Материал: part05

DICOM PS3.5 2020a - Data Structures and Encoding​

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DICOM PS3.5 2020a - Data Structures and Encoding​

DICOM PS3.5 2020a - Data Structures and Encoding​

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Application Entity​

See [ISO 7498].​

OSI Presentation Protocol​

See [ISO 7498].​

Presentation Context​

See [ISO 8822].​

Presentation Data Value (PDV)​

See [ISO 8822].​

Transfer Syntax​

See [ISO 8822].​

Transfer Syntax Name​

See [ISO 8822].​

Attribute​

Attribute.​

Command Element​

Command Element.​

Data Dictionary​

Data Dictionary.​

Service-Object Pair Class (SOP​

Service-Object Pair Class (SOP Class)​

Class)​

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DICOM PS3.5 2020a - Data Structures and Encoding​

Attribute Tag​

AttributeTag.​

Information Entity​

Information Entity.​

Information Object Definition​

Information Object Definition.​

(IOD)​

Multi-frame Image​

Multi-frame Image.​

Basic Offset Table (BOT)​

A table of 32-bit pointers to individual frames of an encapsulated Multi-frame Image.​

Big Endian​

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.​

Character Repertoire​

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).​

Code String​

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.ACodeStringisformallyanarbitrarycoderepresentingasemanticconcept;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.​

Data Element​

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.​

Data Element Tag​

AuniqueidentifierforaDataElementcomposedofanorderedpairofnumbers(aGroupNumber​

followed by an Element Number).​

Data Element Type​

Used to specify whether an Attribute of an Information Object Definition or an Attribute of a SOP​

ClassDefinitionismandatory,mandatoryonlyundercertainconditions,oroptional.Thistranslates​

to whether a Data Element of a Data Set is mandatory, mandatory only under certain conditions,​

or optional.​

Data Set​

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.​

DICOM PS3.5 2020a - Data Structures and Encoding​

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Defined Term​

The Value of a Data Element is a Defined Term when the Value of the element may be one of​

anexplicitlyspecifiedsetofstandardvalues,andthesevaluesmaybeextendedbyimplementers.​

Element Number​

The second number in the ordered pair of numbers that makes up a Data Element Tag.​

Enumerated Value​

The Value of a Data Element is an Enumerated Value when the value of the element must be​

one of an explicitly specified set of standard values, and these values shall not be extended by​

implementers.​

Extended Offset Table (EOT)​

A table of 64-bit pointers to individual frames of an encapsulated Multi-frame Image.​

Group Number​

The first number in the ordered pair of numbers that makes up a Data Element Tag.​

Item​

A component of the Value of a Data Element that is of Value Representation Sequence of Items.​

An Item contains a Data Set.​

Item Delimitation Data Element​

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.​

Little Endian​

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.​

Nested Data Set​

A Data Set contained within a Data Element of another Data Set. Data Sets can be nested​

recursively.OnlyDataElementswithValueRepresentationSequenceofItemsmay,themselves,​

contain Data Sets.​

Pixel Cell​

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.​

Pixel Data​

Graphical data (e.g., images) of variable pixel-depth encoded in the Pixel Data, Float Pixel Data​

or Double Float Pixel Data Element.​

Pixel Sample Value​

A value associated with an individual pixel. An individual pixel consists of one or more Pixel​

Sample Values (e.g., color images).​

Private Data Element​

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.​

Repeating Group​

Standard Data Elements within a particular range of Group Numbers where elements that have​

identical Element Numbers have the same meaning within each Group (and the same VR, VM,​

andDataElementType).RepeatingGroupsshallonlyexistforCurvesandOverlayPlanes(Group​

Numbers (50xx,eeee) and (60xx,eeee), respectively) and are a remnant of older versions of this​

Standard.​

Retired Data Element​

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.​

Sequence Delimitation Item​

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.​

Sequence of Items​

A Value Representation for Data Elements that contain a sequence of Data Sets. Sequence of​

Items allows for Nested Data Sets.​

Standard Data Element​

ADataElementdefinedintheDICOMStandard,andthereforelistedintheDICOMDataElement​

Dictionary in PS3.6.​

DICOM Transfer Syntax​

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.​