A diagram showm atherosclerosis of the carotid artery leading to carotid artery stenosis. Two illustrations of arteries are shown, in one there is plaque build up and the other is normal. Image by Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons