IMAGING OF THORACIC AND LUMBAR SPINAL EXTRADURAL ARACHNOID CYSTS - REPORT OF 2 CASES

Extradural arachnoid cysts are uncommon expanding lesions in the spina l canal which may communicate with the subarachnoid space, Usually in the lower thoracic spine, they may cause symptoms by compressing the s pinal cord or nerve roots. We report cases of thoracic and lumbar arac hnoid cysts studied by cystography, myelography, CT and MRI, These tec hniques showed extradural cystic lesions containing cerebrospinal flui d, with variable communication with the subarachnoid space, causing an terior displacement and flattening of the spinal cord.