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The less spoken of extreme: Fetal macrosomia
Abstracts Questions to consider: Do I need to ask this woman if she has any current lumps or concerns? Do I need to look at the mammogram? Do I need to look at prior studies? Do I need to interpret the lesion as benign, indeterminate or malignant before I take the image? Do I need to consider this woman who is connected to the breast I am scanning? The answer to all these questions is yes. This is particularly important when the imaging, and the women connected to the breasts you are imaging are “difficult”. Through a series of “difficult” case studies I hope to offer an approach to breast ultrasound imaging that will maximise your ability to provide meaningful, and accurate information that will benefit the woman who came in with the question could it be cancer?
SESSION 6E: OBSTETRICS Abnormally adherent placenta Heron Werner Jr Fetal Medicine, clinica de diagnostico por imagem - CDPI, Rio de Janeiro, Brazil Advances in image-scanning technology have led to vast improvements in medicine, especially in the diagnosis of fetal anomalies and placenta evaluation. In general, two main technologies are used to obtain images within the uterus during pregnancy ultrasound (US) and magnetic resonance imaging (MRI). US examination is the primary method of gravid uterus assessment because it is patient-friendly, effective, cost-efficient and considered to be safe. MRI is generally used when US cannot provide sufficiently high-quality images. It offers high-resolution fetal and placenta imaging with excellent contrast that allows visualization of internal tissues. Placenta percreta is the most feared form of abnormally adherent placenta. Its incidence has increased because of high cesarean section rates. The main imaging findings in abnormally adherent placenta are: Loss of the “clear zone” or irregularity of the hypoechoic plane in the myometrium underneath the placental bed. Abnormal placental lacunae. Presence of numerous lacunae including some that are large and irregular often containing turbulent flow. Bladder wall interruption. Placental bulge. Deviation of the uterine serosa away from the expected plane. The uterine serosa appears intact, but the outline shape is distorted. Focal exophytic mass. Placental tissue seen breaking through the uterine serosa and extending beyond it. Color Doppler imaging shows uterovesical hypervascularity. Bridging vessels appearing to extend from the placenta across the myometrium and beyond the serosa into the bladder or other organs. Often running perpendicular to the myometrium. The key concern of this talk will be: The risk of placenta accreta increases according the number of Cesarean-section. Placenta accreta is mostly associated with placenta previa. The most sensitive US finding for placenta accreta is the presence of placenta lacunae, that can also be observed in MRI. MRI may aid in diagnosis by demonstrating increased intraplacental vascularity, fibrin band of dark T2 signal and direct placental invasion of adjacent structures.
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The less spoken of extreme: Fetal macrosomia Jacques Abramowicz Director, Ultrasound Services, University of Chicago, USA When describing growth, a fetus may be appropriate for gestational age (AGA), too small (SGA, sometimes confused with intra uterine growth restriction, IUGR) or too large (LGA), a condition often defined as macrosomia. While the literature on IUGR is extensive and many lectures/conferences are dedicated to this topic, macrosomia is less often discussed. Macrosomia is a term that should be applied only to the newborn, since it relates to an actual weight. When describing a fetus, the only term one should use is LGA. There are various definitions for macrosomia. In developed countries, the most commonly used threshold is weight above 4500 g (9 lb 15 oz). Weight above 4000 g (8 lb 13 oz) or 10 lb (4536 g) are also commonly used. When describing fetuses, weight percentiles for gestational age, rather than actual estimated weight, are preferable. Etiologies for macrosomia include metabolic (maternal diabetes), genetic (various overgrowth syndromes such as Beckwith-Wiedemann), constitutional as well as maternal factors, such as obesity and excessive gestational weight gain. There are maternal and fetal risk factors: for example, increased incidence of cesarean deliveries and genital tract lacerations as well as shoulder dystocia. During pregnancy, ultrasound is the ideal diagnostic tool, although its precision declines as fetal weight increases. Sonographic measurements of the fetal head, abdomen and femur are the most commonly employed criteria but soft tissues and volumes (obtained, generally, by 3D methods) have also been described. Measuring the fetal abdominal circumference (AC) may be the best tool for diagnosing risk of macrosomia, with AC >35 cm identifying >90% of fetuses with macrosomia that are at risk for shoulder dystocia.
Pitfalls in the use of shear wave elastography on the cervix Sandra O’Hara,1,2 Marilyn Zelesco,3 Zhonghua Sun2 1 Ultrasound, SKG Radiology, Perth, WA, Australia, 2 Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia, 3 Department of Medical Imaging, Fiona Stanley Hospital, Perth, WA, Australia Introduction: Ultrasound shear wave elastography has the potential to assess the strength of the maternal cervix for signs of insufficiency.1, 2 The reliability of shear wave elastography in biological tissues can be affected by numerous ultrasound artifacts and prestress of tissues in the region of interest can also affect the shear wave speed. This study investigates the use of the transvaginal ultrasound approach to obtain shear wave speeds in the uterine cervix with the aim of identifying factors that affect shear wave speed and transmission. Objectives: The primary aim of this study is to identify biological and technical confounders for the use of two dimensional shear wave elasography applied to the uterine cervix. The goal was to identify confounders, and develop shear wave technique in the low risk non-gravid population. Methods: Sixty nine non-gravid participants with varying medical history and ethnicity consented to be part of this research. Inter-operator testing was performed on fifteen participants.Imaging methodology As an adjunct to the normal imaging examination extra imaging of cervical speed measurements using two dimensional shear wave elastography was performed.The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography
SESSION 6E: OBSTETRICS Abnormally adherent placenta Heron Werner Jr Fetal Medicine, clinica de diagnostico por imagem - CDPI, Rio de Janeiro, Brazil Advances in image-scanning technology have led to vast improvements in medicine, especially in the diagnosis of fetal anomalies and placenta evaluation. In general, two main technologies are used to obtain images within the uterus during pregnancy ultrasound (US) and magnetic resonance imaging (MRI). US examination is the primary method of gravid uterus assessment because it is patient-friendly, effective, cost-efficient and considered to be safe. MRI is generally used when US cannot provide sufficiently high-quality images. It offers high-resolution fetal and placenta imaging with excellent contrast that allows visualization of internal tissues. Placenta percreta is the most feared form of abnormally adherent placenta. Its incidence has increased because of high cesarean section rates. The main imaging findings in abnormally adherent placenta are: Loss of the “clear zone” or irregularity of the hypoechoic plane in the myometrium underneath the placental bed. Abnormal placental lacunae. Presence of numerous lacunae including some that are large and irregular often containing turbulent flow. Bladder wall interruption. Placental bulge. Deviation of the uterine serosa away from the expected plane. The uterine serosa appears intact, but the outline shape is distorted. Focal exophytic mass. Placental tissue seen breaking through the uterine serosa and extending beyond it. Color Doppler imaging shows uterovesical hypervascularity. Bridging vessels appearing to extend from the placenta across the myometrium and beyond the serosa into the bladder or other organs. Often running perpendicular to the myometrium. The key concern of this talk will be: The risk of placenta accreta increases according the number of Cesarean-section. Placenta accreta is mostly associated with placenta previa. The most sensitive US finding for placenta accreta is the presence of placenta lacunae, that can also be observed in MRI. MRI may aid in diagnosis by demonstrating increased intraplacental vascularity, fibrin band of dark T2 signal and direct placental invasion of adjacent structures.
S29
The less spoken of extreme: Fetal macrosomia Jacques Abramowicz Director, Ultrasound Services, University of Chicago, USA When describing growth, a fetus may be appropriate for gestational age (AGA), too small (SGA, sometimes confused with intra uterine growth restriction, IUGR) or too large (LGA), a condition often defined as macrosomia. While the literature on IUGR is extensive and many lectures/conferences are dedicated to this topic, macrosomia is less often discussed. Macrosomia is a term that should be applied only to the newborn, since it relates to an actual weight. When describing a fetus, the only term one should use is LGA. There are various definitions for macrosomia. In developed countries, the most commonly used threshold is weight above 4500 g (9 lb 15 oz). Weight above 4000 g (8 lb 13 oz) or 10 lb (4536 g) are also commonly used. When describing fetuses, weight percentiles for gestational age, rather than actual estimated weight, are preferable. Etiologies for macrosomia include metabolic (maternal diabetes), genetic (various overgrowth syndromes such as Beckwith-Wiedemann), constitutional as well as maternal factors, such as obesity and excessive gestational weight gain. There are maternal and fetal risk factors: for example, increased incidence of cesarean deliveries and genital tract lacerations as well as shoulder dystocia. During pregnancy, ultrasound is the ideal diagnostic tool, although its precision declines as fetal weight increases. Sonographic measurements of the fetal head, abdomen and femur are the most commonly employed criteria but soft tissues and volumes (obtained, generally, by 3D methods) have also been described. Measuring the fetal abdominal circumference (AC) may be the best tool for diagnosing risk of macrosomia, with AC >35 cm identifying >90% of fetuses with macrosomia that are at risk for shoulder dystocia.
Pitfalls in the use of shear wave elastography on the cervix Sandra O’Hara,1,2 Marilyn Zelesco,3 Zhonghua Sun2 1 Ultrasound, SKG Radiology, Perth, WA, Australia, 2 Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia, 3 Department of Medical Imaging, Fiona Stanley Hospital, Perth, WA, Australia Introduction: Ultrasound shear wave elastography has the potential to assess the strength of the maternal cervix for signs of insufficiency.1, 2 The reliability of shear wave elastography in biological tissues can be affected by numerous ultrasound artifacts and prestress of tissues in the region of interest can also affect the shear wave speed. This study investigates the use of the transvaginal ultrasound approach to obtain shear wave speeds in the uterine cervix with the aim of identifying factors that affect shear wave speed and transmission. Objectives: The primary aim of this study is to identify biological and technical confounders for the use of two dimensional shear wave elasography applied to the uterine cervix. The goal was to identify confounders, and develop shear wave technique in the low risk non-gravid population. Methods: Sixty nine non-gravid participants with varying medical history and ethnicity consented to be part of this research. Inter-operator testing was performed on fifteen participants.Imaging methodology As an adjunct to the normal imaging examination extra imaging of cervical speed measurements using two dimensional shear wave elastography was performed.The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography