Spinal Cord Injury: AI-Powered MRI & X-ray Analysis

The American Spinal Injury Association (ASIA) Impairment Scale (AIS) classifies injury severity based on the International Standards for Neurological Classification of SCI (ISNCSCI). AIS A (complete) indicates no motor or sensory function preserved in sacral segments S4–S5. AIS B (sensory incomplete) preserves sensation but not motor function below the neurological level including S4–S5. AIS C (motor incomplete) preserves motor function below the level with more than half of key muscles having a grade less than 3. AIS D (motor incomplete) means more than half of key muscles below the level have grade 3 or better. AIS E indicates normal motor and sensory function throughout. The neurological level of injury (NLI) is the most caudal level with intact motor and sensory function bilaterally. Sacral sparing (preserved perianal sensation or voluntary anal contraction) is the critical distinction between complete and incomplete injury.

Acute MRI within 24 hours of injury provides critical prognostic information. Cord hemorrhage (low signal on T2, high signal on susceptibility-weighted or gradient echo sequences) is associated with the worst neurological outcomes and AIS A or B classification in the majority of cases. T2 hyperintensity within the cord without hemorrhage represents edema or contusion and carries intermediate prognosis — the craniocaudal extent of T2 signal (measured in cord segment lengths) correlates inversely with recovery. Normal cord signal on MRI in the context of transient neurological symptoms suggests spinal cord concussion with favorable prognosis. STIR sequences detect ligamentous injury (posterior ligamentous complex disruption), epidural hematoma, and cord compression from bone or disc fragments that may require urgent surgical decompression. Post-injury MRI is also used to detect cord atrophy and syringomyelia formation during rehabilitation.

The primary goals are preventing secondary injury by maintaining spinal cord perfusion pressure (MAP target 85–90 mmHg for the first 7 days), avoiding hypoxia, and immobilizing the spine. High-dose methylprednisolone is no longer standard of care due to lack of proven benefit and significant complication risk. Surgical indications include persistent cord compression from bone, disc, or hematoma; spinal instability on CT or MRI; and progression of neurological deficits. Early surgical decompression (within 24 hours of injury) is associated with significantly improved neurological outcomes compared with delayed surgery in multiple observational studies and meta-analyses — a finding supported by the STASCIS study showing AIS grade improvement in 19.8% of early versus 8.8% of late surgery patients. Cervical injuries are typically approached anteriorly for disc or vertebral pathology; thoracolumbar injuries may require combined anterior–posterior approaches for deformity and instability correction.