# Labels in VTK js for annotations in image slice

**URL:** https://discourse.vtk.org/t/labels-in-vtk-js-for-annotations-in-image-slice/685
**Category:** Support
**Created:** [April 4, 2019, 2:47pm UTC](https://discourse.vtk.org/t/labels-in-vtk-js-for-annotations-in-image-slice/685 "2019-04-04T14:47:26Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![Andrzej\_Marciniak](https://discourse.vtk.org/user_avatar/discourse.vtk.org/andrzej_marciniak/32/259_2.png) [@Andrzej\_Marciniak](https://discourse.vtk.org/u/Andrzej_Marciniak)
#### Post date: [April 4, 2019, 2:47pm UTC](https://discourse.vtk.org/t/labels-in-vtk-js-for-annotations-in-image-slice/685/1 "2019-04-04T14:47:26Z")

</div>

Hi all,  
Is there any way to add annotations using vtkLabelWidget (or something else) which will work in a way that annotation is visible only on a particular slice? More precisely, is it possible to “attach” label to a point or voxel (using ijk coords), so that annotation would be visible in each direction (sagittal, coronal, axial) if slice contains this voxel.  
Best and thank you  
Andrzej

---

<div class="post-metadata">

### Author: ![Forrest](https://discourse.vtk.org/user_avatar/discourse.vtk.org/forrest/32/300_2.png) [@Forrest](https://discourse.vtk.org/u/Forrest)
#### Post date: [April 17, 2019, 5:38pm UTC](https://discourse.vtk.org/t/labels-in-vtk-js-for-annotations-in-image-slice/685/2 "2019-04-17T17:38:25Z")

</div>

Hi Andrzej, we currently don’t have a vtkLabelWidget in vtk.js. We do have a way to map 3D coordinates to screen space, as seen in this [example with labels](https://kitware.github.io/vtk-js/examples/SpheresAndLabels.html).

There is some work similar in scope, e.g. placing landmarks. You can check out the vtk.js [PolyLine Widget](https://kitware.github.io/vtk-js/examples/PolyLineWidget.html) for an example widget that places points in the scene. Something like that could be modified to restrict points to a slice, and then you’ll have to write logic to hide labels that aren’t on the current slice.