# Duplicate data in MRML tree

**URL:** <https://discourse.slicer.org/t/duplicate-data-in-mrml-tree/4461>\
**Category:** Support\
**Created:** [October 19, 2018, 10:39am UTC](https://discourse.slicer.org/t/duplicate-data-in-mrml-tree/4461 "2018-10-19T10:39:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![torquil](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@torquil](https://discourse.slicer.org/u/torquil)\
**Post date:** [October 19, 2018, 10:39am UTC](https://discourse.slicer.org/t/duplicate-data-in-mrml-tree/4461/1 "2018-10-19T10:39:24Z")

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Hi!

After loading a CT DICOM file, then saving the data, closing the scene, and then opening the data again, I seem to end up with duplicate data in the MRML tree, similar to what is described here:

> [@Slicer save function creating copies of dataset instead of overwrite](https://discourse.slicer.org/t/slicer-save-function-creating-copies-of-dataset-instead-of-overwrite/2311):
>
> Hi, I am not sure if this is how it is supposed to work. But when i load the data folder i saved previously, slicer creates copies of all files and assigns them a suffix like ‘\_1’ . If I were to save the data again after updating a few segmentations for example, everything gets saved along with suffixed duplicates, hence doubling storage and creating confusion, unless i manually unselect the suffixed duplicates. Screenshot showing contents of folder loaded into slicer, there are no duplicates …

The response to that question recommended to use “Close scene”, but this is something I always do, so that is not the solution in this case. In addition, I often get several “Default Scene Camera” items in the Data module.

Below is an example where I’m ending up with two copies of a volume initially called L\_PreOp. The reason I’m asking about this is that when I worked on registration between two CTs, then saving data and loading data, I end up with duplicate data where half of the items have names with the suffix \_1, as described in the link above.

Here are some screenshots of the process, showing the Data module between each step:

After Slicer startup:

 ![00_after_startup](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/e/fef3561de6cd7f3874095c353e2c3c6bdf2e1859.png)

After loading the DICOM file:

 ![01_after_dicom_load](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/a/eaf87dd1065bc8cdc6e906da4f1cb15d4284a2fc.png)

After saving the data:

 ![02_after_data_save](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/3/033b76c995229109543e8374fc49db0e2637a04b.png)

After File → Close scene:

 ![03_after_close_scene](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/b/2b2558353b9e7281bb33924219bd3326ac82d06e.png)

Adding the data that was saved:

 ![04_add_data](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/3/a/3a3fb3c542662919991ef4921a4d2f453f4eef7c.png)

After adding the data:

 ![05a_after_add_data](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/0/1009e990549a0e8cab49fbea4d9d8d71e59743fd.png)

The nodes tab:

 ![05b_nodes](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/6/9/69f667eb5cb24947ebf816c64aeb6742b4d4b051.png)

I’m using the latest Slicer 3d nightly build on Linux.

Best regards,  
Torquil Sørensen

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [October 19, 2018, 11:31am UTC](https://discourse.slicer.org/t/duplicate-data-in-mrml-tree/4461/2 "2018-10-19T11:31:02Z")

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You add one instance of the volume by loading the scene (mrml file) and you add the second instance by loading the image (nrrd file).

If you want to load a saved scene then double-click the scene file or drag-and-drop the scene file (not the entire folder) to the application window.