Indications For Head - CT

Tumours
- astrocytoma
- medulloblastoma
- craniopharyngioma
- plexus papilloma
- glioma
- oligodendroglioma
- glioblastoma
- meningioma
- neurinoma
- metastases
- haemangioblastoma

Vascular
-arteriovenous malformation (AVM)
- aneurysm
- infarction
- ischaemia

Infectious
- encephalitis
- abscess
- meningitis
- tuberculosis
Degenerative
- cerebral atrophy
- hydrocephalus
- multiple sclerosis

Trauma
- fracture
- cerebral contusion
- pneumatocele

Haemorrhage
- extradural
- subarachnoid
- subdural (acute/chronic)
- extradural
- petechial
- parenchymal

Other
- subarachnoid cysts
- subdural hygroma

Indications

- Headache
- transient ischaemic attack
- dementia screen
- cerebrovascular attack
- MRI contraindicated/ not available

Criteria

Visualisation imaging criteria
- whole cerebrum
- whole cerebellum
- whole skull base
- vessels after the introduction of IV contrast media

Image reproduction criteria
- sharp reproduction of the border between grey and white
matter
- sharp reproduction of the basal ganglia
- sharp reproduction of the ventricular system
- sharp reproduction of the cerebrospinal fluid space
around the mesencephalon
- sharp reproduction of the cerebrospinal fluid space over
the brain
- sharp reproduction of the great vessels and the choroid
plexuses after the introduction of IV contrast media

Anatomy covered

- from the foramen magnum to the skull vertex

Gantry scan plane
- 10-12 degrees above the orbito-meatal (OM) line to reduce
dose to the lenses of the eye (refer figure 4)

Sequence Technic

A sequence brain protocol can be useful for patients that are unable to keep still. Generally it is a lot easier and quicker to repeat a single scan slice, rather that the entire spiral/helical range. If the patient is really uncooperative a sequence scan with the fastest tube rotation time possible should be used