MRI OF THE CERVICAL SPINE

Michael Wilczynski, DO FAOCR

Diagnostic Radiology Department Chair

Franciscan St James Healthcare

Chicago, IL

Donald Kim, DO

Radiology Residency, St James Healthcare

Abdominal Imaging Fellowship, UCSF

CLINICAL INDICATIONS• Absent or reduced sensation on clinical examination

• Absent or reduced reflexes

• Muscle wasting

• Severe intractable arm pain where symptoms have been present for more than 6 weeks

• Cervical radicular pain persisting for greater than 6 weeks

• Axial neck pain persisting for greater than 3 months

• Reduced power on physical examination

• CNS Tumor, Infection, Inflamation

• Tumor of the meninges

• Congenital malformations of the spinal cord, including vascular malformations

• Spinal surgery follow up

• Trauma

CERVICAL RADICULOPATHY WORKUP• Plain radiography

• Radiography of the cervical spine is usually the first diagnostic test ordered in patients who present with neck and limb symptoms

• More often than not, this study is diagnostic of cervical disc disease as the cause of the radiculopathy

• The American College of Radiology recommends plain radiographs as the most appropriate initial study in all patients with chronic neck pain• Lateral, anteroposterior, and oblique views

• On the lateral view

• Look for disc-space narrowing, comparing the level above and below

• Typically, the cervical disc spaces get larger from C2-C6, with C5-C6 being the widest disc space in normal necks, and C6-C7 slightly narrower.

• Besides narrowing, look for subchondral sclerosis and osteophyte formation.

• On oblique views

• Look for foraminal stenosis at the level of the suspected radiculopathy, comparing it with the opposite foramina

CERVICAL RADICULOPATHY WORKUP• Plain radiography

• Other views:

• An open-mouth view should be ordered to rule out injury to the atlantoaxial joint when significant acute trauma has occurred

• If C7 can not be properly seen, then a "swimmer's view" (supine oblique view, in which the patient's arm is extended over the head)

• The atlantodens interval (ADI) is the distance from the posterior aspect of the anterior C1 arch and the odontoid process.

• This interval should be less than 3 mm in adults and less than 4 mm in children

• An increase in the ADI suggests atlantoaxial instability, such as from trauma or rheumatoid arthritis.

• Flexion and extension (lateral) views can be helpful in assessing spinal mobility and stability

• Limitations

• Problems with both specificity and sensitivity exist

• Correlations of findings on plain radiographs and cadaver dissections have found a 67% correlation between disc-space narrowing and anatomic findings of disc degeneration

• However, radiographs identified only 57% of large posterior osteophytes and only 32% of abnormalities of the apophyseal joints that were found on dissection

NORMAL

CERVICAL RADICULOPATHY WORKUP

• CT of the Cervical spine• CT scanning provides good visualization of bony elements and can be helpful in the assessment of

acute fractures

• It can also be helpful when C6 and C7 cannot be clearly seen on traditional lateral radiographic views

• The accuracy of CT imaging of the cervical spine ranges from 72-91% in the diagnosis of disc herniation.

• CT with contrast myelography

• Has an accuracy approaching 96% for diagnosis of cervical disc herniation

• The addition of contrast material allows for the visualization of the subarachnoid space and assessment of the spinal cord and nerve roots

• Even with myelography, however, soft-tissue visualization with CT is inferior to that provided by magnetic resonance imaging (MRI)

NORMAL DJD (also C2 fracture)

CERVICAL RADICULOPATHY WORKUP• MRI

• The American College of Radiology recommends routine MRI as the most appropriate imaging study in patients with chronic neck pain who have neurologic signs or symptoms but normal radiographs.

• MRI has become the method of choice for imaging the neck to detect significant soft-tissue pathology, such as disc herniation

• MRI can detect ligament and disc disruption, which cannot be demonstrated by other imaging studies

• The entire spinal cord, nerve roots, and axial skeleton can be visualized

• MRI has been found to be quite useful in evaluating the amount of cerebrospinal fluid (CSF) surrounding the cord in the evaluation of patients with cervical canal stenosis, although the T2-weighted images tend to exaggerate the degree of stenosis.

• Although MRI is considered the imaging method of choice for the evaluation of cervical radiculopathy, abnormalities have also been found in asymptomatic subjects.

• In one study,

• 10% of subjects younger than 40 years, were noted to have disc herniations

• 20% of subjects older than 40 years, had evidence of foraminal stenosis and 8% had disc protrusion or herniation

• Therefore, as with all imaging studies, the MRI findings must be used in conjunction with the patient's history and physical examination findings.

NORMAL Disc bulges and DJD

MRI CONTRAINDICATIONS• It is necessary to update continuously knowledge regarding the safety

issues related to MR technology, as well as to the technology of implants, devices, contrast agents, and other aspects related to the magnetic resonance imaging (MRI) examination

• MRI has become an increasingly used imaging modality in many fields of medicine, including cardiovascular imaging; therefore, careful patient screening before the examination, accurate evaluation of the individual risk, and qualified patient supervision is mandatory

• Most reported cases of MR related injuries and the few fatalities that have occurred have apparently been the result of failure to follow safety guidelines or from the use of inappropriate or outdated information related to the safety aspects

• Be aware of your radiology department requirements, as many strictly require documentation of any devices or clips

MRI SAFETY RESOURCE

STANDARD C-SPINE SEQUENCES• T1-weighted

• Axial

• Sagittal

• T2-weighted

• Axial

• Sagittal

• STIR or T2 fat sat

• Sagittal

• Gradient Echo

• Axial

• (T1 post contrast, if needed)

C-SPINE MRI APPROACH

• Basic principles are same for the lumbar spine

C-SPINE MRI APPROACH: ABCDE

• A

• B

• C

• D

• E

C-SPINE MRI APPROACH: ABCDE

• Alignment

• Bone

• Cord/Canal

• Discs

• Everything else

C-SPINE MRI APPROACH

• Alignment

• Anterior portion of vertebral bodies

• Posterior portion of vertebral bodies

• Facets

• Posterior spinal canal line

• Spinous processes

28-year-old man with atypical hangman’s fracture. C2 body fracture with anteroposterior displacement of fracture fragments (fat C2 body sign) is seen. Fracture disrupts Harris ring posteriorly and causes posterior offset of spinolaminar line from C1 to C3 (dotted line).

• Bilateral interfacetal dislocation.• 50% anteroposition C5-C6 as a

result of the dislocation.• In unilateral dislocation the

anteroposition is usually only 25%.

• Widened space between spinousprocesses C5 and C6 due to ligament rupture.

• Ruptured disc space.

• Soft tissue swelling anteriorly• Disruption of the disc• Non-hemorrhagic cord injury

Notice on the axial image that the cord injury is located in the grey matter, which is more sensitive to damage.

C-SPINE MRI APPROACH

• Bone

• Fractures

• Vertebral body compression

• Blastic or lytic lesions

THE MOST COMMON FRACTURE MECHANISM IN CERVICAL INJURIES IS HYPERFLEXION.

ANTERIOR SUBLUXATION OCCURS WHEN THE POSTERIOR LIGAMENTS RUPTURE. SINCE THE ANTERIOR AND MIDDLE COLUMNS REMAIN INTACT, THIS FRACTURE IS STABLE.

SIMPLE WEDGE FRACTURE IS THE RESULT OF A PURE FLEXION INJURY. THE POSTERIOR LIGAMENTS REMAIN INTACT. ANTERIOR WEDGING OF 3MM OR MORE SUGGESTS FRACTURE. INCREASED CONCAVITY ALONG WITH INCREASED DENSITY DUE TO BONY IMPACTION. USUALYINVOLVES THE UPPER ENDPLATE.

UNSTABLE WEDGE FRACTURE IS AN UNSTABLE FLEXION INJURY DUE TO DAMAGE TO BOTH THE ANTERIOR COLUMN (ANTERIOR WEDGE FRACTURE) AS THE POSTERIOR COLUMN (INTERSPINOUS LIGAMENT).

UNILATERAL INTERFACET DISLOCATION IS DUE TO BOTH FLEXION AND ROTATION.

BILATERAL INTERFACET DISLOCATION IS THE RESULT OF EXTREME FLECTION. UNSTABLE AND IS ASSOCIATED WITH A HIGH INCIDENCE OF CORD DAMAGE.

FLEXION TEARDROP FRACTURE IS THE RESULT OF EXTREME FLECTION WITH AXIAL LOADING. IT IS UNSTABLE AND IS ASSOCIATED WITH A HIGH INCIDENCE OF CORD DAMAGE.

FLEXION INJURIES

EXTENSION INJURIES

Hangman's fracture: Traumatic spondylolisthesisof C2.

Extension teardrop fracture

Hyperextension in preexisting spondylosis: “Open mouth fracture”

FRACTURES

Mild / Subtle Fractures Severe Fracture / Subluxation

The axial CT and MRI in the same patient show the displaced fragment pressing on the thecalsac.

On the sagittal CT and MRI there are no signs of posterior ligamentous injury.The anterior longitudinal ligament is disrupted.

The right facet joint looks a bit widened on the CT and there is some fluid in the joint on the MRI.

DIFFUSE BONY METASTASES

Sagittal T1WI MR shows patchy hypointensereplacement of fatty marrow throughout cervical and thoracic spine , with discs appearing brighter than adjacent marrow, typical of diffuse metastases.

C-SPINE MRI APPROACH

• Cord/Canal

• Cord compression

• Canal hematoma

• Canal stenosis

• Neuroforaminal stenosis

ANATOMY

POSTERIOR

CERVICAL CANAL STENOSIS• Causes of spinal stenosis may include:

• Overgrowth of bone

• Wear and tear damage from osteoarthritis on your spinal bones can prompt the formation of bone spurs, which can grow into the spinal canal.

• Paget's disease, a bone disease that usually affects adults, also can cause bone overgrowth in the spine.

• Herniated disks

• Discs tend to dry out with age. Cracks in a disk's exterior may allow some of the soft inner material to escape and press on the spinal cord or nerves.

• Thickened ligaments

• Ligaments may become stiff and thickened over time. These thickened ligaments can bulge into the spinal canal.

• Tumors

• Abnormal growths can form inside the spinal cord, within the membranes that cover the spinal cord or in the space between the spinal cord and vertebrae.

• Spinal injuries

• Car accidents and other major trauma can cause dislocations or fractures of one or more vertebrae. Displaced bone from a spinal fracture may damage the contents of the spinal canal. Swelling of adjacent tissue immediately following back surgery also can put pressure on the spinal cord or nerves.

•

CANAL STENOSIS

Axial GRE MR shows the severity of the central canal stenosis with flattening of the ventral cord and loss of all normal surrounding CSF signal. There is diffuse cord hyperintensity, with a slightly more prominent signal from the central gray matter.

Central spinal cord injury in a patient with a hyperextension injury and preexisting spondylosis and stenosis.

NEUROFORAMINAL STENOSIS

• Causes include:• Herniated disc

• Bulging disc

• Bone spurs

• Spondylolisthesis

• Facet disease

• Degenerative disc disease

• And others

Axial CT at C6-7 in the same patient shows the severe central stenosis at the level below the fusion , as well as severe bilateral foraminalstenosis

Sagittal CT myelogramshows C3-6 fusion with severe degeneration of C6-7 . There is severe central stenosis with loss of the contrast column .

NEUROFORAMINALSTENOSIS

Axial T2* GRE MR shows marked central stenosis with large ventral disc osteophyte . There is bilateral foraminal stenosis.

NEUROFORAMINALSTENOSIS

NORMAL

Changes in cord edema.

(a) Initial sagittal T2W image shows cord compression of the cervical cord with high signal change localized to the level of C3-4 indicating early cord edema.

(b) (b) A repeat scan 3 days later demonstrates an increase in the length of the signal change in keeping with longitudinal extension of the cord edema.

CORD EDEMA

There is a strong correlation between the length of the spinal cord edema and the clinical outcome.

The most important factor however is whether there is hemorrhage, since hemorrhagic spinal cord injury has an extremely poor outcome.

Hemorrhagic with areas of low signal intensity within the area of edema.

Non-hemorrhagic with only high signal on MR due to edema.

CORD EDEMA

LEPTOMENINGEAL METASTASES

C-SPINE MRI APPROACH

• Discs

• Disc height loss

• Disc bulge/protrusion

MRI shows a disc herniation between the C4 and C5 vertebrae. Also shown are signs of spinal stenosis

Herniated Cervical Disc. Cervical Disc Bulge

C-SPINE MRI APPROACH

• Everything else

• Paraspinal soft tissues

• Thyroid

• Aorta

• Pneumothorax

STERNAL FRACTURE

massive thoracic aortic aneurysm- mixed signal intensity mass anterior to vertebrae

massive thoracic aortic aneurysm- mixed signal intensity mass anterior to vertebrae

REVIEWC-SPINE MRI APPROACH: ABCDE• Alignment

• Bone

• Cord/Canal

• Discs

• Everything else

ADDITIONAL CASES

64-year-old man with hyperextension dislocation.A. Midsagittal CT image shows slight anterior disc space widening at C3–4 and osteophyte chip fracture (arrow). Spinal column is otherwise well aligned.B. Midsagittal T2-weighted MRI shows prevertebral soft-tissue edema with disruption of anterior longitudinal ligament (arrow). Contused spinal cord is squeezed between traumatic disc herniation (arrowhead) and ligamentum flavum. Posterior soft-tissue injury is indicated by high signal changes.

TRAUMA

32-year-old woman with variant Jefferson burst fracture.A and B, Transaxial (A) and coronal (B) CT reformations show lateral spread of fracture fragments, which indicates transverse ligament rupture and instability.

Flexion tear drop fracture

Soft tissue injury anteriorly and posteriorly with ligamentum flavumand interspinous ligament rupture and CSF leakage.Hemorrhagic spinal cord injury!

TRAUMA

NAMED FRACTURES

• Jefferson fracture• Burst fracture of C1

• Originally described as a four-part fracture with double fractures through the anterior and posterior arches, but three-part and two-part fractures have also been described

NAMED FRACTURES

• Hangman fracture• Also known as traumatic

spondylolisthesis of the axis

• Fracture which involves the pars interarticularis of C2 on both sides

• Results from hyperextension and distraction

NAMED FRACTURES

• Odontoid process (dens) fracture

• Fracture through the odontoid process of C2

• Three subtypes

NAMED FRACTURES

• Atlanto-occipital dissociation injuries

• Hyperextension injury

• Usually fatal

• basion-dens interval (BDI) >12 mm in adults

• basion-axial interval (BAI) >12 mm in adults

NAMED FRACTURES

• Atlanto-occipital dissociation injuries

• Hyperextension injury

• Usually fatal

• basion-dens interval (BDI) >12 mm in adults

• basion-axial interval (BAI) >12 mm in adults

NAMED FRACTURES

• Clay-Shoveler’s Fracture

• Avulsion fracture of spinous process of C6 or C7

• Occurs as result of rotation of trunk relative to neck

• No neurologic deficit

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• http://www.statdx.com/

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• http://www.radiologyassistant.nl/

• http://headneckbrainspine.com/

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