| Cadaver cervical spine specimens from the Medical College of Ohio Anatomy Department were scanned using various protocols on two separate CT scanners. The slice thickness, technique parameters and image algorithms were varied and compared. The CT measurements were compared to actual physical measurements from the specimens and correlated. The study concluded that CT is useful for evaluation of osseous structures in the cervical spine and adequately demonstrate the relationship to essential neurovascular structures. Partial volume averaging is a considerable problem in sectional imaging. This study found that a smaller slice thickness minimized the partial volume averaging, minimized the overestimation of size of small structures, such as the pedicle, and provided a more accurate pre-surgical assessment. The choice of image algorithm for pre-surgical planning of the cervical spine is the bone algorithm. The standard or soft tissue algorithm results in overestimation of size. A simple theoretical calculation of CT numbers to determine percent bone in voxel necessary for the voxel to be identified as bone show 20% bone will identify the voxel as bone at 60, 80 and 100 keV. |
