# LongitudinalPETCT extension

**URL:** <https://discourse.slicer.org/t/longitudinalpetct-extension/22050>\
**Category:** Support\
**Tags:** extensions-manager\
**Created:** [February 18, 2022, 4:14pm UTC](https://discourse.slicer.org/t/longitudinalpetct-extension/22050 "2022-02-18T16:14:44Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![dicom](https://avatars.discourse-cdn.com/v4/letter/d/e480ec/32.png) [@dicom](https://discourse.slicer.org/u/dicom)\
**Post date:** [February 18, 2022, 4:14pm UTC](https://discourse.slicer.org/t/longitudinalpetct-extension/22050/1 "2022-02-18T16:14:44Z")

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Hi all,

I am trying to open a DICOM image of from a PET device using Slicer3D.  
Importing my folder, it fails with the following error message:  
 ![Slicer_msg](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/5/25ddc86c7857b45f11ea88678606b6a953b6ed66.png)

Like other users I cannot find this module in the extension manager and looking at previous messages in the forum did not solve my problem. Do you know how I can bypass this extension?

I am using Slicer3D version 4.11.20200930

Best,  
M.

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**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:** [February 18, 2022, 6:47pm UTC](https://discourse.slicer.org/t/longitudinalpetct-extension/22050/2 "2022-02-18T18:47:35Z")

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This is just an informational message, recommending some extensions that could be useful if you work with PET images. You can safely ignore it. If you have an trouble loading PET images then I would recommend to try the latest Slicer Preview Release and if it does not work as you expect (e.g., PET image cannot be loaded) then let us know.

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**Author:** ![dicom](https://avatars.discourse-cdn.com/v4/letter/d/e480ec/32.png) [@dicom](https://discourse.slicer.org/u/dicom)\
**Post date:** [February 21, 2022, 8:26am UTC](https://discourse.slicer.org/t/longitudinalpetct-extension/22050/3 "2022-02-21T08:26:29Z")

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Dear Andras,  
Thanks a lot for helping.  
I installed the most recent stable version of Slicer3D for linux (4.11.20210226) and the warning message disappeared.

However, I still cannot load the image. Do I have to install an other extension?

Best regards,  
Marina

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**Author:** ![dicom](https://avatars.discourse-cdn.com/v4/letter/d/e480ec/32.png) [@dicom](https://discourse.slicer.org/u/dicom)\
**Post date:** [February 21, 2022, 2:05pm UTC](https://discourse.slicer.org/t/longitudinalpetct-extension/22050/4 "2022-02-21T14:05:36Z")

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Dear all,

I investigate the error message provided by Slicer, I identified a few problems that I solved. However I still have one, linked to my Dicom format implementation I guess. I’ll close this topic and open a new one related to the error message I am facing.

Thanks a lot Andras for your help, it was very useful.

Best,  
Marina