pynetdicom.pdu_items.AbstractSyntaxSubItem

class pynetdicom.pdu_items.AbstractSyntaxSubItem[source]

An Abstract Syntax Sub-item.

An Abstract Syntax is the specification of data elements with associated semantics. In particular it allows communicating Application Entities to negotiate an agreed set of DICOM Data Elements and/or Information Object Class definitions.

Notes

An Abstract Syntax Sub-item requires the following parameters:

  • Item type (1, fixed value, 0x30)

  • Item length (1)

  • Abstract syntax name (1)

Abstract Syntax Names

Abstract Syntax Names are OSI Object Identifiers in a numeric form as defined by ISO 8824. They may be either DICOM registered or privately defined. They’re encoded as an ISO 646:1990-Basic G0 Set Numeric String of bytes (characters 0-9), separated by the character . (0x2e) and shall not exceed 64 total characters. No separator or padding shall be present before the first digit of the first component or after the last digit of the last component.

Encoding

When encoded, an Abstract Syntax Item has the following structure, taken from Part 8, Table 9-14 of the DICOM Standard (offsets shown with Python indexing). Items are always encoded using Big Endian. Encoding of the Abstract Syntax Name parameter follows the rules in Part 8, Annex F.

Offset

Length

Description

0

1

Item type

1

1

Reserved

2

2

Item length

4

Variable

Abstract syntax name

References

__init__() → None[source]

Initialise a new Abstract Syntax Item.

Methods

__init__()

Initialise a new Abstract Syntax Item.

decode(bytestream)

Decode bytestream and use the result to set the field values of the PDU item.

encode()

Return the encoded PDU as bytes.

Attributes

abstract_syntax

Return the item's Abstract Syntax Name field value.

abstract_syntax_name

Return the item's Abstract Syntax Name field value.

item_length

Return the item's Item Length field value as int.

item_type

Return the item's Item Type field value as int.
property abstract_syntax: Optional[UID]

Return the item’s Abstract Syntax Name field value.

property abstract_syntax_name: Optional[UID]

Return the item’s Abstract Syntax Name field value.

property item_length: int

Return the item’s Item Length field value as int.