# Contrast for Imaging

<mark style="color:$danger;">**This Editorial Guide is used for Education Purposes Only. It is used in the Authoring Courses and Certifications. It is based on the January 2026 Editorial Guide.**</mark>

It is essential to express when contrast is part of a procedure and that descriptions are constructed consistently.

* For example,
  * 702501008 | Computed tomography of knee with contrast (procedure)|
    * FSN: Computed tomography of knee with contrast (procedure)
    * PT: CT of knee with contrast
    * SYN: Computed tomography of knee with contrast

The descriptions for all procedure concepts that use contrast must explicitly state ‘with contrast.’ All procedures that use contrast, including 420040002 |Fluoroscopic angiography with contrast (procedure)| and all subtypes, must include the attribute 424361007 |Using substance (attribute)| and a value of 385420005 |Contrast media (substance)| or a subtype in the role group.

Where the value for the method imaging action is 278110001 |Radiographic imaging - action (qualifier value)| or a subtype, the value for 424361007 |Using substance (attribute)| must be 419098001 |Radiographic imaging contrast media (substance)| or a subtype to denote the radio-opaque nature of the substance.

* Exception: procedures which specify negative contrast which is non-radio-opaque

{% hint style="info" %}
This guidance should be applied to new content, the process of updating existing content will be carried out as time and resources permit.
{% endhint %}

It is unnecessary to add the word *media* to contrast.

It is agreed that the linking word to associate the contrast use with the procedure is *with* - not *for,* *or,* etc.

{% hint style="warning" %}
**Contrast**

Additional concept detail is required when it is necessary to know the more precise nature of contrast (e.g. iodinated with various osmolalities, barium, or gas).
{% endhint %}

## Imaging without contrast

Although considered a negation, this term is used in clinical records. *Without contrast* imaging procedures are acceptable.

For example,

* 566341000119106 | Computed tomography of ankle without contrast (procedure)|
  * FSN: Computed tomography of ankle without contrast (procedure)
  * PT: CT of ankle without contrast
  * SYN: Computed tomography of ankle without contrast

## Unacceptable concept qualification

*With and without* and *With or without* imaging concepts are not acceptable due to ambiguity. Two concepts should be used to express these separately.

<a href="https://docs.google.com/forms/d/e/1FAIpQLScTmbZIf0UEQwYDkY27EEWBkaiYkHSbR0_9DmFrMLXoQLyL7Q/viewform?usp=pp_url&#x26;entry.1767247133=SCT+Editorial+Guide&#x26;entry.670899847=Contrast%20for%20Imaging" class="button primary">Provide Feedback</a>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.snomed.org/education/snomed-ct-education-editorial-guide/readme/authoring/domain-specific-modeling/procedure/index-1/index/contrast-for-imaging.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.