Twelve representative volumes arranged by gestational age Twelve representative volumes arranged by gestational age. The first and fourth columns are strict sagittal sections obtained with volume contrast imaging, with sections 1- to 2-mm thick. The second and fifth columns are strict right lateral views of the dissected ventricular system, and the third and sixth columns are anteroinferior views (45 degrees from the longitudinal axis of the metencephalon). The white bars used for length reference on the left edges of the images in the first and fourth columns are 10-mm long. The reference dots on the left of each 3D rendering are 5-mm apart. The ages of the embryos are 7 weeks 4 days (crown-rump length [CRL], 13.6 mm) and 7 weeks 6 days (CRL, 14.6 mm) in the first row; 8 weeks 1 day (CRL, 16.5 mm) and 8 weeks 3 days (CRL, 19.1mm) in the second row; 8 weeks 6 days (CRL, 22.5 mm) and 9 weeks 2 days (CRL, 25.3 mm) in the third row; 9 weeks 4 days (CRL, 28.1 mm) and 9 weeks 6 days (CRL, 30 mm) in the fourth row; 10 weeks 6 days (CRL, 39.1 mm) and 11 weeks 1 day (CRL, 42.2 mm) in the fifth row; and 11 weeks 5 days (CRL, 49.2 mm) and 12 weeks (CRL, 53.3 mm) in the sixth row. (Reproduced with permission from Kim MS, Jeanty P, Turner C, et al. Three-dimensional sonographic evaluations of embryonic brain development. J Ultrasound Med. 2008;27:119-24.) Source: OBSTETRICAL APPLICATIONS FOR 3D ULTRASONOGRAPHY, Sonography in Obstetrics and Gynecology: Principles & Practice, 7e Citation: Fleischer AC, Toy EC, Lee W, Manning FA, Romero RJ. Sonography in Obstetrics and Gynecology: Principles & Practice, 7e; 2014 Available at: https://obgyn.mhmedical.com/DownloadImage.aspx?image=/data/books/1414/fle_ch44_f010.png&sec=76397304&BookID=1414&ChapterSecID=76397273&imagename= Accessed: December 31, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved