Computed tomography of sacral and perisacral lesions.

The sacrum and perisacral soft tissues are not readily amenable to investigation by conventional radiological techniques. Computed tomography (CT) has provided an excellent imaging modality for the evaluation of these areas. This article describes the normal CT anatomy of the sacrum, the CT technique for evaluating the sacrum and perisacral soft tissues and the contribution of CT to the assessment of the many disorders that may involve the sacrum. Conditions discussed include osseous tumors of the sacrum, spinal dysraphism, cauda equina tumors and cysts, lesions arising primarily in the presacral space and sacral trauma. The use of CT scanning of the sacrum following intrathecal administration of Metrizamide is described.