Difference between revisions of "Documentation:Nightly:Registration:RegistrationLibrary:RegLib C40"

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=== Keywords ===
 
=== Keywords ===
 
micro-CT, deformation modeling
 
micro-CT, deformation modeling
 +
 +
== Video Screencasts ==
 +
#[[Media:RegLib_C40.mov|Movie/screencast showing registration steps]]
  
 
== Procedure ==
 
== Procedure ==

Revision as of 21:01, 2 October 2013

Home < Documentation:Nightly:Registration:RegistrationLibrary:RegLib C40

Back to Registration Library

Slicer Registration Library Case #40:
micro-CT of material wood sample

Input

this is the fixed reference image. All images are aligned into this space lleft this is the moving image. The transform is calculated by matching this to the reference image
fixed image/target moving image

Modules used

Download (from NAMIC MIDAS)

Why 2 sets of files? The "input data" mrb includes only the unregistered data to try the method yourself from start to finish. The full dataset includes intermediate files and results (transforms, resampled images etc.). If you use the full dataset we recommend to choose different names for the images/results you create yourself to distinguish the old data from the new one you generated yourself.

Description

We have 2 micro-CT scans of a material (wood) sample under different environmental conditions (e.g. moisture). We seek to use a nonrigid registration to capture and model the structural changes (deformations) that occur when conditions change. We register the two volumes to eachother and then interpret the deformation in this registration as a surrogate of the change that occurred.

Keywords

micro-CT, deformation modeling

Video Screencasts

  1. Movie/screencast showing registration steps

Procedure

  1. Affine Registration: open the General Registration (BRAINS) module.
    1. Fixed Image Volume: "sample1"
    2. Moving Volume: "sample2"
    3. Registration phases: check boxes for Rigid" ,"Scale", "Affine"
    4. Slicer Linear Transform: select "create new transform", rename to "Xf1_Affine" or similar
    5. leave rest at defaults. Click Apply
    6. registration should take ~ 10 secs.
    7. use fade slider to verify alignment; compare with result snapshots shown below. Alignment will not be perfect but should be better than before.
    8. note: you can also change the colormaps for the fixed and moving volumes to better judge the alignment: go to the Volumes module and in the Display tab, select "green" and "magenta" as the respective colormaps for the two volumes.
  2. Nonrigid Registration: open the General Registration (BRAINS).
    1. Fixed/Moving Image Volume: as above
    2. Registration phases: uncheck boxes for rigid, scale and affine and check box for BSpline
    3. Output: Slicer Linear transform: set to None
    4. Output: Slicer BSpline transform: create new, rename to "Xf2_BSpline" or similar
    5. Output Image Volume: create new, rename to "sample2_Xf2"; Pixel Type: "unsigned short"
    6. Registration Parameters: increase Number Of Samples to 300,000; Number of Grid Subdivisions: 5,5,5
    7. Leave all other settings at default
    8. click apply

Registration Results

RegLib C40 unregistered.gif baseline and follow-up before registration (click to enlarge)
RegLib C40 registered Affine.gif after affine alignment. Note the residual shape differences (click to enlarge)
RegLib C40 registered BSpline.gif after nonrigid BSpline registration (click to enlarge)
RegLib C40 DeformationOnly.gif| visualization of the nonrigid deformation component only

Acknowledgments

Registration problem and dataset kindly provided by Alessandra Patera from the Swiss Federal Institute of Technology (ETHZ) in collaboration with the Swiss Federal Laboratories for Material Science and Technology (EMPA).