# DICOM metadata constraints
<a name="dicom-metadata-constraints"></a>

When you use `UpdateImageSetMetadata` to update HealthImaging [metadata](getting-started-concepts.md#concept-metadata) attributes, the following DICOM constraints are applied.
+  Cannot update or remove private attributes on Patient/Study/Series/Instance level attributes unless the update constraint applies to both `updatableAttributes` and `removableAttributes` 
+  Cannot update the following AWS HealthImaging generated attributes: `SchemaVersion`, `DatastoreID`, `ImageSetID`, `PixelData`, `Checksum`, `Width`, `Height`, `MinPixelValue`, `MaxPixelValue`, `FrameSizeInBytes` 
+  Cannot update the following DICOM attributes unless the `force` flag is set: `Tag.PixelData`, `Tag.StudyInstanceUID`, `Tag.SeriesInstanceUID`, `Tag.SOPInstanceUID`, `Tag.StudyID` 
+  Cannot update attributes with VR type SQ (nested attributes) unless the `force` flag is set 
+  Cannot update multivalued attributes unless the `force` flag is set 
+  Cannot update attributes with values that are not compatible with the attribute VR type unless the `force` flag is set 
+  Cannot update attributes which are not considered valid attributes according to the DICOM standard unless the `force` flag is set 
+  Cannot update attributes across modules. For example, if a Patient level attribute is given at the Study level in customer payload request, the request can be invalidated. 
+  Cannot update attributes if the associated attribute module is not present in existing `ImageSetMetadata`. For example, you are not allowed to update attributes for a `seriesInstanceUID` if the Series with `seriesInstanceUID` is not present in existing image set metadata.