Patient examination: Radiological evaluation (XR,CT, MRI)
1. Preliminary Remarks
Radiological evaluation of an injured spine includes plain radiographs, Computerized tomography (CT) and Magnetic Resonance Imaging (MRI) scan. The purpose of radiological evaluation is to:
- identify the location and extent of injury
- determine features of vertebral instability
- assess the severity of neurological compression and injury
- classify injury patterns
identify multilevel injuries
2. Plain radiographs
I ntroduction
Good quality plain radiograph in two planes (antero-posterior and lateral) must be performed in all patients with suspected spinal trauma.
The appropriate radiograph is performed based on local tenderness or deformity and the presence of neurology (in case of neurological injury).
For the upper cervical spine one can use a C2 targeted X-ray examination.
AP view is recorded thorough the open mouth.
Lateral incudes occiput to C3.
If the radiographs are not satisfactory or inconclusive, CT scan must be performed.
What is seen in the AP radiograph
In the antero-posterior film, the following factors are observed:
Anatomical landmarks in AP view
- Odontoid
- C2 body
- C1-C2 facet joint
- C1 lateral mass
- C0-C1 joint
- Occiput
- Bifid spinal process
What is seen:
- Lateral dislocation of the lateral mass of C1 (Positive Spence sign if dislocation exceeds 7mm)
What it indicates:
- Type 4 ATLAS fracture
What is seen:
- Fracture line of the odontoid
- Fracture lines of the odontoid are usually not easily seen in the AP view.
What it indicates:
Anderson D'Alonzo Type II or III fracture
3. What is seen in the lateral x-rays
Anatomical landmarks seen in the lateral view:
- Occiput
- Anterior and posterior arch of C1
- Odontoid
- C2 body
- Isthmus and lamina of C2
What is seen:
- Large atlanto occipital distance
What it indicates:
- Axial atlanto occipital dislocation
What is seen:
- Increased atlanto axial distance
What it indicates:
- Atlanto axial instabillity
What is seen:
- Fracture of the posterior arch C1
What it indicates:
- Fracture of C1
What is seen:
- Left shows fracture of the neck the odontoid with extension
- Right image shows fracture of the neck the odontoid with posterior dislocation
What it indicates:
- C2 odontoid fracture
What is seen:
- Fracture of the pars interarticularis of C2 and slight anterior slippage of C2 body
What it indicates:
- Traumatic spondylolisthesis of C2
What is seen
- Anterior slippage of the C2 body
What it indicates
- Unstable traumatic spondylolisthesis
4. What is seen in CT scans
CT can reveal associated injuries as well as rule out suspected fractures which are not present.
What is seen:
- Precise fracture morphology
- Associated injuries
- Extent of vertebral body comminution and displacement
Which view:
- Sagittal, axial, and coronal
What is seen:
- Fracture of the pars and angulation C2-C3
Which view:
- Lateral
What it indicates:
- Spondyloschisis type IIa
What is seen
- Occipito condyle fracture
Which view
- Lateral, coronal
What it indicates
- Fracture of C0 (occipital condyle)
What is seen
- C1 atlas fracture
Which view
- Coronal, axial
What it indicates
- Fracture of the C1 ring
What is seen
- Odontoid fracture
Which view
- Sagittal, axial
What it indicates:
- Fracture of the dens axis (odontoid)
What is seen
- Traumatic spondylolisthesis of C2
Which view
- Sagittal, axial
What it indicates
- Fracture of C2
What is seen
- Prevertebral hematoma and effusion in the C1-C2 joint
- Sagittal reconstruction
What it indicates
- Occipito condyle dislocation
What is seen
- Hyperintense signal changes in cord
What it indicates
- Cord injury
