Projects:RegistrationLibrary:RegLib C13

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v3.6.3Slicer Registration Library Case #13: Liver Tumor Cryoablation 2

Input

fixed image/target		moving image	moving image	moving image

Objective / Background

We seek to align the pre-operative CT&MRI with the post-operative CT.

Keywords

MRI, CT, IGT, intra-operative, liver, cryoablation, change detection, non-rigid registration

Input Data

• reference/fixed : 0.57 x 0.57 x 5 , 512 x 512 x 37 voxels
• moving: 0.57 x 0.57 x 5 mm, 512 x 512 x 33 voxels
• moving: 1.56 x 1.56 x 2.5 mm, 256 x 256 x 88
• moving: 1.56 x 1.56 x 6 mm, 256 x 256 x 36

Registration Results

This case is currently unsolved with standard Slicer 3.6 technology. Special/custom modifications to registration modules (SlicerIGT Registration) are under way and will be incorporated into future releases. Also expected upgrades to ITK4 present in Slicer4 will likely improve performance.

Download

• download input image data (Input Data, NRRD images, zip file 28 MB)

Procedure

• Phase I: register CTpre - CTpost

1. open the General Registration (BRAINS) module
   1. Fixed Image Volume: CTpost
   2. Moving Image Volume: CTpre
   3. Output Settings:
      1. Slicer BSpline Transform": create new transform, rename to "Xf1_Ctpre-CTpost_BSpline"
      2. Slicer Linear Transform: none
      3. Output Image Volume: create new volume, rename to "CTpre_Xf1"
   4. Registration Phases: check boxes for Rigid , Rigid+Scale , Affine and "BSpline"
   5. Main Parameters:
      1. B-Spline Grid Size: 7,7,3
   6. Leave all other settings at default
   7. click: Apply; runtime ~ 1 min (MacPro QuadCore 2.4GHz)

Discussion: Registration Challenges

• large differences in FOV
• strong differences in image contrast between MRI & CT
• contrast enhancement and pathology and treatment changes cause additional differences in image content
• we have strongly anisotropic voxel sizes with much less through-plane resolution