01884nas a2200133   4500008004100000020001400041245007800055210006900133260001200202300001400214490000700228520147500235856004001710       2002                        eng d  a0278-006200aSpiral-CT-based assessment of tracheal stenoses using 3-D-skeletonization0 aSpiralCTbased assessment of tracheal stenoses using 3Dskeletoniz  c2002///  a263 - 2730 v213 aPURPOSE: 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). 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 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%. CONCLUSION: 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.
  uhttps://inf.u-szeged.hu/en/node/896