# Tutorial on terminologies

**URL:** <https://discourse.slicer.org/t/tutorial-on-terminologies/23400>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [May 13, 2022, 5:13am UTC](https://discourse.slicer.org/t/tutorial-on-terminologies/23400 "2022-05-13T05:13:31Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [May 13, 2022, 5:13am UTC](https://discourse.slicer.org/t/tutorial-on-terminologies/23400/1 "2022-05-13T05:13:31Z")

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How does one go about creating a custom segmentation terminology/colors and using that during the segmentation process (I.e., renaming segment\_1 segment\_2 with consistent names and colors)…

Linked sample json file in the [terminologies documentation](https://slicer.readthedocs.io/en/latest/user_guide/modules/terminologies.html) is a bit too complex to understand.

Let’s say I want to make a terminology for all cranial bones (Left Nasal, Right Nasal, Occipital, Frontal so forth)

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [May 13, 2022, 8:29am UTC](https://discourse.slicer.org/t/tutorial-on-terminologies/23400/2 "2022-05-13T08:29:39Z")

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There are simpler examples such as this: [SlicerHeart/SlicerHeartPDAVesselsCategoryTypeModifier\_A\_Normal.json at master · SlicerHeart/SlicerHeart · GitHub](https://github.com/SlicerHeart/SlicerHeart/blob/master/ValveAnnulusAnalysis/Resources/SlicerHeartPDAVesselsCategoryTypeModifier_A_Normal.json)

Do you think it would solve the issue if we replaced one of the examples in the documentation page you linked with this? Or do you have more questions and a more comprehensive guide would be needed?

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [May 13, 2022, 5:22pm UTC](https://discourse.slicer.org/t/tutorial-on-terminologies/23400/3 "2022-05-13T17:22:59Z")

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It is simpler, but I think a bit more guidance is needed. For example what does the nested levels means (section under “Type”), or what is the significance of Code Value field, why some are numeric and some alpha-numeric?

```auto
"Category": [
      {
        "CodeMeaning": "PDA adjacent vessels (A - Normal)",
        "CodingSchemeDesignator": "SlicerHeart",
        "CodeValue": "85756008",
        "Type": [
          {
            "CodeMeaning": "PDA",
            "CodingSchemeDesignator": "SlicerHeart",
            "CodeValue": "sh-pda-pda",
            "recommendedDisplayRGBValue": [128, 174, 128]
          },
          {
            "CodeMeaning": "Ascending aorta",
            "CodingSchemeDesignator": "SlicerHeart",
            "CodeValue": "sh-pda-ascending-aorta",
            "recommendedDisplayRGBValue": [216, 101, 79]
          },

```

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**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:** [May 14, 2022, 11:07pm UTC](https://discourse.slicer.org/t/tutorial-on-terminologies/23400/4 "2022-05-14T23:07:54Z")

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> [@muratmaga](#):
>
> For example what does the nested levels means (section under “Type”)

`Type` list contains all the types you define in the file.

> [@muratmaga](#):
>
> what is the significance of Code Value

In short:

- **coding scheme designator:** specifies the terminology. For example, `TA2`, `FMA`, `MeSH`, …
- **code value:** specifies the identifier in that terminology. For example, [identifier of `Nasal bone` in TA2 is `748`](https://en.wikipedia.org/wiki/Nasal_bone), so the code value is `748`.
- **code meaning:** human-readable string, just for convenience (for example, if an application does not know the used terminology then it can display this string) and debugging. For example, `nasal bone`.

You can find detailed description of how `Coding scheme designator`, `Code value`, and `Code meaning` used in DICOM in the [DICOM standard](https://dicom.innolitics.com/ciods/general-ecg/patient-study/00101021/00080102).

Left/right can be specified using modifier. For example, for types specified using SNOMED Clinical Terms (SCT) we usually use this modifier: `{"CodingSchemeDesignator": "SCT", "CodeValue": "24028007", "CodeMeaning": "Right"}`. For TA2, you can find a convenient browser [here](https://ta2viewer.openanatomy.org), and according to that the [code value of the `Right` is `7`](https://ta2viewer.openanatomy.org/?id=7).