9.3.3.3 User information item structure

The User Information Item shall be made of a sequence of mandatory length fields followed by a variable field. Table 9-20 shows the sequence of the mandatory fields.

The variable field shall consist of one or more User-Data Sub-Items.

Note: The User-Data Sub-Items may be present in any order within the User-Information Item. No significance should be placed on the order of User-Data Sub-Items within the User Information Item. Sending applications should be aware that some older applications might expect Sub-Items to be encoded in ascending order of Item-type within the enclosing Item.

Table 9-20 USER INFORMATION ITEM FIELDS

Item bytes Field name Description of field
1 Item-type 50H
2 Reserved This reserved field shall be sent with a value 00H but not tested to this value when received.
3-4 Item-length This Item-length shall be the number of bytes from the first byte of the following field to the last byte of the User-data-information field(s). It shall be encoded as an unsigned binary number.
5-xxx User-data This variable field shall contain User-data sub-items as defined by the DICOM Application Entity. The structure and content of these sub-items is defined in Annex D.