Skull Fracture (Non-depressed) — CT Brain Features
1. Linear (most common)
- Thin radiolucent line in bone window
- Sharp, non-sclerotic margins
- Often crosses vascular grooves (vs grooves: branching, sclerotic margins)
- May cross sutures (vs sutures: serrated, symmetric)
- No displacement or depression
2. Diastatic fracture
- Widening of cranial sutures beyond normal
- Common in children
- Typically along coronal, sagittal, lambdoid sutures
3. Comminuted (non-depressed)
- Multiple intersecting fracture lines
- Bone fragmented but no inward displacement
4. Basilar skull fracture
- Often indirect signs predominate:
- Pneumocephalus
- Air-fluid levels in paranasal sinuses
- Opacification of mastoid air cells
- Fracture line may be subtle (bone window essential)
- Common sites: temporal bone, sphenoid, occipital base
General CT Clues (All Types)
- Best seen in bone window
- Look for overlying scalp swelling/hematoma
- Assess for associated intracranial injury (EDH, SDH, contusion)
- Use multiplanar reconstructions (MPR) for subtle fractures
Quick Differentiation
- Fracture line → sharp, straight, may cross sutures
- Suture → zig-zag, symmetric, sclerotic edges
- Vascular groove → branching, tapered
