S
E M I N A R S I N
P
E R I N A T O L O G Y
39 (2015) 71–72
Available online at www.sciencedirect.com
www.elsevier.com/locate/semperi
MR Imaging of the Developing Brain: Introduction This issue of Seminars in Perinatology is devoted to magnetic resonance (MR) imaging of the developing brain. The successful application of ground-breaking MR imaging techniques in critically ill newborns and, more recently, in the living fetus is affording us with an unparalleled opportunity to accelerate our understanding of the onset, timing, and evolution of early-life brain insults that are associated in lifelong and wide-ranging neurodevelopmental disabilities. This in turn is opening windows of therapeutic opportunity, previously inaccessible, allowing us to begin harnessing the ameliorative effects of brain plasticity and set the stage for promising protective and rehabilitation therapies. The selected topics highlighted in this issue illustrate how recent advances in MR imaging are transforming our understanding of the origins of fetal–neonatal brain injury and illustrate the future role that MR imaging can play in reducing the burden of brain-based disorders resulting in adverse birth outcomes. We begin this series with an update on MR imaging evaluation and safety for the developing brain. Drs. Tocchio KlineFath, Kanal, Schmithorst, and Panigrahy present a detailed discussion of current and emerging MRI hardware and software technology dedicated to the developing brain, including MRIconditional neonatal incubators and dedicated small-foot print neonatal intensive care unit scanners. This article also addresses clinical challenges and important safety issues related to MRI, including the implications of increased magnetic field strength, logistics related to transporting and monitoring of critically ill neonates, and sedation considerations. Contemporary advances in MR imaging of the living fetus are now affording vital, previously unavailable insights into critical events that occur throughout gestation that impact individuals across the lifespan. Dr. Studholme summarizes how novel quantitative in vivo MR imaging techniques are allowing us to map the developing human brain in fetal life. The article explores how MRI technologies hold the promise of dramatically expanding our understanding of normal and abnormal brain development in-utero and offer a range of new MRI tools for measuring and monitoring the compromised brain. Abnormalities in placental development and function are increasingly recognized as critical underpinnings for major pathologies in pregnancy and associated brain injury including,
preterm birth, fetal growth restriction, and preeclampsia. The complex interplay between placental and brain health and disease, alongside the emerging role of advanced MR imaging of the placenta, is appraised by Drs. Niforatos, du Plessis, and Limperopoulos. Exciting developments in multimodal placental MR imaging are affording novel ways to assess the development and function of the human placenta across gestation non-invasively and providing a future foundation for better pregnancy monitoring in the clinical setting. Understanding the complex mechanisms that underlie injury and recovery following early-life brain injury remains an important challenge. Dr. Wintermark describes how noninvasive MR perfusion imaging techniques are expanding our understanding of the complex regulation of cerebral blood flow in fragile, critically ill infants and sheds new light on the resulting perturbations following perinatal brain insults and recovery after injury. Equally exciting are recent seminal developments in resting-state functional MRI presented by Drs. Smyser and Neil, who explore the application of restingstate functional connectivity MRI to study the earliest forms of functional cerebral development and its effects of cerebral injury in prematurely born infants. The authors summarize the technical challenges of resting-state functional MRI unique to the developing brain and propose exciting future directions. Nowhere is the brain more plastic, changing and highly responsive to environmental stimulation than in the early postnatal period. Drs. Fiori and Guzzetta explore the intriguing question of how brain mapping techniques and in particular functional MRI can be used to interrogate the immature brains' response to early-life brain injury and probe the underlying mechanisms of cerebral plasticity and functional reorganization in the immature brain. This will be essential for more targeted prescription and tuning of personalized therapeutic interventions. The final two articles offer an update on neurodevelopmental outcome in very preterm and high-risk, full-term infants, with a focus on the predictive value of conventional and advanced MRI for neurodevelopmental disabilities among surviving infants. Drs. Anderson, Cheong, and Thompson's review highlights the increasingly valuable role of neonatal MRI for prediction of outcome in high-risk preterm infants and explores the potential for improved
72
SE
M I N A R S I N
P
E R I N A T O L O G Y
predictive utility with advancements in both image acquisition and post-image analysis. Dr. Massaro considers the role of conventional and advanced MRI in reshaping our landscape for studying the impact of early-life brain injury on neurodevelopmental disabilities in neonates with hypoxic–ischemic encephalopathy, ischemic perinatal stroke, need for extracorporeal membrane oxygenation life support, congenital heart disease, and other neonatal neurological conditions. Her review underscores the need for ongoing longitudinal studies to better ascertain the predictive value of MRI for later developmental outcomes in these high-risk populations. In summary, advanced MR imaging technologies have become a powerful tool that is transforming our ability to non-invasively assess health and wellness in the living fetus and newborn infant. Faster, more comprehensive MRI pulse sequences and dedicated post-processing pipelines are now capable of reconstructing three-dimensional representations of the developing brain, allowing for the precise delineation of highly orchestrated developmental events that occur throughout pregnancy and early postnatal life. The increasing availability of normative reference values for fetal–neonatal brain growth, micro-organization, metabolism, blood flow, and function is revolutionizing our ability to accurately identify and monitor disruptions of the circuitry map of the brain in high-risk infants. Ongoing developments of MR imaging technologies will require intense, collaboration
39 (2015) 71–72
between clinicians, neuroscientists, and engineers for the successful uptake of new clinical tools into advanced diagnostics and novel therapies. The successful dissemination of these emerging imaging biomarkers in the clinical setting will also require ongoing validation and a substantial reduction in the current computational burden that is inherent to many of these techniques. The next research front will involve investigating new targets for personalized treatment that will nurture and protect the developing brain. I am enormously grateful to the contributing authors for graciously sharing their formative work in the field of MR imaging that is driving rapid and critical advances in our understanding of injury and plasticity in the developing brain. I hope this compilation will offer clinicians a better understand of recent advances, ongoing challenges and limits of MRI, as well as future opportunities in this rapidly developing field of neurotechnologies available to study the developing brain.
Catherine Limperopoulos, PhD Division of Diagnostic Imaging and Radiology, Children's National Health System, 111 Michigan Ave. NW Washington, DC 20008 E-mail address: [email protected] http://dx.doi.org/10.1053/j.semperi.2015.01.001 0146-0005/& 2015 Elsevier Inc. All rights reserved.
E M I N A R S I N
P
E R I N A T O L O G Y
39 (2015) 71–72
Available online at www.sciencedirect.com
www.elsevier.com/locate/semperi
MR Imaging of the Developing Brain: Introduction This issue of Seminars in Perinatology is devoted to magnetic resonance (MR) imaging of the developing brain. The successful application of ground-breaking MR imaging techniques in critically ill newborns and, more recently, in the living fetus is affording us with an unparalleled opportunity to accelerate our understanding of the onset, timing, and evolution of early-life brain insults that are associated in lifelong and wide-ranging neurodevelopmental disabilities. This in turn is opening windows of therapeutic opportunity, previously inaccessible, allowing us to begin harnessing the ameliorative effects of brain plasticity and set the stage for promising protective and rehabilitation therapies. The selected topics highlighted in this issue illustrate how recent advances in MR imaging are transforming our understanding of the origins of fetal–neonatal brain injury and illustrate the future role that MR imaging can play in reducing the burden of brain-based disorders resulting in adverse birth outcomes. We begin this series with an update on MR imaging evaluation and safety for the developing brain. Drs. Tocchio KlineFath, Kanal, Schmithorst, and Panigrahy present a detailed discussion of current and emerging MRI hardware and software technology dedicated to the developing brain, including MRIconditional neonatal incubators and dedicated small-foot print neonatal intensive care unit scanners. This article also addresses clinical challenges and important safety issues related to MRI, including the implications of increased magnetic field strength, logistics related to transporting and monitoring of critically ill neonates, and sedation considerations. Contemporary advances in MR imaging of the living fetus are now affording vital, previously unavailable insights into critical events that occur throughout gestation that impact individuals across the lifespan. Dr. Studholme summarizes how novel quantitative in vivo MR imaging techniques are allowing us to map the developing human brain in fetal life. The article explores how MRI technologies hold the promise of dramatically expanding our understanding of normal and abnormal brain development in-utero and offer a range of new MRI tools for measuring and monitoring the compromised brain. Abnormalities in placental development and function are increasingly recognized as critical underpinnings for major pathologies in pregnancy and associated brain injury including,
preterm birth, fetal growth restriction, and preeclampsia. The complex interplay between placental and brain health and disease, alongside the emerging role of advanced MR imaging of the placenta, is appraised by Drs. Niforatos, du Plessis, and Limperopoulos. Exciting developments in multimodal placental MR imaging are affording novel ways to assess the development and function of the human placenta across gestation non-invasively and providing a future foundation for better pregnancy monitoring in the clinical setting. Understanding the complex mechanisms that underlie injury and recovery following early-life brain injury remains an important challenge. Dr. Wintermark describes how noninvasive MR perfusion imaging techniques are expanding our understanding of the complex regulation of cerebral blood flow in fragile, critically ill infants and sheds new light on the resulting perturbations following perinatal brain insults and recovery after injury. Equally exciting are recent seminal developments in resting-state functional MRI presented by Drs. Smyser and Neil, who explore the application of restingstate functional connectivity MRI to study the earliest forms of functional cerebral development and its effects of cerebral injury in prematurely born infants. The authors summarize the technical challenges of resting-state functional MRI unique to the developing brain and propose exciting future directions. Nowhere is the brain more plastic, changing and highly responsive to environmental stimulation than in the early postnatal period. Drs. Fiori and Guzzetta explore the intriguing question of how brain mapping techniques and in particular functional MRI can be used to interrogate the immature brains' response to early-life brain injury and probe the underlying mechanisms of cerebral plasticity and functional reorganization in the immature brain. This will be essential for more targeted prescription and tuning of personalized therapeutic interventions. The final two articles offer an update on neurodevelopmental outcome in very preterm and high-risk, full-term infants, with a focus on the predictive value of conventional and advanced MRI for neurodevelopmental disabilities among surviving infants. Drs. Anderson, Cheong, and Thompson's review highlights the increasingly valuable role of neonatal MRI for prediction of outcome in high-risk preterm infants and explores the potential for improved
72
SE
M I N A R S I N
P
E R I N A T O L O G Y
predictive utility with advancements in both image acquisition and post-image analysis. Dr. Massaro considers the role of conventional and advanced MRI in reshaping our landscape for studying the impact of early-life brain injury on neurodevelopmental disabilities in neonates with hypoxic–ischemic encephalopathy, ischemic perinatal stroke, need for extracorporeal membrane oxygenation life support, congenital heart disease, and other neonatal neurological conditions. Her review underscores the need for ongoing longitudinal studies to better ascertain the predictive value of MRI for later developmental outcomes in these high-risk populations. In summary, advanced MR imaging technologies have become a powerful tool that is transforming our ability to non-invasively assess health and wellness in the living fetus and newborn infant. Faster, more comprehensive MRI pulse sequences and dedicated post-processing pipelines are now capable of reconstructing three-dimensional representations of the developing brain, allowing for the precise delineation of highly orchestrated developmental events that occur throughout pregnancy and early postnatal life. The increasing availability of normative reference values for fetal–neonatal brain growth, micro-organization, metabolism, blood flow, and function is revolutionizing our ability to accurately identify and monitor disruptions of the circuitry map of the brain in high-risk infants. Ongoing developments of MR imaging technologies will require intense, collaboration
39 (2015) 71–72
between clinicians, neuroscientists, and engineers for the successful uptake of new clinical tools into advanced diagnostics and novel therapies. The successful dissemination of these emerging imaging biomarkers in the clinical setting will also require ongoing validation and a substantial reduction in the current computational burden that is inherent to many of these techniques. The next research front will involve investigating new targets for personalized treatment that will nurture and protect the developing brain. I am enormously grateful to the contributing authors for graciously sharing their formative work in the field of MR imaging that is driving rapid and critical advances in our understanding of injury and plasticity in the developing brain. I hope this compilation will offer clinicians a better understand of recent advances, ongoing challenges and limits of MRI, as well as future opportunities in this rapidly developing field of neurotechnologies available to study the developing brain.
Catherine Limperopoulos, PhD Division of Diagnostic Imaging and Radiology, Children's National Health System, 111 Michigan Ave. NW Washington, DC 20008 E-mail address: [email protected] http://dx.doi.org/10.1053/j.semperi.2015.01.001 0146-0005/& 2015 Elsevier Inc. All rights reserved.
