The LIBERTY™ Posterior Spinal System was not directly tested; the CD HORIZON™ Spinal System was selected to represent that system due to similarity of materials and a configuration at least as challenging to MRI imaging as the LIBERTY™ Posterior Spinal System. Non-clinical testing demonstrated the CD HORIZON™ Spinal System is MR-Conditional. A patient with this device can be safely scanned immediately after device placement under the following conditions: