From the Guidelines
Cervical spinal stenosis is typically diagnosed using a combination of clinical evaluation and imaging studies, with the most reliable diagnostic criteria including CT scans to evaluate the spinal canal and neuroforaminal narrowing, as well as MRI to assess cord abutment and signal changes secondary to spinal canal narrowing 1.
Diagnostic Criteria
- CT scans: provide superior spatial resolution to identify regions of neuroforaminal and spinal canal narrowing, and are particularly useful in evaluating patients with suspected ossification of the posterior longitudinal ligament (OPLL) 1
- MRI: useful in assessing cord abutment and signal changes secondary to spinal canal narrowing, as well as evaluating exiting nerve roots in the setting of radiculopathy, although detection of OPLL on MRI is limited 1
- CT myelography: may be considered in patients with clinically apparent radiculopathy and contraindication to MRI, or in the setting of equivocal MRI findings, to help identify regions of position-dependent cord compression related to cervical spinal stenosis from OPLL 2 ### Key Considerations
- The choice of imaging modality depends on the patient's clinical presentation and the suspected underlying cause of cervical spinal stenosis
- CT scans are more reliable than radiographs in identifying OPLL and evaluating sequelae related to its diagnosis 1
- MRI has mostly supplanted CT myelography as a first-line imaging modality for complex cervical radiculopathy, but CT myelography may still be useful in certain cases 2
From the Research
Diagnostic Criteria for Cervical Spinal Stenosis
The diagnostic criteria for cervical spinal stenosis can be summarized as follows:
- Cervical spinal stenosis occurs at the craniovertebral junction, usually incident to a congenital malformation, or it appears as a developmental defect with diffuse narrowing of the cervical canal 3
- Congenital cervical stenosis (CCS) is characterized by a decreased spinal canal diameter at multiple levels of the cervical spine in the absence of degenerative changes 4
- The pathoanatomy of CCS is associated with a decrease in the lamina-pedicle angle and an increase in the lamina-disc angle, ultimately leading to a smaller spinal canal diameter 4
- Cervical stenosis can be defined as an abnormal narrowing of the cervical spinal canal, which can lead to altered cervical spinal cord function and cervical radiculopathy 5
Anatomic Measurements
Anatomic measurements that can be used to diagnose cervical spinal stenosis include:
- Mid-sagittal canal diameter (mid-SCD) (<10 mm) at multiple sub-axial cervical levels (C3-C7) 4
- Coronal vertebral body, AP vertebral body, pedicle width, pedicle length, laminar length, AP lateral mass, posterior canal distance, lamina-pedicle angle, and lamina-disc angle (LDA) 4
- Spinal canal narrowing can be characterized by relative values, such as adapted Maximal Canal Compromise (aMCC) and adapted Spinal Cord Occupation Ratio (aSCOR) 6
Imaging Techniques
Imaging techniques that can be used to diagnose cervical spinal stenosis include:
- Magnetic Resonance Imaging (MRI) 3, 4, 6
- 3D T2-weighted MRI segmentation of spinal cord and cerebrospinal fluid space 6
Clinical Evaluation
Clinical evaluation of cervical spinal stenosis can include: