Hydrocephalus (summary)

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

Hydrocephalus describes the situation where the intracranial ventricular system is enlarged because of increased pressure. It may be caused by obstruction of CSF flow. If this is the case, the location of obstruction can be determined by the pattern of hydrocephalus. In some cases, hydrocephalus is caused by altered CSF dynamics rather than obstruction.

Reference article

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

Summary

  • anatomy
  • pathophysiology
    • pattern of ventricular dilatation dependent on cause
      • unilateral lateral ventricle
        • midline shift; mass at the foramen of Monro
      • bilateral lateral ventricles
        • 3rd ventricular mass
      • lateral and 3rd ventricles
        • aqueduct of Silvius obstruction; 4th ventricular mass
      • lateral ventricles, 3rd and 4th
        • most likely non-obstructive

Imaging

CT head | MRI brain

  • role of imaging
    • is there hydrocephalus?
    • is it stable or progressive? (pre-existing hydrocephalus)
    • obstructive or non-obstructive?
      • level of obstruction?
      • likely cause? e.g. tumor, stroke
    • transependymal CSF spread?
    • complications?
  • radiographic features
    • dilatation of the ventricular system
      • lateral ventricles: temporal horns dilate first
    • transependymal CSF shift
      • periventricular edema
        • reduced density on CT
        • high signal on fluid-sensitive MRI sequences (T2, FLAIR)
Medical student radiology curriculum