# Otsu segmentation on Head and Neck PET image

**URL:** https://discourse.slicer.org/t/otsu-segmentation-on-head-and-neck-pet-image/21235
**Category:** Support
**Created:** [December 27, 2021, 12:22pm UTC](https://discourse.slicer.org/t/otsu-segmentation-on-head-and-neck-pet-image/21235 "2021-12-27T12:22:31Z")
**Posts on this page:** 1
**Showing post:** 2

<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: [December 27, 2021, 12:52pm UTC](https://discourse.slicer.org/t/otsu-segmentation-on-head-and-neck-pet-image/21235/2 "2021-12-27T12:52:15Z")

</div>

Otsu threshold is not typically used for this. 40-43% of maximum SUV value is used instead. There have been a few discussions about this, for example:

> [@Segmentation from curved plane by markup points](https://discourse.slicer.org/t/segmentation-from-curved-plane-by-markup-points/16629/6):
>
> For the first question is this something like what you are building @RafaelPalomar ? Regarding your second question, that’s a mode I also want to implement for a PET project I’m involved with. Probably it can just be a simple segment editor effect that would be used as follows: use the Paint (or any tool) to draw anything that is possibly lesion and then the effect would calculate the max value of the background in that segment and then only keep the places where the background are 41% of that…

---

_[View the full topic](https://discourse.slicer.org/t/otsu-segmentation-on-head-and-neck-pet-image/21235)._