# Getting DICOM instance metadata from HealthImaging
<a name="dicomweb-retrieve-instance-metadata"></a>

Use the `GetDICOMInstanceMetadata` action to retrieve the metadata from a DICOM instance in a HealthImaging [ data store](getting-started-concepts.md#concept-data-store) by specifying the Series, Study, and Instance UIDs associated with the resource. The API will only return instance metadata from primary image sets unless the optional [ image set](getting-started-concepts.md#concept-image-set) parameter is provided. You can retrieve any instance metadata (from primary or non-primary image sets) in the data store by specifying the `imageSetId` as a query parameter.

**To get DICOM instance metadata (`.json`)**  


1. Collect HealthImaging `datastoreId` and `imageSetId` parameter values.

1. Use the [https://docs.aws.amazon.com/healthimaging/latest/APIReference/API_GetImageSetMetadata.html](https://docs.aws.amazon.com/healthimaging/latest/APIReference/API_GetImageSetMetadata.html) action with the `datastoreId` and `imageSetId` parameter values to retrieve associated metadata values for `studyInstanceUID`, `seriesInstanceUID`, and `sopInstanceUID`. For more information, see [Getting image set metadata](get-image-set-metadata.md).

1. Construct a URL for the request using the values for `datastoreId`, `studyInstanceUID`, `seriesInstanceUID`, `sopInstanceUID`, and `imageSetId`. To view the entire URL path in the following example, scroll over the **Copy** button. The URL is of the form:

   ```
   GET https://dicom-medical-imaging.region.amazonaws.com/datastore/datastore-id/studies/study-instance-uid/series/series-instance-uid/instances/sop-instance-uid/metadata?imageSetId=image-set-id
   ```

1. Prepare and send your request. `GetDICOMInstanceMetadata` uses a HTTP GET request with [AWS Signature Version 4](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_sigv.html) signing protocol. The following code example uses the `curl` command line tool to get DICOM instance metadata (`.json` file) from HealthImaging.

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#### [ Shell ]

   ```
   curl --request GET \
     'https://dicom-medical-imaging.us-east-1.amazonaws.com/datastore/d9a2a515ab294163a2d2f4069eed584c/studies/1.3.6.1.4.1.5962.1.2.4.20040826285059.5457/series/1.3.6.1.4.1.5962.1.3.4.1.20040825185059.5457/instances/1.3.6.1.4.1.5962.1.1.4.1.1.20040826186059.5457/metadata?imageSetId=459e50687f121185f747b67bb60d1bc8' \
     --aws-sigv4 'aws:amz:us-east-1:medical-imaging' \
     --user "$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY" \
     --header "x-amz-security-token:$AWS_SESSION_TOKEN" \
     --header 'Accept: application/dicom+json'
   ```

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**Note**  
The Transfer Syntax UID indicated in the metadata matches the Stored Transfer Syntax UID (`StoredTransferSyntaxUID`) in HealthImaging.