Spine Trauma Imaging Approach¶

Overview¶

The imaging evaluation of spinal trauma requires a systematic approach that balances the need for rapid diagnosis with comprehensive assessment of bony, ligamentous, and neurological structures. The choice of imaging modality and the urgency of evaluation depend on the mechanism of injury, the patient's clinical status, and the presence or absence of neurological deficits.

Initial Assessment¶

When to Image¶

Clinical decision rules — specifically the NEXUS criteria and the Canadian C-Spine Rule — guide the decision to obtain imaging in alert trauma patients with potential cervical spine injury. These validated tools identify patients at very low risk for clinically significant injury who can be safely cleared without imaging.

For the thoracolumbar spine, imaging is generally indicated in patients with back pain or tenderness after significant trauma, neurological deficits, altered mental status, or distracting injuries.

Imaging Modality Selection¶

CT is the primary imaging modality for spine clearance in blunt trauma. It offers sensitivity exceeding 99% for fracture detection, far surpassing plain radiography (approximately 50–70% sensitivity). The American College of Radiology Appropriateness Criteria recommend CT as the first-line study for cervical spine clearance in high-risk trauma patients.

Radiography retains a limited role in low-risk patients and in resource-limited settings. Adequate cervical spine radiographic evaluation requires lateral, anteroposterior, and open-mouth odontoid views, and all seven cervical vertebrae must be visualized through the C7–T1 junction.

MRI is indicated when ligamentous injury, spinal cord injury, epidural hematoma, or traumatic disc herniation is suspected. MRI is essential for evaluating neurological deficits that are unexplained by CT findings and for assessing the posterior ligamentous complex (PLC), which is a key determinant of spinal stability.

Systematic CT Interpretation¶

A structured approach to spine CT interpretation should include:

Alignment — Assess the anterior vertebral body line, posterior vertebral body line, spinolaminar line, and interspinous distance on sagittal images. On coronal images, evaluate lateral listhesis and scoliosis.
Bone — Evaluate each vertebral body, pedicle, lamina, facet, spinous process, and transverse process for fracture lines, cortical disruption, and height loss.
Cartilage/disc — Assess disc space height and any vacuum phenomenon. Widened disc spaces may indicate distraction injury.
Soft tissue — Evaluate prevertebral soft tissue swelling (cervical spine) and paravertebral soft tissue changes (thoracolumbar spine). Prevertebral soft tissue thickness greater than 6 mm at C2 or 22 mm at C6 is abnormal and suggests hemorrhage or edema.

Clinical Pearl

Prevertebral soft tissue swelling on CT or lateral radiograph is an important indirect sign of cervical spine injury. However, its absence does not exclude a fracture — approximately 50% of cervical fractures present without significant prevertebral swelling.

MRI Protocol for Spine Trauma¶

A trauma MRI protocol typically includes:

Sagittal T1 — Evaluates vertebral body marrow signal, alignment, and anatomy
Sagittal T2 — Evaluates the spinal cord, disc spaces, and ligaments
Sagittal STIR — Most sensitive sequence for detecting bone marrow edema (acute fracture) and ligamentous injury
Axial T2 — Evaluates the spinal cord cross-section, neural foramina, and facet joints

Clinical Pearl

STIR sequences are the most sensitive MRI sequence for detecting acute injury. A vertebral body fracture that is occult on CT may show marrow edema on STIR. Similarly, posterior ligamentous complex disruption — which is a critical determinant of stability — is best evaluated on sagittal STIR and T2 images.

Classification Systems¶

Several classification systems guide the characterization and management of spinal fractures:

Denis Three-Column Model — Divides the spine into anterior, middle, and posterior columns; injury to two or more columns implies instability
AO Spine Classification — Comprehensive system using fracture morphology (Type A compression, B distraction, C translation) with neurological status and modifiers
TLICS (Thoracolumbar Injury Classification and Severity Score) — Scoring system incorporating morphology, PLC integrity, and neurological status to guide surgical decision-making
SLIC (Subaxial Cervical Spine Injury Classification) — Similar to TLICS but adapted for the subaxial cervical spine

Special Populations¶

Pediatric Patients¶

Children have unique anatomical features (ligamentous laxity, relatively large head size, horizontal facet orientation, synchondroses) that predispose them to upper cervical injuries and SCIWORA (Spinal Cord Injury Without Radiographic Abnormality). MRI is the study of choice when spinal cord injury is suspected in children.

Elderly Patients¶

Elderly patients, particularly those with osteoporosis or ankylosing spondylitis, may sustain significant spinal injuries from low-energy mechanisms. In patients with ankylosing spondylitis or DISH, even minor trauma can cause unstable fracture-dislocations through the fused spinal segments. These fractures frequently involve all three columns and carry high morbidity.

Obtunded or Intubated Patients¶

Spine clearance in obtunded patients remains controversial. Options include CT alone (with high negative predictive value), CT plus MRI, or delayed clinical clearance when the patient's mental status improves. Many institutions now use high-quality CT with multiplanar reformats as sufficient to clear the cervical spine in obtunded patients if no fracture or malalignment is identified.

Key Points¶

CT is the primary imaging modality for spine clearance in blunt trauma, with sensitivity exceeding 99% for fractures
NEXUS criteria and the Canadian C-Spine Rule guide the decision to image the cervical spine in alert trauma patients
MRI is essential for evaluating the spinal cord, ligaments, and posterior ligamentous complex
STIR is the most sensitive MRI sequence for acute bone and ligamentous injury
A systematic approach (alignment, bone, cartilage/disc, soft tissue) ensures comprehensive evaluation
Special attention is required for pediatric patients, elderly patients with ankylosing spondylitis or osteoporosis, and obtunded patients

References¶

Hassankhani A, Freeman CW, Banks J, et al; Expert Panel on Neurological Imaging. ACR Appropriateness Criteria® Acute Spinal Trauma: 2024 Update. J Am Coll Radiol. 2025;22(5S):S48-S66. doi:10.1016/j.jacr.2025.02.013. PMID: 40409895. https://pubmed.ncbi.nlm.nih.gov/40409895/
Beckmann NM, West OC, Nunez D Jr, et al; Expert Panel on Neurological Imaging and Musculoskeletal Imaging. ACR Appropriateness Criteria® Suspected Spine Trauma. J Am Coll Radiol. 2019;16(5S):S264-S285. doi:10.1016/j.jacr.2019.02.002. PMID: 31054754. https://pubmed.ncbi.nlm.nih.gov/31054754/
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