Three dimensional spiral CT for craniofacial surgical planning and evaluation

To evaluate measurement accuracy of three dimensional volumetric medical imaging from Spiral CT for craniofacial surgical planning. Material and Methods: The study population consisted of 5 cadaver heads that were imaged on a Spiral CT scanner (Toshiba Xpress S/X Toshiba -America, Medical System Inc., Tustin, CA) with volumetric technique high-resolution contiguous axial slices 3mm thickness and 2mm/sec table feed, with 120Kvp and 200 mA The archived CT data were stored on optical disks to allow full retrospective review of any image. The data sets were transferred to a networked computer workstation (Sun Microsystems with Cemax version 1.4 software, Fremont, CA), to generated three-dimensional volumetric images for subsequent manipulation and analyses. The computer graphics workstation allowed to do measurements, based on conventional craniometric anatomic landmarks, by 2 observers with 2 sessions each. The specimens were then submitted to a dynamic blunt force, in an effort to simulate craniofacial fractures, scanned and measured again. The soft tissues were then partially subsequently removed and the measurements were repeated by (3 Space) electromagnetic digitizer (Polhemus Navigation Sciences Division, Me Donnell Douglas Electronic Company, Colchester, VE). Statistical analysis was done using analysis of variance. Results: Measurements from three-dimensional Spiral CT scans can be precise with high repeatability and sufficient accuracy for surgical planning. Conclusion: Three-dimensional computer graphics by Spiral CT allowed, in vitro, sufficient precision for assessment of surgical management. Digital volumetric Spiral CT imaging is valid quantitatively and qualitatively for craniofacial surgical planning and evaluation.