Tests
1st tests to order
multidetector computed tomography (MDCT)
Test
Noncontrast, MDCT is the initial imaging modality of choice to evaluate the cervical spine.[14][30]
More effective than x-ray for evaluation of cervical spine alignment, possibility of fracture, or soft-tissue swelling. The cervical spine is imaged from the skull base or craniocervical junction, through the cervicothoracic junction. Thinner slices increase sensitivity but may add to the radiation burden. Contiguous axial slices of no greater than 3 mm are recommended to obtain reformatted images in axial, coronal, and sagittal planes in the cervical spine.[14][31]
The main limitation of CT rests in its relative inability to detect changes in soft tissues, including the spinal cord and ligamentous structures.[14] Despite the high sensitivity of the MDCT in identifying bony abnormalities, interpretation may be difficult in patients with severe degenerative changes or osteopenia.[14]
In obtunded or intubated patients, the use of CT alone is sufficient to exclude unstable cervical spine injuries.[37]
Result
may show cervical spine vertebral misalignment, fracture, and prevertebral soft-tissue swelling
Tests to consider
CT whole spine
Test
If a cervical spine injury or a fracture is identified, a CT scan of the whole spine is indicated to identify a concomitant thoracolumbosacral fracture.[11] See Thoracolumbar spine trauma.
Result
may be normal; may show a concomitant thoracolumbosacral fracture
cervical spine x-ray series
Test
CT is now considered the primary imaging modality to evaluate the cervical spine.[14][30] Plain radiographs of the cervical and thoracolumbar spine are not recommended in the initial screening of spinal trauma because of their low sensitivity.[14][30] Multiple randomized control trials with Class I evidence now consider plain radiography to be insufficient to identify clinically relevant fractures.[14][32][33][34][35][36]
In the absence of CT, plain x-rays remain effective at evaluating for cervical spine misalignment, and prevertebral soft-tissue measurements. Views in this series include anteroposterior, lateral, open-mouth odontoid, and swimmer's (pull down) view.
All levels between the occiput and upper half of T1 need to be visualized. If this cannot be accomplished on a lateral view, a lateral swimmer's or pulldown view is required.
Anteroposterior and lateral views are useful at evaluating for misalignment, and prevertebral soft-tissue thickening. An open-mouth odontoid view can be used to assess for fractures of the dens or for transverse ligament injury. Ligamentous injury should be suspected if the combined overhang of the C1 lateral masses on C2 is >7 mm.[Figure caption and citation for the preceding image starts]: Normal cervical spine: lateral, AP, and open-mouth odontoid viewFrom the personal collection of Michael G. Fehlings [Citation ends].
Result
may show cervical spine vertebral misalignment, fracture, prevertebral soft-tissue swelling, suspected transverse ligament injury
MRI cervical spine
Test
MRI is complementary to CT in the assessment of cervical spinal injuries.[14] It has high sensitivity for the identification of soft-tissue injuries and is considered the reference standard in identifying injuries to the spinal cord and discoligamentous complex.[14] It is the only modality for evaluating the internal structure of the spinal cord.[62] Caution should be taken when interpreting MRI results as the specificity for identifying significant soft-tissue injuries is shown to be only modest. Therefore, clinical correlation is of essence in each patient scenario.[43] MRI is not reliable in the identification of osseous injuries.
MRI is recommended in the following clinical scenarios: patients with clinical or imaging findings suggesting mechanically unstable cervical spine or ligamentous disruption; patients with neurologic deficit, suspected spinal cord injury or nerve root injury; comatose patients with normal CT of the cervical spine, to assess for possible ligamentous injury; and patients with normal CT of the cervical spine with persistent neck pain/tenderness, to assess for possible ligamentous injury.[30]
AOSpine guidelines suggest that when feasible, and as long as there are no contraindications, MRI should be used in spinal cord injury patients prior to surgical intervention to improve clinical decision making and to predict the neurologic outcome.[44] Patients on ventilator support, with hemodynamic instability or who are unable to remain still for prolonged periods of time often require help from an anesthesiologist for adequate sedation.
Result
may show cervical disk herniation, anterior or posterior ligament disruption, cord compression, spinal canal compromise, and intramedullary T1- and/or T2-weighted hyperintensity and/or hypointensity
CT myelogram
Test
In the event that MRI is unobtainable, CT myelogram can be used for the assessment of traumatic spinal canal narrowing due to disc herniation, extradural hematoma, or preganglionic nerve root avulsions.[30] However, CT myelography is inferior to MRI and is limited in assessing spinal cord contusion, cord hemorrhage, and postganglionic nerve root injuries.[30][45][46][47] CT myelogram is not recommended in suspected unstable spine injury because it can be technically challenging.[30]
Result
May show traumatic spinal canal narrowing due to disc herniation, extradural hematoma, or preganglionic nerve root avulsions
CT angiography (CTA) and MR angiography (MRA)
Test
CTA and MRA can be used in individuals with suspected arterial injury secondary to cervical spine trauma.[30] Although both modalities were found to be inferior to catheter angiography, they were largely comparable in their ability in identifying all the clinically significant arterial injuries.[48][49][50][51][52] MRA is especially valuable in assessing arterial injuries in patients who have a high risk of iodinated-contrast allergies.[30]
Result
May show evidence of vascular injury, arterial dissection, pseudoaneurysm, stenosis, occlusion, transection, intramural hematoma, thrombus, etc.
flexion-extension (F/E) cervical spine x-rays
Test
In the acute situation where imaging is indicated by Canadian C-Spine Rule or National Emergency X-Radiography Utilization Study criteria, F/E do not add useful clinical information and rarely demonstrate cervical instability not identified on conventional cervical radiographs or CT.[30][38][39][40][41][42] However, in the subacute period after injury, F/E radiographs can supplement MRI in the assessment of patients with ongoing neck pain but no unstable injury initially and no new neurologic symptoms. In this scenario, F/E may detect unrecognized ligamentous instability in the presence of negative MRI results.[30]
Result
may show ligamentous instability in the presence of negative MRI
nerve conduction studies
Test
Ordered if radiculopathy is suspected. Slowing of nerve conduction occurs with peripheral nerve compression.
Result
slowing of nerve conduction velocity
electromyography
Test
Ordered if radiculopathy is suspected. Results require interpretation by a neurologist. However, do not order electromyography for isolated neck pain after a motor vehicle accident.[63] If neck pain is not associated with arm pain, arm tingling, arm weakness, or arm numbness, electromyography does not improve outcomes.[63]
Result
radiculopathy: altered S potentials and insertion potential
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