Causes of intracranial calcification
- Normal
- Pineal gland
- Dural (commonly falx)
- Vascular (carotid arteries)
- Basal ganglia
- Abnormal
- Tumours - craniopharyngioma, meningioma
- Arteriovenous malformations
- Aneurysms
- Vault or sinus osteomas
Criteria for skull x-rays after recent head injury
- Loss of consciousness or amnesia at any time
- Neurological symptoms or signs
- CSF leak from nose or ear
- Suspected penetrating injury or foreign body
- Tense fontanelle, scalp bruising or laceration in a child < 5 years
- Presence of other trauma that might imply a strong impact
- Alcoholic intoxication
Types of views
- Lateral - right or left according to site of injury
- Anteroposterior
- Half axial (Towne's) view
Causes of skull radiolucencies
- Normal
- Squamous temporal bone
- Pacchionian granulations
- Air
- Superficial - after scalp injury
- Intracranial - after open fracture
- Outer skull table
- Inner skull table
- Slow growing tumours
- Chronic subdural haematoma
- Diffuse lesions
- Metastases
- Multiple myeloma
- Paget's disease
- Hyperparathyroidism
Causes of skull vault densities
- Generalised
- Renal osteodystrophy
- Fibrous dysplasia
- Acromegaly
- Drugs - e.g. Phenytoin
- Multifocal
- Sclerotic metastases
- Paget's disease
- Localised
- Foreign body
- Hyperostosis frontalis interna
- Osteoma
- Meningioma
Characteristics of fractures, sutures and vascular markings
Fractures
-
Straight translucent lines
-
Mores radiolucent - factures affect both tables
-
Most are straight but can change direction suddenly
-
Sharply demarcated
-
Parallel margins - no tapering
-
May run across sutures
Sutures
Vascular markings
-
Less translucent - affect inner table only
-
Not sharply demarcated
-
Meningeal grooves taper as they run peripherally
-
Branching pattern and symmetrical
-
Diploetic venous channels are wide
Bibliography
Nicholson D A, Driscoll P A, Hodgkinson D W, Forbes W St C. The skull. Br
Med J 1993; 307: 1476-1481.
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