Making Waves in Sonography Research | January 2023

JANUARY 2023

Making waves IN SONOGRAPHY RESEARCH

Content EMERGING TECHNOLOGIES

Deep

learning radiomics based on contrast-enhanced ultrasound images for assisted diagnosis of pancreatic ductal adenocarcinoma and chronic pancreatitis

3

CARDIAC

Recommendations

for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: An update from the American Society of Echocardiography (ASE) in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Magnetic Resonance & the Society of Cardiovascular Computed Tomography

5

MUSCULOSKELETAL

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

7

MUSCULOSKELETAL

ltrasound findings in subcutaneous plantar vein thrombosis: U retrospective analysis of seven patients

9

RESEARCH

esearch interest, experience and confidence of allied R health professionals working in medical imaging: a cross-sectional survey

10

VASCULAR

he reproducibility of measuring maximum abdominal aortic T aneurysm diameter from ultrasound imaging

12

PAEDIATRIC

Paediatric neck ultrasonography: a pictorial essay

13

PAEDIATRIC

Persistence of the processus vaginalis and its related disorder

15

WOMEN’S HEALTH

Ductus venosus agenesis and portal system anomalies – association and outcome

16

WOMEN’S HEALTH

Reproductive outcomes in 326 women with unicornuate uterus

17

© Australasian Sonographers Association 2023. Disclaimer: The information in this publication is current when published and is general in nature; it does not constitute professional advice. Any views expressed are those of the author and may not reflect ASA’s views. ASA does not endorse any product or service identified in this publication. You use this information at your sole risk and ASA is not responsible for any errors or for any consequences arising from that use. Please visit www.sonographers.org for the full version of the Australasian Sonographers Association publication disclaimer

Making waves

JANUARY 2023 | 2

EMERGING TECHNOLOGIES REVIEWED BY Kosta Hellmanns ASA SIG: Emerging technologies REFERENCE

Deep learning radiomics based on contrast-enhanced ultrasound images for assisted diagnosis of pancreatic ductal adenocarcinoma and chronic pancreatitis

Authors: Tong T, Gu J, Xu D, Song L, Zhao Q, Cheng F, Yuan Z, Tian S, Yang X, Tian J, Wang K & Jiang T Journal: BioMed Central 2022; 20(74) Open Access: Yes READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED The study aims to develop a deep learning model using advanced feature analysis (radiomics) on contrast-enhanced ultrasound (CEUS) images to assist radiologists in identifying pancreatic duct adenocarcinoma (PDAC) and chronic pancreatitis (CP), thus increasing diagnostic accuracy and avoiding unnecessary biopsy and surgery for patients.

HOW THE STUDY WAS PERFORMED The study was undertaken with retrospective datasets from three hospitals. The hospital with the largest dataset was used as the primary cohort – patients admitted in 2020 used as the training cohort and those admitted in 2021 used as the internal validation cohort. The datasets from the remaining hospitals were smaller, and as such, used as two external validation cohorts. The inclusion criteria for the study were patients with pathologically confirmed CP without progression to pancreatic cancer in the six proceeding months or PDAC without distant metastasis, patients whose CEUS examinations were performed just prior to biopsy and surgery, and the availability of CEUS videos/images. The exclusion criteria were the presence of multiple lesions in the pancreas, a history of pancreatic surgery/chemotherapy, and inadequate image quality. This resulted in a sample of 351 for the training cohort, 109 for the internal validation cohort, 50 and 48 for the external validation cohorts.

For the analysis, one key CEUS image from each of the patient examinations was selected showing the maximum diameter of the lesion at approximately 35 seconds from injecting the contrast agent (early pancreatic phase of contrast perfusion). From this image, a region of interest (ROI) of the lesion area was determined by the radiologist on the raw greyscale image of CEUS acquisition, following which the ROI was marked at the same location on the CEUS images, before converting it to greyscale (for consistency across US machines) and resized to be appropriate for analysis. As shown below (extracted Figure 2), resized and grayscale ROI images were fed into the DLR model developed for the study, which then returned an AI score and heatmap for each lesion. In the first round read, radiologists made an initial decision on the lesions as per usual (i.e. blinded to each other, the original diagnostic reports and final pathology results, and without AI assistance). In the second round, radiologists could refine their first round of diagnoses with the additional AI score and heatmap information.

Making waves

JANUARY 2023 | 3

EMERGING TECHNOLOGIES

Deep learning radiomics based on contrast-enhanced ultrasound images for assisted diagnosis of pancreatic ductal adenocarcinoma and chronic pancreatitis

“Utilising deep learning with contrast-enhanced ultrasound to increase the accuracy of diagnosis for pancreatic duct adenocarcinoma and chronic pancreatitis.”

Figure 1. Workflow of ROI extraction, processing and the deep learning model

WHAT THE STUDY FOUND Diagnoses were compared with confirmed pathological findings from biopsy or surgery in all patients. The statistical results of the cohorts are reported within the article. Results highlighted that the diagnoses of the five radiologists were either worse or comparable to those of the DLR model, with the model achieving better sensitivity and specificity than all radiologists in the first round read. In the second round read with AI assistance – all radiologists achieved higher sensitivity, with four out of the five radiologists achieving higher specificity in the internal validation cohort, two out of the five in the external cohort 1 and one out of the five in the external cohort 2.

RELEVANCE TO CLINICAL PRACTICE The DLR model is an effective tool that can be utilised to assist radiologists in the diagnosis of PDAC and CP.

Making waves

JANUARY 2023 | 4

CARDIAC

REVIEWED BY Susannah Mahar ASA SIG: Cardiac REFERENCE

Recommendations for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: An update from the American Society of Echocardiography (ASE) in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Magnetic Resonance & the Society of Cardiovascular Computed Tomography

Authors: Abraham T, Armour AC, Desai MY, Dragulescu A, Gilliland Y, Lester SJ, Maldonado Y, Mohiddin S, Nagueh SF, Nieman K, Phelan D, Sperry BW, Woo A Journal: Journal of the American Society of Echocardiography 2022; June READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED AND WHAT THE STUDY FOUND This article was written to review the evolution of multiple imaging techniques used to assess and differentiate hypertrophic cardiomyopathy from other causes of left ventricular hypertrophy (LVH). The article is composed of three sections. The first focuses on imaging, including echocardiography, cardiac magnetic resonance, cardiac computed tomography and cardiac nuclear imaging. The second section reviews the use of imaging for risk stratification and prognostication, and the final section discusses the role of multimodality imaging in common clinical scenarios. In conclusion, the article highlights the importance of using as many modalities as possible to evaluate, diagnose and guide treatment in patients with hypertrophic cardiomyopathy.

Initially, the article outlines the specific characteristics and symptoms of hypertrophic cardiomyopathy (HCM). It reviews the benefits and pitfalls of each technique and sums up how to differentiate HCM from other phenotypes including athletic remodelling, hypertension, inflammation and infiltration.

Echocardiography is the primary modality used for assessing the pattern of left ventricular hypertrophy. When the images are suboptimal, then ultrasound enhancing agents (UAEs) are recommended. Cardiac magnetic resonance (CMR) and cardiac computed tomography are also suggested due to their high spatial resolution. Cardiac resonance uses late gadolinium enhancement (LGE) with T1 and T2 mapping, which is beneficial in evaluating patients who have increased wall thickness.

Thorough assessment of the patient also includes looking for concomitant pathology such as aortic stenosis, subaortic membrane, apical aneurysm, thrombus and mid-cavity obstruction which can mimic hypertrophic cardiomyopathy.

The following assessments are also required: • left ventricular systolic function • diastolic function • dynamic left ventricular outflow tract obstruction • mitral valve anatomy.

Section two highlights the use of multimodality imaging to help with risk stratification and prognostication. Sudden cardiac death (SCD) is low in patients with hypertrophic cardiomyopathy. Currently, there is an algorithm that calculates the risk of sudden cardiac

Making waves

JANUARY 2023 | 5

CARDIAC

Recommendations for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: An update from the American Society of Echocardiography (ASE) in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Magnetic Resonance & the Society of Cardiovascular Computed Tomography

death (HCM-SCD score) based on age, maximal wall thickness, LA diameter and maximal left ventricular outflow tract gradient, but this article questions the sensitivity of the score and suggests including more imaging guidelines to direct treatment. Inclusion of the following parameters: apical aneurysm, late gadolinium enhancement (LGE) by CMR, LV systolic dysfunction and ischaemia are necessary to support treatment options such as implantable cardiac defibrillator (ICD) pacemakers and septal reduction therapy (SRT).

The final section highlights the importance of multimodality imaging in common clinical scenarios such as chest pain and coronary artery disease. Myocardial perfusion imaging techniques such as positron emission topography (PET), cardiac computed tomographic angiography (CCTA) and cardiac magnetic resonance (CMR) are the preferred methods of investigation. The best noninvasive assessment of the coronary arteries is CCTA, and both PET and CMR are preferred techniques for stress perfusion. Echocardiography is used initially as a screening tool and for patients in the pre and postprocedural setting.

“Appropriate understanding and utilisation of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM.”

IN CONCLUSION THE RELEVANCE TO CLINICAL PRACTICE Multimodality imaging plays a crucial role in the initial evaluation of patients with known or suspected hypertrophic cardiomyopathy. It is central to risk stratification for sudden cardiac death and can be used in common clinical settings such as chest pain and coronary artery disease. When performed by an experienced practitioner, and in conjunction with clinical findings, imaging can confirm or refute findings and guide relevant therapies.

Making waves

JANUARY 2023 | 6

MUSCULOSKELETAL REVIEWED BY Sheri Anne Rae ASA SIG: Musculoskeletal REFERENCE

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

Authors: Morrison T, Jones S, Causgy RS, Thoirs K, PLoS ONE 16(9): e0257790 READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED In people with diabetes mellitus, the plantar foot soft tissue can undergo structural changes including reduced thickness or elasticity impairing the foot’s ability to resist and absorb mechanical loads and causing the foot to become vulnerable to ulceration. Amputation is a serious sequela in diabetics with foot ulcerations. Ultrasound may be used to assess the plantar soft tissue in the feet of people with diabetes who are at increased risk of pathological changes. The aim of this study was to determine the intra and interobserver reliability of soft tissue characteristic assessments using ultrasound and to determine the intraobserver reliability of plantar soft tissue measurements performed on unloaded and compressed ultrasound images obtained at foot sites with known risk of tissue injury in people with diabetes mellitus.

HOW THE STUDY WAS PERFORMED A convenience sample of 15 participants with (N = 6) and without diabetes (N = 9) was recruited for the repeated measures design study. Ultrasound images were taken in both unloaded and compressed states at four plantar foot sites known for increased peak plantar pressure and frequency of ulceration: • heel • lateral sesamoid of the hallux • second sub-metatarsal head • third sub-metatarsal head.

At each of the four plantar foot sites, thickness measurements were undertaken by one experienced sonographer twice to control the test-retest environment at discrete tissue layers (Figure 1) including: • skin • superficial subcutaneous (microchamber) • horizontal fibrous band • deep subcutaneous (macrochamber) • total soft tissue depth.

“Ultrasound measurement of the unloaded total soft tissue depth is the most sensitive for detecting small change and thus is the preferred measurement method.”

Figure 1. Ultrasound image demonstrating the plantar heel with the transducer in the longitudinal plane and measurement locations.

Asterisk indicates gel stand-off

Making waves

JANUARY 2023 | 7

MUSCULOSKELETAL

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

For the soft tissue characteristic assessments, an a priori sample size of 22 participants with (intraobserver N = 13, interobserver N = 9) and without (intraobserver N = 9, interobserver N = 13) diabetes was recruited. Ultrasound tissue characteristics of the previously noted plantar foot sites in an unloaded state were assessed for each anatomical soft tissue layer. The echogenicity and the distinctness of the anatomical layers were compared with a reference set of images from a healthy young adult foot and assessed with the dichotomous variables same or not same. For intraobserver testing, one experienced sonographer independently performed tissue characterisation assessments and scored the images. For the interobserver testing, two experienced sonographers independently analysed and scored the images.

WHAT THE STUDY FOUND Intraobserver reliability was achieved with measurements of the total soft tissue depth in an unloaded state at all anatomical sites in the test and retest trials. Relative intraobserver reliability was also achieved for unloaded state measurements of the deep subcutaneous (macrochamber) layer. However, the unloaded total soft tissue depth measurements were more sensitive for detecting small changes than the unloaded deep subcutaneous (macrochamber) measurements. Absolute reliability for measurements of the deep subcutaneous (macrochamber) layer and total soft tissue depth was always higher in the unloaded state when compared to the compressed state. Reduced reliability for measurements made in the compressed state may be attributable to variations in the manual pressure applied through the handheld transducer causing the transducer to slip from the central measurement position.

Plantar skin thickness measurements demonstrated intraobserver reliability only when made at the site where the skin was thickest – at the heel pad. Measurement of the superficial subcutaneous (microchamber) layer and the horizontal fibrous bands was not consistently reliable across any of the anatomical sites. Surface undulations, poor differentiation of the anatomical layers and the relative thinness of the skin, superficial subcutaneous (microchamber) layer and horizontal fibrous band may make calliper placement difficult and susceptible to measurement error. While intraobserver agreement was demonstrated for some of the tissue characteristic assessments (heel skin, lateral sesamoid fat pad and the second and third sub-metatarsal heads skin and fat pad), acceptable interobserver agreement was not demonstrated for any of the tissue characteristic assessments.

RELEVANCE TO CLINICAL PRACTICE Regular clinical risk assessment may not necessarily capture the subclinical manifestations (such as tissue degeneration, stiffening and atrophy) that can proceed ulcer development.

Ultrasound can be used to depict these characteristics and has potential for a further positive impact in assessing the risk of plantar foot ulceration in people with diabetes mellitus.

Ultrasound measurement of the unloaded total soft tissue depth is the most sensitive for detecting small change, and thus is the preferred measurement method for detecting differences between groups and changes in individuals across repeated measurements. Serial ultrasound soft tissue characterisation assessments of plantar foot soft tissue on the same patient should be made by the same observer where possible.

Making waves

JANUARY 2023 | 8

MUSCULOSKELETAL

REVIEWED BY Michelle Fenech ASA SIG: Musculoskeletal REFERENCE

Ultrasound findings in subcutaneous plantar vein thrombosis: retrospective analysis of seven patients

Authors: Bortolotto C, Draghi F, Bianchi S Journal: Acta Radiologica 2022; 63(11):1522–1527 READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED Subcutaneous plantar vein thrombosis (SCPVT) is an uncommon cause of forefoot pain. It involves thrombosis of the veins which sit superficial to the plantar fascia. Although deep plantar vein thrombosis is a recognised entity, SCPVT is less well appreciated, and prior to this study, SCPVT has previously been reported once before in radiologic literature. This study was performed to review cases in which SCPVT was sonographically identified and reported to enhance sonographic knowledge regarding this condition.

HOW THE STUDY WAS PERFORMED A retrospective search of studies performed where SCPVT had been sonographically diagnosed between January 2016 to 2020 was undertaken. Seven positive cases were identified (3 men, 4 women; 47–61 years of age). Sonographic B-mode and colour and power Doppler imaging demonstrating SCPVT was retrieved and reviewed, as well as the clinical symptoms of presenting patients. The sonographic technique, B-mode (location, echogenicity, margins, shape, change with compression) and colour and power Doppler features of SCPVT and adjacent veins (to describe if they appeared within normal limits, dilated, or compressed) were documented.

WHAT THE STUDY FOUND A localised painful plantar nodule was palpable at physical examination in 5 of 7 patients who presented for imaging. In patients without a plantar nodule, diffuse pain of the plantar aspect of the foot was reported. No skin changes were identified on any patients. The subcutaneous thrombosed vein appeared as a rounded or oval-shaped nodule in the subcutaneous plantar tissues ranging from 4–7 mm in size, which was connected to adjacent patent veins. Light and adjustable transducer pressure was required to demonstrate the superficial plantar veins.

Thrombosed veins failed to compress completely during real-time scanning. Adjacent plantar foot structures were within normal limits in 5/7 patients, while one patient demonstrated concurrent plantar fasciitis and another patient demonstrated a small third intermetatarsal space Morton’s neuroma.

STRENGTHS AND LIMITATIONS OF THE STUDY A retrospective analysis was conducted and ultrasound only was used as the imaging modality to confirm the diagnosis of SCPVT. Although the sample size reviewed for this report is small, this is expected in a rare entity. All patients were followed up and made a complete recovery.

RELEVANCE TO CLINICAL PRACTICE

“Although reported as a rare entity, it may be underreported, and should be considered as a differential diagnosis to avoid invasive studies or surgical exploration.”

This work highlights the importance of considering SCPVT as a condition that may be encountered sonographically when patients present with nodules and pain in the plantar aspect of the foot. Although reported as a rare entity, it may be underreported and should be considered as a differential diagnosis to avoid invasive studies or surgical exploration.

Other causes of plantar nodules can include, most commonly, Ledderhose disease (plantar fibromatosis), which is a benign nodular thickening (may be singular or multiple) of the plantar fascia/aponeurosis, which does not usually demonstrate any vascularity inside the lesion on colour/power Doppler. Other conditions which may result in plantar nodules include plantar fascia tears, leiomyoma, schwannoma, warts, infected cysts and other less frequently encountered conditions (xanthoma, foreign body reactions, diabetic fascial disease, and local infections). These other conditions do not demonstrate any relationship with the superficial plantar veins. If SCPVT is identified sonographically, concurrent conditions of the plantar aspect of the foot still need to be excluded including Morton’s neuroma, intermetatarsal bursitis, adventitial bursitis, plantar plate tears, and metatarsophalangeal synovitis.

Making waves

JANUARY 2023 | 9

RESEARCH REVIEWED BY Ling Lee ASA SIG: Research REFERENCE

Research interest, experience and confidence of allied health professionals working in medical imaging: a cross-sectional survey

Authors: Dennett AM, Cauchi T, Harding KE, Kelly P, Ashby G, Taylor NF Journal: J Med Radiat Sci 2021; 68:121–130 READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED The authors first acknowledged the importance of a strong research culture in health services by stating the benefits of a positive research culture, such as improved health services using evidence-based practices, staff satisfaction within the organisation and better patient care, which led to the growing interest and investment in research capacity in allied health professions, including medical imaging.

The article stated the strategies to increase research capacity specific to medical imaging are i) the implementation of a ‘research radiographer’; and ii) the introduction of ‘pop up’ research centres. Both strategies have successfully contributed to the appointment of two research fellows in two metropolitan health services within the Allied Health Clinical Research Office, an initiative by the Victorian Department of Health, to assist medical imaging allied health professionals in performing research.

There has been little research performed to measure the research skills and experience of medical imaging allied health professionals (hereby referred to as MI), including radiographers, sonographers and nuclear medicine technologists when compared to other allied health therapy professionals (hereby referred to as AHT), such as physiotherapists, occupational therapists, psychologists, speech pathologists, and so on.

The aim of the study was to identify the self-reported research participation of MI, more specifically in the areas of research interest, experience, and confidence, and compare the findings to AHT.

HOW THE STUDY WAS PERFORMED A quantitative, cross-sectional survey (paper and online formats) was distributed to medical imaging allied health professionals working at a large metropolitan health network in Melbourne, Australia. The health network consists of three acute hospitals, two subacute sites, a small regional hospital, and several small community-based sites.

The inclusion criteria for the survey were radiographers, sonographers, and nuclear medicine technologists. The exclusion criteria were nurses, radiologists, and non-allied health professionals. No radiation therapists were included as none were employed by the health network.

The data was collected over a period of three months from August to October 2019. The result was compared to the survey results collected from allied health therapy professionals in 2015 from the same health network.

The research SPIDER tool was used to report the data collected towards i) research interest; ii) research experience; and iii) research confidence, respectively. These three aspects were rated against ten categories as below: 1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

writing research proposal/protocol using quantitative methods publishing research writing and presenting research report analysing and interpreting results using qualitative methods critically reviewing literature finding relevant literature generating research ideas applying for research funding.

Each category was measured by a 5-point Likert scale from 1 (none) to 5 (very).

Making waves

JANUARY 2023 | 10

RESEARCH

Research interest, experience and confidence of allied health professionals working in medical imaging: a cross-sectional survey

WHAT THE STUDY FOUND There was a total of 126 medical imaging allied health professionals working at the health network at the time of the study but only 65% (82) of the surveys were completed. Most of the participants were radiographers (59), while the remaining were 13 sonographers and 9 nuclear medicine technologists. Overall, the research participation and awareness towards existing research promotions and training initiatives were significantly lower among MI when compared to AHT. When using the research SPIDER tool to report results on the three aspects (research interest, experience and confidence), MI and AHT had very similar findings which were ‘some research interest’ (median 3, IQR 2 to 4); ‘little research experience’ (median 2, IQR 1 to 3); and ‘little research confidence’ (median 2, IQR 1 to 3). MI reported the highest level of interest, experience, and confidence in the category of finding relevant literature and the lowest level of interest, experience, and confidence in the category of applying for research funding.

For research interest, AHT had significantly higher interest in four categories when compared to MI, which were using qualitative methods, critically reviewing literature, finding relevant literature and generating research ideas. The finding showed research interest and confidence were moderately correlated with research experience. According to the survey result, there was no difference in interest, experience, and confidence between different medical imaging professions, which were radiography, sonography, and nuclear medicine.

LIMITATIONS OF THE STUDY A small sample size, moderate response rate and data collected from a single health network were the limitations of the study. It was recognised that the comparison from the two surveys collected from different time frames (years 2015 and 2019) might not be a true reflection; however, the authors mentioned that there were no changes over time in the research interest and experience in the cohort of AHT based on previous research conducted in the same health network.

“The first step is to view research as part of our clinical role, instead of a separate entity.”

RELEVANCE TO CLINICAL PRACTICE Given that all health practitioners are required to deliver evidence-based practice, various efforts and strategies are required to grow the research capacity within the health professions, including medical imaging allied health professionals.

This was the first study conducted in Australia to evaluate the research interest, experience, and confidence among MI as an initiative to gain understanding on how to further develop a research culture. MI was traditionally perceived to evince a lack of interest in research participation due to the nature of the workflow, workplace hierarchy and disassociation of research responsibility from the clinical workload. The study successfully demonstrated that research interest among MI was similar to AHT, a cohort that traditionally has been provided with more research support. Thus the authors suggested a better research culture is feasible among MI by applying successful strategies adopted by other allied health professions.

The study mentioned the Allied Health Clinical Research Office within the health network has been focusing on providing support and training to allied health professionals. The strategies offered by the research office include a research training scheme, quarterly newsletter, monthly research clinics, an annual research forum, leadership of major externally funded projects, onsite higher degree research supervision and consultancy.

The above strategies and initiatives could be incorporated into our clinical practice to grow a strong research culture in our field. The first step is to view research as part of our clinical role instead of a separate entity.

Making waves

JANUARY 2023 | 11

VASCULAR REVIEWED BY Daniel Rae ASA SIG: Vascular REFERENCE

The reproducibility of measuring maximum abdominal aortic aneurysm diameter from ultrasound imaging

Authors: Matthews EO, Pinchbeck J, Elmore K, Jones RE, Moxon JV and Golledge J Journal: The Ultrasound Journal READ THE FULL ARTICLE HERE

WHY THE STUDY WAS PERFORMED The most important established predictor of abdominal aortic aneurysm (AAA) growth and rupture is the maximum AAA diameter. This is used in clinical practice to guide patient management and surgical decision making.

Reproducible methods to measure AAA diameter are therefore both important clinically and in research. Disparate methods of calliper placement have been reported to cause differences of up to 5 mm.

HOW THE STUDY WAS PERFORMED A sample of 50 participants was selected with infrarenal aneurysms measuring between 30–55 mm in maximum diameter. Three observers were present: a qualified vascular sonographer, a clinical medical student, and a research worker. Five total measurements were taken of the aortic aneurysm: • three were in the anterior-posterior plane – outer-to-outer (OTO), inner-to-inner (ITI) and leading edge-to-leading edge (LETLE) • two were in the transverse plane – outer-to-outer and inner-to-inner.

Figure 1 shows ideal placement of callipers for ITI ( / ), LETLE ( ), OTO ( / ) in both anterior-posterior and transverse direction. OTO: outer-to-outer; LETE: leading edge-to-leading edge; ITI: inner-to-inner The test was then repeated later with observers blinded to their previous results.

Figure 1: Illustration of a transverse view of an abdominal aortic aneurysm with the participant in the supine position.

WHAT THE STUDY FOUND The data suggests that the calliper position in the anterior-posterior (AP) plane, with measurements obtained perpendicular to the orientation of the ultrasound probe, showed no statistical difference between ITI, OTO and LETE placement. These findings indicate that measurements in the AP plane should be used in clinical practice and clinical trials. The measurement of transverse ITI or OTO diameter is not as reproducible.

Reproducibility was demonstrated to be better within rather than between operators, suggesting repeat measurements should be taken by the same observer.

RELEVANCE TO CLINICAL PRACTICE The results from this study highlight the importance of taking AAA measurements in an AP plane rather than in a transverse plane for diagnostic accuracy and reproducibility. It also raises the suggestion of having the same operator perform surveillance studies due to increased accuracy of intraoperator observations.

Making waves

“The results from this study highlight the importance of taking AAA measurements in an AP plane rather than in a transverse plane for diagnostic accuracy and reproducibility.

It also raises the suggestion of having the same operator …”

JANUARY 2023 | 12

PAEDIATRIC REVIEWED BY Ilona Lavender ASA SIG: Paediatric REFERENCE

Paediatric neck ultrasonography: a pictorial essay

Authors: Caprio MG, et al.

Journal: Journal of Ultrasound READ THE FULL ARTICLE HERE

WHY THE REVIEW WAS PUBLISHED Ultrasound of the paediatric neck is a common examination; however, not all sonographers are familiar with the range of pathologies which can be found in this region. This article describes the normal appearances seen in the paediatric neck and covers the most common pathologies which could be encountered.

WHAT THE ARTICLE LOOKED AT The article commences by stating the importance of a high frequency transducer such as a 10–15 MHz and having a systematic approach when scanning. The systematic approach recommended when scanning the paediatric neck is to: 1. p erform cross-sectional scans of the entire thyroid gland, comparing the two lobes and measuring the anterior-posterior and transverse diameters 2. make longitudinal scans, measuring the longitudinal diameter 3. identify any focal lesions, measuring the largest one, where present.

The normal anatomy of the neck is described, including the thymus, which is often seen in the paediatric patient – it is usually hypoechoic with thin hyperechoic straps and shouldn’t be mistaken for pathology. The lymph node levels are clearly described (Levels I–VII) and the normal measurements of the thyroid are given.

In most cases, to adequately assess the neck, the thyroid, salivary glands and lymph nodes should be examined.

This article describes a range of pathologies (with corresponding ultrasound images) which could be found when scanning the paediatric neck.

THYROID DISEASES Thyroid dysgenesis This umbrella term includes a series of conditions such as aplasia, hypoplasia, hermiplasia and ectopic.

Thyroiditis This is an inflammatory process resulting in the thyroid being heterogeneous, often with multiple hypoechoic regions. Colour Doppler is essential as there is hypervascularity in the acute phase and hypovascularity in the chronic stage.

Thyroid nodules Nodules are rare with > 85% being benign. As FNA in the paediatric setting often requires sedation, care must be taken to describe the nodules. The article does not specify which nodules require a fine needle biopsy (FNA).

LYMPHADENOPATHIES The average patient will have 5–6 normal lymph nodes which appear oval, have a hyperechoic hilum and are less than 1 cm with the exception of the jugulodigastric nodes which can be up to 2 cm.

Making waves

JANUARY 2023 | 13

PAEDIATRIC

Paediatric neck ultrasonography: a pictorial essay

CYSTIC LESIONS Thyroglossal duct cysts This is the most frequent malformation in the neck in paediatric patients, mainly affecting females < 5 years of age. These are located in the midline and generally mobility is observed during swallowing.

Branchial cysts These anomalies most commonly arise from the second brachial sulcus, and although congenital, appear in adolescence or puberty. They appear as cystic formations with clear margins, however, are at a high risk of infection.

Dermoid cysts These are benign lesions often located along the medial line in the neck. While its margins are defined, the texture can be homogeneous or heterogeneous depending on its content.

Histology is required to confirm the diagnosis.

“Ultrasound of the paediatric neck is a common examination; however, not all sonographers are familiar with the range of pathologies which can be found in this region.”

Haemangiomas and vascular malformations Haemangiomas are benign lesions usually clinically diagnosed and appear within the first few weeks of life. A typical characteristic on ultrasound is its hypervascularity. Vascular malformations are present at birth and generally grow proportional to the child’s development.

Fibromatosis colli These are often referred to as sternocleidomastoid (SCM) tumours and are thought to be due to ischaemia of the muscle, often associated with forceps delivery. The SCM appears as a fusiform region with consequent shortening.

Pilomatrixoma This is a benign tumour of the subcutaneous tissue appearing as an oval, heterogeneously hyperechoic lesion with a hypoechoic halo with calcifications.

RELEVANCE TO CLINICAL PRACTICE Assessment of the paediatric neck is a common examination. This article is a good resource when pathology in the paediatric neck is observed with good descriptors and corresponding ultrasound images. Furthermore, this article gives normal ranges for the thyroid gland.

Making waves

JANUARY 2023 | 14

PAEDIATRIC REVIEWED BY Allison Holley ASA SIG: Paediatric REFERENCE

Persistence of the processus vaginalis and its related disorder

Authors: Brainwood M, Berne G, Fenech M Journal: Australasian Society for Ultrasound in Medicine Open Access: Yes

WHY THE STUDY WAS PERFORMED

READ THE FULL ARTICLE HERE

Persistence of the processus vaginalis can result in a number of congenital pathologies in both the male and female patient. There is little published on the embryology, descent, and the ultimate closure of the processus vaginalis in terms of what can be visualised under ultrasound.

Ultrasound-based material is also limited when it comes to differentiation of a spectrum of conditions caused by the different stages of obliteration failure in males. It is worth noting that there is even less written regarding ultrasound involvement with pathologies in the female patient with a persistent canal of Nuck. This article was written to address both these voids.

HOW THE STUDY WAS PERFORMED Literature review

WHAT THE STUDY FOUND The article gives a concise, easy-to-follow review of the embryology in both males and females.

It clearly discusses the combined role of the processus vaginalis and the gubernaculum in testicular descent in males and goes on to discuss the comparative role of the gubernaculum and canal of Nuck in the location and stabilisation of the ovaries and uterus in the female. The side-by-side comparison of the male processus vaginalis to the female equivalent, the canal of Nuck, highlights the differences and similarities between sexes. The article gives a good description of the stages of obliteration of processus vaginalis and discusses in depth the anomalies that occur when different stages of obliteration fail. The role of ultrasound and the ultrasound appearances of each of the pathologies is discussed. The article also describes the criteria for confirming the presence of a contralateral patent processus vaginalis, which is an important role for ultrasound in the presurgical assessment.

RELEVANCE TO CLINICAL PRACTICE The article provides excellent tabulated descriptions of the different forms of hydrocele to enable accurate diagnosis and therefore treatment. These descriptions are accompanied by good quality ultrasound images for visual reference and assessment. The table provides an excellent reference chart for correctly classifying the pathologies and would be valuable if displayed in departments for easy reference.

Making waves

“The [article] provides an excellent reference chart for correctly classifying the pathologies and would be valuable if displayed in departments for easy reference.”

JANUARY 2023 | 15

WOMEN’S HEALTH REVIEWED BY Ann Quinton ASA SIG: Women’s Health REFERENCE

Ductus venosus agenesis and portal system anomalies – association and outcome WHY THE STUDY WAS PERFORMED

Authors: Nagy RD, Cernea N, Dijmarescu AL, Manolea M-M, Zorila G-L, Dragusin RC, et al.

Journal: Biology 2022; 11:548 READ THE FULL ARTICLE HERE

There has been limited research assessing the association of fetal portal venous system (PVS) anomalies (both partial and total agenesis) and agenesis of the ductus venosus (DV).

HOW THE STUDY WAS PERFORMED Prospective cohort study in a European tertiary prenatal unit of referred and routine second and third trimester scans. Sonographers were trained to identify i) DV in the longitudinal plane of the upper fetal abdomen; and ii) PVS in the transverse plane of the fetal abdomen at the level of the stomach and umbilical vein (UV). Junction of the portal sinus with the right and left portal veins and main portal vein were identified. All cases of agenesis DV were rescanned by maternal fetal specialists. Pregnant patients were offered karyotype and/or offered autopsy after termination or stillbirth. Live births had 6-month postnatal follow-up.

WHAT THE STUDY FOUND Agenesis of DV is three times more common than PVS anomalies. Incidence of agenesis DV was 5.1%, and PVS anomalies was 1.9%. The best predictor of adverse outcomes for agenesis of DV was the presence of other fetal anomalies. Other anomalies included major cardiac anomalies and gastrointestinal atresias. There were in total 19/3517 cases of agenesis DV and/ or PVS anomalies: 12 cases with agenesis DV and normal PVS; three cases with agenesis DV and total PVS agenesis; three cases with agenesis DV and partial PVS agenesis; one case of DV present with partial PVS agenesis. When agenesis of the DV occurs, drainage can be i) via the PVS (intrahepatic), usually the left portal vein; or ii) connect to systemic veins outside of the liver (extrahepatic) including the femoral vein, inferior vena cava, azygous vein, coronary sinus or direct to atria. Fourteen cases of agenesis DV had intrahepatic drainage, three extrahepatic and one combined intra and extrahepatic drainage. Isolated agenesis DV occurred in 28% of these cases and 5/19 cases had abnormal karyotype (T21, 45X0, mosaicism). The authors felt PVS development is DV dependent, and as isolated agenesis of the DV had a good outcome, they questioned whether the poor outcomes reported in the previous work of agenesis DV are overestimated.

STRENGTHS AND LIMITATIONS OF THE STUDY

“This article describes new research which depicts how to scan the fetal portal venous system (PVS) and ductus venosus (DV) and assess for agenesis in both systems. It demonstrates how assessment of the PVS and DV can be incorporated into a routine scan.”

Prospective study on a mixed population of low and high risk pregnancies. Provided excellent labelled images of the PVS and DV and anomalous drainage and techniques for imaging.

Outcomes being available in all cases was a strength, although postnatal outcomes were only up to 6 months, so long-term outcomes of partial PVS anomalies were not ascertained.

Limitation: small numbers of cases of agenesis DV and PVS anomalies.

RELEVANCE TO CLINICAL PRACTICE This work demonstrates how assessment of the DV and PVS can be incorporated into routine and tertiary practice. Isolated agenesis DV can have a good outcome. PVS anomalies were frequent in cases of agenesis DV with total PVS agenesis found in all cases of agenesis DV. When agenesis DV is found, the PVS should be interrogated. Total PVS anomalies and agenesis DV with other fetal anomalies are a predictor of poor fetal outcome.

Making waves

JANUARY 2023 | 16

WOMEN’S HEALTH REVIEWED BY Sarah Srayko Robinson ASA SIG: Women’s Health REFERENCE

Reproductive outcomes in 326 women with unicornuate uterus WHY THE STUDY WAS PERFORMED To evaluate and compare gynaecological and obstetrical outcomes in women with unicornuate uteri to those with no congenital uterine anomaly.

Authors: Tellum T, Bracco B, de Braud LV, Knez J, Ashton-Barnett R, Amin T, Chaggar P and Jurkovi D Journal: Ultrasound in Obstetrics and Gynaecology 2022; eISSN 1469-0705 Open Access: Yes READ THE FULL ARTICLE HERE

HOW THE STUDY WAS PERFORMED This was a single centre, retrospective cohort study of women over 16 years of age presenting with a unicornuate uterus compared to a control group who had a normally shaped uterus. All women were examined using either transvaginal or transrectal ultrasound, using a 4–9 MHz probe with 3D facility. A dynamic 2D transvaginal ultrasound was performed to assess the position and morphological appearances of the pelvic organs. The examination of the uterus included performing a series of parallel transverse sections and a right to left sweep in the longitudinal plane to visualise the endometrium and perform a measurement of its thickness.

3D transvaginal ultrasound volumes of the uterus were also acquired in all women.

WHAT THE STUDY FOUND Outcomes of the study focused on live birth rate, rates of pregnancy loss, ectopic pregnancy and the proportion of women who suffered recurrent miscarriages. Further outcomes focused on rates of preterm delivery and mode of delivery. Included in the results were findings of women diagnosed with endometriosis, adenomyosis, uterine fibroids, and genitourinary and anorectal tract abnormalities.

Three hundred and twenty-six women were included in the final analysis in addition to 326 matched controls, resulting in a study population of 652 patients. A rudimentary horn was observed in 218/326 women with a unicornuate uterus, with non-functional horns being more common than the functional type. There were a total of 88 vaginal, urinary tract or cloacal abnormalities in 68/326 women with unicornuate uteri, compared to a single abnormality in the control group.

The rate of miscarriage was significantly higher in women with unicornuate uteri compared to the control group, resulting in a significantly lower live birth rate. However, there was no apparent difference in the number of total pregnancies, miscarriages, or miscarriage rates between women with and without a functional rudimentary horn.

Another important finding of this study was that having a unicornuate uterus significantly increased the risk of ectopic pregnancy of any type. The number of women diagnosed with endometriosis was significantly higher in women with unicornuate uteri compared to the control group.

“Findings indicate that having a unicornuate uterus or rudimentary uterine horn is associated with a lower live birth rate, a higher risk of ectopic pregnancies and a higher risk of adenomyosis or endometriosis.”

The proportion of women who experienced a preterm delivery < 37 weeks was three times higher in the study group compared to the control group, and women with a unicornuate uterus were significantly more likely to require delivery by Caesarean section.

RELEVANCE TO CLINICAL PRACTICE This study demonstrates that the unicornuate uterus is associated with an increased risk of adverse pregnancy outcomes requiring close monitoring for the duration of the pregnancy. The risk of ectopic pregnancies is increased in all women with unicornuate uteri and ultrasound examinations of pregnant women with a unicornuate uterus should be arranged early in pregnancy. A detailed and systematic examination of uterine morphology should be standard routine in clinical practice to detect unicornuate uteri and expansion of the ultrasound examination to include the urinary tract should be performed when a unicornuate uterus is suspected.

Making waves

JANUARY 2023 | 17