title: A study of volumetric visualization and quantitative evaluation of bone trabeculae in helical CT.
abstract: OBJECTIVE
  The aim of this study was to investigate the reliability of quantitative evaluation of bone trabeculae by helical CT.
  
  
  METHODS
  Ten specimens of human cadaver mandibular condyles were examined using both micro-CT and helical CT, and volume rendered three-dimensional (3D) images were obtained from the CT data. Micro-CT was used as the reference standard. From the micro-CT data images, bone trabeculae in each condyle were extracted by image processing and their volumes were calculated automatically. From the helical CT data images, the cortical bone was manually removed and bone trabeculae in each condyle were extracted using opacity curve and colour mapping thresholds. The optimal cut-off CT value that resulted in a similar volume of bone trabeculae obtained from helical CT and micro-CT data was investigated.
  
  
  RESULTS
  The optimal cut-off CT value to assess the volume of bone trabeculae accurately on 3D images obtained with helical CT data was found to be 200 Hounsfield units.
  
  
  CONCLUSIONS
  This study suggests that quantitative evaluation of bone trabeculae using helical CT might be a valid and useful method.
authors.affiliation: Division of Oral and Maxillofacial Radiology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. fukiko@dent.niigata-u.ac.jp
authors.forename: F
authors.initials: F
authors.lastname: Kobayashi
authors.forename: J
authors.initials: J
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Maeda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008335:Mandibular Condyle / Q000000981:diagnostic imaging*; D008852:Microradiography; D008875:Middle Aged; D015203:Reproducibility of Results; D013382:Subtraction Technique; D036542:Tomography, Spiral Computed