Dural dimpling in the dog.
Indentation of the dura has been proposed as the cause of subatmospheric pressure in the extradural space, but has never been demonstrated directly in humans. In this study, radiographs have been produced showing dimpling of the dura by a needle tip lying in the extradural space in the dog. Pressure tracings demonstrate that advancement of the needle tip produces a progressive decrease in extradural pressure, and observations made using an image intensifier have confirmed that the pressure changes are proportional to the degree of dural indentation.
D000767:Anesthesia, Epidural; D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D004388:Dura Mater / Q000000981:diagnostic imaging / Q000502:physiology*; D004824:Epidural Space / Q000000981:diagnostic imaging / Q000502:physiology; D011312:Pressure; D011859:Radiography