VSRIBS

VisionX V4

NAME

vsribs - segments and labels individual rib bones from a bone image.

SYNOPSIS

vsribs if= ig= ih= of= [og=] [oh=] [or=] [-f] [-v] [-w]

DESCRIPTION

vsribs is a rib segmentation program that labels individual rib bones. The required input files are the segmented bone image (if=), the dilated lung mask (ig=), and the filtered CT image (ih=). The bone image and lung mask may be obtained using vsbone and vslung, respectively. Typically, the CT image (ih=) is filtered with 3x3 mean filter before being passed into vsribs. The output (of=) of the program is the byte image with 0 for the background and non-zero labels corresponding to each rib.

The program first traces the spinal canal’s centerline (oh=) beginning at the bottom of the scan. It then identifies the

starting point of each rib (og=) based on the location of the centerline. The starting points are at the COM of the intersection of the bone region with two vertical bounding planes, one at each side of the spinal cord, located at a distance of 45 mm from the spinal cord itself.

From the starting points, the rib bones are grown into full ribs using 3D region growing. The leakage into other bone structure is detected based on the grown volume and resolved using dilated lung mask (ig=), considering the fact that the rib bones are adjacent to the lung.

The gap between the starting point and the spine is segmented by cylinder fitting along the rib bone. By default, the gap-filling part of the program is disabled and may be enabled selecting -f .

CONSTRAINT

ih= is a whole-lung chest CT image (pre-filtered, e.g. with a 3x3 mean filter). if= and ig= must be binary byte images of the bone region and the lung region dilated by a 40x40x20 structuring element (s=40,40,20), respectively.

OPTIONS

	if=		input segmented bone
	ig=		input dilated lung mask
	ih=		input CT scan
	of=		output labeled ribs
	og=		output labeled rib starting points
	oh=		output spinal canal centerline
	or=		output the coordinates of rib roots in csv (each row: label,x,y,z)
	-f		get full ribs (enable cylinder tracking)
	-v		verbose mode
	-w		wish output

SEE ALSO

vsbone, vslung

AUTHOR

J. Lee