Category Archives: General/Abdominal

Ultrasound’s Hidden Superpowers and Why We Celebrate Them Every October

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Every October, the medical imaging community comes together to observe Medical Ultrasound Awareness Month (MUAM), a period dedicated to raising public understanding of the ultrasound’s vital role in healthcare. Sponsored by organizations such as the American Institute of Ultrasound in Medicine (AIUM), the American Registry of Diagnostic Medical Sonographers (ARDMS), the American Society of Echocardiography (ASE), Cardiovascular Credentialing International (CCI), the Society of Diagnostic Medical Sonography (SDMS), and the Society for Vascular Ultrasound (SVU), MUAM seeks to dispel the common misconception that ultrasound is mainly for pregnancy and to shine a light on its many other life-changing uses.

While many people immediately think of fetal imaging when they hear “ultrasound,” that’s only one of many applications. In fact, ultrasound helps patients at every stage of life, from newborns to seniors, across numerous medical fields. MUAM is a perfect time to celebrate the often-unseen breadth of ultrasound and the professionals who use it.

Why a Special Month for Ultrasound?

Ultrasound is safe, widely available, and cost-effective. Because it doesn’t rely on ionizing radiation (as with X-rays or CT scans), it offers a gentler imaging option, particularly for soft tissues.

The purpose of MUAM is to encourage professionals to educate patients, colleagues, and the public about how ultrasound supports diagnosis, monitoring, and treatment across a diversity of conditions.

Beyond Babies: Diverse Applications of Medical Ultrasound

Here’s a look at just a few of the many ways ultrasound is used outside obstetrics:

1. Cardiac / Echocardiography

  • Ultrasound is widely used to visualize the heart’s structure and function, assess valve integrity, detect fluid around the heart (pericardial effusion), and monitor things like left ventricular ejection fraction.
  • Doppler ultrasound can also show blood flow velocities, helping to detect stenosis or regurgitation in valves.

2. Vascular and Circulatory Imaging

  • Doppler vascular ultrasound can assess veins and arteries, detecting blockages, clots (eg, deep vein thrombosis), or stenosis.
  • It’s used to examine carotid arteries (for stroke risk), peripheral arteries (leg circulation), and vascular grafts.

3. Abdominal and Pelvic Imaging

  • Ultrasound is often used to evaluate organs like the liver, gallbladder, spleen, kidneys, pancreas, and bladder.
  • It can detect gallstones, kidney stones, hydronephrosis, liver masses, or fluid collections (eg, ascites).
  • In the pelvis outside pregnancy, it helps assess uterine/ovarian pathology, fibroids, pelvic fluid, or masses.

4. Musculoskeletal (MSK) Imaging

  • Ultrasound is used to image muscles, tendons, ligaments, joints, and nerves.
  • It helps in diagnosing tendon tears, bursitis, muscle strain, nerve entrapment (eg, carpal tunnel), and joint inflammation.
  • It also guides injections or aspirations.

5. Pediatric Imaging

  • In infants and children, ultrasound is often the first-line imaging for soft tissues, head/neck, hips (developmental dysplasia), and neonatal brain (via fontanelles).
  • Because it’s radiation-free, it’s especially favorable for young patients.

6. Point-of-Care Ultrasound (POCUS)

  • In emergency, critical care, and bedside settings, physicians use handheld or portable ultrasound to rapidly evaluate ailments such as fluid around the lungs (pleural effusion), free fluid in the abdomen, cardiac tamponade, or guidance during central line placement.
  • This real-time use can expedite diagnosis and treatment.

7. Interventional / Intraoperative Ultrasound

  • Surgeons sometimes use ultrasound during procedures to locate lesions, guide resections, or assist in biopsies or ablations.
  • Interventional radiologists may use ultrasound guidance for needle placements (biopsy, drainage) and local therapies.

8. Therapeutic Ultrasound & Special Applications

  • Beyond imaging, ultrasound has therapeutic uses (eg, high-intensity focused ultrasound, ultrasound-assisted drug delivery).
  • In neurology and neuroscience, for example, therapeutic ultrasound is being explored in treating conditions like Alzheimer’s disease or other brain disorders.
  • In space medicine, ultrasound is one of the few imaging options available aboard the International Space Station (ISS). As part of the Advanced Diagnostic Ultrasound in Microgravity project, astronauts use ultrasound to assess various organ systems in microgravity.

How You Can Support Ultrasound Awareness
(Especially This October)

  • Share knowledge: If you’re a clinician or educator, talk with colleagues or patients about the many roles of ultrasound.
  • Use social media: Companies and organizations often use hashtags like #MUAM2025 to share educational images, infographics, or stories.
  • Celebrate sonographers and ultrasound technologists: Recognize the skill, dedication, and meticulous work of these professionals.
  • Invite engagement: Host a webinar, post Q&A content, or distribute simple “Did you know?” facts about ultrasound to patients.

Final Thoughts

Medical Ultrasound Awareness Month is more than a promotional event. It’s an opportunity to correct a common misconception: ultrasound is not just for pregnancy. From the heart to the knees to the kidneys, even to outer space, ultrasound plays a vital, versatile role in modern medicine.

Let’s use October’s spotlight to help people see inside, not just for babies but for better health at every age.

Cynthia Owens, BA, is the Publications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

Logo of the American Institute of Ultrasound in Medicine (AIUM) featuring the words 'Association for Medical Ultrasound' and 'American Institute of Ultrasound in Medicine' in blue.

Abdominal Aortic Aneurysms and Ultrasound

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An abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta that, if undetected or untreated, can lead to life-threatening rupture. Often asymptomatic, AAAs can lead to catastrophic outcomes if they rupture, making early detection and monitoring crucial. Fortunately, ultrasound imaging plays a central role in early diagnosis, ongoing surveillance, and even postoperative management, making it a cornerstone in efforts to reduce AAA-related deaths.

What is an Abdominal Aortic Aneurysm?

The abdominal aorta is the largest artery in the abdomen, supplying blood to the lower body. An AAA occurs when a segment of this artery becomes weakened and bulges outward. An aortic diameter of 3.0 cm or more is typically considered aneurysmal. Risk factors include age (especially over 65), male sex, smoking, high blood pressure, and a family history of aneurysms.

Because most AAAs do not cause symptoms, routine screening is essential in high-risk populations. Men over 65 who have ever smoked are commonly advised to undergo a one-time screening, which is most effectively conducted using ultrasound.

The Role of Ultrasound in Diagnosis

Ultrasound is the first-line imaging modality for AAA screening due to its noninvasive nature, lack of ionizing radiation, cost-effectiveness, and accuracy. It can detect an aneurysm with high sensitivity and specificity, and provide precise measurements of the aorta’s diameter, helping determine whether an aneurysm is present and how large it is.

A recent study published in an article in the Journal of Ultrasound in Medicine (JUM; doi:10.1002/jum.15401) underscores the value of ultrasound in identifying aortic pathology early. This study showed that ultrasound training using low-cost, realistic phantoms improved detection accuracy, supporting the widespread use of ultrasound screening programs and skill development among clinicians.

In emergency settings, ultrasound can be deployed at the bedside for rapid diagnosis in patients with suspected AAA rupture. This is particularly valuable in hemodynamically unstable patients, where time is critical. Real-time imaging allows clinicians to confirm the presence of an aneurysm and initiate life-saving interventions without delay.

Monitoring and Surveillance

Not all AAAs require immediate surgery. For aneurysms under 5 cm in diameter, regular monitoring is typically recommended. Ultrasound allows for safe, repeatable, and accurate measurements over time to assess growth rates and determine when intervention is necessary.

Postoperative Follow-Up

In cases in which surgery was needed, however, ultrasound is also integral in post-treatment monitoring, especially following endovascular aneurysm repair (EVAR). It can identify complications such as endoleaks—continued blood flow into the aneurysm sac outside the stent graft—which may increase the risk of rupture. Surveillance protocols often rely on ultrasound to reduce the need for repeated CT scans, limiting patient exposure to radiation and contrast agents.

Another article in the JUM (doi:10.1002/jum.16374) examined advanced ultrasound methods for identifying endoleaks, highlighting how innovations like coded-excitation imaging can improve diagnostic clarity and reliability in follow-up care.

Ultrasound image showing a localized abdominal aortic aneurysm (AAA) with measurements indicated, displaying the cross-section of the aorta.

Evolving Techniques and Considerations

Ultrasound technology continues to evolve. For instance, recent investigations into the effects of transducer pressure on aortic wall stiffness measurements (arXiv:2312.07980) indicate that even subtle operator-dependent variables can impact results. Standardization in measurement techniques will enhance consistency and accuracy in monitoring AAAs, particularly as stiffness metrics gain interest for their potential to reflect aneurysm stability.

Additionally, the development of realistic and inexpensive ultrasound phantoms has facilitated better training and demonstration of aortic pathology detection, improving diagnostic accuracy and clinician proficiency.

Final Thoughts

Ultrasound’s versatility, safety profile, and diagnostic precision make it indispensable in the detection and management of abdominal aortic aneurysms. From identifying at-risk individuals during routine screenings to guiding urgent interventions and long-term follow-up, ultrasound’s role in vascular care continues to grow. As research and technology refine its capabilities, the potential to further improve outcomes for patients with AAAs becomes ever more promising.

Overcoming Common Ultrasound Scanning Challenges: Practical Tips for Sonographers

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Ultrasound is an essential imaging tool in modern medicine, offering visualization of soft tissues, organs, and vascular structures. However, even the most experienced sonographers encounter obstacles that can make obtaining clear images difficult. From excessive bowel gas obscuring structures to scanning patients with high body mass indexes (BMIs), these challenges require skill, adaptability, and technical adjustments. Here are some of the most common ultrasound scanning challenges and practical solutions to optimize imaging.

1.  Imaging the Aorta in Gassy Patients

Few things are as frustrating as trying to visualize the aorta when excessive bowel gas gets in the way. Gas scatters ultrasound waves, making it difficult to see vascular structures clearly.

Solutions:

  • Use an Intercostal Approach: Instead of scanning anteriorly, try navigating through the intercostal spaces on the right side to bypass gas-filled loops of bowel.
    • Apply Steady, Firm Pressure: Pressing gently on the abdomen can help displace gas and improve sound wave penetration.
  • Change the Frequency: A lower-frequency transducer (such as a curvilinear probe at 1–6 MHz or 2–5 MHz) allows deeper penetration, sometimes improving visibility despite gas interference.

Video Link: Watch here

2.  Scanning High BMI Patients

Larger patients present challenges due to increased soft tissue thickness, which can reduce image resolution and penetration.

Solutions:

  • Use a Lower Frequency Transducer: A 1–6 MHz or 2–5 MHz curvilinear transducer enhances penetration, even if it sacrifices some resolution. This is especially useful when scanning larger patients, such as when ruling out lower extremity DVTs. While linear probes are common for vascular imaging, don’t hesitate to use whatever transducer best visualizes the patient’s anatomy, whether it’s curvilinear, phased array, or another alternative.
    • Increase the Time Gain Compensation (TGC): Adjusting the TGC enhances contrast and clarity in deeper structures.
  • Optimize Patient Positioning: Having the patient roll onto their side allows gravity to shift excess tissue, improving visualization. Right Lateral Decubitus (RLD) positioning works well for imaging the spleen and left kidney, while Left Lateral Decubitus (LLD) positioning is ideal for the right kidney, gallbladder, and the dome of the liver.
  • Utilize Harmonic Imaging: This setting helps reduce artifacts and enhances contrast resolution for clearer imaging.
Ultrasound image showing a longitudinal view of the proximal aorta, used for evaluating vascular structures and potential obstructions.
Photo: This image shows the aorta of a patient with a BMI of 50+, captured using an intercostal approach. (Fun fact: “Intercostal” just means between the ribs!)

3.  Evaluating Deep or Small Vessels

Poor acoustic access can make visualizing small or deep vessels, such as the popliteal artery or small renal arteries, difficult.

Solutions:

  • Use Color and Power Doppler: Increasing Doppler sensitivity helps detect slow-moving blood flow in deep or small vessels.
  • Optimize the Angle of Insonation: Keeping the Doppler angle between 45 and 60 degrees improves velocity accuracy.
  • Apply Gentle Compression: This technique helps differentiate veins from arteries and optimize visualization. I frequently use this when assessing ankle-brachial index (ABI) ratios in calcified arteries near the ankle.

4.  Differentiating Cysts From Solid Masses

Distinguishing between cystic and solid structures can be tricky, especially when artifacts mimic fluid-filled lesions.

Solutions:

  • Use Multiple Imaging Planes: Scanning from different angles helps confirm whether a structure is truly cystic or solid. Always assess the kidneys from multiple planes—exophytic masses and cysts love to hide where you least expect them.
  • Apply Color Doppler: Cysts will not show internal blood flow, while vascularized solid masses will have detectable Doppler signals.
  • Adjust Gain Settings: Lowering overall gain can help differentiate hypoechoic solid structures from fluid-filled cysts.

Conclusion

Ultrasound scanning challenges are inevitable, but a skilled sonographer can overcome them with the right techniques. Adjusting transducer settings, modifying patient positioning, and using alternative scanning approaches can significantly improve image quality. By staying adaptable, sonographers can ensure optimal imaging, leading to more accurate diagnoses and better patient outcomes.

Let’s Stay Connected!

Theresa Jenkins, BS, RDMS, RVT

I hope these tips help you tackle ultrasound challenges with confidence! Connect with me on LinkedIn or check out my YouTube channel, Path2Passing, for more ultrasound insights and updates!

🔗 LinkedIn: Theresa Jenkins
🎥 YouTube Channel: Path2Passing
✍ Author: Theresa Jenkins, BS, RDMS, RVT

Theresa Jenkins BS, RDMS, RVT, is a seasoned sonographer with nearly seven years of experience, having worked in top facilities nationwide. Credentialed in general, vascular, and pediatric ultrasound, she is also an educator and author with plans to become a leading voice in sonography.

This posting has been edited for length and clarity. The opinions expressed in this posting are the author’s own and do not necessarily reflect the view of their employer or the American Institute of Ultrasound in Medicine.

The Next Frontiers of Intestinal Ultrasound for the Assessment of Inflammatory Bowel Disease (IBD): CEUS, SICUS, and Elastography

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In recent years, the utility of intestinal ultrasound (IUS) in diagnosing and managing inflammatory bowel disease (IBD) has gained substantial momentum. The Scan featured a blog post in June 2024 describing the features and uses of IUS for diagnosing and monitoring IBD. That previous article highlighted the many features that can be monitored to assess IBD disease activity and severity right at the bedside using B-mode ultrasound, highlighting that bowel wall thickness (BWT), Doppler signaling (hyperemia), loss of stratification of bowel wall layers (BWS), and peri-intestinal hyperechoic fat are important features of inflammatory on IUS.1 However, adjunct techniques, such as using contrast with ultrasound, may permit better detection of disease complications and activity, particularly in Crohn’s disease, where patients are at risk of developing intestinal strictures (narrowing), bowel perforation, and abscesses. Indeed, these advanced ultrasound techniques push the boundaries of what noninvasive imaging can offer. This blog post delves into three promising techniques—contrast-enhanced ultrasound (CEUS), small intestinal contrast-enhanced ultrasound (SICUS), and elastography—each providing new dimensions to our understanding of IBD and its management.

Contrast-Enhanced Ultrasound (CEUS): Adding Depth to Vascular Assessment

CEUS represents a significant advancement in IUS, particularly in assessing disease activity and vascularization. By injecting a contrast composed of gas-filled microbubbles stabilized by a lipid capsule into the bloodstream, CEUS enhances the visualization of bowel wall vascularity, which is a key indicator of inflammation in IBD. The evaluation relies on the dynamic assessment of the contrast uptake in areas with increased vascular activities, whose intensity can change over time.2 Although visual evaluation can demonstrate areas of activities on CEUS, advanced software is also used to generate time-intensity curves, which measure the signal intensity from the first bubble arrival in the bowel segment of interest and progressive decline in intensity (wash-out) usually over 2 minutes of image capture.3

CEUS can be used in various clinical contexts to monitor Crohn’s disease. The time-intensity curves generated by CEUS are used to calculate the signal’s peak intensity and area under the curve (AUC). Wilkens et al demonstrated that peak intensity and AUC are increased in patients with active disease as compared to controls.4 Further studies have demonstrated promising results in differentiating Crohn’s disease lesions with active inflammation instead of lesions composed predominantly of fibrostenotic tissue.5 Variations in outcomes may be related to the type of contrast used, the quantitative CEUS value of interest analyzed, and the variability in the ultrasound system and analysis software used, which are not standardized between systems.5 However, such findings may be important in predicting response to therapy instead of prioritizing surgical options, as limited data demonstrated higher inflammation quantified by CEUS had a higher response rate to therapies.6

CEUS has emerged as a valuable tool in monitoring complications of Crohn’s disease (CD), particularly in assessing the presence and extent of fistulas and abscesses. By enhancing the visibility of vascular structures and inflammatory activity, CEUS allows for the precise identification and measurement of these complications, which can be challenging to characterize with conventional imaging methods. This enhanced visualization is crucial for guiding clinical decisions, including the need for surgical intervention or adjustments in medical therapy.7

Small Intestinal Oral Contrast-Enhanced Ultrasound (SICUS): Expanding the Reach of IUS

While CEUS focuses on enhancing vascular imaging, SICUS takes a different approach by improving the visualization of the small intestine, an area notoriously difficult to image using traditional ultrasound techniques. SICUS is performed in the fasted state and involves the oral administration of a non-absorbable contrast medium, generally a polyethylene glycol solution, that distends the small bowel loops, allowing for better visualization of the bowel wall and lumen. The exam may last 30 to 45 minutes for the contrast to arrive at the areas of interest.8

This technique is particularly valuable in the assessment of small bowel CD, where skip lesions and strictures can be challenging to detect and characterize. SICUS enhances the delineation of these abnormalities, providing a clearer picture of the disease’s extent and severity. Moreover, SICUS can be employed alongside B-mode and CEUS to offer a comprehensive assessment of the small intestine. The combined use of these modalities allows for a more nuanced evaluation of both the inflammatory and structural components of the disease, leading to more informed treatment strategies.9

Elastography: A Noninvasive Window Into Fibrosis

One of the most challenging aspects of managing IBD is differentiating between inflammation and fibrosis, particularly in chronic CD, where long-standing inflammation can lead to fibrotic changes in the bowel wall. Elastography, a technique that measures tissue stiffness, is a promising solution to this issue. By applying mechanical waves to the tissue and measuring the speed at which they propagate, elastography can provide a quantitative assessment of bowel wall stiffness—a surrogate marker for fibrosis.5 Again, this is essential in predicting lesions that would be amendable to medical therapy as opposed to surgery. However, challenges exist in the assessment of the bowel using this technique, as measurements can be affected by peristalsis, and a large body habitus can impede the penetration of the sound waves. Values are not yet standardized between ultrasound systems, making the validation of specific thresholds difficult between centers.5 As research continues to validate its accuracy and reliability, elastography may become a standard tool in the long-term management of IBD.

The Future of IUS in IBD Management

The integration of CEUS, SICUS, and elastography into the IUS toolkit marks a significant step forward in the management of IBD. These advanced techniques not only enhance our ability to diagnose and monitor the disease but also provide critical insights that can tailor treatment strategies to the individual patient.

As we continue to refine these methods and validate their use in clinical practice, the future of IUS in IBD management looks promising. The ability to assess the disease’s inflammatory and fibrotic components in real-time, noninvasively, and with high accuracy will undoubtedly improve patient outcomes and quality of life. However, to move toward more widespread adoption, more training in these techniques will be necessary, and further validation of the data generated is warranted.

In conclusion, the advancements in IUS, particularly with the advent of CEUS, SICUS, and elastography, are poised to transform the landscape of IBD management. These techniques offer a more detailed and nuanced understanding of the disease, enabling us to make more informed decisions that ultimately benefit our patients. As we look to the future, the continued evolution of IUS will undoubtedly play a pivotal role in the quest for better outcomes in IBD care.

Mallory Chavannes, MD, MHSc, FRCPC, FAAP, is an Assistant Professor of Pediatrics in the Division of Gastroenterology, Hepatology, & Nutrition, and is Medical Director of the Inflammatory Bowel Disease Program, at Children’s Hospital Los Angeles.

References:

  1. Novak KL, Nylund K, Maaser C, et al. Expert consensus on optimal acquisition and development of the international bowel ultrasound segmental activity score [IBUS-SAS]: a reliability and inter-rater variability study on intestinal ultrasonography in Crohn’s disease. J Crohns Colitis 2021; 15:609–616. doi: 10.1093/ecco-jcc/jjaa216. PMID: 33098642; PMCID: PMC8023841.
  2. Pecere S, Holleran G, Ainora ME, et al. Usefulness of contrast-enhanced ultrasound (CEUS) in inflammatory bowel disease (IBD). Dig Liver Dis 2018; 50:761–767. doi: 10.1016/j.dld.2018.03.023. Epub 2018 Apr 3. PMID: 29705029.
  3. Merrill C, Wilson SR. Ultrasound of the bowel with a focus on IBD: the new best practice [published online ahead of print August 14, 2024]. Abdom Radiol (NY) doi: 10.1007/s00261-024-04496-1. PMID: 39141152.
  4. Wilkens R, Wilson A, Burns PN, Ghosh S, Wilson SR. Persistent enhancement on contrast-enhanced ultrasound studies of severe Crohn’s disease: stuck bubbles? Ultrasound Med Biol 2018; 44:2189–2198. doi: 10.1016/j.ultrasmedbio.2018.06.018. PMID: 30076030.
  5. Coelho R, Ribeiro H, Maconi G. Bowel thickening in Crohn’s disease: fibrosis or inflammation? Diagnostic ultrasound imaging tools. Inflamm Bowel Dis 2017; 23:23–34. doi: 10.1097/MIB.0000000000000997. PMID: 28002125.
  6. Quaia E, Gennari AG, Cova MA, van Beek EJR. Differentiation of inflammatory from fibrotic ileal strictures among patients with Crohn’s disease based on visual analysis: feasibility study combining conventional B-mode ultrasound, contrast-enhanced ultrasound and strain elastography. Ultrasound Med Biol 2018; 44:762–770. doi: 10.1016/j.ultrasmedbio.2017.11.015. PMID: 29331357.
  7. Pecere S, Holleran G, Ainora ME, et al. Usefulness of contrast-enhanced ultrasound (CEUS) in inflammatory bowel disease (IBD). Dig Liver Dis 2018; 50:761–767. doi: 10.1016/j.dld.2018.03.023. PMID: 29705029.
  8. Losurdo G, De Bellis M, Rima R, et al. Small intestinal contrast ultrasonography (SICUS) in Crohn’s disease: systematic review and meta-analysis. J Clin Med 2023; 12(24):7714. doi: 10.3390/jcm12247714. PMID: 38137782; PMCID: PMC10744114.

Mocci G, Migaleddu V, Cabras F, et al. SICUS and CEUS imaging in Crohn’s disease: an update. J Ultrasound 2017; 20:1–9. doi: 10.1007/s40477-016-0230-5. PMID: 28298939; PMCID: PMC5334271.

Advancing Inflammatory Bowel Disease Management: Harnessing Intestinal Ultrasound for Screening and Monitoring

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Inflammatory bowel disease (IBD) encompasses a group of chronic inflammatory conditions of the gastrointestinal tract, primarily including Crohn’s disease and ulcerative colitis. The rate of patients affected by these conditions has been growing in the last decades, with an estimated 2.39 million Americans living with this diagnosis in 2020.1 About 25% of those affected are children.2 Active inflammation in the context of IBD increases the risk of disease complications, such as requiring surgery and developing colon cancer. However, symptoms have been shown to not accurately correlate to intestinal inflammation and ongoing bowel damage.3,4 Therefore, the assessment of disease activity relies on invasive techniques, such as colonoscopy and cross-sectional imaging (ie, Computer Tomography Enterography and Magnetic Resonance Enterography), which are costly and laborious tests. Repeated imaging using these techniques is important to assess for the complete reversal of inflammation, termed mucosal healing, which was shown to lead to much better long-term outcomes.5

Intestinal ultrasound (IUS) has emerged as a valuable technique for screening patients with concerning symptoms of IBD and monitoring individuals with known disease. It has the advantages of being feasible at the bedside in the gastrointestinal clinic, noninvasive, painless, requiring no preparation from the patient, and not exposing the patient to ionizing radiation. IUS has been used for monitoring disease activity for many years in Europe and is now being rapidly adopted in the United States.

IUS Features of Intestinal Inflammation

IUS is generally performed using a high-frequency linear transducer to visualize the intestinal wall and surrounding structures in real-time and a curvilinear low-frequency transducer to assess for disease complications, often located in the pelvis. The thickness of the bowel wall, which comprises layers such as the mucosa, submucosa, and muscularis, measures under 3mm in healthy adults, but this measurement increases in the setting of inflammation.6 Bowel layers can be distinct or more disturbed depending on disease severity. Other important features include the presence of abnormal increased Doppler signals in and along the bowel wall, which are usually absent in healthy patients and progressively more prominent in diseased bowel. Furthermore, peri-intestinal fat can be increased in the presence of disease. Examples of these IUS features are illustrated in Figure 1.

Figure 1A
Figure 1B

Screening With IUS

One of the key advantages of IUS in IBD management is its ability to screen for the presence of disease in patients with nonspecific symptoms that could be due to IBD. By visualizing the thickness of the intestinal wall, the presence of bowel wall edema, and the extent of inflammation, ultrasound can help identify active disease and assess its severity. Indeed, a study demonstrated that IUS could distinguish between patients with Irritable Bowel Syndrome (IBS) or functional symptoms and patients with new or flaring IBD.7,8 The use of IUS by trained providers can help with resource allocation and expedite invasive testing in the right patient without delays, and avoid unnecessary invasive investigation in patients who do not require it.

Monitoring Disease Progression and Treatment Response

In addition to screening, IUS can have a central role in monitoring response to treatment. Although there is a growing armamentarium of treatments for IBD, no single treatment has led to endoscopic remission rates higher than about 40–50%.9 Repeat ultrasound examinations can track changes in the thickness of the intestinal wall and complications over time. This real-time feedback allows for the timely optimization of treatment strategies, with subsequent improvement in patient outcomes. This proactive approach to objective evaluation of disease activity and continuous optimization of therapies, named the treat-to-target approach, has been demonstrated to improve long-term complication-free remission.5,10 Moreover, ultrasound can detect complications such as strictures, abscesses, and fistulas, guiding treatment decisions and surgical planning.

Advantages of IUS

Several factors contribute to the growing popularity of IUS in IBD management:

  1. Noninvasive: IUS does not require the insertion of instruments into the body, minimizing patient discomfort and reducing the risk of complications.
  2. Radiation-free: Unlike CT scans, which involve ionizing radiation, ultrasound uses harmless sound waves, making it safe for repeated examinations by professionals, including in pregnant women and children.
  3. Real-time imaging: IUS provides immediate feedback, allowing healthcare providers to assess disease activity and complications on the spot.
  4. Cost-effective: Compared to other imaging modalities, IUS is relatively affordable, potentially increasing patient accessibility in various healthcare settings.

Conclusion

Intestinal ultrasound (IUS) has emerged as a valuable tool in the screening and monitoring of inflammatory bowel disease. Its noninvasive nature, lack of radiation exposure, real-time imaging capabilities, and cost-effectiveness make it an attractive option for healthcare providers and patients alike. By incorporating IUS into the diagnostic algorithm for IBD, clinicians can improve the accuracy of diagnosis, optimize treatment strategies, and enhance patient outcomes.

In the ever-evolving landscape of IBD management, IUS stands out as a versatile and effective imaging modality, offering valuable insights into disease activity and treatment response. As research continues to elucidate its utility and refine its techniques, IUS is poised to play an increasingly prominent role in the personalized care of individuals living with IBD.

References:

  1. Lewis JD, Parlett LE, Jonsson Funk ML, et al. Incidence, prevalence, and racial and ethnic distribution of inflammatory bowel disease in the United States. Gastroenterology 2023 Nov; 165(5):1197–1205.e2. doi: 10.1053/j.gastro.2023.07.003. Epub 2023 Jul 20. PMID: 37481117; PMCID: PMC10592313.
  2. Abraham BP, Mehta S, El-Serag HB. Natural history of pediatric-onset inflammatory bowel disease: a systematic review. J Clin Gastroenterol 2012; 46:581–589.
  3. Modigliani R, Mary JY, Simon JF, et al. Clinical, biological, and endoscopic picture of attacks of Crohn’s disease. Evolution on prednisolone. Groupe d’Etude Thérapeutique des Affections Inflammatoires Digestives. Gastroenterology 1990; 98:811–818. doi: 10.1016/0016-5085(90)90002-i. PMID: 2179031.
  4. Jharap B, Sandborn WJ, Reinisch W, et al. Randomised clinical study: discrepancies between patient-reported outcomes and endoscopic appearance in moderate to severe ulcerative colitis. Aliment Pharmacol Ther 2015; 42:1082–1092. doi: 10.1111/apt.13387
  5. Ungaro RC, Yzet C, Bossuyt P, et al. Deep remission at 1 year prevents progression of early Crohn’s disease. Gastroenterology 2020 Jul; 159(1):139–147. doi: 10.1053/j.gastro.2020.03.039. Epub 2020 Mar 26. PMID: 32224129; PMCID: PMC7751802.
  6. Novak KL, Nylund K, Maaser C, et al. Expert consensus on optimal acquisition and development of the international bowel ultrasound segmental activity score [IBUS-SAS]: a reliability and inter-rater variability study on intestinal ultrasonography in Crohn’s disease. J Crohns Colitis 2021; 15:609–616. doi: 10.1093/ecco-jcc/jjaa216. PMID: 33098642; PMCID: PMC8023841.
  7. Novak KL, Jacob D, Kaplan GG, et al. Point of care ultrasound accurately distinguishes inflammatory from noninflammatory disease in patients presenting with abdominal pain and diarrhea. Can J Gastroenterol Hepatol 2016; 2016:4023065. doi: 10.1155/2016/4023065. Epub 2016 Apr 20. PMID: 27446838; PMCID: PMC4904691.
  8. St-Pierre J, Delisle M, Kheirkhahrahimabadi H, et al. Bedside intestinal ultrasound performed in an inflammatory bowel disease urgent assessment clinic improves clinical decision-making and resource utilization. Crohns Colitis 360 2023 Sep 21; 5(4):otad050. doi: 10.1093/crocol/otad050. PMID: 37809033; PMCID: PMC10558199.
  9. Cholapranee A, Hazlewood GS, Kaplan GG, Peyrin-Biroulet L, Ananthakrishnan AN. Systematic review with meta-analysis: comparative efficacy of biologics for induction and maintenance of mucosal healing in Crohn’s disease and ulcerative colitis controlled trials. Aliment Pharmacol Ther 2017 May; 45(10):1291–1302. doi: 10.1111/apt.14030. Epub 2017 Mar 22. PMID: 28326566; PMCID: PMC5395316.
  10. Colombel JF, Panaccione R, Bossuyt P, et al. Effect of tight control management on Crohn’s disease (CALM): a multicentre, randomised, controlled phase 3 trial. Lancet 2017 Dec 23; 390(10114):2779–2789. doi: 10.1016/S0140-6736(17)32641-7. Epub 2017 Oct 31. Erratum in: Lancet 2018 Dec 23; 390(10114):2768. PMID: 29096949.

Mallory Chavannes, MD, MHSc, is an Assistant Professor of Pediatrics in the Division of Gastroenterology, Hepatology, & Nutrition, and is Medical Director of the Inflammatory Bowel Disease Program, at Children’s Hospital Los Angeles.

Recommendations for Improved Safety of Lung Ultrasound

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Lung ultrasound (LUS) has been emerging as a vital clinical tool. LUS aids in diagnosing a range of conditions, from pneumonia to respiratory distress syndrome or pulmonary edema. LUS was also very significant at the height of the COVID-19 pandemic, when point-of-care lung monitoring modalities were crucial.  

Diagnostic ultrasound standards and safety guidelines were established in the late 20th century to ensure the safety of ultrasound imaging and avoid ultrasound bioeffects in tissues. The Thermal Index (TI) and Mechanical index (MI) are two ultrasound exposure indices that respectively indicate the risks of tissue heating and cavitation and which must be displayed in real time during scanning. However, the lung is a tissue like no other, and the bioeffects observed in animal studies (in mice, rabbits, pigs, and monkeys) are very different from the bioeffects observed in other tissues. Capillary pulmonary hemorrhage is a unique bioeffect that is correlated to the MI. In order to avoid such specific ultrasound bioeffects, a new safety paradigm must be created for LUS.

Despite guidelines recommending MI ≤ 0.4, recent research suggests that a further reduction to MI ≤ 0.3 for enhanced safety might be needed. In addition, it is critical to account for the actual MI in situ, which is influenced by the thickness of the chest wall. This is particularly concerning in neonatal LUS safety, due to thin chest walls and intensive use.

Existing safety education varies among practitioners, and surveys indicate a lack of knowledge regarding lung ultrasound safety. In the absence of an appropriate preset, pre-installed on all machines, for neonatal LUS guaranteeing an MI ≤ 0.3, the risk of error and exposure to higher MI is significant. In pediatric and adult patients with a thicker chest wall, a higher MI would be acceptable, as long as adherence to the “as low as reasonably achievable” (ALARA) safety principle is maintained.

Overall, the recommendations for Improved Safety  of Lung Ultrasound are:

  1. To install a preset on all ultrasound machines limiting MI to ≤ 0.3 for neonatal cases.
  2. To provide a user-friendly means for practitioners to select the safety preset without manual adjustments.
  3. To allow higher MI values for pediatric and adult patients when needed for optimal imaging, considering higher ultrasound attenuation in thicker chest walls.
  4. To guide practitioners in adhering to the As Low As Reasonably Achievable (ALARA) principle and by considering the chest wall attenuation for MI > 0.3.
  5. To develop a specific Mechanical Index for Lung (MIL). The creation of a unique MIL for LUS, displayed on-screen to estimate pleural exposure accurately would increase safety and safety awareness among practitioners.

Enhancing safety in LUS requires a multifaceted approach, encompassing preset implementation, practitioner education, and technological advancements. The proposed recommendations aim to address current safety challenges, ensuring the continued effectiveness and safety of lung ultrasound in diverse clinical settings and for diverse populations (from neonates to high BMI patients). By combining technological innovations with user-friendly controls, the proposed safety paradigm seeks to strike a balance between optimal imaging outcomes and patient safety in the evolving landscape of LUS.

For more information, see the “Statement and Recommendations for Safety Assurance in Lung Ultrasound” from the American Institute of Ultrasound in Medicine (AIUM)

Marie Muller, PhD, is an Associate Professor of Mechanical and Aerospace Engineering at NC State University.

You Won’t Be Left in the Dark at UltraCon (except during the total eclipse!)

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Have you considered how you will spend April 8 (well, April 6–10, 2024, actually)? The place to be on the 8th is somewhere you can be in the path of totality during the total solar eclipse, and what better place to be than Austin, TX, where you can see the eclipse and get your fill of everything ultrasound?

(and probably the cheapest way to get a hotel room is to register for UltraCon 2024 and grab a room while we still have affordable rooms in our block).

The AIUM brings our annual meeting to Austin, TX, for the first time, and there will be lots to take in. We are bringing back Educational Tracks. No matter where your interests lie, MSK or Fetal Echo or General US or OB or GYN, there is a track for you! There is something for you, whether you are early in your career or an experienced sonographer/sonologist. You will hear presentations from experts that will keep you up to date on changes in the field and tell you what is coming down the pike. For our members who are deep into the basic sciences, some presentations will stimulate new thinking and show you what other colleagues are up to. One of the best parts of the program is that you aren’t stuck in one track—you can mix and match to customize your experience. Check out the tracks here.

UltraCon brings you more than just the educational tracks. Is there a product that you have always wanted to develop and commercialize? Perhaps an invention, a training program, or another idea you are sure could be monetized? If so, the AIUM’s Shark Tank is for you! Put together your best proposal and present it to our panel of experts from industry, venture capital, and academia. $1,000 is up for grabs, but win or lose, you will gain valuable insights and critical appraisal of your concept, along with suggestions for what you need to do to take your proposal to the next step.

Scientific sessions run throughout the meeting, allowing you to hear cutting-edge research that will help answer some of the questions you might be having or possibly give you ideas to pursue on your own. You will hear from young researchers just starting out their careers as well as experienced scientists who have gotten us where we are today but aren’t done leading us yet.

One of the best aspects of the annual meeting is the chance to hear from luminaries and others with cutting-edge ideas, whether in ultrasound directly or in fields that will impact ultrasound, such as artificial intelligence and other new technologies. This year’s plenary sessions will be captivating as we hear from Dr Omar Ishrak on the future of ultrasound technology and from Dr Gil Weinberg on an amazing application of ultrasound to offer amputees the opportunity to play musical instruments.

Other talks will cover how CPT codes are developed, how to efficiently complete your application for accreditation, and so much more that will round out your experience in Austin.

UltraCon 2024 promises to be a Top Shelf event that you really don’t want to miss—and yes, we have scheduled a break to go outside to see the eclipse, so you won’t be asked to decide between these 2 once-in-a-lifetime events! Note that our hotel block is probably the least expensive deal in town, as our rates were negotiated years ago before many were paying attention to this eclipse. It is entirely possible we will sell out our block of rooms, so make your plans and register as soon as possible!

David C. Jones, MD, FACOG, FAIUM, the AIUM’s President Elect, is a Professor at the University of Vermont and the Director of the Fetal Diagnostic Center at the University of Vermont Medical Center.

Ultrasound in the Diagnosis and Management of Chronic Obstructive Pulmonary Disease

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Chronic Obstructive Pulmonary Disease (COPD) is a prevalent and debilitating respiratory condition that affects millions of people worldwide. While traditional diagnostic methods like spirometry and imaging techniques such as CT scans have played a vital role in managing this disease, ultrasound is emerging as a powerful tool in both diagnosis and treatment.

The Basics of COPD

COPD is a progressive lung disease characterized by the restriction of airflow due to chronic bronchitis and emphysema. The primary symptoms include breathlessness, coughing, and excessive mucus production. It is typically associated with a history of smoking, but environmental factors also play a role. Diagnosing and monitoring the progression of COPD is crucial for effective management.

The Role of Ultrasound in Diagnosis

Sonographic Assessment of Lung Morphology: Ultrasound imaging offers a noninvasive and radiation-free approach to assess lung morphology. Studies published in the Journal of Ultrasound in Medicine have demonstrated the effectiveness of ultrasound in evaluating lung parenchyma,1 pleura,1 and diaphragm.2 By examining these elements, clinicians can identify changes in the lung structure and rule out other conditions that might mimic COPD symptoms.

Evaluation of Diaphragm Function: COPD often affects diaphragm function, resulting in respiratory muscle weakness. Ultrasound allows for real-time assessment of diaphragm movement, enabling clinicians to detect early signs of diaphragmatic dysfunction.2 This information is valuable in selecting the appropriate treatment strategy for each patient.

Ultrasound-Guided Thoracentesis

In some cases, COPD patients develop pleural effusion, a condition characterized by an abnormal buildup of fluid in the pleural cavity. Ultrasound can be used to guide thoracentesis, a procedure in which this excess fluid is drained. A Journal of Ultrasound in Medicine report has highlighted the accuracy and safety of ultrasound guidance during this procedure, minimizing complications and improving patient outcomes.3

Monitoring Disease Progression

Ultrasound is not limited to the initial diagnosis but also plays a crucial role in monitoring COPD progression. Repeat ultrasound examinations can help evaluate changes in lung structure, assess diaphragm function, and track the effectiveness of ongoing treatments. Regular ultrasound monitoring can lead to more tailored and effective care plans for COPD patients.

Point-of-Care Ultrasound in COPD

Point-of-care ultrasound (POCUS) is a valuable tool for quickly assessing COPD exacerbations in emergency situations. It allows healthcare providers to rapidly evaluate lung abnormalities, pneumothorax, and pleural effusion, guiding immediate treatment decisions.4

Future Implications

As technology continues to advance, ultrasound is likely to play an even more prominent role in the diagnosis and management of COPD. Developments in portable and handheld ultrasound devices are making it easier for clinicians to perform ultrasound examinations at the bedside, providing real-time information to aid in decision-making.

Conclusion

The use of ultrasound in the diagnosis and management of COPD is a promising and evolving field. It offers a noninvasive, safe, and cost-effective means of assessing lung morphology, diaphragm function, and pleural effusion. With continued research and technological advancements, ultrasound is likely to become an indispensable tool in the fight against this chronic respiratory disease, helping patients receive more accurate diagnoses and tailored treatment plans.

References:

1. Martelius L, Heldt H, Lauerma K. B-lines on pediatric lung sonography: comparison with computed tomography. J Ultrasound Med 2016; 35:153–157. doi: 10.7863/ultra.15.01092.

2. Xu JH, Wu ZZ, Tao FY, et al. Ultrasound shear wave elastography for evaluation of diaphragm stiffness in patients with stable COPD: A pilot trial. J Ultrasound Med 2021; 40:2655–2663. doi: 10.1002/jum.15655.

3. Lane AB, Petteys S, Ginn M, Nations JA. Clinical importance of echogenic swirling pleural effusions. J Ultrasound Med 2016; 35:843–847. doi: 10.7863/ultra.15.05009.

4. Copcuoglu Z, Oruc OA. Diagnostic accuracy of optic nerve sheath diameter measured with ocular ultrasonography in acute attack of chronic obstructive pulmonary disease. J Ultrasound Med 2023; 42:989–995. doi: 10.1002/jum.16106.

Cynthia Owens, BA, is the Publications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

Interested in learning more about lung ultrasound? Check out the following articles from the American Institute of Ultrasound in Medicine’s (AIUM’s) Journal of Ultrasound in Medicine (JUM). After logging into the AIUM, members of AIUM can access them for free. Join the AIUM today!

How Can Ultrasound Contrast Agents Be Used to Sensitize Tumors to Radiation?

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Ultrasound contrast agents (UCAs) have the ability to go throughout the body and reach anywhere there is active vascularity. As clinicians and scientists, we use this to our advantage for diagnostic and therapeutic purposes. A unique characteristic of a UCA is its ability to generate nonlinear responses at sufficient pressure. These nonlinear responses produce harmonics in an acoustic field. UCAs undergo natural oscillations, and, at higher pressures, these UCAs can produce bioeffects. Inertial cavitation is the transient destruction of UCAs from increased pressure, while stable cavitation is a constant oscillation. Both of these cavitation states can produce shear stress on vessel walls, particularly endothelial cells.

Endothelial cells are the cell layer that lines all blood vessels in the body and are responsible for many functions but primarily control the passage of nutrients into tissues.1 In normal tissue, endothelial cells are uniform and form an organized monolayer network with tight junction connections.1 However, in tumor endothelial cells (TECs), it is much more of a chaotic process. In TECs, long, fragile cytoplasmic projections extend into the vessel lumen, creating small openings and gaps in the vessel wall.1 In addition to smaller gaps, larger openings (up to 1.5 µm) have also been identified, which make cell closures more difficult. These small and large gaps in TECs can be harnessed to produce endothelial cell apoptosis by destroying UCAs via inertial cavitation. Utilizing inertial cavitation has been shown to produce endothelial cell apoptosis (cell death) by generating bioeffects (ie, shock waves, microjets, micro streams, and thermal effects) that mechanically perturb TEC membranes.

Moreover, there are many components to a cell membrane, which goes beyond the scope of this blog post; however, sphingolipids are an essential enzyme to a cell membrane.2 Sphingolipids help maintain cellular homeostasis and are closely associated with cellular biologic functions, such as proliferation, apoptosis, or oxidative stress on endothelial cells.2 Some sphingolipids, such as ceramide, are important second signaling molecules that determine cell proliferation or death.

Traditionally, radiation therapy has been thought to act by damaging the DNA of cells via double and single DNA strand breaks, resulting in apoptosis. However, more recent studies have suggested that blood vessels are the determining factor of tumor response to radiation therapy at high doses (>8–19 Gy).3 Endothelial cells exposed to high doses of radiation upregulate the acid-sphingomyelinase pathway (ASMASE), which hydrolyzes sphingomyelin (dominant sphingolipid) into apoptosis, with ceramide acting as the second messenger. El Kaffas et al suggest that a primary factor why endothelial cells respond differently than other cell types is because endothelial cells have a 20x enrichment of a nonlyosomal secretory form of the ASMASE enzyme.4,5 This enzyme is associated with membrane remodeling, restructuring, responses to shear stress, and activation of ceramide from cell stressors.6,7 Additionally, endothelial cells are more sensitive to shear stress and mechanical forces.4 Radiation therapy and inertial cavitation treatments separately have been shown to produce tumor cell death. Combining these two treatments results in an increased accumulation of ceramide production and apoptosis, leading to improved tumor radiosensitivity.

Over the past decade, primarily in pre-clinical research, the benefits of combining microbubbles and radiation have been shown. From one of the original pre-clinical studies validating this concept, Czarnota et al showed that inertial cavitation and radiation therapy in a human prostate xenograft model in mice led to a 10-fold increase in ceramide-related endothelial cell death, confirming the benefits of the combined relationship.7 In addition, the study demonstrated a significant effect with a decreased radiotherapy dose (2 Gy versus 8 Gy) when combined with inertial cavitation compared to stand-alone treatment regimens. This mechanism has mainly been validated with in vivo studies. However, my group at Thomas Jefferson University has a first-ever pilot clinical trial incorporating ultrasound-triggered microbubble destruction (UTMD) to sensitize hepatocellular carcinoma in patients that receive the locoregional therapy, trans-arterial radioembolization (TARE).8 In an interim analysis, there was a greater prevalence of tumor response in the patients receiving TARE plus UTMD as opposed to in those who received TARE alone. Additionally, lab values and liver function tests demonstrated no significant differences between study groups, indicating that adding microbubble cavitation does not affect patient safety or liver functions.

This study is an ongoing clinical trial and will complete enrollment within the next 6 months, and this concept has been incorporated in non-HCC tumors in an ongoing pilot clinical trial at Thomas Jefferson University (NCT# 03199274). As a result of our research to date, we have learned that incorporating UTMD with radiation therapy may help sensitize tumors for improved survival and treatment outcomes. Additional clinical research is needed in this field because the combination treatment regimen may be easily incorporated into non-liver tumors.

References

  1. Dudley AC. Tumor endothelial cells. Cold Spring Harb Perspect Med 2012; 2:a006536. doi: 10.1101/cshperspect.a006536.
  2. Lai Y, Tian Y, You X, Du J, Huang J. Effects of sphingolipid metabolism disorders on endothelial cells. Lipids Health Dis 2022: 21(1):101. doi: 10.1186/s12944-022-01701-2.
  3. Paris F et al. Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice. Science 2001; 293(5528):293–297. doi: 10.1126/science.1060191.
  4. El Kaffas A and Czarnota GJ. Biomechanical effects of microbubbles: from radiosensitization to cell death. Future Oncol 2015; 11(7):1093–1108. doi: 10.2217/fon.15.19.
  5. Tabas I. Secretory sphingomyelinase. Chem Phys Lipids 1999; 102(1):123–130. doi: 10.1016/S0009-3084(99)00080-8.
  6. El Kaffas A, Al-Mahrouki A, Hashim A, Law N, Giles A, Czarnota GJ. Role of acid sphingomyelinase and ceramide in mechano-acoustic enhancement of tumor radiation responses. J Natl Cancer Inst 2018; 110(9):1009–1018. doi: 10.1093/jnci/djy011.
  7. Czarnota GJ et al. Tumor radiation response enhancement by acoustical stimulation of the vasculature. Proc Natl Acad Sci U S A  2012; 109(30): E2033-E2041. doi: 10.1073/pnas.1200053109.
  8. Eisenbrey JR et al. US-triggered microbubble destruction for augmenting hepatocellular carcinoma response to transarterial radioembolization: a randomized pilot clinical trial. Radiology 2021; 298:450–457. doi: 10.1148/radiol.2020202321.

Corinne Wessner, MS, MBA, RDMS, RVT, is a research sonographer at Thomas Jefferson University and a PhD candidate at Drexel University in the School of Biomedical Engineering, Science and Health Systems in Philadelphia, PA. She is also Vice Chair of the American Institute of Ultrasound in Medicine’s (AIUM’s) High-Frequency Clinical and Preclinical Imaging Community (2023–2025).

Interested in reading more from Corinne Wessner? Check out these articles from the Journal of Ultrasound in Medicine (JUM). Members of AIUM can access them for free after logging in to the AIUM. Join the AIUM today!):

Lymphosonography: The use of contrast-enhanced ultrasound as a lymphatic mapping technique

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Ipsilateral axillary diagnostic ultrasound is part of the initial staging for breast cancer to evaluate lymph nodes using a b-mode classification where certain aspects, when present, increase the level of suspicion for metastatic disease, such as cortical thickening and poor hilar visibility.1–3 Diagnostic ultrasound is also used as a method to guide biopsies of the suspicious lymph nodes.1

The majority of patients will have no suspicious lymph nodes findings at the time of diagnosis, the lymphatic system mapping after the injection of blue dye and/or a radioactive tracer followed by a surgical excision becomes the only way to determine the final stage of disease. However, these methods have limitations such as the use of radiation and lack of an imaging component.

In the past, ultrasound could not be used for lymphatic mapping, since mapping requires administration of a tracer. This changed with the use of contrast-enhanced ultrasound (CEUS) to detect lymph nodes after subcutaneous injections of microbubble-based ultrasound contrast agents (UCA), termed “lymphosonography”.4–6 The development of the lymphosonography technique addressed the limitations of the currently used lymphatic mapping techniques.

Our group conducted a clinical trial to evaluate the efficacy of CEUS lymphosonography in the identification of sentinel lymph nodes (SLN) in patients with breast cancer undergoing surgical excision following the injection of blue dye and radioactive tracer as part of their standard of care using pathology results for malignancy as a reference standard.6,7

In the clinical trial, 86 subjects were enrolled and 79 completed the study. The subjects received 4 subcutaneous injections of ultrasound contrast agent around the tumor, for a total of 1.0 ml. A clinical ultrasound scanner with CEUS capabilities was used to identify SLNs. After the ultrasound study examination, the subjects received blue dye and radioactive tracer for guiding SLN excision as part of their standard of care. The SLNs excised during the standard-of-care surgical excision were classified as positive or negative for presence of blue dye, radioactive tracer and UCA, and sent for pathology to determine presence or absence of metastatic involvement.

Example of a sentinel lymph node (SLN) seen with lymphosonography. The arrow indicates the SLN. The arrowhead indicates the lymphatic channel.

A total of 252 SLNs were excised from the 79 subjects. Of the 252 SLNs excised, 158 were positive for blue dye, 222 were positive for radioactive tracer and 223 were positive for UCA. Statistical comparison showed that compared with the reference standards, lymphosonography showed similar accuracy with radioactive tracer (p > 0.15) and higher accuracy (p < 0.0001). The pathology results showed that, of the 252 SLNs excised, 34 had metastatic involvement and were determined malignant by pathology. Of these 34 SLNs, 18 were positive for blue dye (detection rate of 53%), 23 were positive for radioactive tracer (detection rate of 68%) and 34 were positive for UCA (detection rate of 100%; p < 0.0001).

The conclusion of this study indicates that lymphosonography had similar accuracy as the standard-of-care methods for identifying SLNs in breast cancer patients, with the added advantage of an imaging component that allows for a preoperative evaluation of SLNs and that lymphosonography may be a more specific and precise approach to SLN identification in patients with breast cancer.6

Larger multicenter clinical trials are necessary to be able to translate this technique to the clinical setting and to be able to incorporate it as part of the breast cancer patients’ standard of care.

  1. Voit CA, van Akkooi ACJ, Schäfer-Hesterberg G, et al. Rotterdam Criteria for sentinel node (SN) tumor burden and the accuracy of ultrasound (US)-guided fine-needle aspiration cytology (FNAC): can US-guided FNAC replace SN staging in patients with melanoma? J Clinical Oncol 2009; 27(30):4994–5000.
  2. Dialani V, Dogan B, Dodelzon K, Dontchos BN, Modi N, Grimm L. Axillary imaging following a new invasive breast cancer diagnosis—A radiologist’s dilemma. J Breast Imaging 2021; 3:645–658.
  3. Chang JM, Leung JWT, Moy L, Ha SM, Moon WK. Axillary nodal evaluation in breast cancer: state of the art. Radiology 2020; 295:500–515.
  4. Goldberg BB, Merton DA, Liu J-B, Thakur M, et al. Sentinel lymph nodes in a swine model with melanoma: contrast-enhanced lymphatic US. Radiology 2004; 230:727–734.
  5. Goldberg BB, Merton DA, Liu J-B, Murphy G, Forsberg F. Contrast‐enhanced sonographic imaging of lymphatic channels and sentinel lymph nodes. J Ultrasound Med 2005; 24:953–965. doi: 10.7863/jum.2005.24.7.953.
  6. Machado P, Liu J-B, Needleman L, et al. Sentinel lymph node identification in patients with breast cancer using lymphosonography. Ultrasound Med Biol 2023; 49:616–625. Epub 2022 Nov 26.
  7. Machado P, Liu JB, Needleman L, et al. Sentinel lymph node identification in post neoadjuvant chemotherapy breast cancer patients undergoing surgical excision using lymphosonography. J Ultrasound Med 2023; 42:1509–1517. doi: 10.1002/jum.16164. Epub 2023 Jan 2.

Priscilla Machado, MD, FAIUM, is a Research Assistant Professor in the Department of Radiology at Thomas Jefferson University in Philadelphia, PA.

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