Skull X-ray: indications and findings

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Beginner

For decades, the skull X-ray was a routine test after head injury. It is no longer. A skull film shows the bone but not the brain, and a patient can have a life-threatening intracranial haemorrhage with a normal skull X-ray, or a skull fracture with no brain injury. In the UK, head injury is imaged with CT, following NICE NG232. Skull radiographs survive in a handful of specific roles, most importantly in the skeletal survey for suspected physical abuse in young children. This page explains where skull films are and are not appropriate, and how to read one when you meet it.

1. Why not for head injury?

• The clinical question is about the brain. The decisions that matter after head injury depend on haemorrhage, contusion, swelling and mass effect, which only CT (or MRI) can show.
• A normal skull film is false reassurance. Significant intracranial injury can occur without any fracture, particularly in children, whose skulls are more pliable.
• NICE NG232 sets out clinical criteria for CT of the head in adults and children (for example reduced conscious level, signs of skull base fracture, post-traumatic seizure, focal neurological deficit, repeated vomiting, and anticoagulant use), and plain skull films are not part of that pathway.
• Delay: a skull film that leads on to CT anyway adds time and radiation without benefit.

Similarly, plain films are not appropriate for the cervical spine in most injured adults: see cervical spine X-ray. Always check the current version of NG232.

2. Where skull X-ray still has a role

Indication	Why a film is used
Suspected physical abuse in young children (skeletal survey)	Skull views are part of the standard skeletal survey under RCR / Society and College of Radiographers guidance, alongside CT head where indicated. Fractures in a non-mobile child need explanation. See non-accidental injury.
Shunt series	Plain films of the skull, neck, chest and abdomen trace a ventriculoperitoneal shunt to check continuity, disconnection or migration
Metallic foreign body screening (for example the orbits before MRI in metalworkers)	To detect a metallic fragment that could move in the MRI magnet
Myeloma and other bone lesions	Historically part of a myeloma skeletal survey; now largely replaced by whole-body low-dose CT or MRI (NICE NG35)
Craniosynostosis	Sometimes used to assess suture patency, though CT and ultrasound are increasingly used
Penetrating injury or depressed fracture assessment in selected cases	Usually CT is preferred

Facial bone injuries have their own views and decision-making: see facial fractures.

3. Views and normal anatomy

The usual projections are a frontal view (occipitofrontal, or AP in a child), a lateral, and a Towne's view (a fronto-occipital view angled caudally) to show the occipital bone. In trauma, a lateral taken with a horizontal beam can show fluid levels in the sinuses.

Normal structures that are commonly mistaken for pathology:

• Sutures: the coronal, sagittal, lambdoid and squamosal sutures, plus the metopic suture in young children, and in infants the fontanelles.
• Wormian bones: small extra bones within sutures, especially the lambdoid. A few are normal; many can suggest an underlying bone disorder such as osteogenesis imperfecta.
• Vascular markings: grooves of the middle meningeal artery and dural venous sinuses, and diploic venous channels.
• Arachnoid granulations: small, well-defined lucencies near the vertex and the sinuses.
• Calcification of the pineal gland and choroid plexus in adults.

4. Fracture, suture or vascular groove?

This is the core skill in reading a skull film.

Feature	Fracture	Suture	Vascular groove
Edges	Sharp, without sclerotic margins	Serrated (zig-zag), with sclerotic margins in adults	Smooth, with sclerotic (corticated) margins
Course	Straight or angular; may branch abruptly	In a predictable anatomical position	Tapers and branches gradually, like a tree
Lucency	Often more lucent than a groove, because it passes through both tables of the skull	Variable	Less lucent (only the inner table is grooved)
Symmetry	Usually unilateral	Symmetrical	Often symmetrical
Other	May cross sutures or vascular markings; may widen a suture (diastatic fracture)	Matches the expected suture	Follows a known vascular path

5. Other trauma signs

• Depressed fracture: an area of increased density (a "double density") where depressed fragments overlap normal bone, or a visible step in the outline of the vault on a tangential view. Usually needs CT and neurosurgical input.
• Diastatic fracture: a fracture that widens a suture.
• Pneumocephalus: gas within the cranial cavity, indicating a communication with a sinus or the outside, as in a skull base or open fracture.
• Fluid level in the sphenoid sinus on a horizontal-beam lateral, which suggests a skull base fracture with blood or cerebrospinal fluid in the sinus.
• Soft-tissue swelling over the vault (scalp haematoma) may point to the site of impact.

Any of these findings needs CT of the head, regardless of the patient's clinical state.

6. Non-traumatic skull findings

Skull films taken for other reasons, or included on other studies, can show systemic bone disease. These are common exam images.

Appearance	Description	Typical causes
"Raindrop" skull	Multiple small, well-defined, punched-out lytic lesions of fairly uniform size	Multiple myeloma
"Pepperpot" (salt-and-pepper) skull	Fine, mottled, granular lucencies throughout the vault	Hyperparathyroidism
"Cotton-wool" skull	Thickened vault with patchy, fluffy sclerosis	Paget disease (late, mixed phase)
Osteoporosis circumscripta	A large, well-defined lytic area, often frontal or occipital	Early (lytic) phase of Paget disease
"Hair-on-end"	Thickened diploe with vertical striations perpendicular to the vault	Chronic haemolytic anaemias, such as thalassaemia and sickle cell disease
"Copper-beaten" skull	Prominent convolutional markings on the inner table	Raised intracranial pressure or craniosynostosis (can be normal in young children)
Lytic or sclerotic metastases	Irregular, variable-size lesions	Breast, lung, prostate and other primaries

See metabolic bone disease and bone tumours for more.

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	Head injury means CT (NG232). Learn fracture vs suture vs vessel, and the classic skull patterns.
Nurse	Know that skull X-ray is not a head injury test; neurological observations and escalation follow local head injury policy.
Junior doctor	Apply NICE NG232 CT criteria, and recognise the safeguarding implications of skull fractures in young children.
Radiographer	Justification: decline or query skull X-ray requests for head injury according to IR(ME)R and local protocols. Skeletal survey technique.
Advanced / FRCR	Accessory sutures vs fractures in infants, and the differential of lytic skull lesions.

Practise on real skull and face X-rays →

References

1. NICE NG232. Head injury: assessment and early management. nice.org.uk
2. Royal College of Radiologists and Society and College of Radiographers. The radiological investigation of suspected physical abuse in children. rcr.ac.uk
3. NICE CG89. Child maltreatment: when to suspect maltreatment in under 18s. nice.org.uk
4. NICE NG35. Myeloma: diagnosis and management. nice.org.uk
5. Royal College of Radiologists. iRefer. irefer.org.uk

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.