The concept for this book was born many years ago and was preceded by careful acquisition and selection of representative neurosonograms of normal and abnormal cases. The central nervous system is probably the most elaborate and intricate organ or system in the human body. Minute structural abnormalities can, at times, reflect major functional deficiencies. On the other hand, it would appear that at times major anatomic defects do not seem to be associated with significantly deviant function. It is extremely important to study and understand the normal and abnormal fetal and neonatal central nervous system. The central nervous system is one of the common sites of anatomical malformation in the fetus with chromosomal abnormality. The detection of anomalies within the fetal and neonatal brain is feasible using modern imaging techniques, such as ultrasound, computed tomography, and magnetic resonance imaging.
The aim of prenatal ultrasonography is to be able to reassure the pregnant patient as early as possible that fetal development is normal; or if a malformation is detected to counsel the patient about the nature of the problem. Most anomalies of the central nervous system develop early, and we have the tools to detect these as early as 10 to 16 weeks. Early detection of such central nervous system anomalies is probably the most important advance in modern perinatology. Neonatal ultrasound confirms the prenatal diagnosis. In addition, neonatal neurosonography is a powerful tool in diagnosing central nervous system pathology.
The first chapter deals with the development of the human central nervous system. Its authors are the distinguished professors Ronan O’Rahilly and Fabiola Müller, who have a lifetime of professional experience. Professor O’Rahilly not only took time to write about the embryology of the brain, but also invested valuable time in overseeing the correct anatomical terminology used throughout most of the chapters.
The vast imaging possibilities of ultrasound in general and that of transvaginal sonography in particular regarding the fetal brain, are dealt with at the beginning of our book and lead into the chapters describing the detectable pathology in the fetal and neonatal central nervous system. Because fetal and neonatal neurosonographic scanning is performed using the anterior fontanelle and other calvarial openings, the “classical” axial planes cannot be used to describe the images obtained in the fan-shaped sonographic sections. It was our goal to keep the “classic” planes in use by CT and by MRI imaging of the brain and create a separate and well-defined set of planes and sections for the fetal brain imaging. A new nomenclature regarding the scanning planes of the fetal brain is introduced in Chapters 1, 2, 3, and 4.
We felt that a special and dedicated chapter dealing with biometry of the fetal brain should be included. A large number of tables and graphs as well as measurements of the fetal brain are incorporated for reference.
Because the fetal eye and the fetal face are frequently associated with brain pathology, two special chapters are devoted to these structures. Dr. Israel Meizner and Dr. Moshe Bronshtein’s group from Israel have the most imaging experience in these two areas and contributed these two important chapters, which we believe are the most detailed in the literature dealing with those subjects.
Neonatal neurosonology is an established diagnostic entity which has earned its well-deserved place in the armamentarium of the neuroimager since its introduction in 1979. Chapters concerning imaging of the normal and abnormal neonatal brain, and the chapter by Dr. Madhuri Kirpekar dealing with the spine, are included to form a continuum as far as the sonographic neuroimaging workup of the prenatal and neonatal CNS.
The chapter written by Gianluigi Pilu and Vincenso D’Addario and their co-workers from Italy, made a significant contribution to the book by touching on the subject of the midline brain pathologies and the recently introduced attempts to image the fetal brain using MRI.
It is hard and labor intensive to study the physiological aspects of the brain. This was successfully done by recognized authors such as Jan Nijhuis who reviewed the fetal behavioral states coordinated by the brain and by Shimon Degani and Reuven Lewinsky summarizing the clinical uses of measuring the blood flow to the central nervous system.
Finally, the ethical aspects of neurosonography are explored by Frank Chervenak, who over the years has become an authority in the field of medical ethics.
This book was written for the perinatologists, neonatologists. perinatal geneticists, as well as the imaging specialists such as radiologists, obstetricians, and sonographers who see the fetus and neonate in their clinical practice. These specialists scan the fetal and neonatal brain themselves or are directly involved with managing pregnancies with structural malformations or anomalies of the central nervous system. Special emphasis was placed on the creation of an objective and exhaustive updated review of the pertinent literature so that the reader would have a wide reference base on each subject. As far as the illustrations are concerned, the authors were encouraged to be liberal about including an unrestricted number of cases and their sonographic manifestations in their respective chapters. This may, therefore, lead to some duplication by presenting the same disease or pathology more than once. However, by allowing some deliberate repetition in depicting various cases, we, hopefully, covered the commonly occurring pathologies. We consider such occasional and repetitive presentations as one of the advantages of the text enabling the reader to be educated by the experiences of the different authors and their various points of view.
One of the particular strengths of presenting the sonograms is that we chose to include small body images so that readers could orient themselves as to how an individual sonographic view was obtained. This will, we hope, enable readers to quickly grasp and understand the actual planes used to generate the pictures.
We suggest that neuroimaging of the fetus be included in the structural evaluation of the fetus at any gestational age. We also believe that practitioners involved in fetal and/or neonatal neuroimaging will benefit from using this carefully prepared text.
Ilan E. Timor-Tritsch, MD
Ana Monteagudo, MD
Harris L. Cohen, MD