Deidentification Action Attribute
| Tag | (0008,0307) |
|---|---|
| Type | Required (1) |
| Keyword | DeidentificationAction |
| Value Multiplicity | 1 |
| Value Representation | Code String (CS) |
Recommended action to be performed during de-identification on elements listed in Identifying Private Elements (0008,0306) within this Item.
Note
A specific type of action is suggested in order to minimize the impact of de-identification on the behavior of recipients that use the Private Data Elements.
Enumerated Values:
- D
-
replace with a non-zero length value that may be a dummy value and consistent with the VR
- Z
-
replace with a zero length value, or a non-zero length value that may be a dummy value and consistent with the VR
- X
-
remove
- U
-
replace with a non-zero length UID that is internally consistent within a set of Instance
Note
-
No C (clean) action is specified, since replacement with values of similar meaning known not to contain identifying information and consistent with the VR requires an understanding of the meaning of the value of the element. Whether or not to clean rather than remove or replace values is at the discretion of the implementer.
-
No suggested dummy value is provided, since the encoding of the value would depend on the VR of the Data Element.
-
Further explanation of these actions can be found in PS3.15 Section E.3.1 Clean Pixel Data Option.
PS3.15 Section E.3.1 Clean Pixel Data Option
E.3.1 Clean Pixel Data Option
When this Option is specified in addition to the Basic Application Level Confidentiality Profile, any information burned in to the Pixel Data (7FE0,0010) corresponding to the Attribute information specified to be removed by the Profile and any other Options specified shall also be removed, as described in Table E.1-1.
This may require intervention of or approval by a human operator.
The Attribute Burned In Annotation (0028,0301) shall be added to the Dataset with a Value of "NO".
Note
-
This capability is called out as a specific Option, since it may be extremely burdensome in practice to implement and is unnecessary for the vast majority of modalities that do not burn in such annotation in the first place. For example, CT images do not normally contain such burned in annotation, whereas Ultrasound images routinely do.
-
Though image processing and optical character recognition techniques can be used to detect the presence of and location of burned in text, and matching against known identifying information can be applied, deciding whether or not that text is identifying information or some other type of information may be non-trivial. Compliance with this Option requires that identifying information is removed, regardless of how that is achieved. It is not required that information specified to be retained in the non-pixel data by other Options (e.g., physical characteristics, dates or descriptors) also be retained burned-in to the pixel data. Thus the most conservative approach of removing any and all burned in text would be compliant. This may involve sacrificing additional potentially useful information such as localizer posting and manual graphic annotations.
-
The Stored Pixel Values are to be changed (blacked out); it is not sufficient to superimpose an overlay or graphic annotation or shutter to obscure the Stored Pixel Data Values, since those may not be ignored by the receiving system.
-
This Option is intended to apply to the Pixel Data (7FE0,0010) Attribute that occurs in the top level Dataset of an Image Storage SOP Instance. The other standard use of Pixel Data (7FE0,0010) is within Icon Image Sequence (0088,0200), which is already described in Table E.1-1 and the accompanying note as requiring removal. This Option does not require the ability to manually or automatically process the Stoered Pixel Data Values of Pixel Data (7FE0,0010) occurring in any other location than the top level dataset, but it does not prohibit it. Pixel Data (7FE0,0010) occurring within private Attributes will be removed because such Attributes will not be known to be safe.