How to Read a Head CT

Check out the full comic at Radiopaedia written and illustrated by Stefan Tigges.

Head CT Search Patterns

Head CT: Pneumonic

  • H: Hemorrhage, Herniation, Hydrocephalus

  • E: Edema-- Cytotoxic/Vasogenic

  • A: Asymmetry, Artery

  • D: Dura, Dural venous sinus

  • C: Calvaria

  • T: soft Tissues

Outside In

  • Superficial soft tissues

  • Bones

  • Sinuses and Mastoid Air Cells

  • Orbits

  • Extra-axial spaces-- subarachnoid, subdural and epidural space

  • Ventricles: too large, mass effect?

  • Brain Parenchyma-- Mass effect, blurring of gray white? vasogenic edema

Inside Out

  • Brain Parenchyma-- Mass effect? Blurring of gray white? Vasogenic edema? Hemorrhage?

  • Ventricles: too large, mass effect?

  • Extra-axial spaces-- subarachnoid, subdural and epidural space

  • Orbits

  • Superficial soft tissues

  • Bones

  • Sinuses and Mastoid Air Cells

To view through a normal head CT click on the picture above to view in Pacsbin

Find the following:

  • Lobes: Frontal, Parietal, Occipital, Temporal

  • Basal Ganglia and Thalamus

  • Pituitary and Pineal Gland

  • Brainstem: Midbrain, Pons, Medulla

  • Middle Cerebral A., Basilar A, Sagittal Sinus

  • Identify the 3rd Ventricle: Measure the HU in the ventricle

  • Look at the bone window images and identify the Maxillary sinus: What HU measured in sinus?

To view this scrollable set of images in Pacsbin click on the image above

To view this scrollable set of images in Radiopaedia click on the image above

The appearance of normal structures on a head CT will often vary by age. Here are 3 different normal head CT's in patients of different ages. Take a look and see if you can identify changes.