01898nas a2200133   4500008004100000020001400041245012200055210006900177260001200246300001600258490000700274520144300281856004001724       2003                        eng d  a0033-832X00a3D cross section of the laryngotracheal tract. A new method for visualization and quantification of tracheal stenoses0 a3D cross section of the laryngotracheal tract A new method for v  c2003///  a1056 - 10680 v433 aPURPOSE: Demonstration of a technique for 3D assessment oftracheal stenoses, regarding site, length and degree, based on 
spiral computed tomography (S-CT). PATIENTS AND 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 skeletonisation algorithm. Orthogonal to the medial 
axis the LTT 3D cross sectional profile was computed and 
presented as line charts, where degree and length were 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 were found to be 60.5% and 4.32 cm 
in patients compared to minor caliber changes of 8.8% and 2.31 
cm in normal controls (p <0.005). For the phantoms an excellent 
correlation between the true and computed 3D 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%. CONCLUSION: LTT 3D 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 artefacts.
  uhttps://www.inf.szte.hu/en/node/998