What imaging investigations should be performed for a patient with suspected spinal and back trauma?

Imaging Investigations for Spinal and Back Trauma

CT spine without IV contrast is the gold standard initial imaging study for all patients with suspected spinal trauma meeting clinical criteria for imaging, with sensitivity of 94-100% for detecting fractures. 1, 2

Initial Imaging Algorithm

Step 1: Determine if Imaging is Needed

Cervical Spine:

• Use NEXUS or Canadian C-Spine Rule (CCR) criteria to determine if imaging is indicated
• If patient does NOT meet these criteria (low-risk), no imaging is needed 2
• High-risk patients requiring imaging include: altered mental status, neurologic deficits, midline tenderness, intoxication, distracting injury 2

Thoracolumbar Spine:

• Image any high-risk patient: midline thoracolumbar tenderness, high-energy mechanism, age >60 years 2
• Image all unexaminable patients: intoxicated, GCS <15, distracting injury 2
• Critical pitfall: Clinical examination misses 25-52% of thoracolumbar injuries, so maintain low threshold for imaging 2

Step 2: Choose Initial Imaging Modality

CT spine without IV contrast is the first-line study 1, 2:

• Sensitivity 94-100% for fractures vs. 49-82% for plain radiographs 2
• For thoracolumbar spine, reformatted images from chest/abdomen/pelvis CT are adequate—no additional dedicated spine CT needed 2
• Screen the entire spine as 20% of spine injuries have a second noncontiguous injury 2

Plain radiographs are obsolete for acute trauma—they miss two-thirds of fractures visible on CT 2

When to Add MRI (Without IV Contrast)

MRI spine without IV contrast is mandatory in these situations 1, 2:

1. Any neurologic deficit present (spinal cord or nerve root symptoms) 1, 2

   • MRI is the crucial diagnostic tool for spinal cord injury, showing cord compression, hemorrhage, edema, and transection 1
   • These findings predict neurological outcomes and guide surgical decisions 1

2. Suspected ligamentous injury on CT or clinical examination 2

   • CT misses important soft tissue pathology: disk-ligamentous injuries, cord contusions, epidural hematomas, nerve root avulsions 1

3. Obtunded/unexaminable patients with negative CT 2

   • MRI identifies soft-tissue injuries in 5-24% of patients with negative CT 2
   • Recent multicenter trials (ReCONECT) found 23.6% had abnormal MRI findings requiring extended collar placement or surgery 2

4. Unstable fracture requiring surgical planning 2

   • CT and MRI are complementary for treatment planning 2

5. Unexplained neurologic deficits with normal CT 1

Important limitation: MRI has low value in neurologically intact patients without clinical suspicion for ligamentous injury—most findings don't change management 1, 2

Vascular Imaging (When Arterial Injury Suspected)

CTA head and neck with IV contrast OR MRA neck without and with IV contrast are equivalent options when 2:

• High-energy mechanism with cervical spine fracture
• Specific fracture patterns suggesting vascular injury
• Clinical signs of arterial dissection

Do NOT routinely add contrast to spine CT or MRI—there is no evidence supporting IV contrast for detecting spinal trauma 1

Follow-up Imaging

For patients in cervical collar with persistent neck pain but no neurologic symptoms:

• CT, MRI, or flexion-extension radiographs may be appropriate 2
• Flexion-extension views only useful in outpatient setting when patient can tolerate upright positioning 2

Key Pitfalls to Avoid

1. Never delay treatment for imaging—dislocations require immediate reduction 3
2. Don't miss the second fracture—always image entire spine 2
3. Don't rely on clinical exam alone for thoracolumbar injuries—sensitivity is only 48-75% 2
4. Don't skip MRI in obtunded patients—up to 1% have instability not seen on CT 2
5. Avoid flexion-extension views acutely—limited by muscle spasm and rarely show instability not visible on static images 2