Hi all,

I need your valuable suggestion on what value type to be used for a "KOS" and "SR" objects referenced inside another "KOS" object.

Sceanrio:
We have a PACS system, in which while signing off a study we create Key Object Selection Document IOD, which will have references of all the SOP instances which were part of the study while signing off.
Example: consider a CT study which has 5 images,1 SR report, 2 Key Image Note titles(KOS objects).While signing off this study we create a new custom KOS object called "signoff KO" which will have references of the SOP instances of 5 images, 1 SR instances and 2 KOS instances(which were created for KIN titles).

We referred “ Table C.17.3-7 for Value Type definitions” in Dicom part 3 and understood that, While referencing the sop instances inside a KO, for images we need to use "IMAGE" as value type.

Question:But It is not clear what should be the value type for SR instances and KO instances when they are referenced inside another KOS object. should we use "Composite" or "Containers" as value type?

In Table C.17.3-7. Value Type Definitions, in dicom part3, following is the definition given

Value type: COMPOSITE:
Concept Name: Purpose of Reference:
Concept Value: Reference to UIDs of Composite SOP Instances:
Description: A reference to one Composite SOP Instance that is not an Image or Waveform.

Value type: CONTAINER
Concept Name: Document Title or document section heading. Concept Name conveys the Document Title (if the CONTAINER is the Document Root Content Item) or the category of observation.
Concept Value: The content of the CONTAINER. The value of a CONTAINER Content Item is the collection of Content Items that it contains
Description: CONTAINER groups Content Items and defines the heading or category of observation that applies to that content. The heading describes the content of the CONTAINER Content Item and may map to a document section heading in a printed or displayed document.

In my opinion since we are referencing the SR,KOS objects inside another KOS object we should consider the Concept name "Purpose of Reference" and use value type as "COMPOSITE".
We request experts to clarify us on this

Hi,

> In my opinion since we are referencing the SR,KOS objects inside another KOS object we should consider the Concept name "Purpose of Reference" and use value type as "COMPOSITE".
> We request experts to clarify us on this

I don't know what you mean by "referencing ... _inside_ a KOS object", but there are three types of Content Items that can be used for referencing other DICOM SOP Instances from the document tree of an SR / KOS document: IMAGE, WAVEFORM and COMPOSITE. IMAGE is for DICOM images (IODs trhat include the Image IE), WAVEFORM for DICOM waveform objects (IODs that include the Waveform IE) and COMPOSITE for all other types of DICOM IODs / SOP Classes, including other SR and KOS documents. However, as you can read in PS3.16 TID 2010, the "Purpose of reference shall not be present" for these Content Items (Row 8, 9 and 10 of TID 2010).

> We referred “ Table C.17.3-7 for Value Type definitions” in Dicom part 3 and understood that, While referencing the sop instances inside a KO, for images we need to use "IMAGE" as value type.

No, IMAGE is only for referencing DICOM images (see above). And, by the way, the Value Type CONTAINER is for something completely different: for grouping child Content Items, not for referencing other DICOM SOP Instances.

Regards,
Jörg

Thank you Jörg, This helps