C.5.1 Association Negotiation for C-FIND SOP Classes

The following negotiation rules apply to DICOM SOP Classes and Specialized DICOM SOP Classes of the Query/Retrieve Service Class which include the C-FIND operation.

The Association-requester (query SCU role) shall convey in the A-ASSOCIATE request:

The Association-acceptor (query SCP role) of an A-ASSOCIATE request shall accept:

C.5.1.1 SOP Class Extended Negotiation

The SOP Class Extended Negotiation allows, at Association establishment, peer DICOM AEs to exchange application Association information defined by specific SOP Classes. This is achieved by defining the Service-class-application-information field. The Service-class-application-information field is used to define support for relational-queries, combined date time matching, and fuzzy semantic matching of person names.

This negotiation is optional. If absent, the default conditions shall be:

The Association-requester, for each SOP Class, may use one SOP Class Extended Negotiation Sub-Item. The SOP Class is identified by the corresponding Abstract Syntax Name (as defined by PS 3.7) followed by the Service-class-application-information field. This field defines either a single sub-field:

or three sub-fields:

The Association-acceptor shall return a single byte field (single sub-field) if offered a single byte field (single sub-field) by the Association-requester. The Association-acceptor may return either a single byte field (single sub-field) or a three byte field (three sub-fields) if offered a three byte field (three sub-fields) by the Association-requester. A one byte response to a three byte request means that the missing sub-fields shall be treated as 0 values.

The Association-acceptor, for each sub-field of the SOP Class Extended Negotiation Sub-Item offered, either accepts the Association-requester proposal by returning the same value (1) or turns down the proposal by returning the value (0)

If the SOP Class Extended Negotiation Sub-Item is not returned by the Association-acceptor then relational-queries are not supported over the Association (default condition).

If the SOP Class Extended Negotiation Sub-Items do not exist in the A-ASSOCIATE indication they shall be omitted in the A-ASSOCIATE response.

C.5.1.1.1 SOP Class Extended Negotiation Sub-Item Structure (A-ASSOCIATE-RQ)

The SOP Class Extended Negotiation Sub-Item consists of a sequence of mandatory fields as defined by PS 3.7. Table C.5-1 defines the Service-class-application-information field for DICOM Query/Retrieve SOP Classes and Specialized DICOM Query/Retrieve SOP Classes which include the C-FIND operation. This field may be either one or three bytes in length (i.e., item bytes 2 and 3 are optional).

Table C.5-1— SOP CLASS EXTENDED NEGOTIATION SUB-ITEM (service-class-application-information field)—A-ASSOCIATE-RQ

Item Bytes Field Name Description of Field
1 Relational-queries This byte field defines relational-query support by the Association-requester. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – relational queries not supported 1 – relational queries supported
2 Date-time matching This byte field defines whether or not combined date and time attribute range matching is requested by the Association-requester. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – combined matching not requested 1 – combined matching requested
3 Fuzzy semantic matching of person names This byte field defines whether or not fuzzy semantic person name attribute matching is requested by the Association-requester. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – fuzzy semantic matching not requested 1 – fuzzy semantic matching requested
4 Timezone query adjustment This byte field defines whether or not the Attribute Timezone Offset From UTC (0008,0201) shall be used to adjust the query meaning for time and datetime fields in queries. 0 - Timezone query adjustment not requested 1 – Timezone query adjustment requested

C.5.1.1.2 SOP Class Extended Negotiation Sub-Item Structure (A-ASSOCIATE-AC)

The SOP Class Extended Negotiation Sub-Item is made of a sequence of mandatory fields as defined by PS 3.7. Table C.5-2 defines the Service-class-application-information field for DICOM Query/Retrieve SOP Classes and Specialized DICOM Query/Retrieve SOP Classes which include the C-FIND operation. This field may be either one or three bytes in length (i.e., item bytes 2 and 3 are optional).

Table C.5-2—SOP CLASS EXTENDED NEGOTIATION SUB-ITEM(service-class-application-information field)—A-ASSOCIATE-AC

Item Bytes Field Name Description of Field
1 Relational-queries This byte field defines relational-query support for the Association-acceptor. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – relational-queries not supported 1 – relational-queries supported
2 Date-time matching This byte field defines whether or not combined date and time attribute range matching will be performed by the Association-acceptor. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – combined matching not performed 1 – combined matching performed
3 Fuzzy semantic matching of person names This byte field defines whether or not fuzzy semantic person name attribute matching will be performed by the Association-acceptor. It shall be encoded as an unsigned binary integer and shall use one of the following values 0 – fuzzy semantic matching not performed 1 – fuzzy semantic matching performed
4 Timezone query adjustment This byte field defines whether or not the Attribute Timezone Offset From UTC (0008,0201) shall be used to adjust the query meaning for time and datetime fields in queries. 0 – Timezone adjustment of queries not performed 1 – Timezone adjustment of queries performed