This process measures length of the bottom and hull junction of a sulcus by a multi step process.
Step 1 - Create sulcal volume
siGraph2Label is used to create volumes for the sulcal body, bottom, and hull junction.
Step 2 - Close sulcal volume AimsClosing is used to close the sulcal body volume
Step 3 - Mesh sulcal volume
AimsMesh is used to create a mesh from the sulcal body volume. It is possible that more than one mesh may result
Step 4 - Merge sulcal meshes
AimsZCat is used to combine the sulcal body meshes into one
Step 5 - Determing bottom and hull junction lengths
The RicSulcalLengthDeluxe program to create the top and bottom sulcal lines.
This program takes a volume files that contains the top and bottom of a sulcus and maps them to the surface of the sulcal mesh. These line is then sorted along the length of the sulcus. The sorted points are then used as control points in a spline curves, one along the hull junction and the other for the bottom. The required input files are volumes for the top and bottom of a sulcus and a mesh that contains the sulcus. The lines defining the top and bottom of the sulcus are output as linear meshes.
Step 6 - Measuring sulcal depth and width
The RicSulcalDepth program creates a set of depth lines between the top and bottom sulcal lines. A series of width measurements are are made along each depth line.
The depth and thickness measurements of a sulcus are based on the sulcal mesh and the lines defining the top and bottom of the sulcus.
The top and bottom lines will be split into a set of segments. For each segment a plane will be cut at right angles through the sulcus. A set of points will be extracted from the mesh at the intersection of the plane. This set of points will be separated into lines for each side of the sulcus. Those lines will be split into a number of points where width measurements will be taken. At each width measurment, a center point between the surfaces will be used to make a line from the top to bottom of the sulcus, throught the middle of the sulcus.
The program output max and average values for sulcal depth and sulcal width. A file is output containing the subject name and the depth at each segment with the extension suffex _SegDepth.txt. In addition a mesh is output with the suffix _WidthDepth.mesh that shows the sulcal depth lines and the sulcal width lines.
Download Instructions:
Click on the link below to download the file. Place it in the root BrainVISA directory. This directory should have subdirectories bin, brainvisa, include, lib, share. Run gunzip to uncompress the file. The run 'tar -xvf RicSulcalLengthDepth.tar' to put all the files in their proper places. When you run BrainVISA, there will be an additional catagory 'ric' that will contain the plugin.
Download SulcalLengthDepth plugin from NITRC (Linux, Windows and Apple 10.X OS and the source codes are available)