The injured spinal cord. Evaluation with magnetic resonance and intraoperative sonography.

MR is now the study of choice in evaluating both the acutely and previously injured spinal cord. A number of crucial diagnoses can be made with MR that are difficult to obtain otherwise. The discovery of acute disk herniation in association with a fracture/dislocation may indicate the need to remove the disk and stabilize the patient on a relatively urgent basis, and the approach to the stabilization procedure (either anterior or posterior) can be determined by the MR findings. Hemorrhage outside the cord may require immediate surgical attention, and identification of abnormal signals from the cord itself consistent with hemorrhage or edema may help to explain the patient's clinical status. Our experience indicates that obtaining an MR in acutely injured patients who have incomplete injuries is particularly helpful in their surgical management. The presence of intramedullary or extramedullary cysts in the previously injured spine can explain a worsening clinical picture and direct the surgeon to the proper area (or areas) for decompression. Flow-sensitive studies currently under evaluation are giving a greater insight into the dynamics of these cysts. Late decompression of cord tissue and roots requires accurate preoperative MR evaluation of possible bone or disk impingement on neural tissue. In surgery of both the acute and chronically injured spine, intraoperative sonography plays a crucial role. The adequate shunting of intramedullary and subarachnoid cysts, the confirmation of the efficaciously placed Harrington rods, the demonstration of removal of compressive bone or disk fragments, and the uncovering of important but unanticipated abnormalities such as subligamentous hematoma or an incidentally herniated disk all attest to sonography's value in the operating room. MR preoperatively and sonography intraoperatively are important tools utilized in the care of spine-injured patients.