Radioimaging In Spine Injuries – Xray, CT, MRI

After clinical evaluation, radioimging is a very important part of spine assessment. Radiographs or xrays are the first imaging modality used. They are handy, easy, does not require special care and reports are almost instant. Their finding  can guide  the approach to further diagnostic investigation. however radiographs do not provide complete information due to their inherent limitations of two dimensional views. Theref0re computed tomogram is necessary and adds to  information in approximately half of all cases.

Radiographs (Xray)

Following xrays are essential in a patient who has multiple injuries

• Chest x-ray anteroposterior view
• Pelvis x-ray anteroposterior view
• Lateral cervical spine x-ray.

Rest of the imaging for spine is done after patient has been stabilized.

Cervical Spine

After patient is stabilized, a complete imaging of cervical spine views should be obtained. Following  views are generally ordered.

• Open mouth
• Anteroposterior
• Right and left oblique.

Flexion-extension views may be done in case there is doubt of instability.

To avoid further injury the patient is not moved to position for the various views. Instead, the x-ray beam and film position is adjusted.

Lateral radiograph allows visualization of the spine from the occiput to C6 vertebra and C7 if shoulders are pulled during the xray. A  swimmer’s lateral view or a CT scan may be needed if lower cervical spine cannot be visualized.  Follwing things are noted in a cervical spine xray

Lateral View

• Alignment of the cervical vertebrae- Assessed by examining longitudinal lines along vertebral bodies, lamina, and spinous processes.
• The prevertebral soft tissues are also examined for swelling related to acute hemorrhage. If increased, it suggests  acute cervical spine injury.

Anteroposterior View

Shows the C3 to T4 segments. A change in alignment of the uncovertebral joints (Small synovial joints between adjacent lateral lips of the bodies of the lower cervical vertebrae) and spinous processes can indicate an acute injury.

Open mouth view

It is essential for excluding a C1 arch or odontoid process fracture.

Oblique views

To identify injuries of the facet joints, pedicles, and lateral masses.

Flexion-extension views

To  identify any occult cervical ligamentous injury if the patient has pain and tenderness but other xrays are normalThese are dangerous in settings of injury and  should be performed in alert patients, under supervision, and with voluntary unassisted positioning by the patient.

Thraccic, Lumbar  and Sacral Spine

Anteroposterior and lateral thoracic and lumbar radiographs and a pelvis AP view are standard xrays.Alignment, destruction of vertebrae or reduction in height of vertebra, vertebral faractures are signs of injury.

Computed Tomography

CT scans are done for

• Patients with suspected spinal fracture and/or dislocation
• Difficult visualization of their spinal column on radiographs.
• Preoperative planning
• substitute for the open mouth view in unresponsive person
• Junctional injuries – Cervothoracic area, Thoracolumbar junction

CT is superior to MRI in demonstrating bony injury.

Magnetic Resonance Imaging

It is done in patients  with cervical level spinal cord injury, incomplete spinal cord injury, and for assessment of disk or ligament injuries. The purpose of MRI is to look for integrity of the cord and severity of injury to the cord.