Role of MRI
• Higher sensitivity for detection compared to CT.
• Complete tear (seen as discontinuity of ligaments) or partial tear (seen as abnormal signal) can be differentiated.
• Helpful in guiding management by differentiating stable from unstable injuries.
Disc damages and herniations
• Detection of abnormal disc signal related to traumatic herniations.
• Important to diagnose this before closed reduction as undetected disc herniations can cause worsening cord injury.
Extra medullary hemorrhage
• MRI shows extent of hematoma to help in surgical planning.
• Extradural hematoma is commonly encountered and can lead to cord compression.
• Enable detection of arterial injuries, which include an intimal flap, pseudoaneurysm, complete occlusion or active extravasation.
• Undetected vascular injuries can cause spinal cord infarctions.
• Detection of hemorrhagic and non-hemorrhagic cord injuries.
• This is the single most important role of MRI in spinal trauma evaluation.
• Visualized as abnormal cord signal with hemorrhage best seen on gradient recalled echo (GRE) type sequences.
• Presence of hemorrhage is the most important poor prognostic factor.
Acute vs old vertebral fracture
• Age-indeterminate fractures identified on radiography and CT can be classified into acute and old fractures based on the presence or absence of bone marrow edema, respectively.
Benign vs malignant fracture
• Differentiation of benign and malignant fractures.
• Benign fractures show horizontal band of marrow edema, concave appearance of posterior vertebral margin and lack of soft tissue mass.
• Malignant fractures show almost complete involvement of vertebral body, convex posterior margin and associated soft tissue mass.