What is the gold standard imaging for spinal cord compression?

Gold Standard Imaging for Spinal Cord Compression

MRI is the gold standard for detecting spinal cord compression, with MRI without and with IV contrast providing optimal visualization of the spinal cord, epidural space, and compressive pathology with 96% sensitivity and 94% specificity. 1

Primary Imaging Modality

MRI should be performed in all patients with suspected spinal cord compression due to its superior soft-tissue resolution and ability to directly visualize the spinal cord, nerve roots, disc material, hematomas, and bone fragments causing compression. 2, 1

Key MRI Protocol Elements

• T2-weighted sagittal sequences are essential for visualizing cord compression and should be included in all protocols 2, 1
• STIR (Short Tau Inversion Recovery) sagittal sequences combined with T2-weighted axial images provide excellent performance, with 100% sensitivity and 98.6% specificity for detecting cord compression in emergency settings 3
• Contrast administration (gadolinium) should be added when evaluating for infection, inflammation, or neoplastic causes of compression, as it helps distinguish these etiologies 1
• Gradient-echo sequences optimally display compression from disc herniation, bone fragments, and hematomas 1

Clinical Context and Advantages

MRI provides critical information beyond simple detection of compression:

• Characterizes the cause of myelopathy including disc protrusion, hematoma, bone fragments, tumor, or infection 2
• Assesses severity of cord injury including extent of intramedullary hemorrhage, length of edema, and evidence of cord transection, which helps predict outcomes 2
• Evaluates ligamentous instability that may not be apparent on CT imaging 2
• Detects spinal cord injury without radiographic abnormality (SCIWORA), particularly important in pediatric patients 4

Alternative Imaging When MRI is Unavailable or Contraindicated

CT Myelography

• CT myelography is the second-line option when MRI is contraindicated (pacemakers, certain metallic implants) or unavailable 2, 1
• It can assess spinal canal narrowing and cord compression but is significantly inferior to MRI for soft-tissue pathology 1
• Important caveat: Compression from soft tissue masses may be missed on CT without contrast injection 2

CT Without Contrast

• CT is excellent for identifying fractures and bony abnormalities causing compression, particularly in trauma settings where immediate stabilization may be needed 4, 1
• CT has 94-100% sensitivity for thoracolumbar spine fractures but cannot adequately visualize the spinal cord itself 2
• 50% thecal sac effacement on CT predicts significant spinal stenosis 5

Plain Radiography

• Radiographs are inadequate for evaluating spinal cord compression with only 49-62% sensitivity for thoracic spine fractures and 67-82% for lumbar fractures 2
• Plain films cannot visualize the epidural space or spinal cord and should not be used as the initial imaging examination in patients with neurologic compromise 1

Timing and Urgency

• Emergent MRI assessment is recommended for suspected cauda equina syndrome or acute neurologic deficits 5
• Imaging should be obtained within the first 36 hours of suspected acute spinal cord injury to guide management decisions 6
• An abbreviated MRI protocol using STIR sagittal and T2 axial sequences can expedite diagnosis in emergency settings without sacrificing diagnostic accuracy 3

Common Pitfalls to Avoid

• Do not rely on CT alone when neurologic deficits are present, as it significantly underperforms MRI in identifying soft-tissue causes of compression requiring surgical intervention 1
• Avoid using plain radiographs as the primary imaging modality for suspected cord compression, as they are insensitive for epidural space evaluation 1
• Always image the entire spine when cord compression is suspected, as 20% of spine injuries have a second noncontiguous spinal injury 2
• Correlate imaging findings with clinical symptoms, as disc abnormalities and cord compression can be present in asymptomatic patients 5, 7