Computed tomography of "cystic" intramedullary lesions.

Using an EMI 5005 scanner with high resolution option, 75% of syrinxes were shown as low density cavities. Most spinal cord tumours caused isodense swellings, but 41% contained low density zones and cystic elements were demonstrated in 76% of these at surgery or by puncture of the spinal cord; a few (11%) of the isodense tumours were cystic. The differential diagnosis of low density intramedullary lesions is discussed.