| DICOM PS3.5 2024e - Data Structures and Encoding |
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For the purposes of this Standard, the following definitions apply.
This Part of the Standard makes use of the following terms defined in [ISO 7498]:
See [ISO 7498].
See [ISO 7498].
This Part of the Standard makes use of the following terms defined in [ISO 8649]:
See [ISO 8649].
This Part of the Standard makes use of the following terms defined in [ISO 8822]:
See [ISO 8822].
See [ISO 8822].
See [ISO 8822].
See [ISO 8822].
This Part of the Standard makes use of the following terms defined in [ISO/IEC 8824]:
See [ISO/IEC 8824].
This Part of the Standard makes use of the following terms defined in PS3.1:
This Part of the Standard makes use of the following terms defined in PS3.2:
This Part of the Standard makes use of the following terms defined in PS3.3:
This Part of the Standard makes use of the following terms defined in PS3.4:
This Part of the Standard makes use of the following terms defined in PS3.8:
The following definitions are commonly used in this Standard:
A table of 32-bit pointers to individual Frames of an encapsulated Multi-frame Image.
A form of byte ordering where multiple byte binary values are encoded with the most significant byte encoded first, and the remaining bytes encoded in decreasing order of significance.
A finite set of different characters that is considered to be complete for a given purpose and is specified independently of their encoding (also referred to as a character set).
A string of characters identifying a controlled concept, including Defined Terms and Enumerated Values when represented as character strings. The scope of the controlled concept is limited to the Attribute for which the string provides the Value; i.e., the Attribute defines the allowed set of Values for the Code String, and a particular string may have different meanings in different Attributes. A Code String is formally an arbitrary code representing a semantic concept; however, English language words (using the constrained character set of the CS Value Representation) are often used as codes for the semantics of those words.
A unit of information as defined by a single entry in the data dictionary. An encoded Information Object Definition (IOD) Attribute that is composed of, at a minimum, three fields: a Data Element Tag, a Value Length, and a Value Field. For some specific Transfer Syntaxes, a Data Element also contains a VR Field where the Value Representation of that Data Element is specified explicitly.
A unique identifier for a Data Element composed of an ordered pair of numbers (a Group Number followed by an Element Number).
The field within a Data Element structure that contains the Data Element Tag.
Used to specify whether an Attribute of an Information Object Definition or an Attribute of a SOP Class Definition is mandatory, mandatory only under certain conditions, or optional. This translates to whether a Data Element of a Data Set is mandatory, mandatory only under certain conditions, or optional.
Exchanged information consisting of a structured set of Attribute values directly or indirectly related to Information Objects. The value of each Attribute in a Data Set is expressed as a Data Element. A collection of Data Elements ordered by increasing Data Element Tag number that is an encoding of the values of Attributes of a real world object.
The Basic G0 Set of the International Reference Version of [ISO 646] (ISO-IR 6) used as the default repertoire for character strings in DICOM.
The Value of a Data Element is a Defined Term when the Value of the Data Element may be one of an explicitly specified set of standard Values, and these Values may be extended by implementers.
The second number in the ordered pair of numbers that makes up a Data Element Tag.
The Pixel Data Stream is encoded in a form wherein Fragments are contained within Item Tags within the Pixel Data (7FE0,0010) Data Element, usually used for compressed data.
The Value of a Data Element is an Enumerated Value when the Value of the Data Element must be one of an explicitly specified set of standard Values, and these Values shall not be extended by implementers.
An encoding of a Data Element structure where the Value Representation of that Data Element is specified explicitly in the Value Representation Field.
A table of 64-bit pointers to individual Frames of an encapsulated Multi-frame Image.
One part or all of a Pixel Data Stream encoded within Encapsulated Pixel Data.
A Transfer Syntax that allows the Encapsulated Format Pixel Data Stream to be split into one or more Fragments.
The first number in the ordered pair of numbers that makes up a Data Element Tag.
An encoding of a Data Element structure where the Value Representation of that Data Element is specified implicitly, i.e. not in the Value Representation Field. This encoding is used for the DICOM Default Little Endian Transfer Syntax (see Section 10.1).
A component of the Value of a Data Element that is of Value Representation Sequence of Items. An Item contains a Data Set.
Used to mark the end of an Item of Undefined Length in a Sequence of Items. This is the last Data Element in an Item of Undefined Length.
A form of byte ordering where multiple byte binary values are encoded with the least significant byte encoded first; and the remaining bytes encoded in increasing order of significance.
The Pixel Data Stream is encoded in an uncompressed form and occupies the entire Value of the Pixel Data (7FE0,0010) Data Element.
A Data Set contained within a Data Element of another Data Set. Data Sets can be nested recursively. Only Data Elements with Value Representation Sequence of Items may, themselves, contain Data Sets.
A Transfer Syntax that requires the entire Encapsulated Format Pixel Data Stream be encoded in a single Fragment.
The container for a single Pixel Sample Value that may include unused bits. The size of a Pixel Cell shall be specified by the Bits Allocated (0028, 0100) Data Element.
Graphical data (e.g., images) of variable pixel-depth encoded in the Pixel Data, Float Pixel Data or Double Float Pixel Data Element.
The compressed or uncompressed octet-stream that constitutes the Pixel Data itself, without any DICOM-specific encapsulation structures.
A value associated with an individual pixel. An individual pixel consists of one or more Pixel Sample Values (e.g., color images).
Additional Data Element, defined by an implementer, to communicate information that is not contained in Standard Data Elements. Private Data Elements have odd Group Numbers.
Standard Data Elements within a particular range of Group Numbers where Data Elements that have identical Element Numbers have the same meaning within each Group (and the same VR, VM, and Data Element Type). Repeating Groups shall only exist for Overlay Planes (Group Numbers 60xx) and are a remnant of older versions of this Standard.
Repeating Groups were also used for Curves that were previously defined but have been retired. See PS3.5-2004.
A Data Element that is unsupported beginning with the current Standard. Implementations may continue to support Retired Data Elements for the purpose of backward compatibility, but this is not a requirement of the current Standard.
Item used to mark the end of a Sequence of Items of Undefined Length. This Item is the last Item in a Sequence of Items of Undefined Length.
A Value Representation for Data Elements that contain a sequence of Data Sets. Sequence of Items allows for Nested Data Sets.
A Data Element defined in the DICOM Standard, and therefore listed in the DICOM Data Element Dictionary in PS3.6.
A set of encoding rules that allow DICOM Application Entities to unambiguously negotiate the encoding techniques (e.g., Data Element structure, byte ordering, compression) they are able to support, thereby allowing these Application Entities to communicate. See also Transfer Syntax.
The ability to specify an unknown length for a Data Element Value (of Value Representation SQ, UN, OW, or OB) or Item. Data Elements and Items of Undefined Length are delimited with Sequence Delimitation Items and Item Delimitation Data Elements, respectively.
A string of characters used to provide global unique identification of a wide variety of items, guaranteeing uniqueness across multiple countries, sites, vendors and equipment. It uses the structure defined by [ISO/IEC 8824] for OSI Object Identifiers.
A component of a Value Field. A Value Field may consist of one or more of these components.
The field within a Data Element structure that contains the Value(s) of that Data Element.
The field within a Data Element structure that contains the Value Length.
Specifies the number of Values contained in the Value Field of a Data Element.
Specifies the data type and format of the Value(s) contained in the Value Field of a Data Element.
The field where the Value Representation of a Data Element is stored in the encoding of a Data Element structure with Explicit VR.
This Part of the Standard makes use of the following terms defined in [ISO/IEC 2022]
See [ISO/IEC 2022].
See [ISO/IEC 2022].
See [ISO/IEC 2022].
See [ISO/IEC 2022].
See [ISO/IEC 2022].
See [ISO/IEC 2022].
See [ISO/IEC 2022].
| DICOM PS3.5 2024e - Data Structures and Encoding |
|---|