Multiplanar spinal CT 3D reconstruction and measurement of the lower cervical pedicle

Abstract

Objective To evaluate the clinical significance of measuring the lower cervical pedicle using multiplanar spinal CT (MSCT) 3D reconstruction. Methods Eight specimens of adult male ver-tebrae were examined by MSCT. The data were sent to Silicon Graphics 02 for 3D reconstruction according to the parameter requirements for lower cervical pedicle fixation, using reconstruction images of volume rendering (VR) and muhiplanar reformation (MPR). Results Statistically significant differences were found be-tween vertebrae in the following lower cervical data, including the pedicle angle relative to transverse plane= 42.02°±7.55°, with the largest at C4 and the smallest at C7; the pedicle angle relative to sagittal plane =76. 30°±12.01°, with the largest at C7 and the smallest at C3; the distance from the entry-peint to the margin of lower joint=11.23 mm±1.78 mm, with the longest at C6 and the shortest at C3; the distance from the entry-point to the outermost margin of lateral mass=2.65mm±1.21mm, with the longest at C7 and the shortest at C4. The distance from the entry-point to the vertebral anterior border=31.42 mm±2.13mm,with little difference between C3 and C7; the height of pedicle cancellous bone=3.69 mm±1.19 mm and the width = 2.67 mm ± 1.15 ram; the height of pedicle cortical bone=8.43 mm ± 1.30 mm and the width =5.54 mm ± 1.26 ram. The longest inside diameter of pedicle was seen at C7 and the shortest at C4. Generally the height of pedicle was larger than the width of pedicle. Conclusion Since 3 D reconstruction images by VR and MPR techniques can be used to measure various data related to the pedicles, they can help the pre-operative planning for transpedicular screw fixation of the lower cervical spine. Key words: Tomngraphy; spiral computed; Imaging; three-dimensional; Cervical vertebrae