DICOM PS3.2 2024c - Conformance

5 Conventions

5.1 Application Data Flow Diagram

In a Conformance Statement, the relationships between Real-World Activities and Application Entities are illustrated by an Application Data Flow Diagram.

5.1.1 Application Entity

An Application Entity is depicted as a box in an Application Data Flow Diagram, shown in Figure 5.1-1

Application Entity Convention

Figure 5.1-1. Application Entity Convention

5.1.2 Real-World Activity

A Real-World Activity is depicted as a circle in an Application Data Flow Diagram, shown in Figure 5.1-2.

Real-World Activity Convention

Figure 5.1-2. Real-World Activity Convention

Circles representing multiple Real-World Activities may overlap, indicating a degree of overlap in the Real-World Activities.

5.1.3 Local Relationships

A relationship between a local Real-World Activity and an Application Entity is depicted within an Application Data Flow Diagram by placing the local Real-World Activity to the left of the related Application Entity with a dashed line between them as shown in Figure 5.1-3.

Local Relationship Convention

Figure 5.1-3. Local Relationship Convention

An Application Entity may be associated with multiple Real-World Activities.

A Real-World Activity may be associated with multiple Application Entities.

5.1.4 Network-Associations

An Association between a local Application Entity and a remote Application Entity over a network supporting a remote Real-World Activity is depicted within an Application Data Flow Diagram by placing the remote Real-World Activity to the right of the related local Application Entity with one or two arrows drawn between them as shown in Figure 5.1-4. The dashed line represents the DICOM Standard Interface, which could be DICOM DIMSE, DICOM Web Services or DICOM Real-Time Video, between the local Application Entities, and whichever remote Application Entities handle the remote Real-World Activities. An arrow from the remote Real-World Activity to the local Application Entity indicates that the local Application Entity expects to receive an Association request when the remote Real-World Activity occurs, causing the local Application Entity to perform the local Real-World Activity.

Associations Convention

Figure 5.1-4. Associations Convention

5.1.5 Media Storage File-Set Access

Application Entities exchanging information on media use the DICOM File Service as specified in PS3.10 for access to, or creation of, File-sets. This File Service provides operations that support three basic roles, which are File-set Creator (FSC), File-set Reader (FSR), and File-set Updater (FSU).

These roles are depicted on an Application Data Flow diagram by directional arrows placed between the local Application Entities and the DICOM Storage Media on which the roles are applied.

  • File-set Creator (FSC), denoted by

  • File-set Reader (FSR), denoted by

  • File-set Updater (FSU), denoted by

  • Physical movement of the medium, denoted by (with or without arrowhead)

Figure 5.1-5 illustrates the three basic roles.

File-Set Access

Figure 5.1-5. File-Set Access

The local interactions shown on the left between a local Real-World activity and a local Application Entity are depicted by a dashed line. The arrows on the right represent access by the local Application Entity to a File-set on the DICOM Storage Medium. When an Application Entity supports several roles, this combination is depicted with multiple arrows corresponding to each of the roles. The dotted arrow symbolizes the removable nature of media for an interchange application.


The use of two arrows relative to an FSC and an FSR should be distinguished from the case where a double arrow relative to an FSU is used. For example, an FSU may update a File-set without creating a new File-set, whereas a combined FSC and FSR may be used to create and verify a File-set.

DICOM PS3.2 2024c - Conformance