# \#ras

**URL:** https://discourse.slicer.org/tag/ras/497.md

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## [Point on 2D CT slice image to RAS coordinate transformation](https://discourse.slicer.org/t/point-on-2d-ct-slice-image-to-ras-coordinate-transformation/35770)

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**Author:** [@joanne40226](https://discourse.slicer.org/u/joanne40226)\
**Replies:** 0\
**Last updated:** [April 27, 2024, 12:57pm UTC](https://discourse.slicer.org/t/point-on-2d-ct-slice-image-to-ras-coordinate-transformation/35770 "2024-04-27T12:57:38Z")

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Hi community, I encounter problems when doing point on 2D CT slice image to RAS coordinate. I have screen shot an 2D CT image as shown below. i check some imformation for example the actual size of the image in mm is :…