Image Set Selector Sequence Attribute
| Tag | (0072,0022) |
|---|---|
| Type | Required (1) |
| Keyword | ImageSetSelectorSequence |
| Value Multiplicity | 1 |
| Value Representation | Sequence (SQ) |
Sequence containing Image Set selection Attributes and values that are used to identify one type of image or object set for the Hanging Protocol.
One or more Items shall be included in this Sequence.
See Section C.23.1.1.3.
Section C.23.1.1.3
C.23.1.1.3 Image Set Selector Sequence Attributes
The Image Set Selector Sequence (0072,0022) contains Items that specify the DICOM Attribute Data Element Tags and values that shall be used to identify the image or other object set.
The Image Set Selector Usage Flag (0072,0024) indicates whether the Attribute identified by Selector Attribute (0072,0026) causes matching to succeed or fail if the Attribute is not available in an image object.
Within an Item, Selector Attribute (0072,0026) identifies a DICOM Attribute Data Element Tag that is likely to be present in image or other object Instances that are desired for the Image Set. If it is a multi-valued Attribute, the Selector Value Number (0072,0028) indicates which value is intended to be used for matching. The Selector Attribute VR (0072,0050) identifies the Value Representation of Selector Attribute (0072,0026). The value of Selector Attribute VR (0072,0050) determines which Attribute of the Hanging Protocol Selector Attribute Value Macro is required to specify one or more desired values for the DICOM Attribute. If more than one value is specified for the Attribute, or more than one Item is specified in the Selector Code Sequence Value (0072,0080), then image object Instances with a corresponding Attribute that matches any one of the values shall be included in the Image Set.
Note
The values used for Selector Attribute (0072,0026) are intended to identify a type of image set via the general categories of modality, anatomy, procedure intent and/or reason. Therefore the values of the Attributes represented by Selector Attribute (0072,0026) are likely to be coded terms, Enumerated Values, Defined Terms or free text. The use of free text Attributes is less desirable, because their values are less predictable for matching.
In an image object, some Attributes occur at the top level, or nested within a Sequence or Functional Group Sequence, or both. In addition, a Private Attribute may be identified as a Selector Attribute (0072,0026). The Attributes of the Hanging Protocol Selector Attribute Context Macro identify a Sequence, Functional Group Sequence, or Private Group context for Selector Attribute (0072,0026).
The creator of a Hanging Protocol Instance uses this collection of Attributes to identify one type of image set to which the Hanging Protocol is intended to apply. The user of a Hanging Protocol Instance (e.g., softcopy review workstation or pre-fetching application) uses this collection of Attributes to match a specific image set to a Hanging Protocol, and/or to determine which image sets need to be retrieved in order to use a Hanging Protocol Instance. The Key Attributes to match against to obtain image sets are specified in Selector Attribute (0072,0026) and its context in each Sequence Item.
If the value of the Attribute represented by Selector Attribute (0072,0026) contains a free text description (i.e., Selector Attribute VR = LO, SH, ST, LT, UT), whether exact or partial matching is used to identify a specific Image Instance when applying a Hanging Protocol Instance is implementation dependent.