 1.0
Mark Lockhart, MD, MPH, is Professor of Radiology at UAB Department of Radiology in Birmingham, Alabama.
Carpal tunnel syndrome (CTS) is a phenomenon that occurs due to impingement of the median nerve at the wrist. It usually presents as numbness, tingling, and/or pain in the hand involving the thumb, index, and middle fingers. It commonly starts as nighttime numbness and tingling that awakens the patient and it can progress to being painful throughout the day. As it worsens in severity, it can produce weakness of the hand and loss of dexterity as well as radicular pain up the arm proximally toward the shoulder. There are several risk factors including repetitive use of the hands, such as with manual labor jobs, as well as obesity and rheumatologic conditions.
CTS is the most common compression neuropathy affecting 1.8–3.6% of the general population and up to 7% of manual laborers in the United States. Over 500,000 carpal tunnel releases (CTRs) are performed annually in the United States for definitive treatment of severe or refractory CTS. Multiple CTR techniques exist with one common goal—cut (ie, release) the transverse carpal ligament (TCL). Releasing the TCL reduces pressure within the carpal tunnel and, thereby, resolves the compression of the median nerve allowing improvement in associated symptoms.
For many years, the gold standard technique was open CTR (OCTR). OCTR is safe and effective but involves a relatively large incision measuring ~2 inches at the base of the palm. The skin of the palm is thick and takes weeks to months to heal, so patients are often out of work and activity for up to 6–8 weeks post-OCTR. Therefore, the mini-open (m-OCTR) technique has become very popular because the incision size is reduced to ~1 inch. This reduces the size of the scar and healing times slightly, but patients are still restricted in activity for at least 4–6 weeks. Endoscopic CTR (ECTR) is an alternative option that involves two smaller ~0.5-inch incisions but has been associated with a higher risk of transient postoperative nerve symptoms and intraoperative neurovascular injury.
Advances in ultrasound (US) technology and training over the past 20 years have catapulted US-guided procedures into realms most never believed possible. Many current US machines provide extremely high-resolution imaging, allowing providers to confidently perform advanced US-guided procedures in a safe and effective manner. Amongst the procedures being successfully implemented into clinical practices across the country is CTR with US guidance.
CTR with US guidance involves making a very small, ~4 mm, incision in the distal forearm as opposed to incising the skin of the palm. The distal forearm skin is relatively thin and heals rapidly, enabling patients to return to full activity within 1 week. Prior to performing CTR with US guidance, the patient is scanned to ensure adequate visualization of major anatomic structures including the:
Median nerve
Palmar cutaneous branch
Thenar motor branch
3rd common palmar digital nerve
Osseous boundaries of the carpal tunnel (scaphoid, pisiform, trapezium, hook of hamate)
Ulnar vessels within Guyon’s canal
Transverse safe zone (TSZ) between the ulnar aspect of the median nerve and the radial aspect of the ulnar vessels or hook of the hamate, whichever lies more radial
If there are no contraindications to undergoing CTR with US guidance, then the procedure may be performed in either an outpatient clinic or an ambulatory surgical center.
CTR with US guidance is usually performed under local anesthetic. The patient is positioned supine with the arm abducted 90 degrees and the wrist slightly extended. Using a #15 blade scalpel, a ~4-mm incision is made at the level of the proximal wrist crease, penetrating the antebrachial fascia. The surgical device is then advanced under direct US visualization into the carpal tunnel, passing it between the hamate and median nerve within the TSZ, similar to ECTR. The distal tip is advanced such that the blade, when activated, will engage the distal TCL. The position of the device relative to the TSZ and surrounding neurovascular structures is confirmed with US. Using the lever handle, balloons are inflated to increase the TSZ. Next, the cutting knife is deployed and advanced in a retrograde fashion using the thumb slide. The TCL is cut distal to proximal using continuous US visualization. Following TCL transection, the device is removed and a sterile dressing is applied.
Left, See the device in the long axis, distal to left. The “shark fin” is the knife recessed in the device and not yet deployed. The superficial palmar arch artery is seen just distal to the tip of the device. Right, See the device in the short axis, radial to left. See balloons activated with the deployed knife (hyperechoic dot above and centered between balloons) during active release of TCL. The median nerve is seen just radial to the device. The ulnar artery and nerve are seen superficial and ulnar.
Following the procedure, Tylenol and/or NSAIDs is sufficient for pain control. No splinting, occupational therapy, or opioids are required. Patients may begin immediate wrist and hand motion and resume normal activities as tolerated. The only restriction is no lifting, pushing, or pulling greater than 10 pounds with the surgical hand for 1 week. This means that those with desk jobs may return to work the next day; manual laborers may return in 1 week.
Incision at the level of proximal palmar crease immediately following the procedure.
In summary, various CTR techniques exist. Although all techniques have good outcomes at 3 months and beyond, the immediate post-op recovery timeline favors the US-guidance technique. The early success of CTR with US guidance being implemented in clinics across the country is exciting for the field of interventional musculoskeletal ultrasound. The sky is the limit!
Brett J. Kindle, MD, CAQSM, RMSK, is a sports medicine specialist at Andrews Institute for Orthopaedics and Sports Medicine, as well as the Medical Director of EXOS-Florida, the Associate Program Director for Andrews Institute Primary CareSports Medicine Fellowship, and a Team Physician for Pensacola Blue Wahoos.
In his book, The Innovator’s Dilemma, Clayton Christensen discusses the idea of disruptive technology. This market force that challenges industry norms can create new opportunities but also requires traditional market fixtures to adapt in order to maintain effectiveness.
Point-of-care Ultrasound (POCUS) has emerged as a disruptive technology in medical imaging. It relies heavily on education, both for new learners and also for those continuing to advance their knowledge base as skilled sonologists. As ultrasound technology improves and the scope of POCUS expands, two important facets of ultrasound education are collaboration and innovation.
Ultrasound has traditionally been confined to specific rooms within the house of medicine. However, POCUS has grown to include a variety of specialties. Emergency medicine, critical care, hospital medicine, outpatient clinics, and even surgical specialties have all benefitted from “Ultrasound First” and the diagnostic specificity of ultrasound. But just as every disruptive technology creates challenges for traditional users, the democratization of ultrasound has required new users and traditional imaging specialties to rethink the imaging paradigm.
Since each specialty (traditional or new adopter) comes to the table with a unique skillset and expertise, we benefit from collaboration. In the same way that a rising tide lifts all boats, cross-departmental collaboration allows for a broader understanding of the interplay between a patient’s anatomy, physiology, and ultrasound findings.
In our institution, we have sought to use ultrasound as a tool to build bridges between departments. We have brought sonologists from various specialties together to teach anatomy with ultrasound. We have brought our ED residents to the MICU to scan patients with known pathology and MICU fellows to the ED. We have conducted cross-departmental ED/Radiology case conferences discussing the use of bedside ultrasound and traditional imaging. In each of these examples, we have sought ways to build collaborative relationships with other departments and benefit from each other’s particular perspective and experience.
Ultrasound proficiency requires a firm foundation of both didactic knowledge and psychomotor skill. There is a significant interdependency between the classroom and the bedside. By restricting access to both spheres, COVID-19 has interrupted our normal way of living and educating and created a number of challenges to continuing ultrasound education. But, like a silver lining behind every dark cloud, the distance that COVID has created physically has drawn us together in unique ways. Distancing, occupancy limits, and virtual interactions have required us to reimagine ways of reaching learners.
A large part of our continuing ultrasound education is a regular ultrasound lecture series. Virtual education has allowed for more flexibility with attendance. Individuals who traditionally could not attend an in-person lecture due to time or geographical constraints can now participate. We previously included learners from various departments within our institution. However, with virtual lectures, we have included students, residents, fellows, and faculty from other institutions throughout our greater region.
In addition to increasing the participant base, virtual education has allowed us to tap into a broader faculty base. The traditional model of medical education relies on in-person lectures and didactic education. Virtual education opens opportunities to include regional, national, and international experts. Prior to COVID, a visiting lecturer would have to take time away from their personal practice and travel to a particular place. Now, a speaker can attend via Zoom or other platforms. This has allowed us to invite outside experts to our educational forum. And for faculty looking to build an educational portfolio and progress through the academic ranks, virtual education allows for junior faculty to gain experience as visiting lecturers.
As we emerge from the COVID era, I personally look forward to losing the masks, gathering together again, and seeing the word “virtual” used less ubiquitously in the English lexicon. But our imperative as ultrasound educators is to learn from the ways that COVID has changed our existing models for education and has caused us to adapt to new teaching methods. We should embrace the disruptive technologies of the past year and find ways to blend the advantages of cross-departmental, in-person learning with cross-institutional virtual education. To the extent that we are successful in this endeavor, we will find increased cohesion as a community, improved educational opportunities for our learners, and, ultimately, improved outcomes for our patients.
Matthew Tabbut, MD, FACEP, is Director of Emergency Ultrasound at MetroHealth Medical Center in Cleveland, Ohio.
Interested in learning more about POCUS? Check out the following posts from the Scan:
There are those who pretend that we do not need ultrasound anymore to detect fetal anomalies, “Just use maternal blood and with various forms of genetic testing and you will be able to detect the majority of fetal anomalies.”
Well, let me rebuke this insinuation.
Acrania in a fetus at 11 weeks.
Genetics
There is no doubt that prenatal genetic testing has come a long way from using only maternal age to assume a risk of Down syndrome (for instance 1 in 1250 at age 25 and 1 in 385 at age 35). Maternal serum screening came next. At first, levels of alpha-feto-protein (AFP) were found to be lower in mothers carrying fetuses affected with Down syndrome.
Then, other markers, such as human chorionic gonadotropin (hCG), unconjugated estriol, and dimeric inhibin A, were determined to display characteristic patterns in pregnancies with Down syndrome, with the introduction of the double, triple, and quadruple screening in the second trimester. This moved to the first trimester, with incorporation of fetal nuchal translucency (NT), pregnancy-associated plasma protein A (PAPP-A), and the beta subunit of human chorionic gonadotropin (β-hCG). A high detection rate of 85–90% was attained for Down syndrome and 90–95% for trisomy 18, with a 5% false-positive.
A combination of both the first and second trimester was introduced, to further improve the detection rate and, at the same time, decrease the false-positive rate. In some of these tests only serum fetal-placental protein markers were considered (integrated) and in others ultrasound findings (NT) and various serum markers were combined (integrated, sequential, and contingent).
It is widely accepted that testing of the type used nowadays originated from a Lancet paper in 1997 by Lo and colleagues, describing circulating cell-free fetal DNA (ccffDNA) in the plasma of pregnant women. It took almost 15 years for the technology to become clinically available1. At first, it was used to determine the risk of trisomies and sex chromosome anomalies. Originally designed as noninvasive prenatal diagnosis (NIPD) or noninvasive prenatal testing (NIPT), the general opinion is that these are still screening (and not diagnostic) tests, hence the designation noninvasive prenatal screening (NIPS). I prefer noninvasive DNA screening (NIDS) because, after all, ultrasound is NIPT!
Nowadays, NIDS can be used to identify Rhesus group and some single-gene fetal conditions, autosomal dominant, recessive or sex-linked (eg, cystic fibrosis, achondroplasia, thanatophoric dysplasia, sickle cell disorder, congenital adrenal hyperplasia, spinal muscular atrophy, and hemophilia). Most conditions require using a maternal blood sample only but many require a paternal blood sample. Normal karyotype doesn’t mean everything is fine, hence chromosomal microarray, introduced in the prenatal diagnosis clinical setting in 2005. Looking for submicroscopic aberrations <5Mb can provide additional diagnostics in about 10% of fetuses with multiple anomalies1. The latest reiteration of the technology is genome-wide monogenic NIDS2.
Screening beyond the common trisomies is currently not recommended by the American College of Obstetricians and Gynecologists3. So where does ultrasound stand?
Ultrasound is alive and doing fine, thank you
In the general population, chromosomal abnormalities are less frequent than structural abnormalities. A large number of fetal structural abnormalities, especially many lethal ones, can be diagnosed in the first trimester of pregnancy, therefore, ultrasound remains an essential part of the story. Ultrasound diagnosis of fetal anomalies has now moved from the mid-second trimester (18–22 weeks) to the late first–early second-trimester (approximately 11–14 weeks). It should be noted that a repeat scan at the “classical” time (18–22 weeks) is still recommended by most.
Image courtesy of Sergiu Puiu, MD
Two major reasons for the early scan: it’s a perfect time to perform a nuchal translucency (NT) measurement and, at that stage, most structural anomalies that are already present are detectable. A few examples of what is observable include all 4 limbs and all digits, cranial anatomy, estimation of the cardiac axis, and omphalocele (which is associated with Beckwith-Wiedemann and CHARGE syndromes, limb-body stalk anomaly, and Pentalogy of Cantrell, to name a few). Amputations or other unusual cleft due to amniotic band syndrome are visible and cardiac position and orientation can also be determined. In incidences of heart defects, dextrocardia is associated with 90% and situs inversus with levocardia with over 95%.
Most of the above anomalies will be associated with an increased NT, as will pulmonary, gastrointestinal and genitourinary conditions, diaphragmatic hernia, skeletal dysplasia, fetal anemia, and abnormal lymphatic drainage4. A third of congenital abnormalities occurring in fetuses with increased NT may remain undetected in the first trimester of pregnancy, unless cfDNA is used in combination with fetal sonographic NT assessment. When karyotype is normal, 10% of fetuses with an increased NT (>95th percentile) have structural abnormalities5.
In one study5, 65% of structural abnormalities would have potentially been missed in the first trimester if cfDNA had been used as a first-trimester screening test without an early ultrasound scan. Furthermore, if cfDNA only was used, besides structural defects, one third of other anomalies would have been missed: sex chromosome abnormalities, triploidy, single gene disorders, and submicroscopic aberrations <5Mb. In addition to NT measurements and detection of structural anomalies, several other sonographic markers have been described: nasal bone, ductus venosus Doppler anomalies and tricuspid regurgitation, helping to determine a high-risk group for whom genetic screening will have a high yield.
When these or/and other ultrasound-diagnosed fetal anomalies are present, whole-exome-sequencing can add relevant information in cases when an etiology could not be elucidated by fetal karyotype testing or chromosomal microarray6.
In a very recent article, Bedei et al. propose several conclusions, one of them being: “NIPT should always be combined with a skilled ultrasound examination.”7
My thoughts, exactly8.
I purposely do not wish to initiate a discussion on the ethical, moral, philosophical, religious, or emotional values or demerits of prenatal diagnosis. While some will say that all this is a veiled “search and destroy” exercise, others will explain that knowledge is power. Power to choose but also power to be ready when the baby is born or power to correct certain anomalies in the womb or intervene immediately at birth. Both sides of this argument may be defensible, but that is for another blog.
References
1. Talkowski ME, Rehm HL. Introduction of genomics into prenatal diagnostics. Lancet 2019 Feb 23; 393(10173):719–721.
2. Rabinowitz T, Shomron N. Genome-wide noninvasive prenatal diagnosis of monogenic disorders: Current and future trends. Comput Struct Biotechnol J 2020; 18:2463–2470.
3. American College of Obstetricians and Gynecologists screening for fetal chromosomal abnormalities: ACOG practice bulletin summary, number 226. Obstet Gynecol 2020; 136:859–867.
4. Baer RJ, Norton ME, Shaw GM, et al. Risk of selected structural abnormalities in infants after increased nuchal translucency measurement. Am J Obstet Gynecol 2014; 211:675.e1–19.
5. Bardi F, Bosschieter P, Verheij J, et al. Is there still a role for nuchal translucency measurement in the changing paradigm of first trimester screening? Prenat Diagn 2020; 40:197–205.
6. Petrovski S, Aggarwal V, Giordano JL, et al. Whole-exome sequencing in the evaluation of fetal structural anomalies: a prospective cohort study. Lancet 2019;393(10173):758-767
7. Bedei I, Wolter A, Weber A, Signore F, Axt-Fliedner R. Chances and challenges of new genetic screening technologies (NIPT) in prenatal medicine from a clinical perspective: A narrative review. Genes (Basel) 2021; 12:501. 8. Rauch KM, Hicks MA, Adekola H, Abramowicz JS. Aneuploidy screening: the changing role of ultrasound. In: Abramowicz JS (ed). Ultrasound in the First Trimester, a Comprehensive Guide. Switzerland: Springer International Publishing AG; 2016:131–152.
Jacques S. Abramowicz, MD, FACOG, FAIUM, is a professor of OB-GYN and Director of Ultrasound Quality Assurance in the Department of Obstetrics and Gynecology at the University of Chicago.
As the rate of obesity continues to increase worldwide (last reported by the CDC as 42.4% as of 2017–2018), it has become even more evident that there is a great need to improve fetal cardiac visualization in obese pregnant women. Less than 50% of morbidly obese women have successful fetal 4-chamber and outflow tract visualization, compared to almost 90% of nonobese women.
Obese women are also significantly more likely than normal-weight women to have children with a congenital heart disease, with an even higher risk in morbidly obese women, who give birth to children who have higher odds of having atrial septal defects, hypoplastic left heart syndrome, aortic stenosis, pulmonic stenosis, and tetralogy of Fallot.
And when obese pregnant women have reduced rates of complete anatomic surveys, lower detection rates, and increased risk of fetal anomalies due to less than perfect anatomy visualization, how do we improve the fetal cardiac visualization?
A team of researchers from Eastern Virginia Medical School looked into whether ultrasound (US) imaging in early gestation could help.
Amara Majeed, MD; Alfred Abuhamad, MD; Letty Romary, MD; and Elena Sinkovskaya, MD, PhD, performed a study in which all study participants (obese pregnant women) with a gestational age of 13 weeks to 15 weeks 6 days, underwent an US exam using a transvaginal or transabdominal approach and color Doppler US for fetal cardiac screening, which they defined as complete when all components of the 4-chamber, right ventricular outflow tract, left ventricular outflow tract, and 3-vessel views were clearly visualized. The participants also underwent a traditional transabdominal examination at 20 to 22 weeks, and if that exam was incomplete, underwent another 2 to 4 weeks later.
What they found was that the addition of early-gestation US to the 20- to 22-week US exam of obese pregnant women substantially improved the visualization of fetal cardiac anatomy. And for the women with a BMI of greater than 40 kg/m2, the cardiac screening completion rate was even higher (significantly so) for the early-gestation exam plus a traditional exam (90%) than for the traditional exam plus the second traditional exam (72.7%).
Adding an ultrasound exam at a gestation age of 13 weeks to 15 weeks 6 days substantially improved the visualization of fetal cardiac anatomy, particularly for the women with a BMI of greater than 40 kg/m2. Having complete or more complete anatomy screening can enable an earlier, accurate diagnosis.
Can you please raise your arm? A few enlarged and unilateral axillary lymph nodes come into view. The cortex is eccentrically or diffusely thickened, they are enlarged, and they are hypervascular. Spotting an abnormal lymph node is not often the challenge, but knowing what to do with the lymph nodes can certainly be. First, I have a confession to make. I am a breast radiologist by training, and I am also fortunate to work in the body division in our department. This opportunity puts me in a unique position to explore both of the worlds and allows for collaboration and the exchange of knowledge.
Any radiologist who performs or interprets ultrasound exams knows that the patient history is of paramount importance along with available previous imaging exams. For example, a recently diagnosed breast cancer, unilateral cellulitis, and lymphoma all influence the management of axillary adenopathy. Similarly, cervical adenopathy can be seen as a reactive finding with head and neck infection, as well as in the setting of known malignancy like head/neck and thyroid cancers, which are prone to metastasize to neck lymph nodes. Vaccination history is also important when considering unexplained adenopathy, and it becomes particularly important with the introduction of the COVID-19 vaccines, which is a mass vaccination undertaking.
The COVID-19 vaccination is administered in the deltoid muscle. As a result, the reactive locoregional adenopathy in the axilla and cervical region has been observed (1). Axillary and/or cervical adenopathy as unsolicited adverse events for the Pfizer-BioNTech vaccine were reported in up to 0.3% among vaccine recipients (as opposed to 0.1% in the placebo group) (2). This adenopathy had onset about 2 to 4 days after vaccination and lasted an average of about 10 days. In the Moderna trial, 1.1% of the vaccination group versus 0.6% of the placebo group reported axillary and/or cervical adenopathy within 2 to 4 days after vaccination (3). However, the median duration of adenopathy with the Moderna vaccine was reported to be 1 to 2 days. It is important to note that these trials did not pursue the incidence of adenopathy via imaging such as ultrasound or regular physical examinations by a practicing physician after vaccination. Therefore, true incidence of axillary or cervical adenopathy remains unknown and is likely much higher than reported.
A total of 0.02% to 0.04% of otherwise normal screening mammograms present with unilateral adenopathy (4-6). During the early months of 2021, it was surprising to encounter a higher frequency of screening mammograms demonstrating unilateral adenopathy, which subsequently required a screening callback for further evaluation. As word spread in the breast imaging community, the Patient Care and Delivery Committee of the Society of Breast Imaging (SBI) issued a set of management guidelines in January 2021 for axillary adenopathy following the COVID-19 vaccination (7).
The dilemma of unilateral adenopathy extended beyond just screening mammograms. Any exams covering the anatomical regions of the axilla and lower neck started to show enlarged lymph nodes. Some examples of these exams include soft tissue ultrasound in the setting of a palpable mass, screening ultrasound exams for indications such as thyroid cancers, and cross-sectional examinations including MRI shoulder exams, CT Chest, and PET-CT.
Locoregional adenopathy has been encountered in the setting of other vaccines like influenza and shingles. However, unlike other vaccines with documented adenopathy among adults, the COVID-19 vaccine is a mass-scale vaccination program and the incidence of adenopathy is expected to be very high in numbers. Furthermore, the vaccination history is not routinely available in the medical chart, at least in early 2021, presumably due to a lack of automated connection between state health departments and unique health center-based electronic medical records. Therefore, effort should be made to document vaccination history either at the time of scheduling or at the time of imaging. At our Institution, the COVID-19 vaccine history including the timing of dose(s) is now routinely reviewed and documented for all breast exams including mammography (both screening and diagnostic), ultrasound, and MRI exams as well as ultrasound exams evaluating the axillary and/or neck regions.
Cancer screening is an important and challenging responsibility. Early detection is important in order to improve mortality and reduce morbidity. The COVID-19 vaccination campaign continues, and the race to protect as many people as possible is more important than ever. As radiologists, it is imperative to follow the data and carefully evolve in order to appropriately diagnose vaccine-related reactive adenopathy while avoiding the unintentional consequence of missing a cancer diagnosis.
A 64-year-old female patient with a history of adenoid cystic carcinoma of the right tongue with prior multiple recurrences and treatments, now presents with a mass along the left thyroidectomy bed. During the initial CT imaging, left thyroidectomy bed mass was confirmed and enlarged left axillary lymph nodes (a) were also noted (largest measuring 10 mm in short axis). This was followed by the PET-CT exam to identify additional sites of metastatic disease. PET-CT was performed about 2 weeks after the initial CT, and the CT component of PET-CT (b) shows decreased size of left axillary node, now measuring 7 mm in short axis. Axial fused PET-CT image (c) shows FDG-avidity of this lymph node, with SUV measurement of 5.56. Ultrasound image (d) shows a round node with no discernible fatty hilum. It was noted that the patient recently received a COVID-19 vaccine prior to the first CT exam. Since biopsy of the thyroidectomy bed mass showed metastasis, biopsy of left axillary node was also pursued, which revealed no evidence of metastatic disease. The left axillary node enlargement was thought to be secondary to recent COVID-19 vaccination.
So, where do we go from here now that we know adenopathy has been reported with both the Moderna and Pfizer vaccines? Initial consensus statement from a multidisciplinary panel specifically highlights the benefit of prioritizing COVID vaccination among patients with known cancer history, as the protection offered by the vaccine outweighs the unintended side effect of adenopathy (1).
Here, we would like to discuss possible solutions highlighted by the Society of Breast Imaging (SBI) and multi-institutional cancer imaging specialists, along with solutions based on our anecdotal institutional experience, that might be of benefit when faced with the dilemma of adenopathy in your clinical practice following COVID-vaccination.
Collaborate with your colleagues in other divisions and departments. Coordinate and establish a consistent algorithm to assist with the management of unexpected adenopathy in the context of recent COVID-19 vaccination.
Document COVID-19 vaccination history. This could consist of three phases: 1) The collected information could possibly include date of vaccine doses, laterality of the arm receiving the vaccine, and the brand of the vaccine) prior to a screening exam, particularly when it involves a head/neck or axillary evaluation. 2) Once set up, this strategy of vaccination documentation could then be expanded to all modalities including cross-sectional imaging exams, either at the time of scheduling or at the time of patient’s intake on the day of the exam. 3) The final phase would consist of documentation across your entire hospital system at the time of scheduling of various appointments or using online secured tools to encourage patients to document the same on a voluntary basis. Inter-connection between different systems already existing on many Electronic Medical Record (EMR) systems would be a powerful tool in this regard. Organized COVID vaccination history in a standard location within the EMR could improve accessibility for all healthcare providers.
Consider the timing of a routine screening exam. If the screening exam is non-urgent, consider scheduling the exam at a minimum of 4–6 weeks following the second dose of the COVID vaccine (SBI). However, a longer interval of 6 weeks has also been advised in this setting given preliminary evidence of adenopathy persisting at 4 weeks (1). The patient’s existing risk factors and anxiety should also be considered while pursuing delaying the exam.
Keep your patients informed. Discuss the known reports of adenopathy following vaccination. Review short-term follow-up as a reasonable initial option in this situation and when biopsy may be indicated.
Know when tissue diagnosis may be indicated. According to SBI, in the absence of any other suspicious mammographic finding or contributing history beyond the vaccine, short-term follow-up in 4–12 weeks following the second vaccine dose can be considered. If axillary adenopathy persists after that period of time, tissue diagnosis is warranted to exclude breast and non-breast malignancy. However, for patients with a newly diagnosed breast cancer, it may be more appropriate to rule out metastasis with a biopsy instead of short-interval imaging follow-up.
Identify clearly abnormal lymph nodes. Reactive lymph nodes typically present as diffuse enlargement while maintaining their reniform shape. Fatty hilum is present, although could be thinned out. Ultrasound exams might show tiny hypoechoic (not anechoic) areas, indicative of prominent germinal centers. On PET-CT exams, the standardized uptake values (SUVs) of >7.0 have been reported within the lymph nodes as opposed to the typical scenario of reactive lymph nodes in the neck showing SUVs between 2 and 3. However, heterogeneous distribution of SUVs within lymph nodes, clearly necrotic or cystic areas within lymph nodes across all modalities, calcifications on CT and echogenic foci on ultrasound would indicate clearly abnormal lymph nodes, and tissue sampling in these cases will be indicated irrespective of COVID vaccine administration.
It is important to keep in mind that new knowledge and data continue to contribute to evolving guidelines and that current recommendations may change as we learn more.
Dr. Noelle Hoven is an Assistant Professor in the breast imaging division and Dr. Anil Chauhan is an Associate Professor in the thoracoabdominal division in the diagnostic radiology department at the University of Minnesota.
References:
Becker AS, Perez-Johnston R, Chikarmane SA, et. al. Multidisciplinary Recommendations Regarding Post-Vaccine Adenopathy and Radiologic Imaging: Radiology Scientific Expert Panel. [published online ahead of print February 24, 2021] Radiology. doi: 10.1148/radiol.2021210436.
Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med. 2020; 383(27):2603–2615.
Baden LR, El Sahly HM, Essink B, et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med. 2021; 384(5):403–416.
Patel T, Given-Wilson RM, Thomas V. The clinical importance of axillary lymphadenopathy detected on screening mammography: revisited. Clin Radiol. 2005; 60:64–71.
Lim ET, O’Doherty A, Hill AD, Quinn CM. Pathological axillary lymph nodes detected at mammographic screening. Clin Radiol. 2004; 59:86–91.
Chetlen A, Nicholson B, Patrie JT, Harvey JA. Is screening detected bilateral axillary adenopathy on mammography clinically significant? Breast J. 2012; 18:582–587.
Transjugular intrahepatic portosystemic shunt (TIPS) placement is a well-studied procedure for patients with variceal bleeding, refractory ascites, and hepatic hydrothorax on optimal medical therapy. Despite its efficacy, TIPS remains one of the more technically challenging procedures, particularly related to safely gaining access into the portal venous system.
A typical TIPS procedure involves internal jugular venous access, hepatic vein catheterization, venography, and wedged CO2 portography, and the most challenging step—retrograde portal vein access prior to tract dilatation and stent placement. When using CO2 portography as a landmark for portal venous access, usually several needle passes are required and each additional needle pass increases the risk of adverse events, such as hepatic artery injury, hemobilia, and damage to surrounding structures (kidney, colon, and lung parenchyma).
There have been multiple ways to mitigate this issue, such as biplanar angiography, percutaneous transhepatic guidewire placement within the portal venous system, and cone-beam CT guidance. These methods have had various successes but may require increased procedure time, increased radiation dose, or alternative access sites (for example when placing a microwire into the portal venous system via the transhepatic route).
In our opinion, the best solution for accessing the portal venous system during the TIPS procedure is using intravascular ultrasound guidance with a side-firing intracardiac echocardiographic tip (ICE). The benefit of having ICE guidance is intuitive: it allows for direct visualization of the portal venous target, proper selection of the closest hepatic vein to the respective portal vein, and needle guidance using real-time ultrasound visualization. Therefore, ICE guidance reduces the number of needle passes, the risk of hitting critical structures, and the length of the procedure. Previously, ICE guidance has proven its worth in managing complicated TIPS cases, such as portal vein thrombosis, distorted anatomy from prior surgery or neoplastic disease, as well as TIPS for Budd-Chiari syndrome (direct IVC to portal venous access in these cases).
There have been a few retrospective investigations comparing fluoroscopic guidance to ICE guidance for the TIPS procedure. In a study by Kao et al., the authors did a retrospective comparison between ICE and fluoroscopic guidance. It is interesting to note that the ICE operators were only 2 and 3 years out of fellowship versus 20+ years of experience in the conventional group. The data showed that ICE catheter guidance significantly decreased the number of needle passes, contrast volume, fluoroscopy time, procedure time, and radiation exposure. More importantly, ICE largely reduced the number of “outliers” —those occasional cases in which 30+ needle passes and a few hours of fluoroscopy times are required. It is likely in clinical practice that exactly these outlier cases drive up complication rates.
In a different study, by Ramaswamy et al., the authors did a propensity-matched retrospective review. The data showed the procedure time and outcomes were not significantly different between ICE and conventional techniques. However, there was a significant reduction in contrast volume and radiation in the ICE guidance group. The major caveat of the study was that the ICE operators were much earlier in their career than the conventional group, with an average experience of 4.2 years versus 11 years. The difference in operator experience probably indicates that ICE has the potential to decrease the procedure time when adjusted for operator experience.
Based on the available retrospective studies and our experience, a few points can be confirmed.
ICE decreases the number of needle passes, radiation exposure (to both the patient and operator), and contrast volume.
ICE most likely decreases the procedure time, accounting for differences in operator experience.
ICE will largely eliminate outlier cases that are more likely associated with complex anatomy/clinical scenario and have a higher potential to cause major complications.
In our experience, ICE catheter guidance makes the procedure safer in tough situations. Of course, ICE adds costs (~ $1,000/probe). The modality has a pretty steep learning curve, and it requires an additional venipuncture. In addition, the (more inexperienced) conventional operator can achieve excellent results in routine and/or complex scenarios without using ICE.
In our view, ICE guidance is most helpful in dealing with complex TIPS cases in which a large number of needle passes are expected and complications are frequent. Furthermore, it offers a back-up option when a conventional TIPS procedure runs into unexpected challenges. Instead of blindly sticking another 20 times, we should become familiar with using the available tool (ICE catheter guidance) in our procedural arsenal to provide a safer experience for our patients, ultimately improving outcome in the end-stage liver disease population.
This is a patient referred for re-attempt TIPS from an outside hospital, where multiple attempts of accessing the portal venous system have failed and, therefore, TIPS procedure in the outside hospital had to be aborted. Image A shows the access needle (skinny arrow) directed from the hepatic vein towards a right portal branch (fat arrow). Image B shows the access needle and Bentson guidewire (skinny arrow) within the same right portal branch (fat arrow), indicating successful cannulation. Image C confirms the guidewire (white circle) advanced into the main portal vein. Image D shows the TIPS stent connecting the right portal vein (arrow) with the hepatic vein with free flow of contrast. Portal access was successful on the second puncture with ICE guidance for this (challenging) re-attempt TIPS procedure.
All comments are welcomed; Sasan Partovi can be reached at partovs@ccf.org.
References:
Ramaswamy RS, Charalel R, Guevara CJ et al. Propensity-matched comparison of transjugular intrahepatic portosystemic shunt placement techniques: Intracardiac echocardiography (ICE) versus fluoroscopic guidance. Clin Imaging. 2019; 57:40–44.
Kao SD, Morshedi MM, Narsinh KH, Kinney TB et al. Intravascular Ultrasound in the Creation of Transhepatic Portosystemic Shunts Reduces Needle Passes, Radiation Dose, and Procedure Time: A Retrospective Study of a Single-Institution Experience. JVIR. 2016; 27:1148–1153.
Sasan Partovi, MD, is a staff physician in interventional radiology at The Cleveland Clinic Main in Cleveland, Ohio. Dr. Partovi’s research interests are focused on innovative endovascular treatment options for end-stage renal disease and end-stage liver disease patients. Dr. Partovi has been elected as secretary of the American Institute for Ultrasound in Medicine’s (AIUM’s) Interventional-Intraoperative Community of Practice.
Xin Li, MD, is a radiology resident at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania. Dr. Li attended Case Western Reserve University School of Medicine in Cleveland, Ohio, and is pursuing a career in interventional radiology. He currently serves on the Resident, Fellow, and Student Governing Council of the Society of Interventional Radiology.
Interested in learning more about POCUS? Check out the following posts from the Scan:
