# Creation of ROI aligned with freehand ultrasound sweeps -- how to rotate the ROI?

**URL:** <https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325>\
**Category:** Support\
**Created:** [June 24, 2021, 2:59pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325 "2021-06-24T14:59:11Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![AurelieS](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@AurelieS](https://discourse.slicer.org/u/AurelieS)\
**Post date:** [June 24, 2021, 2:59pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/1 "2021-06-24T14:59:11Z")

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Hi,

I think my question is quite a beginner question, but since a year now I am doing freehand 3D ultrasound and I just realised that the ROI I am using has a lot of impact on my volume reconstruction.  
I am therefore trying to adjust the ROI the more possible to the axis of my sweeps.  
However I cannot find how to rotate the ROI ? I tried applying a transform to the ROI, but then the volume reconstruction did not work anymore …

Thanks in advance for your help,  
Cheers,  
Aurélie

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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:** [June 25, 2021, 6:19pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/2 "2021-06-25T18:19:31Z")

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Currently in the Volume Reconstructor module in Slicer you cannot specify axis directions. I’ve submitted an issue to make sure it gets implemented:

> <https://github.com/IGSIO/SlicerIGSIO/issues/11>
>
> We need to add support to markups ROI. It would allow specifying rotated ROIs.
> …
> https://github.com/IGSIO/SlicerIGSIO/blob/837b01ea2702fafa19a7fbba0c492bcc339e91dd/VolumeReconstruction/Logic/vtkSlicerVolumeReconstructionLogic.cxx#L245-L247

Would you like to give it a try and implement it. We can help you getting started, but it requires basic C++ programming skills.

Alternatively, you can rotate your entire reference coordinate system by applying adding a custom transformation. For example, you can add `ReferenceToRotatedReference`) and send all transforms and images in `RotatedReference` instead of `Reference`.

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**Author:** ![AurelieS](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@AurelieS](https://discourse.slicer.org/u/AurelieS)\
**Post date:** [June 28, 2021, 9:11am UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/3 "2021-06-28T09:11:43Z")

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Thank you for your quick answer.  
I apologize but I do not think I have the skills to implement this in Slicer …

As you offered, I applied a custom transformation to my full trial and the volume reconstruction worked well !  
However, my ROI and the axis of my sweeps change for each acquisition I do, since I am sweeping different muscles of different sizes in different body positions … . so it would be a lot easier for me if it was possible to directly adjust the ROI size and orientation.

How can I be kept updated if that becomes possible someday?  
Thanks again,  
Cheers,  
Aurélie

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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:** [June 28, 2021, 2:06pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/4 "2021-06-28T14:06:31Z")

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> [@AurelieS](#):
>
> How can I be kept updated if that becomes possible someday?

Watch the issue referenced above. I think you can set automatic email notification when the state of the issue changes.

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**Author:** ![AurelieS](https://avatars.discourse-cdn.com/v4/letter/a/87869e/32.png) [@AurelieS](https://discourse.slicer.org/u/AurelieS)\
**Post date:** [March 2, 2023, 1:46pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/5 "2023-03-02T13:46:08Z")

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Dear Andras,  
I see that this issue has been resolved on the 21st of November 2021.  
Has it been developped only on PlusServer (as a code line) or also directly in the 3D Slicer GUI ?  
Thanks in advance for your help.  
Best regards,  
Aurélie Sarcher

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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:** [March 2, 2023, 7:29pm UTC](https://discourse.slicer.org/t/creation-of-roi-aligned-with-freehand-ultrasound-sweeps-how-to-rotate-the-roi/18325/6 "2023-03-02T19:29:32Z")

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You can rotate the ROI in the Slicer GUI. Right-click on it and in “Interaction options” submenu enable “Rotation”

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/a/ea84829c6422809b3ff35ecc3c517e40bf74e78e.jpeg)