<prompt> Extradural hemorrhage is seen as:Hyperdense biconvexHypodense biconcaveHyperdense biconcaveHypodense biconvex  <response>: Ans. a Hyperdense biconvexRef: Harrisons 17th ed. Ch 364 Extradural hemorrhage: Bleeding occurs between skull and duramatter. Bleeding occurs due to the rupture ofMiddle meningeal artery. Lucid Interval Consciousness between two periods of unconsciousness exists. In NCCT it shows hyperdensity bleeding, bi-convex or flame shaped bleed. Treatment: Burr hole surgery. Subdural hemorrhage: Occurs due to rupture of Cortical bridging veins. In NCCT it shows concavo- convex or sickle shaped bleed. 