POSTTRAUMATIC SPINAL-CORD LESIONS WITHOUT SKELETAL OR DISCAL AND LIGAMENTOUS ABNORMALITIES - THE ROLE OF MR-IMAGING

The thoracic spine is different from other mobile segments of the spin e because of the presence of ribs and their articulations. The rib cag e makes the thoracic spine much more stable and, during trauma, provid es additional strength and energy-absorbing capacity. This leads to th e conclusion that severe trauma is required to damage the thoracic spi ne, and the skeletal injury is usually evident on radiographs. A spont aneous reducible vertebral luxation (dislocation) is not easy to ident ify, even with magnetic resonance (MR)imaging. Subtle changes in thora cic spine osseous injuries are not seen on radiographs but may be demo nstrated on computed tomography (CT) scans. MR imaging can also demons trate the posterior ligamentous lesions. In this study, we present thr ee cases of thoracic spinal cord changes without spinal fracture and o ne disk herniation (degenerative chronic disease). These patients had a permanent neurologic deficit(complete paraplegia); plain radiographs and CT scans showed nothing abnormal. MR imaging showed lesions in th e thoracic spinal cord and, in one case, a posttraumatic disk herniati on. In cases of posttraumatic cord lesions, MR imaging provides diagno stic information that appears to exceed other imaging modalities. The existence of a neurologic deficit indicates MR as the first examinatio n in cases of traumatic spinal lesions.