10.3.6 N-DELETE PROTOCOL

The information necessary for the N-DELETE request and indication DIMSE-N primitives are conveyed in the N-DELETE-RQ Message. The information necessary for the N-DELETE response and confirmation DIMSE-N primitives are conveyed in the N-DELETE-RSP Message.

10.3.6.1 N-DELETE-RQ

The N-DELETE-RQ Message contains fields as defined in Table 10.3-11. Each field shall conform to DICOM encoding and Value Representation as defined in PS 3.5. Fields are required as specified in the N-DELETE service definition unless otherwise noted in Table 10.3-11. Fields not specified in the N-DELETE service definition but present in Table 10.3-11 are required by the DIMSE-N protocol.

Table 10.3-11 N-DELETE-RQ MESSAGE FIELDS

Message Field Tag VR VM Description of Field
Command Group Length (0000,0000) UL 1 The even number of bytes from the end of the value field to the beginning of the next group.
Requested SOP Class UID (0000,0003) UI 1 SOP Class UID of the SOP Instance to be deleted.
Command Field (0000,0100) US 1 This field distinguishes the DIMSE-N operation conveyed by this Message. The value of this field shall be set to 0150H for the N-DELETE-RQ Message.
Message ID (0000,0110) US 1 Implementation-specific value which distinguishes this Message from other Messages.
Command Data Set Type (0000,0800) US 1 This field indicates that no Data Set is present in the Message. It shall be set to the value of 0101H.
Requested SOP Instance UID (0000,1001) UI 1 Contains the UID of the SOP Instance to be deleted.

10.3.6.2 N-DELETE-RSP

The N-DELETE-RSP Message contains fields as defined in Table 10.3-12 and Annex C. Each field shall conform to DICOM encoding and Value Representation as defined in PS 3.5. Fields are required as specified in the N-DELETE service definition unless otherwise noted in Table 10.3-12. Fields not specified in the N-DELETE service definition but present in Table 10.3-12 are required by the DIMSE-N protocol.

Table10.3-12 N-DELETE-RSP MESSAGE FIELDS

Message Field Tag VR VM Description of Field
Command Group Length (0000,0000) UL 1 The even number of bytes from the end of the value field to the beginning of the next group.
Affected SOP Class UID (0000,0002) UI 1 SOP Class UID of the SOP Instance which was deleted.
Command Field (0000,0100) US 1 This field distinguishes the DIMSE-N operation conveyed by this Message. The value of this field shall be set to 8150H for the N-DELETE-RSP Message.
Message ID Being Responded To (0000,0120) US 1 Shall be set to the value of the Message ID (0000,0110) field used in associated N-DELETE-RQ Message.
Command Data Set Type (0000,0800) US 1 This field indicates that no Data Set is present in the Message. This field shall be set to the value of 0101H).
Status (0000,0900) US 1 The value of this field depends upon the status type. Annex C defines the encoding of the status types defined in the service definition.
Affected SOP Instance UID (0000,1000) UI 1 Contains the UID of the SOP Instance which was deleted.

10.3.6.3 N-DELETE protocol procedures

The N-DELETE procedures are initiated by the invoking DIMSE-service-user issuing an N-DELETE request primitive. On receipt of the N-DELETE request primitive the DIMSE-N protocol machine shall:

⎯ construct a Message conveying the N-DELETE-RQ

⎯ end the Message using the P-DATA request service (See 8.1)

On receipt of a Message conveying an N-DELETE-RQ the DIMSE-N protocol machine shall issue an N-DELETE indication primitive to the performing DIMSE-service-user.

On receipt of the N-DELETE response primitive, issued by the performing DIMSE-service-user, the DIMSE-N protocol machine shall:

⎯ construct a Message conveying the N-DELETE-RSP

⎯ send the Message using the P-DATA request service (See 8.1)

On receipt of a Message conveying an N-DELETE-RSP the DIMSE-N protocol machine shall issue an N-DELETE confirmation primitive to the invoking DIMSE-service-user, thus completing the N-DELETE procedure.