What is the best MRI protocol for evaluating cervical spine disc pathology?

Best MRI Protocol for Cervical Spine Disc Pathology

MRI cervical spine without IV contrast is the optimal imaging study for evaluating cervical disc disease, using a protocol that includes sagittal T1-weighted, sagittal T2-weighted, and axial gradient-echo T2-weighted sequences. 1, 2

Core Protocol Components

The American College of Radiology establishes MRI as the imaging modality of choice for cervical disc pathology due to its superior soft-tissue contrast and ability to visualize disc material, nerve roots, and spinal cord compression. 1

Essential Sequences

• Sagittal T1-weighted spin-echo: Provides excellent contrast evaluation of vertebral body marrow, disc space height, neural canal, and spinal cord, allowing identification of disc herniation, canal stenosis, subluxation, and malalignment. 3

• Sagittal T2-weighted fast spin-echo (FSE): Widely accepted as the primary sequence for cervical spine imaging, offering optimal visualization of disc pathology and spinal cord signal abnormalities. 4, 5

• Axial gradient-echo T2-weighted: Used by 48% of imaging centers nationwide as the standard axial sequence, providing increased conspicuity of extradural disease relative to the neural foramen and thecal sac with reduced motion artifact compared to conventional spin-echo. 3, 4

When to Add Fat-Suppressed Sequences

A critical pitfall: Standard cervical MRI protocols for disc disease may not include fat suppression, which is essential if inflammatory spondyloarthropathy is suspected. 1

• STIR (Short Tau Inversion Recovery) or T2-weighted fat-saturated sequences should be added when evaluating for:
  • Inflammatory disc disease or spondylodiscitis 1
  • Ligamentous injury in trauma settings (STIR shows 90.9% agreement with intraoperative findings versus 69.7% for standard T2) 6
  • Bone marrow edema or vertebral body pathology 5

Contrast Administration Decision Algorithm

Contrast is NOT needed for routine disc herniation evaluation. 1, 2

Add IV gadolinium contrast (without and with protocol) when:

• Suspected infection: MRI has 96% sensitivity and 93% specificity for spinal infection, with contrast improving detection of epidural collections and disc space inflammation. 1

• Post-operative patients: Contrast is essential to distinguish recurrent disc herniation (does not enhance) from postoperative scar tissue (enhances), a critical distinction that directly impacts surgical decision-making. 2, 7

• Suspected malignancy: For evaluating primary or metastatic tumors affecting the cervical spine. 1

• Diffusion-weighted imaging (DWI) can be added to further characterize abscesses and distinguish Modic type 1 endplate changes from infection. 1

Technical Optimization

• Slice thickness: 3-mm sagittal slices provide optimal detail for disc and cord evaluation. 3

• Field strength: 1.5T is standard and adequate; protocols should use surface coils for higher quality examinations. 8, 6

• Motion artifact reduction: Various methods should be employed as motion artifacts are particularly troublesome in spine imaging. 8

• Gradient-echo parameters: Fast, variable flip angle gradient-echo sequences increase cerebrospinal fluid signal relative to extradural elements and cord, improving conspicuity of disc herniations. 3

Common Clinical Pitfalls

MRI findings must be correlated with clinical examination. Disc abnormalities are extremely common in asymptomatic patients—approximately 65% of asymptomatic patients aged 50-59 have radiographic evidence of significant cervical spine degeneration. 1, 9

• Abnormal MRI levels do not always correspond to clinical examination levels. 1

• Failure to document pre-operative physical examination findings that correlate with imaging is a major clinical assessment error. 9

• MRI is frequently positive in asymptomatic patients, and detected abnormalities are not always associated with acute symptoms. 1

Alternative Imaging Considerations

CT myelography serves as an excellent alternative when:

• MRI is contraindicated (pacemakers, severe claustrophobia) 1
• Extensive hardware artifact renders MRI nondiagnostic 1
• Higher spatial resolution is needed for small nerve root evaluation 1

However, CT myelography is inferior to MRI for assessing cord contusion, hemorrhage, and soft-tissue pathology. 1

CT without contrast is superior for evaluating bony structures (osteophytes, uncovertebral joints, facet joints) but less sensitive than MRI for nerve root compression from disc herniation. 1