Reid's base line 1714285 100293594 2007-01-12T20:38:50Z Sagaciousuk 1435445 Removing selflinks {{Infobox Anatomy | Name = {{PAGENAME}} | Latin = | GraySubject = | GrayPage = | Image = Gray1198.png | Caption = Relations of the [[brain]] and [[middle meningeal artery]] to the surface of the [[skull]]. 1. [[Nasion]]. 2. Inion. 3. [[Lambda]]. 4. [[Lateral cerebral fissure]]. 5. [[Central sulcus]]. AA. Reid's base line. B. Point for trephining the anterior branch of the [[middle meningeal artery]]. C. [[Suprameatal triangle]]. D. Sigmoid bend of the [[transverse sinus]]. E. Point for trephining over the straight portion of the [[transverse sinus]], exposing [[dura mater]] of both [[cerebrum]] and [[cerebellum]]. Outline of [[cerebral hemisphere]] indicated in blue; course of [[middle meningeal artery]] in red. | Image2 = | Caption2 = | System = | MeshName = | MeshNumber = | DorlandsPre = l_10 | DorlandsSuf = 12494723 | }} '''Reid's base line''' is used for an unambiguous definition of the orientation of the human [[skull]] in [[X-ray|conventional radiography]], [[computer tomography]] (CT), and [[magnetic resonance imaging]] (MRI) studies. In 1962, the World Federation of [[Radiology]] defined it as the line between the [[infraorbital]] margin and the upper margin of the [[external auditory meatus]]. With the head upright, it is typically tilted about 7 degrees nose up with respect to the horizontal plane. ==See also== * [[Frankfurt plane]] ==External links== * {{eMedicineDictionary|baseline}} * {{Chorus|00345}} {{medicine-stub}} [[Category:Radiology]]