The collection of contrast medium within the spinal cord on delayed CT myelography generally indicates the presence of syringomyelia. We report the cases of cystic myelopathy with intramedullary contrast accumulation on delayed CT myelography. The purpose of this report is to compare MRI with delayed CT myelogram and to discuss the pathogenesis of the intramedullary contrast accumulation on delayed CT myelography.
Methods and materials: Thirty patients with intramedullary contrast accumulation on delayed CT myelography were studied with High Resolution Computed Tomography (Siemens Somatom II) and Magnetic Resonance Imaging (MRI) (0.15T imager, Toshiba MRT 15A). MRI were routinely obtained in both axial plane and sagittal plane. Short spin-echo sequences (30 msec TE, 500 msec TR) were used. This series included 6 cases of cervical disc disease, 5 cases of Chiari malformation, 4 cases of lipomeningocele, 4 cases of adhesive arachnoiditis, 2 cases of thoracolumbar spondylosis, 2 cases of trauma, one case of spinal arachnoid cyst, one case of spinal epidural cyst, and 5 cases of idiopathic type.
Results: 1) In 17 out of the 30 patients (57%), the region corresponding to the region of contrast medium collection, which was visualized on delayed CT myelography, was seen as an area of the low signal intensity on MRI. In 11 cases out of 17, the syrinx cavity was confirmed at surgery. 2) In 13 cases, delayed CT myelogram showed collection of intramedullary contrast medium, but MRI failed to reveal an area of low signal intensity.(ABSTRACT TRUNCATED AT 250 WORDS)