This M-mode image depicts the "seashore sign" where a clear distinction between a wave-like pattern located above the pleural line and a sand-like pattern below it can be made. The granular area below the pleural interface is caused by lung sliding. Source: Chapter 7. Thoracic Ultrasound, Handbook of Critical Care and Emergency Ultrasound Citation: Carmody KA, Moore CL, Feller-Kopman D. Handbook of Critical Care and Emergency Ultrasound; 2011 Available at: https://accessanesthesiology.mhmedical.com/DownloadImage.aspx?image=/data/books/carm1/carm1_c007f009.png&sec=41067279&BookID=517&ChapterSecID=41066793&imagename= Accessed: December 27, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved