
A system of reviewing the structures can also be found here
Be aware that there are a number of serous intracranial pathologies that may not be apparent on plain CT
Initially comment on:
- View – Axial vs Coronal vs Sagittal
- Type of study – Non-contrast vs Contrast (look at the Circle of Willis and Dural sinus)
- Movement artefacts (everything looks blurry)
- Streak artifacts – metal and fillings
Systematically go through structures
- Brain tissue – grey/white differentiation, hypo/hyperdensity and distribution, sulci (prominent/effaced)
- Brainstem
- Ventricles – enlarged e.g. hydrocephalus, cerebral atrophy; compressed/effaced/obliterated, filled with blood
- Basal Cistern – compression
- Bones / Facial skeleton / Sinuses
- Herniations – Midline/Falx, Tentorium, Foramen Magnum
Distribution or Location of abnormalities
- Extra-axial (edges of brain) vs Intra-axial (within the brain) – and if crosses suture lines
- Cortical
- Sub-cortical / Basal Ganglia e.g. intra-parenchymal haemorrhage
- Vascular territories e.g. ACA, MCA
- Subarachnoid cisterns e.g. . Sub-arachnoid haemorrhage
- Base of brain
- Peri-ventricular
- Intra-Ventricular
Comment on how many lobes are effected, how many slices seen. Give dimension in at maximum width or radius. Dimensions in 3 planes easier when there are reconstructs.
Some important shapes to identify
- Biconvex = Extradual haematoma
- Crescentic = Subdural haematoma
- Ring enhancing = Tumours / Abscesses
- Cerebral Oedema
- Periventricular oedema
Remember
- Very white = bone/calcification (can be confused with new blood without checking Hounsfield units)
- White = new blood (but gets greyer as it gets older e.g. chronic subdurals may be difficult to pick)
- Light Grey = White matter
- Dark grey = Neurons (or oedema)
- Black = CSF (which also replaces old infarcted liquified brain)
Hot tips
- Compare left and right hemisphere (but watch out for bilateral pathologies)
- Look carefully that sulci is abutting inner table of skull (might miss old extra-axial blood)
- Look carefully at the last few slices near the vertex (might be the only area of pathology)
- Check bone windows carefully for fractures and especially base of skull
- Look for places where fluid shouldn’t be e.g. sinus including sphenoid, mastoid air cells – could be blood or infection
- Look at facial skeleton not just the brain especially in trauma
- Compare with old! It might be stable pre-existing pathology or progressed since.