A Composite Instance is the official DICOM term for a persistent storable object. Whilst most composite instances are Images (with pixel data), DICOM has plenty of other Composite Instance types, such as:
Structured Reports Key Image Notes Presentation States Radiotherapy Objects Every object in DICOM, whether a permanent Composite Instance or merely a transient Normalised Object as used in Printing has a unique UID called its Instance UID. This is different from the SOP class UID which is shared with all other objects of the same type.
We provide several free services to help those developing DICOM & XDS applications, whether they use our tool kits or not.
Free UID All those who create or modify DICOM instances (including technically those applying lossy compression) must have a unique root UID - we have provided free UIDs for nearly 20 years, and are happy to continue doing so - go to the Free UID page to request a UID.
One of the irritating features of DICOM for small and medium scale developers is the need to obtain an official UID prefix to use for both software implementations and for images and related objects. Although mechanisms do exist to obtain such a prefix, they vary widely in availability, complexity and cost from one country to another, with the result that many developers have resorted to distinctly non-unique prefixes such as “999.
ImplementationUID and ImplementationName
The Implementation Identification information allows implementations of communicating AEs to identify each other at Association establishment time. It is intended to provide non-ambiguous version identification in the event of communication problems encountered between two nodes. This information only relates to the software on the machine, not the machine itself, so it is perfectly permission and normal for multiple pieces of equipment to have the same values.
Every object in DICOM, whether a permanent Composite Object or merely a transient Normalised Object as used in Printing has a unique UID called its Instance UID. This is different from the SOP class UID which is shared with all other objects of the same type.
The Well-Known UIDs are Static Instance UID mostly used in normalised operations. The following is a list of all UIDs in DICOM
Instance StorageCommitmentPush 1.2.840.10008.1.20.1.1 Instance StorageCommitmentPull 1.2.840.10008.1.20.2.1 Instance Printer 1.2.840.10008.5.1.1.17 Instance PrinterConfigurationRetrieval 1.2.840.10008.5.1.1.17.376 Instance PrintQueue 1.2.840.10008.5.1.1.25 Of these, only Instance StorageCommitmentPush and Instance Printer are commonly used.