Brain & C-spine CT scan Analysis for Junior Doctors

Introduction

CT scans are commonly used to evaluate patients with suspected brain or cervical spine injury. As a junior doctor, having a structured approach to CT analysis helps with early recognition of life-threatening pathology and improves communication with radiology and the trauma team.

CT Brain Analysis – Key Features

When reviewing a CT brain, systematically look for:

Midline shift: Displacement of midline structures (falx cerebri, septum pellucidum) suggests mass effect from haemorrhage, tumour or major oedema.
Haemorrhage: Hyperdense areas. Classify as epidural, subdural, intraparenchymal, or subarachnoid based on location and shape.
Ischaemia: Hypodense regions in a vascular territory, loss of grey–white differentiation, sulcal effacement and early swelling.
Ventricular size: Look for dilatation, compression or asymmetry suggesting hydrocephalus, raised ICP or mass effect.
Skull and base of skull: Fracture lines, air in cranial cavity, fluid levels in sinuses.

CT C-Spine Analysis – Key Features

For the cervical spine CT, adopt a “bones, alignment, joints, soft tissue” approach:

Bony injury: Vertebral body, pedicle, lamina, spinous/transverse process fractures.
Alignment: Step-offs, listhesis, abnormal angulation, loss of normal lordosis.
Dislocations/subluxations: Facet dislocation, perched or locked facets.
Spinal canal and cord: Canal compromise, retropulsed fragments, visible cord compression (on CT myelogram or MRI as follow-up).
Soft tissues: Prevertebral soft tissue swelling, ligamentous injury, haematoma.

CT Features of Common Intracranial Conditions

Condition	CT Features
Subdural haemorrhage	Crescent-shaped hyperdensity along brain surface, crossing suture lines, may track over a large area. Often associated with mass effect and possible midline shift.
Epidural haemorrhage	Biconvex (lens-shaped) hyperdensity that typically does not cross suture lines. May cause mass effect and midline shift; commonly related to skull fracture.
Intracerebral / intraparenchymal haemorrhage	Hyperdense collection within brain parenchyma with variable mass effect. Appearance depends on location and size; may extend into ventricles.
Space-occupying lesions (tumours, metastases)	Irregular or rounded mass, often with surrounding hypodense vasogenic oedema, variable contrast enhancement, and possible midline shift.
Meningitis	May show sulcal effacement, diffuse or localised oedema, meningeal enhancement with contrast, and/or ventriculomegaly. CT can be normal; clinical correlation is essential.
Pneumocephalus	Intracranial air appearing as very low-density (black) areas, often after trauma or neurosurgery.
Base of skull fracture	Fracture lines through temporal bone or skull base, air–fluid levels in sinuses or mastoid air cells, possible associated extra-axial haemorrhage.
Subarachnoid haemorrhage (SAH)	Hyperdensity in sulci, basal cisterns, or fissures. Diffuse SAH shows widespread cortical sulcal hyperdensity; localised SAH may be focal in a specific sulcus or cistern.
C-spine fractures	Fracture lines of vertebral bodies or posterior elements, possible malalignment. Look carefully at occipito-cervical and cervico-thoracic junctions.

Example CT Images (Click to Enlarge)

Subdural haemorrhage — Subdural Haemorrhage

Epidural haemorrhage — Epidural Haemorrhage

Intra-cranial haemorrhage — Intra-cranial Haemorrhage

CT of meningitis — CT Features of Meningitis

Base of skull anatomy – diagram 1 — Base of Skull Anatomy – Diagram 1

Base of skull anatomy – diagram 2 — Base of Skull Anatomy – Diagram 2

Diffuse subarachnoid haemorrhage — Diffuse Subarachnoid Haemorrhage

Localised subarachnoid haemorrhage — Localised Subarachnoid Haemorrhage

C-spine fracture on CT — Example of a C-spine Fracture on CT

Intracranial Infarcts and Related Lesions – CT Features

Intracranial Lesion	CT Features
Acute ischaemic stroke	Area of low attenuation in a vascular territory, loss of grey–white differentiation, sulcal effacement; may have mild mass effect.
Haemorrhagic stroke	Hyperdense intraparenchymal blood clot with or without surrounding oedema and mass effect; may have intraventricular extension.
Cerebral venous thrombosis	May show “empty delta sign” with contrast (unenhanced thrombus centrally with enhancing sinus wall), venous infarcts, or haemorrhagic venous infarcts.
Brain abscess	Ring-enhancing lesion with surrounding oedema; often appears as a mass lesion with central low attenuation. MRI and clinical context help distinguish from tumour.
Multiple sclerosis plaque	Well-defined low-attenuation (or subtle) lesions, often periventricular; better seen on MRI, but CT may show hypodense plaques without mass effect.

Acute intracranial infarct — Acute Intracranial Infarct

Haemorrhagic stroke — Haemorrhagic Stroke

Cerebral venous thrombosis — Cerebral Venous Thrombosis

CT of brain abscess — CT of Brain Abscess

Multiple sclerosis plaque — Multiple Sclerosis Plaque

Conclusion

CT brain and C-spine interpretation is complex and radiologist input is essential, but a structured approach allows junior doctors to identify major red flags early, prioritise management and communicate effectively with the team. Keep revisiting real cases and correlate CT findings with clinical presentation to build confidence.