---
title: "Modify instance"
method: POST
path: "/instances/{id}/modify"
tags: ["Instances"]
---

# Modify instance

`POST /instances/{id}/modify`

Download a modified version of the DICOM instance whose Orthanc identifier is provided in the URL: https://orthanc.uclouvain.be/book/users/anonymization.html#modification-of-a-single-instance

## Path parameters

- `id` string, required

## Request body

- object
  - `Force` boolean — Allow the modification of tags related to DICOM identifiers, at the risk of breaking the DICOM model of the real world
  - `Keep` string[] — Keep the original value of the specified tags, to be chosen among the `StudyInstanceUID`, `SeriesInstanceUID` and `SOPInstanceUID` tags. Avoid this feature as much as possible, as this breaks the DICOM model of the real world.
  - `KeepSource` boolean — If set to `false`, instructs Orthanc to the remove original resources. By default, the original resources are kept in Orthanc.
  - `LossyQuality` number — If transcoding to a lossy transfer syntax, this entry defines the quality as an integer between 1 and 100. If not provided, the value is defined by the "DicomLossyTranscodingQuality" configuration. (new in v1.12.7)
  - `PrivateCreator` string — The private creator to be used for private tags in `Replace`
  - `Remove` string[] — List of tags that must be removed from the DICOM instances. Starting with Orthanc 1.9.4, paths to subsequences can be provided using the same syntax as the `dcmodify` command-line tool (wildcards are supported as well).
  - `RemovePrivateTags` boolean — Remove the private tags from the DICOM instances (defaults to `false`)
  - `Replace` object — Associative array to change the value of some DICOM tags in the DICOM instances. Starting with Orthanc 1.9.4, paths to subsequences can be provided using the same syntax as the `dcmodify` command-line tool (wildcards are supported as well).
  - `Transcode` string — Transcode the DICOM instances to the provided DICOM transfer syntax: https://orthanc.uclouvain.be/book/faq/transcoding.html

## Response `200`

---

[API](https://skmtc.net/uclouvain/apis/orthanc-api.md) · [All operations](https://skmtc.net/uclouvain/apis/orthanc-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/uclouvain/orthanc-api/versions/9297c4930d96/schema)