Cervical spine protocol (MRI)

The MRI cervical spine protocol encompasses a set of MRI sequences for the routine assessment of the cervical spine.

Note: This article aims to frame a general concept of an MRI protocol for the assessment of the cervical spine. Protocol specifics will vary depending on MRI scanner type, specific hardware and software, radiologist and perhaps referrer preference, patient factors e.g. implants, specific indications and time constraints.

Indications

The most common indications include ^1,2:

• degenerative disc disease
  • disc herniation and radiculopathy
  • suspected spinal canal stenosis
• spinal trauma, suspected cervical spine fractures, spinal epidural hematoma
• spinal tumors and/or vertebral metastasis
• inflammatory/autoimmune conditions
  • multiple sclerosis
  • acute disseminated encephalomyelitis
  • neuromyelitis optica
  • inflammatory arthritis
• spinal infections such as spondylodiscitis, vertebral osteomyelitis, spinal epidural abscess etc. 
• spinal vascular malformations
• spinal cord infarction
• syringohydromyelia
• congenital spinal malformations and spinal dysraphism
• suspected complications of spinal surgery
• follow up of findings on other examinations

1.5 vs 3 tesla

Examinations of the spine are generally done on both 1.5 and 3.0 tesla systems. Postoperative examinations in patients with metallic implants, however, should be done on 1.5 tesla with metal artifact reduction sequence (MARS). Some examinations might profit from the improved spatial and contrast resolution of 3 tesla.

Patient positioning

An MRI of the cervical spine is usually conducted with the patient in the supine position.

Technical parameters

Coil

• head and neck coil

Scan geometry

• in-plane spatial resolution: ≤0.7 x 0.7 mm
• field of view (FOV): 200-240 (sagittal/coronal) 100-160 (axial)
• slice thickness: ≤3mm ^2-4

Planning

A typical MRI of the cervical spine might look as follows ^1-4:

• sagittal images:
  • angulation: parallel to the cervical spinal axis and the spinous processes
  • volume: includes the whole vertebral bodies and the facet joints, in a craniocaudal direction, should include the craniocervical junction up to the second thoracic vertebra
  • slice thickness: ≤3 mm
• axial images (long stack):
  • angulation: perpendicular to the cervical spine
  • volume: variable depends on the clinical question and/or the visible pathology
  • slice thickness: ≤3 mm
• coronal images*            
  • angulation: parallel to the cervical spinal axis and transverse processes
  • volume: includes the posterior pharyngeal wall and the ligamentum nuchae
  • slice thickness: ≤3 mm

Sequences

The mainstay in spinal imaging is T1 weighted and T2 weighted images. 

The majority of MRIs of the cervical spine will be done for the evaluation of degenerative disc disease and do not require any contrast media, the latter is usually administered in the setting of tumors, infection and postoperative imaging such as suspected complications of spinal surgery. Depending on the exact indication the examination can be supplemented by several adjuncts ^1-5.

Standard sequences

• T1-weighted
  • purpose: bone and/or soft-tissue characterization
  • technique:  T1 fast spin echo
  • planes: sagittal, axial, coronal*
• T2-weighted
  • purpose: bone and/or soft-tissue characterization, detailed anatomy, including ligament and tendon anatomy
  • technique: T2 Dixon / T2 fast spin echo
  • planes: sagittal, axial, coronal*
• T2-weighted (fat-saturated)
  • purpose: bone and soft tissue characterization, assessment of inflammatory changes, fractures
  • technique:  STIR / T2 Dixon, T2 FS fast spin echo, T2 GRE
  • planes: sagittal, axial*

Optional sequences

• chemical shift imaging*
  • purpose: tissue characterization of bone tumors and vertebral lesions
  • technique: T1 Dixon, T1 gradient-echo (GRE) in-phase (IP) and out-of-phase (OP) 
  • planes: sagittal
• phase-sensitive inversion recovery*
  • purpose: might improve detection of cord lesions in multiple sclerosis ^1,6
  • technique: 3D PSIR 
  • planes: sagittal
• diffusion-weighted imaging*
  • purpose: evaluation of spinal cord ischemia, differentiation spondylodiscitis vs degenerative changes ^3,7
  • technique: DWI/DTI  
  • planes: sagittal
• T1-weighted (fat-saturated)*
  • purpose: suspected vertebral artery dissection
  • technique: T1 Dixon, T1 gradient-echo
  • planes: axial, coronal*

Some indications might benefit from the application of contrast media such as e.g. inflammatory conditions, spinal tumors and suspected complications of spinal surgery.

• T1-weighted C+ (fat-saturated)
  • purpose: for inflammatory  conditions, suspected tumors
  • technique:  T1 Dixon, T1 fast spin echo
  • planes: axial, sagittal
• MR perfusion*
  • purpose: evaluation of tumors for their vascularization
  • technique:  T1 GRE (DCE)
  • planes: sagittal or axial

(*) indicates optional planes or sequences

Practical points

• the protocol can and should be tailored to the specific indication or clinical question
• a basic native protocol will consist of 4 sequences
• coronal images might be added for the evaluation of the atlantoaxial/atlantooccipital joint
• nowadays fat saturation can be conveniently achieved by Dixon images
• contrast administration is typically reserved for spinal tumors or spinal vascular malformations