title: Spiral-CT-based assessment of tracheal stenoses using 3-D-skeletonization.
abstract: OBJECTIVE
  Demonstration of a technique for three-dimensional (3-D) assessment of tracheal-stenoses, regarding site, length and degree, based on spiral computed tomography (S-CT).
  
  
  METHODS
  S-CT scanning and automated segmentation of the laryngo-tracheal tract (LTT) was followed by the extraction of the LTT medial axis using a skeletonization algorithm. Orthogonal to the medial axis the LTT 3-D cross-sectional profile was computed and presented as line charts, where degree and length was obtained. Values for both parameters were compared between 36 patients and 18 normal controls separately. Accuracy and precision was derived from 17 phantom studies.
  
  
  RESULTS
  Average degree and length of tracheal stenoses was found to be 60.5% and 4.32 cm in patients compared with minor caliber changes of 8.8% and 2.31 cm in normal controls (p << 0.0001). For the phantoms an excellent correlation between the true and computed 3-D cross-sectional profile was found (p << 0.005) and an accuracy for length and degree measurements of 2.14 mm and 2.53% respectively could be determined. The corresponding figures for the precision were found to be 0.92 mm and 2.56%.
  
  
  CONCLUSIONS
  LTT 3-D cross-sectional profiles permit objective, accurate and precise assessment of LTT caliber changes. Minor LTT caliber changes can be observed even in normals and, in case of an otherwise normal S-CT study, can be regarded as artifacts.
authors: Department of Radiology, University Hospital Graz, Austria. erich.sorantin@kfunigraz.ac.at
authors: Erich
authors: E
authors: Sorantin
authors: Csongor
authors: C
authors: Halmai
authors: Balázs
authors: B
authors: Erdöhelyi
authors: Kálmán
authors: K
authors: Palágyi
authors: László G
authors: LG
authors: Nyúl
authors: Krisztián
authors: K
authors: Ollé
authors: Bernhard
authors: B
authors: Geiger
authors: Franz
authors: F
authors: Lindbichler
authors: Gerhard
authors: G
authors: Friedrich
authors: Karl
authors: K
authors: Kiesler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D004724:Endoscopy; D017143:Fuzzy Logic; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007223:Infant; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000295:instrumentation* / Q000379:methods*; D014135:Tracheal Stenosis / Q000000981:diagnostic imaging*