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What are IOTA easy descriptors and simple rules: How to use them
Abstracts The sophistication of echocardiographic techniques continues to evolve but the wise physician will be cognizant of other noninvasive imaging modalities in an effort to further optimize patient management.
SESSION 3C: VASCULAR Dual frequency contrast ultrasound angiography F. Stuart Foster,1 Christine E.M. Demore,1 Emmanuel Cherin,1 Isabel Newsome,3 Claudia Carnevale,2 Paul A. Dayton3 1 Sunnybrook Research Institute and Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2 Fuji Film Visual Sonics Inc, Toronto, ON, Canada,, 3 Joint Graduate Department of Biomedical Engineering, University of North Carolina and North Carolina State University, NC, USA Acoustic angiography is a contrast imaging approach in which the superharmonics associated with low frequency excitation of microbubbles are received and processed over a broad bandwidth at a much higher frequency. As demonstrated by Dayton and colleagues, this technique facilitates the visualization of the microvasculature with a resolution typical of micro computed tomography and with superior contrast-to tissue-ratios than conventional nonlinear processing. To date dual frequency contrast imaging has been performed with a 2- 4 MHz annulus coaligned with 25-30MHz single element focused transducer operated by a Vevo770 (Visualsonics) scanner. This technology has limitations (mechanical scanning, single focus, limited focal depth) which hinder its clinical use but which could be alleviated using dualfrequency arrays (DFA). In this presentation we first describe the performance and applications of mechanical acoustic angiography and early results from the development of dual frequency array devices for acoustic angiography. The logical extension to array based designs is then explored. We built prototype dual frequency devices in both a vertical and horizonal topology. The horizonal topography consisted of a central 256 element high frequency array (HF, 20 MHz) flanked by two single element low frequency transducers(LF, 2 MHz) that extended for the length of the HF array. The vertical topography consisted of a 32-element LF transmitter array positioned behind a 256-element HF receiver array. Both arrays were built from piezoelectric composites. The HF backing material, between the two piezoelectric layers in the vertical design is weakly and highly attenuating at 2 MHz and 20 MHz, respectively. Two matching layers on the LF array and 4 matching layers on the HF array were used to improve transmission throughout the whole array structure. An elevation lens was added to focus the receive component at around 9 mm. Impedance and hydrophone measurements were performed to evaluate both configurations. Examples of super harmonic contrast imaging for each of the above configurations will be shown for phantom studies and preliminary in vivo images of animal models will be presented.
SESSION 3E: GYNAECOLOGY What are IOTA easy descriptors and simple rules: How to use them Wouter Froyman Consultant Gynaecologist, University Hospitals Leuven, Leuven, Belgium Many adnexal lesions (e.g. dermoid cysts, endometriomas) share typical characteristics which make them easy to identify ‘at a glance’, without needing to apply diagnostic rules or perform risk calculations. Based on this knowledge, the IOTA group proposed four Easy
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Descriptors describing typical features of common benign lesions, and two Easy Descriptors suggestive of malignancy. Lesions that cannot be classified using the Easy Descriptors, can be assessed using other methods such as the Simple Rules. The Simple Rules are based on 5 ultrasound features suggesting a benign lesion (Bfeatures) and 5 features that suggest a malignant lesion (M-features). If at least one of the B-features is present without any M-feature, the lesion is classified as benign. Vice versa, if at least one M-feature is present without any B-feature, the lesion is classified as malignant. If both B and M-features are present, or no features are present, the lesion is not classifiable. The IOTA Simple Rules have become very popular because they are easy to use, and do not require a computer for calculation. In 2011, The Royal College of Obstetricians and Gynaecologists (RCOG) incorporated the Simple Rules in the Green-top Guideline on how to manage premenopausal women with adnexal masses. This was followed in 2016 by the American College of Obstetrician and Gynecologists (ACOG) integrating the Simple Rules into their clinical guideline on the evaluation and management of adnexal masses. In 2017, the Simple Rules were considered as the main diagnostic strategy for the assessment of adnexal masses in a first international consensus report.
SESSION 3G: GENERAL NEONATAL Posterior fossa and cerebellar haemorrhages. Imaging technique and long term outcome Adam Hoellering Neonatologist, Queensland Health, Brisbane, QLD, Australia This presentation gives an approach to image acquisition for the structures of the posterior cranial fossa. There will be an overview of the common structural abnormalities and a focus on cerebellar haemorrhages and infarction. Attention will be paid to the importance of the detection of these lesions and the growing body of evidence regarding their impact on long term neurodevelopmental outcomes.
Necrotising enterocolitis and point of care neonatal abdominal USS Archana Priyadarshi Neonatal Clinician and PHD Student, Westmead Hospital, Westmead, NSW, Australia Neonatal intensive care has seen dramatic improvements over last four decades in rates of survival for most preterm newborns. Limits of survival were generally regarded 27 weeks gestation in the 80’s, are now 23 weeks gestation. These micro-premies are much smaller (500 to 800 grams birth weight) and are now increasingly managed with nasal continuous positive airway pressure as respiratory support. Acute abdominal emergencies are common in these infants and can be difficult to distinguish from dysmotile intestinal function in early stages. Preterm infants treated with nasal continuous positive airway pressure often have distended abdomens with feed intolerance requiring evaluation for potentially life-threatening conditions such as necrotising enterocolitis. Plain abdominal radiography is the gold standard modality for diagnosis, monitoring and guiding management in clinically suspected diseased neonatal bowel states. Timely access of expert surgical opinion poses frequent dilemmas of transporting a critically ill preterm infant to a surgical facility. There is compelling evidence demonstrating diagnostic bowel ultrasound findings in necrotising enterocolitis by trained medical ultrasonographers. There is a growing interest in utility of performing bowel ultrasound amongst point-of-care neonatal clinicians.
SESSION 3C: VASCULAR Dual frequency contrast ultrasound angiography F. Stuart Foster,1 Christine E.M. Demore,1 Emmanuel Cherin,1 Isabel Newsome,3 Claudia Carnevale,2 Paul A. Dayton3 1 Sunnybrook Research Institute and Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2 Fuji Film Visual Sonics Inc, Toronto, ON, Canada,, 3 Joint Graduate Department of Biomedical Engineering, University of North Carolina and North Carolina State University, NC, USA Acoustic angiography is a contrast imaging approach in which the superharmonics associated with low frequency excitation of microbubbles are received and processed over a broad bandwidth at a much higher frequency. As demonstrated by Dayton and colleagues, this technique facilitates the visualization of the microvasculature with a resolution typical of micro computed tomography and with superior contrast-to tissue-ratios than conventional nonlinear processing. To date dual frequency contrast imaging has been performed with a 2- 4 MHz annulus coaligned with 25-30MHz single element focused transducer operated by a Vevo770 (Visualsonics) scanner. This technology has limitations (mechanical scanning, single focus, limited focal depth) which hinder its clinical use but which could be alleviated using dualfrequency arrays (DFA). In this presentation we first describe the performance and applications of mechanical acoustic angiography and early results from the development of dual frequency array devices for acoustic angiography. The logical extension to array based designs is then explored. We built prototype dual frequency devices in both a vertical and horizonal topology. The horizonal topography consisted of a central 256 element high frequency array (HF, 20 MHz) flanked by two single element low frequency transducers(LF, 2 MHz) that extended for the length of the HF array. The vertical topography consisted of a 32-element LF transmitter array positioned behind a 256-element HF receiver array. Both arrays were built from piezoelectric composites. The HF backing material, between the two piezoelectric layers in the vertical design is weakly and highly attenuating at 2 MHz and 20 MHz, respectively. Two matching layers on the LF array and 4 matching layers on the HF array were used to improve transmission throughout the whole array structure. An elevation lens was added to focus the receive component at around 9 mm. Impedance and hydrophone measurements were performed to evaluate both configurations. Examples of super harmonic contrast imaging for each of the above configurations will be shown for phantom studies and preliminary in vivo images of animal models will be presented.
SESSION 3E: GYNAECOLOGY What are IOTA easy descriptors and simple rules: How to use them Wouter Froyman Consultant Gynaecologist, University Hospitals Leuven, Leuven, Belgium Many adnexal lesions (e.g. dermoid cysts, endometriomas) share typical characteristics which make them easy to identify ‘at a glance’, without needing to apply diagnostic rules or perform risk calculations. Based on this knowledge, the IOTA group proposed four Easy
S19
Descriptors describing typical features of common benign lesions, and two Easy Descriptors suggestive of malignancy. Lesions that cannot be classified using the Easy Descriptors, can be assessed using other methods such as the Simple Rules. The Simple Rules are based on 5 ultrasound features suggesting a benign lesion (Bfeatures) and 5 features that suggest a malignant lesion (M-features). If at least one of the B-features is present without any M-feature, the lesion is classified as benign. Vice versa, if at least one M-feature is present without any B-feature, the lesion is classified as malignant. If both B and M-features are present, or no features are present, the lesion is not classifiable. The IOTA Simple Rules have become very popular because they are easy to use, and do not require a computer for calculation. In 2011, The Royal College of Obstetricians and Gynaecologists (RCOG) incorporated the Simple Rules in the Green-top Guideline on how to manage premenopausal women with adnexal masses. This was followed in 2016 by the American College of Obstetrician and Gynecologists (ACOG) integrating the Simple Rules into their clinical guideline on the evaluation and management of adnexal masses. In 2017, the Simple Rules were considered as the main diagnostic strategy for the assessment of adnexal masses in a first international consensus report.
SESSION 3G: GENERAL NEONATAL Posterior fossa and cerebellar haemorrhages. Imaging technique and long term outcome Adam Hoellering Neonatologist, Queensland Health, Brisbane, QLD, Australia This presentation gives an approach to image acquisition for the structures of the posterior cranial fossa. There will be an overview of the common structural abnormalities and a focus on cerebellar haemorrhages and infarction. Attention will be paid to the importance of the detection of these lesions and the growing body of evidence regarding their impact on long term neurodevelopmental outcomes.
Necrotising enterocolitis and point of care neonatal abdominal USS Archana Priyadarshi Neonatal Clinician and PHD Student, Westmead Hospital, Westmead, NSW, Australia Neonatal intensive care has seen dramatic improvements over last four decades in rates of survival for most preterm newborns. Limits of survival were generally regarded 27 weeks gestation in the 80’s, are now 23 weeks gestation. These micro-premies are much smaller (500 to 800 grams birth weight) and are now increasingly managed with nasal continuous positive airway pressure as respiratory support. Acute abdominal emergencies are common in these infants and can be difficult to distinguish from dysmotile intestinal function in early stages. Preterm infants treated with nasal continuous positive airway pressure often have distended abdomens with feed intolerance requiring evaluation for potentially life-threatening conditions such as necrotising enterocolitis. Plain abdominal radiography is the gold standard modality for diagnosis, monitoring and guiding management in clinically suspected diseased neonatal bowel states. Timely access of expert surgical opinion poses frequent dilemmas of transporting a critically ill preterm infant to a surgical facility. There is compelling evidence demonstrating diagnostic bowel ultrasound findings in necrotising enterocolitis by trained medical ultrasonographers. There is a growing interest in utility of performing bowel ultrasound amongst point-of-care neonatal clinicians.