The sacral perineural system: Are there radiological criteria an indication for surgery? First results and literature survey

Purpose: To establish recommendations for diagnostic imaging of cystic lesi ons of the sacral region and to evaluate for potential predictors of therap eutic outcome. Methods: Conventional imaging of the lumbar spine, conventio nal CT, myelography, post myelo-CT and MRI were performed in 7 symptornatic patients. All patients underwent operative decompression and histological examination. The radiographic examinations were reevaluated retrospectively and correlated with the postoperative outcome. Results: In one patient the differential diagnosis of a neurinoma could not be excluded with CT and CT -myelography alone. In all 7 patients MRI provided a definite diagnosis and a precise presentation of the cyst extension. A complete postoperative rem ission of symptoms was noticed in 4, a partial remission in three cases. Th e correlation of cyst extension, cyst shape, and the communication with the subarachnoid space did not provide predictive information concerning opera tive outcome. Conclusion: MR can be used as the sole imaging tool for demon stration of cystic lesions. Relevant disadvantages in comparison to myelogr aphy and myelo-CT were not evident. No imaging modality could predict the v alue of surgical intervention.