For the purpose of accommodating large sets of frames in Multi-frame Image SOP Instances the Real-World Entity Relationship Diagram has been extended to describe the relationships of these instances: Concatenation (see Section 7.5.1) and Dimension Organization (see Section 7.5.2). Figure 7.5-1 depicts the additions to Figure 7-2a.
For implementation specific reasons (such as practical limits on the maximum size of an individual SOP Instance) the content of a multi-frame image may need to be split into more than one SOP Instance. These SOP Instances together form a Concatenation, which is a group of SOP Instances within a Series that is uniquely identified by Concatenation UID (0020,9161).
The Dimension Organization contains a set of dimensions. A dimension is a set of attributes that change on a per-frame basis in a manner that is known before the image is acquired, are defined by the generating application and are especially intended for presentation. Other attributes may also change on a per-frame basis but if they are not present in the Dimension Organization, they are not considered significant as a dimension for organizational purposes.
Receiving applications shall use the order of dimensions for guidance when presenting images if the Multi-frame Dimension Module is present. The first item of the Dimension Index Sequence shall be the slowest varying index.
Note
See Multi-frame Dimension Module section (C.7.6.17) for an example.