Working with Context Groups

The use of Coded Concepts in DICOM facilitates unambiguous communication of concepts or terms. The Coded Concepts are incorporated in IODs using the Code Sequence Attributes as described in PS 3.3 of the DICOM Standard.

A set of related Coded Concepts forms a Context Group. PS 3.16 of the DICOM Standard specifies the DICOM Content Mapping Resource (DCMR), which defines specific Context Groups. These Context Groups are maintained by LEADTOOLS in an internal table. We will refer to this table as the Context Group Table. For a list of the Context Identifiers (CIDs) of these Context Groups, along with their names, refer to Context Identifier Values.

LEADTOOLS provides a number of functions for working with the Context Group Table. The LDicomContextGroup class offered these functions.

Initially, the Context Group Table is empty. Two ways are provided to add Context Groups to the table:

By loading them from the internal table into the Context Group Table. This can be done using the LDicomContextGroup::Load function.

By inserting Context Groups directly to the Context Group Table using the LDicomContextGroup::Insert function.

You can use the following functions to maneuver through the Context Groups in the Context Group Table:

LDicomContextGroup::GetFirst

LDicomContextGroup::GetLast

LDicomContextGroup::GetNext

LDicomContextGroup::GetPrev

You can also use the LDicomContextGroup::GetCount and LDicomContextGroup::FindIndex functions to enumerate the Context Groups in the Context Group Table.

Use the LDicomContextGroup::Find function to search the Context Group Table for the Context Group with a particular Context ID.

Use the LDicomContextGroup::Delete function to remove individual Context Groups from the Context Group Table, and the LDicomContextGroup::Reset function to remove all the Context Groups at once.

You can use the following functions to investigate the Coded Concepts of a Context Group:

LDicomContextGroup::GetFirstCodedConcept

LDicomContextGroup::GetLastCodedConcept

LDicomContextGroup::GetNextCodedConcept

LDicomContextGroup::GetPrevCodedConcept

LDicomContextGroup::GetCountCodedConcept

LDicomContextGroup::FindIndexCodedConcept

LDicomContextGroup::GetContextGroup

Use the LDicomContextGroup::FindCodedConcept function to search a Context Group in the Context Group Table for the Coded Concept with specific Coding Scheme Designator and Code Value.

After a Context Group has been added to the Context Group Table, you can modify the Code Meanings of its Coded Concepts, add new Coded Concepts to the Context Group, and delete existing Coded Concepts from the Context Group by using the following functions:

LDicomContextGroup::SetCodeMeaning

LDicomContextGroup::InsertCodedConcept

LDicomContextGroup::DeleteCodedConcept

If a Context Group in the Context Group Table has a corresponding Context Group in the internal table maintained by LEADTOOLS, you can use the LDicomContextGroup::Default function to discard any changes made to the Context Group in the Context Group Table.

Use the LDicomContextGroup::Exists or LDicomContextGroup::ExistsCodedConcept functions to determine whether a pointer to a Context Group structure or a Coded Concept structure is valid, respectively.