Screening for Chromosomal and Congenital Anomalies

Screening for chromosomal and congenital anomalies has evolved significantly with the use of ultrasound. Adding Serum analytes to the evaluation of congenital anomalies has increased the detection rate. This addition includes maternal serum alpha fetoprotein (MSAFP), b-HCG, Estriol, Inhibin A, Free bHCG, and Pregnancy Associated Plasma Protein A (PAPP-A).

Sequential screening consists of two steps:

  1. Nuchal translucency (NT), with Free b-HCG and PAPP-A during the first trimester, and
  2. Quadruple testing during the second trimester.
    This modality takes the detection of trisomy 21 (T21) to 95%.

More recently, tests that measure the cell free fetal DNA (NIPT) in the maternal serum have become commercially available. The detection rate for T21 is 99%.

Many patients have opted for a first-trimester NT measurement, NIPT, and a 20-week ultrasound for anatomical survey. My concern and question to our group is where do we leave the MSAFP screening? Does your practice offer MSAFP to patients that opt for this approach?

Luis A. Izquierdo, MD, MBA, CPE, FAIUM, is a professor of OB GYN and Maternal Fetal Medicine at the University of New Mexico.

Ultrasound to Differentiate Benign From Malignant Ovarian Tumors—Are We There Yet?

Adnexal (ovarian) tumors present a complex problem. Ovarian cancer (Ovca) is the second most common gynecologic cancer in the United States with the highest mortality rate of all gynecologic cancer, 7th among all cancers, and with a general survival rate of 50%.1 Thus, missing Ovca when performing any kind of test (false negative) will have grave consequences but suspecting it when not present (false positive) can have almost as critical results with morbidity and mortality secondary to (unnecessary) intervention.

The purpose of this post is not to review the differential diagnosis of ovarian tumors nor to discuss chemical markers such as CA125 or cancer-specific signal found on cell-free DNA (cfDNA) but to concentrate on ultrasound. Some tumors are relatively easy to recognize because of defined ultrasound characteristics: corpus luteum with the classic “ring of fire” or endometrioma with the ground-glass appearance content, for instance (image 1a and b). Conversely, a large, multilocular lesion with solid components and profuse internal Doppler blood flow leaves little doubt about its malignant nature (image 2).

Image 2: A large, multilocular lesion with solid components.

What are the ultrasound characteristics we look at?

  1. Size: Unilocular cystic ovarian tumor < 10 cm in diameter or simple septated cystic ovarian tumor < 10 cm in diameter rarely, if ever, are neoplastic.2
  2. Volume: Normal volume for premenopausal and postmenopausal ovaries are < 20 cm3 and 10 cm3, respectively.
  3. Appearance: Risk of malignancy in simple, unilocular anechoic cyst, less than 5 cm is < 1% in premenopause and about 2.8% in postmenopause.3
  4. Blood flow criteria: The rationale is that arteries formed by neovascularization in malignant tumors lack tunica media, resulting in lowered impedance (= less resistance to blood flow). Thus, resistance indices will be lower in cancer than in benign tumors. Malignancy was suspected with Doppler indices: pulsatility index (PI)<1 and/or resistive index (RI)<0.4.4 However, too much overlap makes reliance on only Doppler unjustified.

A very important point is that the expert performs very well when analyzing the ultrasound images of an ovarian mass, with a sensitivity of 92–98% and a specificity of 89%. The issue is how to help the non-expert decide whether he/she can continue the care of the patient or needs to refer her to a specialist. Based on several ultrasound criteria, scoring systems were implemented. The first one, in 1990, included appearance (unilocular, unilocular solid, multilocular, multilocular solid, or solid cyst) and presence of papillae (graded according to their number: 0 [none], 1 [one to five], or 2 [more than five]). This method had a sensitivity (true positive rate, or chance that person testing positive actually has Ovca) for malignancy of 82% with a specificity (true negative rate or chance that person with a negative test does not have Ovca) of 92%.5 Two important additional scoring systems were described later: the Morphology Index (MI) combining tumor volume, wall structure, and septal structure and the Risk of Malignancy Index (RMI), the product of ultrasound morphology score, CA 125 level, and menopausal status.6 Additional systems included the Logistic Regression 1 (LR1) and 2 (LR2). None of the published scoring systems were superior to image assessment by an expert, including in a meta-analysis of 47 articles, including over 19000 adnexal masses7 and, in reality, were not used widely in clinical practice.

The International Ovarian Tumor Analysis (IOTA) models

In 2000, a large group of European experts (gynecologists, radiologists, statisticians, biology, and computer experts) published a standardized terminology for the characterization of adnexal masses.8

The two important systems are the Simple Rules (SR) and the Assessment of Different NEoplasias in the adneXa (ADNEX) model. These were externally validated in numerous centers across the world but not in the USA.9 Recently, however, validation on the largest hitherto US population was published.10 This study showed for the first time that the models were effective in this population, regardless of menopausal status or race. These models are easy to learn and are geared towards non-experts.11 It is important to note that the IOTA group was one of the first to incorporate acoustic shadow as a key feature, and the acoustic shadow has been shown to be an important sonographic feature to consider.12

  1. Simple Rules: The IOTA Simple-Rules consist of 2 sets of 5 elements each: benign and malignant.13 Three simple rules are applied: if only benign characteristics are present, the mass is classified as benign. If only malignant features are present, the mass is considered malignant. If no features or both are, the findings are inconclusive. This model works well in about 80% of cases. The other 20% should be referred to an expert.
  2. ADNEX model14: This is a multiclass prediction model to differentiate between benign and malignant tumors and allows automatic calculation of sub-classification of malignant tumors into borderline tumors, Stage I, and Stage II–IV primary cancers, and secondary metastatic tumors. “The advantage of this model is that it gives a personalized risk score for each patient, based on age, whether the patient is seen at an oncology center or not, maximal diameters of the lesion and the solid parts, number of cysts and papillary projections, whether acoustic shadows are present, whether ascites is present and CA125 value (if available, not mandatory for calculation). With a cut-off value for malignancy risk set at 10%, the ADNEX model (with CA125) had a sensitivity of 94.3%, with a specificity of 74%, positive predictive value of 76%, and negative predictive value of 93.6%.”14

The O-RADS model

In 2020, the American College of Radiology convened an international multidisciplinary committee that developed an ultrasound model based on an MRI model used in mammography (the BI-RADS atlas), the O-RADS model (the Ovarian-Adnexal Reporting and Data System) to facilitate differentiation between benign and malignant ovarian tumors.15 It relies on the sonographic nomenclature developed by the IOTA group, but it classifies tumors into 1 of 6 categories (O-RADS 0–5), from normal to high risk of malignancy. O-RADS also includes guidelines for the management of the findings. It should be noted that the O-RADS first model did not take into account the presence or absence of an acoustic shadow, although this has now been amended.

A description of the most recent common ultrasound scoring systems (SR, ADNEX, and O-RADS) is available in the Journal of Ultrasound in Medicine (JUM): Yoeli-Bik R, Lengyel E, Mills KA, Abramowicz JS. Ovarian masses: The value of acoustic shadowing on ultrasound examination. J Ultrasound Med 2023; 42:935–945.    

References

  1. https://www.cancer.org/cancer/types/ovarian-cancer/about/key-statistics.html
  2. Saunders et al. Risk of malignancy in sonographically confirmed septated cystic ovarian tumors. Gynecol Oncol 2010; 118:278–282.
  3. Valentin et al. Risk of malignancy in unilocular cysts: a study of 1148 adnexal masses classified as unilocular cysts at transvaginal ultrasound and review of the literature. Ultrasound Obstet Gynecol 2013; 41:80–89.
  4. Bourne et al. Transvaginal colour flow imaging: a possible new screening technique for ovarian cancer. BMJ 1989; 299:1367–370.
  5. Granberg S et al. Tumors in the lower pelvis as imaged by vaginal sonography. Gynecol Oncol 1990; 37: 224–229.
  6. Yamamoto Y, Yamada R, Oguri H, Maeda N, Fukaya T. Comparison of four malignancy risk indices in the preoperative evaluation of patients with pelvic masses. Eur J Obstet Gynecol Reprod Biol 2009; 144:163–167.
  7. Meys EM et al. Subjective assessment versus ultrasound models to diagnose ovarian cancer: A systematic review and meta-analysis. Eur J Cancer 2016; 58:17–29.
  8. Timmerman D, Van Calster B, Testa A, et al. Predicting the risk of malignancy in adnexal masses based on the simple rules from the international ovarian tumor analysis group. Am J Obstet Gynecol 2016; 214:424–437.
  9. Abramowicz JS, Timmerman D. Ovarian mass-differentiating benign from malignant: the value of the International Ovarian Tumor Analysis ultrasound rules. Am J Obstet Gynecol 2017; 217:652–660.
  10. Yoeli-Bik R, Longman RE, Wroblewski K, Weigert M, Abramowicz JS, Lengyel E. Diagnostic performance of ultrasonography-based risk models in differentiating between benign and malignant ovarian tumors in a US cohort. JAMA Netw Open 2023; 6:e2323289.
  11. Valentin L, Ameye L, Jurkovic D, et al. Which extrauterine pelvic masses are difficult to correctly classify as benign or malignant on the basis of ultrasound findings and is there a way of making a correct diagnosis? Ultrasound Obstet Gynecol 2006; 27:438–444.
  12. Yoeli-Bik R, Lengyel E, Mills KA, Abramowicz JS. Ovarian masses: The value of acoustic shadowing on ultrasound examination. J Ultrasound Med 2023; 42:935–945.
  13. Timmerman D, Testa AC, Bourne T, et al. Simple ultrasound-based rules for the diagnosis of ovarian cancer. Ultrasound Obstet Gynecol 2008; 31:681–90.
  14. Van Calster B, et al. Evaluating the risk of ovarian cancer before surgery using the ADNEX model to differentiate between benign, borderline, early and advanced stage invasive, and secondary metastatic tumours: prospective multicentre diagnostic study. BMJ 2014; 349:g5920.
  15. Andreotti RF, Timmerman D, Strachowski LM, et al. O-RADS US risk stratification and management system: a consensus guide-line from the ACR ovarian-adnexal reporting and data system committee. Radiology 2020; 294:168–185.

Appendix

Classification of primary ovarian tumors

  1. Ovulatory: functional or corpus luteum cyst; theca lutein cyst; polycystic ovary
  2. Infectious or inflammatory: tubo-ovarian abscess; hydrosalpinx
  3. Benign: serous or mucinous cystadenoma; endometrioma; mature cystic teratoma (most common primary benign tumor of the ovary); paraovarian/paratubal cysts
  4. Borderline: serous, mucinous
  5. Malignant
  6. Epithelial: high-grade serous carcinoma (HGSC; 70 to 80%); endometrioid carcinoma (10%); clear cell carcinomas (10%); mucinous carcinoma (3%); Low-grade serous carcinoma (LGSC; <5%); Brenner tumor; carcinosarcoma or malignant mixed müllerian tumor (MMMT); undifferentiated,
  7. Germ cell (20%): teratoma: immature, specialized teratomas of the ovary (struma ovarii, carcinoid tumor); dysgerminoma; yolk sac tumor: endodermal sinus tumor; embryonal carcinoma; choriocarcinoma: <1% of ovarian tumors; malignant mixed germ cell tumor
  8. Sex cord / stromal ovarian tumors (8–10%): fibrothecoma (fibroma, thecoma); Sertoli-Leydig cell tumor; granulosa cell tumor (juvenile or adult); small cell carcinoma

Jacques S. Abramowicz, MD, is a professor in the Department of Obstetrics and Gynecology at the University of Chicago.

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

Mastering Ovarian Tumor Analysis: Join the AIUM-IOTA Partnership Course for Advanced Gynecologic Ultrasound

Ovarian lesions are a common finding among women, with etiologies ranging from ovarian changes related to normal hormonal function to aggressive malignancies. Therefore, the proper diagnosis and management of ovarian lesions are critical to women’s health. Here, I’ll give a brief description of ovarian tumor analysis, including descriptors, pattern recognition, and the application of the International Ovarian Tumor Analysis (IOTA) group’s Simple Rules, the IOTA ADNEX model, and O-RADS ultrasound characterization.

An ultrasound image of ovarian lesions.

Descriptive Analysis of Ovarian Tumors

The first step in the diagnosis of ovarian tumors is descriptive analysis. This step involves a detailed examination of the tumor’s characteristics, including its size, shape, texture, and location. This information is obtained through various imaging techniques, such as ultrasound, MRI, and CT scans. The following descriptors are used in descriptive analysis:

  • Size: The size of the tumor is measured in centimeters and is one of the critical factors in determining the type of tumor.
  • Shape: The shape of the tumor is described as either round or irregular. An irregular shape is often associated with malignant tumors.
  • Texture: The texture of the tumor is classified as either solid, cystic, or mixed.
  • Location: The location of the tumor is described as either unilateral or bilateral. Unilateral tumors are located on one ovary, while bilateral tumors are located on both ovaries.

Pattern Recognition of Ovarian Tumors

An essential aspect of ovarian tumor analysis is pattern recognition. It involves identifying specific patterns associated with malignant and benign tumors. The following patterns are commonly observed in ovarian tumors:

  • Solid: Solid tumors are characterized by the absence of cystic components and are often associated with malignancy.
  • Cystic: Cystic tumors are characterized by the presence of fluid-filled spaces and are typically benign.
  • Mixed: Mixed tumors have both solid and cystic components and can be either benign or malignant.

Application of the Simple Rules, the IOTA ADNEX Model, and O-RADS Ultrasound Characterization

The Simple Rules, the IOTA ADNEX Model, and O-RADS ultrasound characterization are 3 widely used methods for differentiating ovarian tumors.

  • The Simple Rules: The Simple Rules are a set of guidelines that assist in the diagnosis of ovarian tumors. The rules are based on the tumor’s size, shape, texture, and location. According to the Simple Rules, a tumor is considered benign if it meets all 3 of the following criteria: 1) it is purely cystic, 2) it is less than 10 cm in size, and 3) it has a thin, smooth wall.
  • IOTA ADNEX Model: The IOTA ADNEX Model is a predictive model that uses a combination of clinical and ultrasound findings to diagnose ovarian tumors. The model considers the tumor’s size, shape, texture, location, and other factors, such as the patient’s age and menopausal status. Then, the model provides a probability score for each tumor, indicating the likelihood of malignancy.
  • O-RADS Ultrasound Characterization: O-RADS is a standardized ultrasound reporting system that categorizes ovarian tumors based on their likelihood of malignancy. The system uses a 5-point scale, ranging from 1 (very low risk) to 5 (very high risk). The O-RADS system considers the tumor’s size, shape, texture, location, and vascularity.

The proper diagnosis and management of ovarian lesions are critical to women’s health. Descriptive analysis, pattern recognition, and the application of the Simple Rules, the IOTA ADNEX Model, and O-RADS ultrasound characterization are essential aspects of ovarian tumor analysis. These methods aid in accurately diagnosing and differentiating ovarian tumors and can guide appropriate treatment decisions.

Are you a healthcare professional looking to enhance your skills in gynecologic ultrasound and ovarian tumor analysis? Look no further than the Advanced Gynecologic Ultrasound course offered by the American Institute of Ultrasound in Medicine (AIUM) in partnership with the International Ovarian Tumor Analysis (IOTA) group.

This course offers a unique and valuable opportunity for healthcare professionals looking to enhance their skills in gynecologic ultrasound and ovarian tumor analysis. The comprehensive curriculum, hands-on training, and networking opportunities make it a worthwhile investment for healthcare professionals looking to improve patient outcomes and advance their careers. Register now for the course, taking place this June, at the AIUM Headquarters in Laurel, Maryland.

Sources
https://www.cancer.org/cancer/types/ovarian-cancer/about/what-is-ovarian-cancer.html
https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/cncr.11339
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620878/
https://pubmed.ncbi.nlm.nih.gov/18504770/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4402441/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9728190/
https://www.mdpi.com/2075-4418/13/5/885

Arian Tyler, BS, is the Digital Media and Communications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

The Value of a Repeat Nasal Bone Evaluation in First-Trimester Screening for Down Syndrome

First-trimester screening for Down syndrome, a genetic disorder caused by the presence of an extra chromosome, usually involves a combination of maternal blood tests and an ultrasound exam (ie, a combined first-trimester screening [FTS]), which is performed between 11 and 14 weeks of pregnancy.

During the ultrasound exam, the healthcare provider evaluates various markers that can indicate an increased risk of Down syndrome, such as the thickness of the nuchal translucency (a fluid-filled space at the back of the fetus’s neck) and the presence of certain physical features, including the nasal bone. Because research has shown that fetuses with Down syndrome are less likely to have a visible nasal bone on ultrasound than fetuses without the condition, evaluating the nasal bone can help healthcare providers assess the risk of Down syndrome more accurately.

Although visualizing the nasal bone is not a mandatory component of the screening, the inclusion of fetal nasal bone evaluation in the screening improves the clinical performance of the screen for the detection of fetal Down syndrome. Unfortunately, factors such as maternal body habitus (such as increased body mass index [BMI]), poor acoustic windows, unfavorable fetal position, delayed nasal bone ossification, and early gestational age can hinder nasal bone visualization then. In addition, ethnicity may also affect the visualization of the fetal nasal bone as the development of the fetal nasal bone differs between populations. Acknowledging and integrating the differences in facial structure between different racial and ethnic groups can help to promote equity in prenatal imaging and ensure the provision of accurate, personalized risk counseling across patient populations.

Therefore, a recent study aimed to determine if repeat nasal bone evaluation provided a significant improvement in refining the specificity of Down syndrome risk assessment by combined FTS, as well as determine the efficacy of a repeat nasal bone evaluation across various maternal ethnicities.

The study reviewed the medical records of patients who underwent a first-trimester ultrasound evaluation in an American Institute of Ultrasound in Medicine (AIUM)-accredited center between January 2015 and January 2018. The study focused on patients with fetal nasal bone labeled as “absent or hypoplastic” or “unable to be adequately visualized” during the ultrasound. The researchers reviewed the records to assess factors such as patient age, ethnicity, follow-up evaluations, and fetal anomalies. They analyzed the combined FTS results and followed up with patients with abnormal results. They then conducted statistical analyses to compare patient ethnicity and nasal bone visualization on the second exam, as well as to compare patient ethnicity and fetal Down syndrome risk by combined FTS.

The study identified 589 cases (8.7%) of absent or uncertain fetal nasal bone on initial nuchal translucency (NT) ultrasound evaluation among the 6780 total NT ultrasounds performed, with the most frequently represented ethnicities being African American/Caribbean (46.2%) and White (36.8%). Of the total, 125 patients (21.2%) did not complete a repeat nasal bone evaluation, and 105 patients with additional risk factors pursued genetic counseling. Of these patients, 20 pursued chorionic villus sampling (CVS), and 11 of these cases (55.0%) reported abnormal karyotypes. Of the 376 eligible patients who completed a second nasal bone evaluation (exam 2), 82 patients (21.8%) had an absent fetal nasal bone, 26 (6.9%) had an uncertain fetal nasal bone, and 268 (71.2%) had a present fetal nasal bone. White patients were statistically significantly more likely than African American/Caribbean patients to have a present nasal bone on exam 2 (82.9% and 59.2% respectively, P < .0001), as were Asian Indian patients (100% and 59.2%, respectively, P < .0001).

Combined FTS can identify fetuses at high risk for aneuploidy, but it has a relatively high false positive rate. Therefore, proper identification of the absence or presence of the fetal nasal bone during FTS plays a critical role in identifying and counseling patients at increased risk for fetal aneuploidy. The study found that repeat nasal bone evaluation could reduce false positive FTS results, particularly in African American/Caribbean populations.

Even with the widespread use of cell-free DNA screening, combined FTS, including nasal bone assessment, remains an important tool for first-trimester aneuploidy risk assessment.

To read more about this study, download the Journal of Ultrasound in Medicine article, “Follow Your Nose: Repeat Nasal Bone Evaluation in First-Trimester Screening for Down Syndrome” by Kristen A. Miller, MGC, et al. Members of the American Institute of Ultrasound in Medicine (AIUM) can access it for free. Join the AIUM today!

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

Why Have UltraCon FOMO When You Can Be a Part of the Transformation of Medical Ultrasound?

Are you still on the fence about deciding whether or not to attend UltraCon, a reimagined take on the American Institute of Ultrasound in Medicine’s annual meeting? The transformation of the AIUM’s annual ultrasound meeting into UltraCon is an exciting step forward for the field. It will provide a platform to connect professionals, share ideas, and learn from each other. 

Previously, we’ve highlighted the benefits of attending Day 1 and Day 2 of UltraCon, but what about Day 3? Just one look at the UltraCon schedule, and you can tell that this is going to be its busiest day yet! Despite the jam-packed program, there are a ton of amazing professional development opportunities ready for you to explore. On Tuesday, four new symposia will kick off, covering topics from 3D/4D imaging to musculoskeletal sonography. There’s also a shark tank competition, an e-poster kiosk hall, the annual AIUM Awards session, and don’t forget about the William J. Fry Memorial Lecture. 

Let’s dive into the first new symposia, Early Pregnancy Ultrasound: Implications and Impacts on Care. This TED-talk-style forum is a great resource for learning about critical issues in the first trimester, such as providing equitable care in the emergency department and managing life-threatening situations. It has not only valuable information for medical professionals but also provides important insight into how to support patients after Dobbs. Participants can earn up to 1.5 CMEs.

Next, we have Optimizing Outcomes in Prenatal Imaging. During this symposia, participants can increase the quality and patient experience in obstetric imaging with a multidisciplinary approach. A group of specialists will present TED talks on topics such as early trimester issues, health inequities, and maternal/fetal life-threatening situations. Improve imaging outcomes via a perception bias workshop, challenging cases, and using the 3D world to understand ultrasound. Plus, roundtables with industry on image optimization and a special session on understanding the lifecycle of prenatal imaging. Participants can earn up to 3.0 CMEs.

POCUS: Cutting-Edge Uses and Controversies is the third symposium of Day 3. Point-of-care ultrasound (POCUS) is revolutionizing the way clinicians diagnose and treat patients. By providing real-time insights, POCUS offers quick, accurate, and cost-effective diagnosis of clinical problems. From development to bedside, POCUS has changed the game for clinicians worldwide. Are you seeking an engaging and informative symposium to discuss current POCUS advancements in medical ultrasound? Look no further than POCUS: Cutting-Edge Uses and Controversies symposium, which discusses topics such as global health, first-trimester concerns, scan ownership, POCUS workflow, and more. With an array of activities, including lectures, panel discussions, and workshops, this is sure to be a stimulating symposium that will leave you informed and inspired.

Breaking the Sound Barrier: Shaping the Future of Ultrasound is the last symposium of the day. The highly interactive symposium on ultrasound technologies is a great opportunity for clinicians, technologists, researchers, industry, and other stakeholders to learn about the latest advancements in ultrasound technology. This symposium will provide an invaluable platform for experts to share their knowledge and insights on how to utilize ultrasound techniques in clinical settings effectively. Attendees will have a chance to interact with leading professionals from around the world and discuss potential solutions for existing challenges within this field.

Outside of attending the symposia, there are several other interactive activities for participants to engage in. Firstly, the AIUM supports an ePoster program every year where attendees can explore and learn at their own pace through self-guided exploration. Secondly, attendees who have a great ultrasound idea and want to pitch it to industry can submit an application to pitch their ideas to venture capitalists, leaders from the industry, and an IP attorney, for the chance to win a cash prize of $1,000. Lastly, don’t forget to attend the 2023 William J. Fry Lecture given by pioneer in gynecologic ultrasound, Dr. Steven R. Goldstein, entitled “Do You Do POCUS: Why reinvent the wheel?”.  

UltraCon will be the must-attend event of the year for medical professionals who want to stay up-to-date on the latest advancements in ultrasound technology. With a wide variety of engaging sessions and workshops, there’s something for everyone, so avoid getting caught with FOMO. All of this is just what is available on the third day of symposia at UltraCon. Check out the Full Schedule to start planning out your UltraCon journey.

Arian Tyler, BS, is the Digital Media and Communications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

Optimize Screening of the Fetal Heart

The keys to optimizing screening of the fetal heart are to understand how the ultrasound machine’s functions and controls can affect your image, utilize the entire maternal abdomen, adjust your image presets, and optimize your angle of insonation. So how do you do all that?

You start with the transducer. Be sure to select a transducer that allows for adequate penetration and optimal resolution. All transducers have different operating frequencies and capabilities; high frequencies produce better detail resolution but, of course, with limited sound penetration. These frequencies can be applied in all trimesters, particularly since the advent of high-resolution transducers, which are helpful when imaging delicate heart structures, such as the valves and vessel walls. If, however, the imaging is subpar with a high-frequency transducer, switch to a low-frequency transducer, which is more useful in your patients with a high body mass, in the late second trimester, in the third trimester, and in the event that there is also polyhydramnios syndrome, even when there is rib shadowing. Keep in mind too, that transvaginal imaging is helpful for evaluating the fetal heart in the first or early second trimester, in the event that there is suspected fetal cardiac abnormality, and even when maternal body habitus causes imaging to be difficult.

For your next step, adjust your image presets to optimize your temporal resolution so that you maintain a high frame rate of greater than 25 frames per second. A few of the technical settings that affect temporal resolution are the frame rate (in Hz), frequency selection, depth & focus, sector angle width, and zoom magnification. The better the temporal resolution, the improved detail resolution. To optimize your image, avoid unnecessary depth and make sure your focus is on the region of interest. A multiple focal zone may be applied to structures that don’t move, such as the placenta, but when looking at the 4-chamber heart, you will need a single focal zone. In addition, adjust your sector angle width. Reducing it increases lateral line density, which improves the image quality. Finally, make small adjustments to your settings, such as applying speckle-reduction imaging, adjusting the dynamic range (more or less gray), and scanning in different tones.

When incorporating color Doppler, the color box, color gain, wall motion filter, velocity scale/pulse repetition frequency (PRF), balance, and angle of insolation can each affect the image. The color box slows the frame rate by a significant degree so the smaller the color box, the higher the frame rate. Set color gain initially on low (ie, less color) and gradually increase it until you have optimized the amount of color. The wall motion filter eliminates signals caused by wall motion and low velocities. The velocity scale is the range of mean velocities or PRF in the region of interest. If it is too low, it can produce aliasing, which could lead to a misdiagnosis; too high and the low-velocity flow will not be displayed. Here is a sample of potential ideal velocity flows:

High-velocity flow (>60–80 cm/sec)Low-velocity flow (<30 cm/sec)
Atrioventricular valvesPulmonary veins
Semilunar valvesBicaval (IVC/SVC)
The great vessels (3VV)Evaluating atrial and ventricular septum
The scale is dependent on factors such as body mass index and fetal positioning within the uterus.

The balance allows you to display how much grayscale and color Doppler information you would like to see. Reducing the balance will show grayscale elements within the color box. And, finally, the angle of insonation is very important to keep in mind as the signal from the transducer should be parallel to the direction of blood flow.

J of Ultrasound Medicine, Volume: 35, Issue: 1, Pages: 183-188, First published: 01 January 2016, DOI: (10.7863/ultra.15.02036)

One of the major challenges in ultrasound imaging is scanning a morbidly obese patient. This is a result of the increased distance between the transducer and fetal anatomy, causing degraded resolution. Some techniques for optimizing your imaging in these cases include scanning above the tissue, when the patient’s bladder is full, through the umbilicus, or when the patient is in the Sim’s position (with the patient on their left side), which allows the extra tissue to fall to the left side. Also, keep in mind that when scanning an obese patient, the color doesn’t always fill in. Lowering the color attenuation can help clarify the image.

So, remember, the key to optimizing your fetal heart imaging is in understanding your machines’ functions and controls and how they can affect your image, utilizing the entire maternal abdomen, adjusting your image presets, and optimizing your angle of insonation!

To learn more and see case scenarios, see the American Institute of Ultrasound in Medicine’s (AIUM’s) on-demand webinar with speaker Mishella Perez, MS, RDMS, RDCS, “Fetal Heart Image Optimization: The Key to Screening”, from which this post was adapted. AIUM members can access the webinar for free.

Interested in learning more about fetal imaging? Check out the following resources from the American Institute of Ultrasound in Medicine (AIUM):

O-RADS: Standardizing the way we assess adnexal lesions (and an app to make it easy!)

“When a word has many meanings, it has no meaning at all”. (Anonymous)

Let’s face it: ovarian lesions seen on ultrasound can be some of the most challenging to assess and describe. When not a simple cyst, generic terms such as “complex” are commonly used providing limited insight to the provider and patient regarding the level of concern for risk of malignancy. For instance, shown here are 3 different lesions that could all be described as “complex” or “heterogeneous”, yet range from nonneoplastic to malignant.

Figure 1. Hemorrhagic cyst
Figure 2. Benign dermoid cyst
Figure 3. Endometriod carcinoma

Compound the ambiguity of nonspecific descriptors in the imaging report with the angst of possibly missing an ovarian cancer, a rare but deadly disease, and the result is “over treatment”. Too often, surgery or additional imaging are performed for physiologic and benign findings with the added unintended consequences of associated morbidity and patient anxiety.

Enter O-RADS, an acronym for the Ovarian/Adnexal Reporting and Data System.

Similar to other American College of Radiology (ACR) “RADS” systems (ie, BI-RADS for breast imaging), O-RADS gets everyone speaking the same language AND provides a risk of malignancy using a numeric scale of 0 to 5 (Table 1).

Table 1. Risk of malignancy (ROM) associated with O-RADS Risk Stratification and Scoring System for US and MRI. (NOTE: US systems allow for greater sensitivity at the expense of specificity to avoid not missing a cancer.)

In O-RADS, there are two arms: 1) ultrasound (US), the primary imaging modality for the adnexa used by practitioners from many disciplines; and 2) magnetic resonance imaging (MRI), considered a problem-solving tool for radiologists. With O-RADS ultrasound, management guidance is also provided on triaging lesions to follow-up (clinical or imaging surveillance), additional characterization (by a specialist in US or with an MRI exam), or surgery. For the latter group, this is further divided into those lesions that can be excised by a general gynecologist, and those best managed by a gynecologic-oncologist, an important factor in improving long-term survival in the setting of ovarian malignancy.

Using the available descriptors in the O-RADS lexicon and an algorithmic approach, characterizing adnexal lesions is simplified. First, determine whether a finding in a menstruating patient meets criteria for a physiologic finding (follicle or corpus luteum). If it does not, or the patient is postmenopausal, assess for a “classic benign lesion”, a phrase coined for fairly common lesions that are almost certainly benign when typical features are seen (hemorrhagic cyst, endometrioma, dermoid cyst, paraovarian cyst, hydrosalpinx or peritoneal inclusion cyst). The remainder of lesions are assigned to 1 of 5 categories based on their solid or cystic appearance, and if cystic, the presence of septations and solid components as follows: solid lesion, unilocular cystic ± solid component(s), multilocular cystic ± solid component(s). Subsequently, features such as degree of internal vascularity, lesion size, ascites, and peritoneal nodules may come into play.

To score a lesion, color-coded O-RADS risk stratification tables are readily available and a useful resource. I personally find the O-RADS smartphone app to be an efficient and handy tool to quickly obtain a score and management recommendations. On average, I can reach a score in under 30 seconds and all the information I need for the imaging report is literally at my fingertips.

Since we started using O-RADS, our referring clinicians are asking for an O-RADS score whenever we describe an adnexal lesion as it gives them so much more useful information to counsel their patients. For instance, the patient in figure 1 with a hemorrhagic cyst did not require any imaging follow-up, the patient in figure 2 with a dermoid cyst has safely elected to undergo US surveillance in 1 year, and the patient in figure 3 with endometrioid cancer is doing well under the care of her gynecologic-oncologist.

For me, replacing vague terms (with many meanings) with standardized reporting systems not only makes sense, it’s truly meaningful.

Additional resources:

Dr. Lori Strachowski is a Clinical Professor of Radiology at the University of California, San Francisco, where she holds an adjunct title in the department of Obstetrics, Gynecology and Reproductive Sciences. She is a member of the ACR O-RADS committee serving on the steering committee and chairs the education committee for O-RADS US.

Ultrasound-Guided Obstetric and Gynecologic Procedures in the Pelvis

Ultrasound guidance can be a safe and effective technique in obstetric and gynecologic procedures. Before beginning such a procedure, consider which approach will you take, transabdominal, transgluteal, or transvaginal. The approach that uses the shortest distance to the area of interest without transversing other structures is usually the best tolerated by the patient and will rarely result in complications, which are uncommon and usually minor, such as pain or self-limited bleeding. To select the shortest and safest path for access, review prior cross-sectional imaging and determine it on a case-by-case basis.

In cases of fluid management, such as benign adnexal cyst or peritoneal inclusion cyst fluid collection, note that you may need a larger needle gauge (18+) in those instances in which the fluid is thick. If you intend to test for malignancy, also take into account that fluid is generally less likely than solid tissue to give up the cells needed for a diagnosis.

Fine-needle aspiration in a case with mixed cyst and solid mass.

Ultrasound guidance can also enable delivery of vascular acting medications directly where it is needed, as well as to guide direct gestation sac injection of potassium chloride (KCl) and/or methotrexate for cervical, interstitial, or C-section ectopic or heterotopic pregnancies in appropriate patients.

In conclusion, transvaginal or percutaneous ultrasound guidance can be used in the search for a diagnosis, in fluid collections, and to treat obstetric and gynecologic pathology, such as delivering medications to treat ectopic pregnancy or vascular conditions in select cases.

To learn more about this topic and see examples of its use, watch the full on-demand webinar, “Ultrasound-Guided Interventions to Treat Obstetric and Gynecologic Disease” presented by Tara A. Morgan, MD. Members of the American Institute of Ultrasound in Medicine can access it for free. Join today!

Read more from Tara A. Morgan, MD, on ultrasound guidance in the Journal of Ultrasound in Medicine:

Getting Sonography Students Hands-on Experience

As the Program Director of a Commission on Accreditation of Allied Health Education Programs (CAAHEP)-accredited General sonography program, I have a request for all OB/GYN practices. Please open your practice to accept sonography students. The future of the OB sonographer depends upon it.

If schools cannot provide graduates with good entry-level OB skills, there will not be enough sonographers to fill the OB sonography positions within private practices and this includes the MFM specialties.

Student rotations are down because the sonographers are too busy to allow students to scan. I have been given the following reasons why they are too busy:

  1. Patients are scheduled every 30 minutes all day.
  2. Work-ins are expected to be added daily into the already booked schedule
  3. It is not uncommon for a single sonographer to perform 15–20 patients per day.
  4. There are usually no breaks except for lunch, maybe.
  5. Some practices have more than one sonographer but each performs the same amount of studies so there is no relief person to help out.

This type of scheduling (over-scheduling) sets up a whole new set of questions.

  1. How long can one sonographer sustain such a schedule without suffering from burn-out and choose to leave employment?
  2. How long can one sonographer sustain such a schedule without suffering from repetitive stress injuries that will force their retirement?
  3. If sonographers are having to rush through studies to get all of the patients through, what are they missing?
  4. What is the satisfaction level of the patient who feels they are on an assembly line when getting their sonogram?  I do believe this is one reason many “peek-a-boo -see your baby” businesses are flourishing; OB patients want to experience fetal bonding with their families, time for which the private practice schedules do not allow. (“The AIUM advocates the responsible use of diagnostic ultrasound and strongly discourages the non-medical use of ultrasound for entertainment purposes.” See The Issue with Keepsake Ultrasounds for more information.)

Although there is value in observation, which the students may be allowed to do, nothing can replace a hands-on experience with supervision and instruction. And, yes, labs help, but the accrediting bodies require our students to scan patients not models.

For at least 2 decades, educators have struggled to find OB clinical sites that would allow their students to gain the scanning skills needed to complete their clinical competency exams, which are required for graduation. With no resolution in sight, even the Joint Review Committee on Education in Diagnostic Medical Sonography (JRC-DMS) and CAAHEP have recognized that some General accredited programs could not meet all the standards and, therefore, have now provided us a way to separate out the specialties. This allows for the deletion of the OB specialty from their accredited programs. This is a way for educators to deal with the problem of not being able to gain access to 2nd- and 3rd-trimester OB patients for their students, but it will ultimately be bad news for the OB community in general.

I believe the sonography community is an intelligent and creative group. We can find ways to integrate students into a busy environment. I actually have some clinical sites that do a very good job of it. I encourage you to think outside of the box and let’s get creative so that the schools will be able to provide qualified graduates when they are needed. If we don’t, we will begin seeing private OB “cross-training” on the job, again.

Is that what we really want? Comments, opinions, rebuttals, suggestions are encouraged and I look forward to reading them all.

Kathy A. Gill, MS, RT, RDMS, is a Program Director of the Institute of Ultrasound Diagnostics in Spanish Fort, Alabama. Kathy has been a Registered Diagnostic Medical Sonographer since 1977 and has been involved in sonography education for 30+ years.

Interested in learning more about ultrasound in medical education? Check out the following posts from the Scan:

COVID Life in the Prenatal Ultrasound Suite

It is crazy to think that we are approaching the end of the second year of the worldwide COVID-19 pandemic. If the pandemic were a child, it would be walking, talking, and soon entering the “terrible twos”. In fact, my son was born in late February 2020, so all he knows is the pandemic. To him, masks are normal. He has even started to ask to wear a mask because that’s what everyone else does—mom, dad, his daycare teachers, his grandparents, his cousins. Though once he has one on, he quickly realizes that he prefers life without a mask.

Don’t we all, Andy?

As with most people, work life since the pandemic has changed. As a maternal-fetal medicine fellow, I’ve dedicated my training to the care of pregnant people and their fetuses, and I find the most fulfillment in the ultrasound suite. As cases rose, rooms filled with family and friends waiting for the words on the screen, “It’s a girl!”, during an anatomic survey became rooms with only a masked pregnant person and a masked sonographer (and the unmasked fetus, of course). While one adult support person has always been allowed to accompany each patient at our institution, they were frequently absent, whether they were working from home, caring for other children who are not allowed at appointments, or trying to limit exposures. Sonologists that previously were in and out of ultrasound rooms, scanning and counseling patients, were reading exams and counseling remotely.

Despite all the changes, the work continued. In fact, the pandemic has reminded us all that prenatal ultrasound is a medical necessity. At the height of the pandemic, elective medical procedures were canceled across the country. But the prenatal sonographers and maternal-fetal medicine specialists donned their N95s and face shields, and the prenatal ultrasound suite continued operation. In fact, cases that would have previously been managed with twice weekly non-stress tests were managed with weekly biophysical profiles instead to minimize potential exposures for a patient. Even with a current maternal diagnosis of COVID, arrangements were made to continue weekly umbilical artery Doppler studies for cases of fetal growth restriction. Some scans just cannot be delayed for 2 weeks. Despite all the changes, our purpose was clearer than ever—to provide excellent care for our patients, maternal and fetal.

With the widespread distribution of the vaccine and the decrease in cases, work life has settled into a “new normal”. Children have returned to in-person school, and the support person has returned to the ultrasound suite. N95s have been replaced by more comfortable surgical masks. Counseling a patient and their partner is no longer accompanied by the same degree of fear of a COVID exposure. But life is still far from my expectation of normal. The smiles after receiving the good news that there is one healthy intrauterine pregnancy with a strong heartbeat are still hidden behind cloth, as is the discomfort of an amniocentesis and the anguish when informed of a lethal fetal diagnosis. The impact that the mask continues to make on my ability to connect with and care for my patients cannot be understated.

As we head into the “terrible twos”, I know the pandemic will continue on and there will continue to be ups and downs. Misinformation regarding vaccination still limits widespread acceptance, but as research continues to demonstrate the safety and efficacy of vaccination, I still hold on to the hope that one day I will again be able to sit in a room with a patient unmasked and take in the unspoken communication I’ve so missed. But in the meantime, I’ll take the “new normal” and make the best of it for myself, my family, my colleagues, and my patients.

Kathy Bligard, MD, MA, FACOG, is a loving mom and third-year maternal-fetal medicine fellow at Washington University School of Medicine in St. Louis, MO.

Interested in learning more about patient care? Check out the following posts from the Scan: