[The sacral perineural system--are there radiological criteria for an indication for surgery? First results and literature survey].

Purpose: To establish recommendations for diagnostic imaging of cystic lesions of the sacral region and to evaluate for potential predictors of therapeutic outcome.

Methods: Conventional imaging of the lumbar spine, conventional CT, myelography, post myelo-CT and MRI were performed in 7 symptomatic [corrected] 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 remission of symptoms was noticed in 4, a partial remission in three cases. The correlation of cyst extension, cyst shape, and the communication with the subarachnoid space did not provide predictive information concerning operative outcome.

Conclusion: MR can be used as the sole imaging tool for demonstration of cystic lesions. Relevant disadvantages in comparison to myelography and myelo-CT were not evident. No imaging modality could predict the value of surgical intervention.