VSBONE | VisionX V4 |
vsbone - segment bone
SYNOPSISvsbone if=<ifile> of=<ofile> [th=<threshold>] [m=<minvol>] [-e] [-s] [-v] [-w]
DESCRIPTIONvsbone segments the bone structures from a whole lung CT scan.
The streaking artifact on the scan is reduced with a median filter. With -s flag the filter is only applied on the first 1/4 of the slices. The pre-filtering may be disabled with -s flag when an input image has already been filtered externally.
The entire image is then thresholded at a specified threshold (default: 250HU). The connected component analysis is run and small volumes are removed from the results (default: < 4500mm^3). The possible inclusion of scan table is removed by locating a component with low center of mass (y < 100voxel).
Modification: a post-processing step is added. If the segmented bone region has more than 90 connected components (CCs), it is considered as a wrong segmentation (usually occurs in high noise images). Then the whole segmentation process is repeated: if the number of CCs is between 90 and 500, a larger pre-filtering filter (5x5 instead of 3x3 convolution) is used; if the number of CCs is larger than 500, a larger filter (5x5) and an elevated threshold (50HU higher) is used.
CONSTRAINTInput must be a short image of a whole-lung CT scan.
OPTIONS|
if= |
input whole lung CT scan | ||
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of= |
output 3D binary image of bone | ||
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th= |
threshold value in HU (default: 250) | ||
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m= |
minimum volume to keep in mm^3 (default: 4500) | ||
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-e |
no pre-filtering (input is filtered externally) | ||
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-s |
adaptive filter: apply median filter to only 1/4 of total frames | ||
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-v |
verbose mode | ||
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-w |
wish format (output connected component numbers before post-processing) |
vpix, v3connect, v3sc, v3ps
AUTHORJ. Lee