| Abstract: | MRI at 0.3 T and CT with myelo-graphic contrast (CTM) were compared in the retrospective evaluation of 35 patients investigated for the development of new neurological symptoms following longstanding spinal cord injury. Compared with MRI, CTM was relatively accurate for the demonstration of spinal cord compression, but failed to identify 23% of patients with spinal cord atrophy, and 43% of patients with post-traumatic syrinx formation. However, 5 patients had unsatisfactory MR imaging, either due to motion or metallic artifact, and in 3 of these, CTM demonstrated a syrinx. Although MRI is the method of choice in the investigation of this problem. CTM may still be required for patients with an unsatisfactory MR examination. Magnetic Resonance (MR) imaging is now an established technique for imaging the spine, with accurate depiction of the spinal cord, as well as the adjacent soft tissues (1, 2). However, the cost of this technique, and its as yet limited availability in Australasia, has resulted in the necessity to demonstrate its superiority over other imaging modalities for any specific clinical problem (3). One of the major areas of impact of MR has been in the investigation of the problem of acute neurological deterioration in patients with past spinal trauma (4, 5, 6). Some of these patients will have treatable causes of deterioration, either a post-traumatic syrinx, or spinal cord compression (6), and MR can be used to image these conditions (7), which, until recently, were investigated with computed tomography with myelographic contrast medium (CTM), (8, 9). In the largest reported study comparing MR and CTM, Betz et al (6) reported the results of 43 children who were investigated up to 48 months from original injury, of whom 24 had CTM. They concluded that although MR was indicated for the evaluation of subacute and chronic spinal cord injured patients, CT-myelography remained essential before considering surgery for spinal cord decompression (6). We retrospectively evaluated the results of MR and CT-myelography in 35 patients who developed new symptoms following past spinal cord injury to determine whether there was still any place for CTM in the evaluation of this problem. |
