Acute spinal trauma: prognostic value of MRI appearances at 0.5 T.

Thirty-two patients with post-traumatic myelopathy were examined with a 0.5 T MRI system within 4 days of injury and the MRI findings analysed with respect to the immediate and residual functional deficit and (in 20 patients) the MRI appearances of the spinal cord in the chronic phase. In the acute phase a normal spinal cord was associated with only slight clinical deficit in four patients. Signal abnormalities in the spinal cord at the site of trauma were identified on T2-weighted spin-echo or T2*-weighted gradient-recalled echo images in 28 patients. The 12 most functionally impaired patients showed focal low signal suggestive of intramedullary haemorrhage: the other 16 had homogeneous high signal consistent with diffuse oedema. Swelling of the spinal cord and mild persistent cord compression following reduction were noted in 17 and 26 patients respectively. All patients were treated conservatively other than undergoing surgical decompression. Four died of complications. No patient with low signal in the spinal cord on initial MRI showed significant clinical improvement. Five whose spinal cord was hyperintense remained unchanged, whereas nine made a significant recovery, as did all patients with normal-appearing spinal cords. Cord compression on the initial examination was not relevant to clinical outcome. Intramedullary scars were identified at follow-up in 18 patients and were more extensive in those with haemorrhagic acute lesions. Haemorrhagic contusion of the spinal cord can be demonstrated in the acute phase with midfield MRI and is a valuable predictor of the functional outcome in patients with traumatic myelopathy.