title: Craniofacial measurements based on 3D-CT volume rendering: implications for clinical applications.
abstract: OBJECTIVE
  This study was designed to determine the precision and accuracy of anthropometric measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems for craniofacial clinical applications, and to compare the craniometric landmarks using bone and soft tissue protocols.
  
  
  METHODS
  The study population consisted of 13 cadaver heads that were examined with spiral CT. The archived CT data were transferred to a workstation, and 3D-CT volume rendered images were generated using computer graphics tools. Linear measurements (n = 10), based upon conventional craniometric anatomical landmarks (n = 08), were identified in 2D-CT and in 3D-CT images by two radiologists twice each independently, and then performed by 3D-CT imaging using a computer graphics systems using bone and soft tissue protocols. In total, 520 imaging measurements were made. The soft tissues were subsequently removed from the cadaver heads and the measurements were repeated using an electromagnetic 3 Space trade mark digitizer.
  
  
  RESULTS
  The results demonstrated no statistically significant difference between interobserver and intraobserver measurements or between imaging and physical measurements in both 3D-CT protocols. The standard error was found to be between 0.45% and 1.44% for all the measurements in both protocols, indicating a high level of precision. Furthermore, there was no statistically significant difference between imaging and physical measurements (P > 0.01). The error between the mean actual and mean 3D-based linear measurements was 0.83% for bone and 1.78% for soft tissue measurements, demonstrating high accuracy of both 3D-CT protocols.
  
  
  CONCLUSIONS
  3D-CT volume rendering images using craniometric measurements can be used for anthropological studies involving craniofacial applications.
authors.affiliation: Department of Radiology, College of Dentistry, University of São Paulo,São Paulo, Brazil. mgpcaval@usp.br
authors.forename: M G P
authors.initials: MG
authors.lastname: Cavalcanti
authors.forename: S S
authors.initials: SS
authors.lastname: Rocha
authors.forename: M W
authors.initials: MW
authors.lastname: Vannier
mesh_terms: D000368:Aged; D002102:Cadaver; D002508:Cephalometry / Q000379:methods*; D002680:Chin / Q000000981:diagnostic imaging; D003196:Computer Graphics; D055590:Electromagnetic Phenomena / Q000295:instrumentation; D005147:Facial Bones / Q000000981:diagnostic imaging*; D005624:Frontal Bone / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008875:Middle Aged; D009295:Nasal Bone / Q000000981:diagnostic imaging; D009666:Nose / Q000000981:diagnostic imaging; D015588:Observer Variation; D010579:Petrous Bone / Q000000981:diagnostic imaging; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D012886:Skull / Q000000981:diagnostic imaging*; D036542:Tomography, Spiral Computed / Q000379:methods*; D015050:Zygoma / Q000000981:diagnostic imaging