# How is Ventilation heterogeneity calculated?

**URL:** <https://discourse.slicer.org/t/how-is-ventilation-heterogeneity-calculated/6369>\
**Category:** SlicerCIP\
**Created:** [April 2, 2019, 1:40pm UTC](https://discourse.slicer.org/t/how-is-ventilation-heterogeneity-calculated/6369 "2019-04-02T13:40:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Yoss](https://avatars.discourse-cdn.com/v4/letter/y/ebca7d/32.png) [@Yoss](https://discourse.slicer.org/u/Yoss)\
**Post date:** [April 2, 2019, 1:40pm UTC](https://discourse.slicer.org/t/how-is-ventilation-heterogeneity-calculated/6369/1 "2019-04-02T13:40:19Z")

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Hello,

I’m unfamiliar with ventilation heterogeneity displayed in CIP parenchymal analysis. Can I refer to the calculation formula of ventilation heterogeneity?

Thanks.

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**Author:** ![nikkikto](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/nikkikto/32/3404_2.png) [@nikkikto](https://discourse.slicer.org/u/nikkikto)\
**Post date:** [April 8, 2019, 10:36am UTC](https://discourse.slicer.org/t/how-is-ventilation-heterogeneity-calculated/6369/2 "2019-04-08T10:36:43Z")

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I would also like to know what is meant by ventilation heterogeneity please. This is not a familiar term to clinicians and could involve HU, specific volume, specific gas volume, or other units.

Thank you.