Intracranial hemorrhage (summary)

This is a basic article for medical students and other non-radiologists

Intracranial hemorrhage refers to bleeding within the intracranial cavity and is, therefore, a catch-all term which includes parenchymal (intra-axial) hemorrhage and the various types of extra-axial hemorrhage including, subarachnoid, subdural and extradural hemorrhage.

Reference article

This is a summary article; read more in our article on Intracranial hemorrhage.

Summary

• anatomy
  • brain
  • meninges
  • ventricular system
• pathophysiology
  • etiology and pathophysiology dependent on the type of hemorrhage
    • parenchymal
      • trauma
      • stroke
      • degeneration (amyloid angiopathy)
    • subarachnoid
      • trauma
      • ruptured aneurysm
    • subdural
      • venous bleed from low-impact trauma
    • extradural
      • arterial bleed from high-energy trauma and skull fracture

Imaging

• role of imaging
  • is there any hemorrhage?
  • where is it?
  • is the cause visible on the scan, e.g. fracture, aneurysm)?
  • are there any complications, e.g. mass effect, midline shift?
• radiographic features
  • acute hemorrhage is hyperdense (white) on CT
  • as the blood ages, the density decreases
    • chronic blood approaches the density of CSF
  • sizable hemorrhage may cause mass effect and midline shift