# Annotations in 3D slicer to prepare training datasets

**URL:** <https://discourse.slicer.org/t/annotations-in-3d-slicer-to-prepare-training-datasets/13528>\
**Category:** Support\
**Created:** [September 17, 2020, 1:57pm UTC](https://discourse.slicer.org/t/annotations-in-3d-slicer-to-prepare-training-datasets/13528 "2020-09-17T13:57:33Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jigabytes](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jigabytes/32/4467_2.png) [@Jigabytes](https://discourse.slicer.org/u/Jigabytes)\
**Post date:** [September 17, 2020, 1:57pm UTC](https://discourse.slicer.org/t/annotations-in-3d-slicer-to-prepare-training-datasets/13528/1 "2020-09-17T13:57:33Z")

</div>

Hi,Can we use 3D Slicer to do annotation on medical image slices and then prepare annotated data to build training data sets to build neural network from scratch? Can you point me to tutorial or example of it?

---

<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:** [September 18, 2020, 12:21am UTC](https://discourse.slicer.org/t/annotations-in-3d-slicer-to-prepare-training-datasets/13528/2 "2020-09-18T00:21:08Z")

</div>

This is probably one of the most common use cases of Slicer nowadays. See an overview of basic segmentation concepts [here](https://slicer.readthedocs.io/en/latest/user_guide/image_segmentation.html) and step-by-step tutorials [here](https://www.slicer.org/wiki/Documentation/Nightly/Training#Segmentation).

If you need to segment hundreds or thousands of data sets then it is probably worth setting up [Case iterator](https://github.com/JoostJM/SlicerCaseIterator) (for single-click switch between data sets).