DICOM PS3.3 2017c - Information Object Definitions

C Information Module Definitions (Normative)

C.1 Elements of a Module Definition

A Module Definition is composed of the following Sections

  1. Module Description

  2. Module Definition

  3. Attribute Description (Optional)

Section C.1.1, Section C.1.2 and Section C.1.3 define the requirements of a. through c. above.

C.1.1 Module Description

This Section briefly describes the Module and references the Module Definition.

C.1.2 Module Definition

This Section contains a table that enumerates each Attribute contained in the Module. For each Attribute in the table the following information is given:

  1. Attribute Name (see Section C.1.2.1)

  2. Data Element Tag (see Section C.1.2.2)

  3. Type Designation (see Section C.1.2.3)

  4. Attribute Definition (see Section C.1.2.4)

C.1.2.1 Attribute Name

This name shall be used whenever referencing the Attribute. This name shall also identify the Attribute in PS3.6.

C.1.2.2 Attribute Tag

Each Attribute has a tag that uniquely identifies the Attribute (also used for encoding into a Data Set - see PS3.5). This tag also serves as an index into the Data Dictionary of PS3.6.

C.1.2.3 Type Designation

Each Attribute contained in a Module referenced by a Composite IOD defines a Type designation that indicates if a specific Attribute is required for all DIMSE operations/notifications associated with a SOP Class using this Module. PS3.5 defines a choice of generic Type designations available for DICOM Attributes.


The Type designation specified is generally determined by the value most appropriate for the C-STORE DIMSE Service.

The Type designation given in a Module is a default value and as such may be overridden by an IOD referencing the Module. Some Attributes may also be contained in more than one Module for the IOD. In that case, the Type designation applicable for the Attribute of the specific IOD is the lowest Type value (e.g., if type 2 is specified in one Module and type 3 in another, then type 2 shall apply), unless explicitly stated by the Attribute description.

The Type designation given in a Module (and/or IOD) may also be overridden by Service Class Definitions referencing the IOD containing the Module. PS3.4 specifies the Service Class Definitions.

Modules referenced only by Normalized IODs do not contain Type designations. Modules referenced by both Normalized IODs and Composite IODs will contain a Type designation that only applies to Composite IODs and any specific conditions for Conditional Types (type 1C and 2C) also only apply to Composite IODs.

C.1.2.4 Attribute Definition

A brief definition will be provided for each attribute in the Module definition table. The description shall provide a context for the use of the Attribute and provide general elucidation. Defined Terms and Enumerated Values applicable to the Attribute may also be listed in the Attribute Description.

C.1.3 Attribute Descriptions

Additional information may be provided if necessary for selected Attributes. Such information shall be placed following the Module definition table. Dependencies between Attributes may be specified in this Section.

DICOM PS3.3 2017c - Information Object Definitions