Presentation:

62 year-old male with history of trauma, depressed respiratory status, limited upper extremity exam, priapism, and poor rectal tone.

Key findings:

Disruption of the anterior longitudinal ligament at the level of C3-C4 with widening of the anterior intervertebral disc space.
Traumatic disc herniation with severe narrowing of the central canal at C3-C4.
Buckling of the posterior longitudinal ligament at C3-C4.
Punctate signal hypointensity on T2* imaging and traumatic cord edema from C3-C5.
Prevertebral and posterior papraspinal soft tissue edema.

Diagnosis:

1. Extension type injury of C3-C4 with disruption of the ALL and traumatic disc herniation with severe central canal narrowing.

2. Concern for intramedullary microhemorrhage without diffusion restriction.

High-yield Sequences:

Spinal Cord Injury:

T1 - Focal cord enlargement at level of trauma without signal change.
Potential low T1 signal above or below (contusion) or centrally (hematoma).
T2 - Increased T2 signal from edema. High signal rim in a contusion (thick) or hemorrhage (thin).
T2* (GRE, SWI) - More sensitive to hemorrhage. Signal blooming along areas of contusion or hemorrhage.

Discoligamentous Injury:

T1 - Intermediate signal intensity
T2 - Hyperintense signal
STIR - High sensitivity, hyperintense signal

Discussion:

The cervical spine accounts for about half of all spine injuries. 5-10% of patiets following blunt trauma have a C-spine injury. Discoligamentous injuries more often occur with high-impact trauma.

MRI is test of choice for imaging soft tissue injuries of the spine. Primary indication is neurological deficit referable to the spinal cord. MRI is also used in obtunded trauma patients that cannot complete neurological exam.

General principles of spine trauma:

Occasionally there is soft tissue/cord injury without osseous abnormality.
Majority of spinal cord injuries occur at C1-C2, C5-C7, and thoracolumbar spine.
Compressive forces typically cause osseous injury.
Rotation and shear forces are more likely to cause discoligamentous injury.
Injuries to spinal ligaments are considered unstable, especially if involving the posterior complex.

Areas of spine trauma radiology report:

Type and extent of ligamentous injury
Intervertebral disc
Fractures/bony avulsions
Associated spine hematoma (perivertebral, epidural)
Traumatic spine cord injury

Resources:

Schwartz, Emergency radiology: Case studies 2008