The first-trimester fetal central nervous system: a novel ultrasonographic perspective Harsha Shah, MBBS; Maya Al-Memar, MBBS; Bernadette de Bakker, MD; Hanine Fourie, MBBS; Christoph Lees, MD; Tom Bourne, PhD Case Notes A 32-year-old nulliparous pregnant woman presented for a routine first-trimester obstetric ultrasound scan that demon- strated a viable intrauterine pregnancy with a crown-rump length of 67 mm (13 weeks and 1 day gestation). On 2-dimensional imaging using a WS80 Elite system (Samsung Medison Ltd, Seoul, Republic of Korea), all fetal anatomical structures examined appeared normal within the limitations of the examination and gestation. A 3-dimensional (3D) volume of the fetus was obtained by sagittal and coronal acquisition and examined using Crystal Vue and Realistic Vue software (Samsung-Medison, Korea), 1 which revealed a novel 3D impression of the fetal ventricular system comparable to digitally reconstructed embryological models 2 (Figure). Comment The fetal central nervous system and, in particular, ventricular system, is usually difficult to examine in any great detail in the first trimester as it is rapidly changing. Furthermore, visuali- zation of the anatomical complexity of the central nervous system is limited by image resolution. 3 The technical challenges of imaging the fetal brain during the first trimester have been evidenced by the difficulty of implementing routine first-trimester examination of posterior fossa intracranial FIGURE Three-dimensional perspective of the first-trimester fetal ventricular system A, Coronal view with Crystal Vue and Realistic Vue software (Samsung-Medison, Korea). B, Digital reconstruction of ventricular system of stage-23 human embryo from 3-dimensional atlas of human embryology. 2 C, Sagittal view with software. D, Schematic drawing of ventricular system as pre- sented in sagittal plane. Shah. Novel first-trimester fetal CNS ultrasonography. Am J Obstet Gynecol 2017. From the Department of Surgery and Cancer, Institute of Reproductive and Development Biology, Imperial College of Science, Technology, and Medicine, London, United Kingdom (Dr Shah, Miss Al-Memar, Dr Fourie, Dr Lees, and Prof Bourne); and Department of Anatomy, Embryology, and Physiology, Academic Medical Center, Amsterdam, The Netherlands (Dr de Bakker). Received March 28, 2017; accepted May 23, 2017. Financial support for this research was provided by Genesis Research Trust by way of an educational grant and the loan of Samsung Equipment by Samsung Medison Co Ltd, South Korea. There was no involvement by the sponsor in the study design, writing of the report, or decision to submit the article for publication. C.L. and T.B. received speaking fees and travel funding from Samsung Medison Co Ltd, Republic of Korea. Corresponding author: Tom Bourne, PhD. t.bourne@ic.ac.uk 0002-9378  Crown Copyright ª 2017 Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by- nc-nd/4.0/).  http://dx.doi.org/10.1016/j.ajog.2017.05.053 220 American Journal of Obstetrics & Gynecology AUGUST 2017 Images in Obstetrics ajog.org