Computing Anisotropy
You can compute the degree of anisotropy, which is a measure of how highly oriented substructures are within a volume, for any selected region of interest. Results, which can be computed using the mean intercept length (MIL) or star volume distribution (SVD) method, appear in a message box after the computation is complete, as shown below.
Anisotropy computation
The settings for computing the degree of anisotropy, for example of segmented trabecular bone, are available in the Set Anisotropy Parameters dialog, shown below.
Set Anisotropy Parameters dialog
Refer to the table below for a description of the settings applicable to anisotropy computations.
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|
Description |
|---|---|
|
Max iterations |
Is the maximum number of random points in the sample that will be analyzed. Fitting will stop automatically after this number is completed or if the coefficient of variation (tolerance) is reached. |
|
Sampling |
Is the resolution, or distance between subsequent samples along each vector. You should note that the entered value can be equal to the voxel size of the input region of interest. |
|
Orientations |
Is the number of lines to analyze per sampling sphere. |
|
Min iterations |
Is the minimum number of random points in the sample that will be analyzed. |
|
Radius |
Is the radius of the sampling sphere, which determines the length of each sampling vector. |
|
Tolerance |
Is the coefficient of variation. Sampling new random points will continue until either a coefficient of variation equal to the tolerance is reached or the maximum number of iterations is completed. |
How to Compute Anisotropy
- Right-click the region of interest you want to analyze in the Data Properties and Settings panel.
- Choose Compute Anisotropy Using > Mean Intercept Length (MIL) or Compute Anisotropy > Star Volume Distribution (SVD) in the pop-up menu.
- Enter the required settings in the Set Anisotropy Parameters dialog.
Refer to the table Settings for computing anisotropy for information about the available parameters.
- Click OK
When processing is complete, the result appears in the Anisotropy dialog.
