What is the initial screening modality for a patient with suspected spinal cord injury after a 15-foot fall?

Initial Imaging for Suspected Spinal Cord Injury After High-Energy Trauma

CT scan without contrast is the initial screening modality of choice for this patient with suspected spinal cord injury after a 15-foot fall. 1

Rationale for CT as Primary Screening

CT demonstrates near 100% sensitivity for detecting clinically significant spinal column injuries, with specificities approaching 100% and a negative predictive value of 99.7%. 1 This patient meets multiple high-risk criteria that mandate immediate imaging:

• High-energy mechanism (fall from 15 feet, which exceeds the 3 feet/5 stairs threshold) 1
• Focal neurologic deficit (inability to move legs, sensory level at umbilicus suggesting T10 injury) 1
• Clinical evidence of myelopathy 1

Why Not Other Modalities Initially

Plain radiographs are inadequate for initial screening in this scenario:

• Sensitivity ranges only 31-94% (pooled sensitivity 52%) for detecting significant spinal injuries 1
• Miss approximately 53% of fractures that CT readily identifies 1
• Have been largely supplanted by CT in modern trauma protocols 1

MRI is not the initial screening tool, despite being indicated later:

• While MRI is the gold standard for evaluating spinal cord injury itself, it should not be used for initial screening 1
• MRI has a false-positive rate of 25-40% for ligamentous injuries 1
• Takes significantly longer to perform than CT, delaying critical management decisions 2, 3
• MRI should be obtained urgently after CT in this patient given the clear neurological deficit, but CT must come first to assess spinal stability and bony injury 1

Ultrasound has no role in acute spinal trauma imaging 1

Algorithmic Approach

1. Immediate CT spine without contrast (cervical through lumbar given mechanism and neurologic findings) 1

   • Can be performed as part of trauma pan-CT protocol (head to pelvis) 1, 2
   • Reformatted images provide excellent visualization without additional radiation 2

2. Urgent MRI spine following CT to evaluate:

   • Spinal cord compression or contusion 1, 3
   • Epidural hematoma 2, 3
   • Ligamentous injuries 1
   • Disc herniation 2

3. Consider vascular imaging if CT shows fractures involving transverse foramina (vertebral artery injury risk) 1, 2

Critical Pitfalls to Avoid

• Do not delay CT to obtain plain films first - this wastes time and provides inferior information 1
• Do not skip CT and go directly to MRI - you must first assess bony stability and rule out contraindications to MRI (metallic foreign bodies from trauma) 1
• Scan the entire spine, not just the symptomatic level - 20% of spinal fractures have non-contiguous injuries at other levels 1
• Ensure adequate visualization of cervicothoracic junction - this is a commonly missed area on plain films but well-seen on CT 1

Time-Sensitive Considerations

CT can be completed in 11-12 minutes as a standalone study or 20-30 minutes when added to head CT, which is significantly faster than obtaining and interpreting adequate plain film series. 1 Given this patient's neurological deficit, rapid identification of surgically correctable compression is critical for optimizing neurological recovery. 1, 3