| Tag | (0400,0550) |
|---|---|
| Type | Required (1) |
| Keyword | ModifiedAttributesSequence |
| Value Multiplicity | 1 |
| Value Representation | Sequence (SQ) |
Sequence that contains all the Attributes, with their previous values, that were modified or removed from the top level Data Set.
See Section C.12.1.1.9.
Only a single Item shall be included in this Sequence.
Every transfer of a SOP Instance may result in data element coercion (see Section B.4.1.3 “Coercion of Attributes” in PS3.4) by the receiving application. The receiving application may also detect and correct or remove errors in SOP Instances to bring them into conformance with the SOP Class definition without changing the SOP Instance UID or creating a derived Instance (see status Warning in Section 9.1.1.1.9 “Status” in PS3.4 and Section B.2.3 “Statuses” in PS3.4. When performing such actions, the application may add an Item to the Original Attributes Sequence (0400,0561) describing the change and the prior values of coerced, modified, or removed Attributes. Any existing Items in the Original Attributes Sequence shall be preserved.
Attributes that were modified or removed shall be placed in the Modified Attributes Sequence (0400,0550) with their prior values. If an Attribute within a Sequence was modified or removed, the entire prior value of the Sequence shall be placed in the Modified Attributes Sequence; this applies recursively up to the enclosing Sequence Attribute in the top level Data Set.
Attributes that were empty or absent and for which values have been added may be present in the Modified Attributes Sequence with a zero length value.
If an Attribute was modified or removed because its value was nonconforming to its Value Representation or Value Multiplicity, it shall be included in the Modified Attributes Sequence with a zero length value.
Any Private Data Elements present in the Item shall be accompanied by their respective Private Data Element Creator Attribute.
If an Attribute was modified or removed because its value was nonconforming to its Value Representation or Value Multiplicity, the original value (which was replaced by a zero length value in the Modified Attributes Sequence) may be recorded in the Nonconforming Modified Attributes Sequence (0400,0551).
The nonconforming Attribute is identified by the attributes of the Selector Attribute Macro. Because a single Attribute is being identified, Selector Attribute (0072,0026) shall be present.
The Data Set to which the Selector Attribute Macro applies is the single Item of the Modified Attributes Sequence (0400,0550) within the same Item of the Original Attributes Sequence (0400,0561). Therefore, the Modified Attributes Sequence (0400,0550) is not identified in the Selector Sequence Pointer (0072,0052).
This is effectively the same as a pointer to the equivalent attribute in the original top level Data Set.
Characters in text attributes non-conformant to the identified Specific Character Set (0008,0005) may be considered non-conformant to the VR.
For example, if Body Part Examined had a nonconforming value, the Modified Attributes Sequence Item would have the Attributes:
|
(0072,0026) |
00180015 |
Selector Attribute |
|
(0072,0028) |
1 |
Selector Value Number |
|
(0400,0552) |
ABDOMEN&PELVIS |
Nonconforming Data Element Value |
The Nonconforming Data Element Value (0400,0552) has Value Representation OB, which allows an arbitrary byte string to be encoded.