# Configuring vtkMRMLSliceNode

**URL:** <https://discourse.slicer.org/t/configuring-vtkmrmlslicenode/2028>\
**Category:** Development\
**Created:** [February 5, 2018, 8:55pm UTC](https://discourse.slicer.org/t/configuring-vtkmrmlslicenode/2028 "2018-02-05T20:55:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![asheu](https://avatars.discourse-cdn.com/v4/letter/a/db5fbb/32.png) [@asheu](https://discourse.slicer.org/u/asheu)\
**Post date:** [February 5, 2018, 8:55pm UTC](https://discourse.slicer.org/t/configuring-vtkmrmlslicenode/2028/1 "2018-02-05T20:55:12Z")

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I’m currently trying to configure the vrkMRML slice node so that I can create a Slicer viewer (for example the coronal slice) that is able to be switched between two image datasets (say CT and MR images). I would like to develop a slider that helps move between these two files. However, since I have just started Slicer development, I am unsure how to approach this issue.

Should I write a separate Python script or would it be possible to configure the existing vrkMRML file to add new custom layouts?

Any insight would be helpful, thank you!

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [February 6, 2018, 5:36pm UTC](https://discourse.slicer.org/t/configuring-vtkmrmlslicenode/2028/2 "2018-02-06T17:36:38Z")

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What you describe sounds like putting one image in the foreground and one in the background and crossfading? if so you want to look at the vtkMRMLSliceCompositeNode and this example.

[https://www.slicer.org/wiki/Documentation/4.8/Modules/CompareVolumes](https://www.slicer.org/wiki/Documentation/4.8/Modules/CompareVolumes)

> <https://github.com/pieper/CompareVolumes/blob/master/CompareVolumes.py#L354-L416>