3 Definitions

For the purposes of this Standard the following definitions apply.

3.1 Reference Model Definitions

This Part of the Standard is based on the concepts developed in [ISO 7498-1] and [ISO 7498-2] and makes use of the following terms defined in them:

Application Entity (AE)

See [ISO 7498-1].

Service or Layer Service

See [ISO 7498-1].

3.2 Service Conventions Definitions

This Part of the Standard makes use of the following terms defined in [ISO/TR 8509]:

Primitive

See [ISO/TR 8509].

3.3 DICOM Introduction and Overview Definitions

This Part of the Standard makes use of the following terms defined in PS3.1:

Attribute

See PS3.1.

Command

See PS3.1.

Data Dictionary

See PS3.1.

Message

See PS3.1.

3.4 DICOM Service Class Specifications

This Part of the Standard makes use of the following terms defined in PS3.4:

Real-World Activity

See PS3.4.

Real-World Object

See PS3.4.

Service Class

See PS3.4.

Service Class User (SCU)

See PS3.4.

Service Class Provider (SCP)

See PS3.4.

Service-Object Pair Class (SOP Class)

See PS3.4.

Service-Object Pair Instance (SOP Instance)

See PS3.4.

Preformatted Grayscale Image

See PS3.4.

Preformatted Color Image

See PS3.4.

Related General SOP Class

See PS3.4.

3.5 DICOM Data Structures and Encoding

This Part of the Standard makes use of the following terms defined in PS3.5:

Data Element

See PS3.5.

Data Element Tag

See PS3.5.

Data Element Type

See PS3.5.

Data Set

See PS3.5.

Defined Term

See PS3.5.

Enumerated Value

See PS3.5.

Sequence of Items

See PS3.5.

Unique Identifier (UID)

See PS3.5.

3.6 DICOM Message Exchange

This Part of the Standard makes use of the following terms defined in PS3.7:

DICOM Message Service Element (DIMSE)

See PS3.7.

DIMSE-N Services

See PS3.7.

DIMSE-C Services

See PS3.7.

3.7 DICOM Upper Layer Service

This Part of the Standard makes use of the following terms defined in PS3.8:

DICOM Upper Layer Service

See PS3.8.

3.8 DICOM Information Object

Attribute tag

A unique identifier for an Attribute of an Information Object composed of an ordered pair of numbers (a Group Number followed by an Element number).

Composite IOD

an Information Object Definition that represents parts of several entities in the DICOM Application Model. Such an IOD includes Attributes that are not inherent in the Real-World Object that the IOD represents but rather are inherent in related Real-World Objects.

Derived image

an image in which the pixel data was constructed from pixel data of one or more other images (source images).

DICOM information model

an Entity-Relationship diagram that is used to model the relationships between the Information Object Definitions representing classes of Real-World Objects defined by the DICOM Application Model.

DICOM application model

an Entity-Relationship diagram used to model the relationships between Real-World Objects that are within the area of interest of the DICOM Standard.

Information entity

that portion of information defined by a Composite IOD that is related to one specific class of Real-World Object. There is a one-to-one correspondence between Information Entities and entities in the DICOM Application Model.

Information object definition (IOD)

a data abstraction of a class of similar Real-World Objects that defines the nature and Attributes relevant to the class of Real-World Objects represented.

Module

A set of Attributes within an Information Entity or Normalized IOD that are logically related to each other.

Multi-frame image

Image that contains multiple two-dimensional pixel planes.

Normalized IOD

an Information Object Definition that represents a single entity in the DICOM Application Model. Such an IOD includes Attributes that are only inherent in the Real-World Object that the IOD represents.

Cine run

A set of temporally related frames acquired at constant or variable frame rates. This term incorporates the general class of serialography.

Note

A Cine run is typically encoded as a multi-frame image.

Specialization

Specialization is the replacement of the Type, value range and/or description of an Attribute in a general Module of an IOD, by its Type, value range and/or description defined in a modality-specific Module of an IOD.

Note

The same Attribute may be present in multiple Modules in the same IOD but not specified to be "Specialized".

Functional Group

A set of logically related Attributes that are likely to vary together. May be used in Multi-frame IODs to describe parameters that change on a per frame basis.

Code Sequence Attribute

Attribute that (usually) includes the string "Code Sequence" in the Attribute Name and has a VR of SQ (Sequence of Items). Its purpose is to encode concepts using code values and optional text meanings from coding schemes. Section 8.1 through Section 8.8 specify the Attributes of which the Sequence Items (Attribute Sets) of Code Sequence Attributes are constructed.

3.9 Character Handling Definitions

This part of the standard makes use of the following terms defined in [ISO/IEC 2022]:

Coded character set; code

See [ISO/IEC 2022].

Code extension

See [ISO/IEC 2022].

Escape sequence

See [ISO/IEC 2022].

3.10 Radiotherapy

This Part of the Standard is based on the concepts developed in [IEC 61217] and makes use of the following terms defined in it:

FIXED REFERENCE system

See [IEC 61217].

GANTRY system

See [IEC 61217].

BEAM LIMITING DEVICE system

See [IEC 61217].

WEDGE FILTER system

See [IEC 61217].

X-RAY IMAGE RECEPTOR system

See [IEC 61217].

PATIENT SUPPORT system

See [IEC 61217].

TABLE TOP ECCENTRIC system

See [IEC 61217].

TABLE TOP system

See [IEC 61217].

3.11 Macros

Attribute Macro

A set of Attributes that are described in a single table that is referenced by multiple Module or other tables.

3.12 Device Independent Pixel Values

This Part of the Standard makes use of the following terms defined in PS3.14:

P-Value

The definition in PS3.14 is "A device independent value defined in a perceptually linear grayscale space. The output of the DICOM Presentation LUT is P-Values, i.e., the pixel value after all DICOM defined grayscale transformations have been applied. P-Values are the input to a Standardized Display System."

Profile Connection Space Value (PCS-Value)

A device independent color value that is created by the application of the transformation specified in an ICC profile.

3.13 Codes and Controlled Terminology Definitions

This Part of the Standard makes use of the following terms defined in PS3.16:

Baseline Context Group Identifier (BCID)

See PS3.16.

Defined Context Group Identifier (DCID)

See PS3.16.

Context Group

See PS3.16.

Context Group Version

See PS3.16.

Context ID (CID)

See PS3.16.

Mapping Resource

See PS3.16.

Relationship Type

See PS3.16.

DICOM Content Mapping Resource (DCMR)

See PS3.16.

Template

See PS3.16.

Template ID (TID)

See PS3.16.

Value Set

See PS3.16.

Baseline Template Identifier (BTID)

See PS3.16.

Defined Template Identifier (DTID)

See PS3.16.

Coding schemes

See PS3.16.

3.14 Reference Model Security Architecture Definitions

This Part of the Standard makes use of the following terms defined in [ISO 7498-2]:

Digital Signature

The definition is "Data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit to prove the source and integrity of that unit and protect against forgery e.g., by the recipient."

Data Confidentiality

The definition is "the property that information is not made available or disclosed to unauthorized individuals, entities or processes."

Data Origin Authentication

The definition is "the corroboration that the source of data received is as claimed."

Data Integrity

The definition is "the property that data has not been altered or destroyed in an unauthorized manner."

Key Management

The definition is "the generation, storage, distribution, deletion, archiving and application of keys in accordance with a security policy."

3.15 Security Definitions

This Part of the Standard makes use of the following terms defined in [ECMA 235]:

Security Context

The definition is "security information that represents, or will represent a Security Association to an initiator or acceptor that has formed, or is attempting to form such an association."

3.16 DICOM Security Profiles

This Part of the Standard makes use of the following terms defined in PS3.15:

Message Authentication Code (MAC)

See PS3.15.

Certificate

See PS3.15.

3.17 Multi-dimensional Definitions

Reference Coordinate System (RCS)

The RCS is the spatial coordinate system in a DICOM Frame of Reference. It is the chosen origin, orientation and spatial scale of an Image IE in a Cartesian space. The RCS is a right-handed Cartesian coordinate system i.e., the vector cross product of a unit vector along the positive x-axis and a unit vector along the positive y-axis is equal to a unit vector along the positive z-axis. The unit length is one millimeter. Typically, the Image IE contains a spatial mapping that specifies the relationship of the image samples to the Cartesian spatial domains of the RCS.

Fiducial

A fiducial is some unique feature or landmark suitable as a spatial reference or correlation between similar objects. The fiducial may contribute to the definition of the origin and orientation of a chosen coordinate system. Identifying fiducials in different data sets is a common means to establish the spatial relationship between similar objects.

Fiducial Point

A Fiducial Point defines a specific location of a Fiducial. A Fiducial Point is relative an image or to an RCS.

3.18 Display Equipment Definitions

Display System, as applies to emissive displays only

See “Display System” in PS3.14 .

Display Subsystem

A part of a Display System. A Display Subsystem consists of one Display Device and zero or more other devices (such as controllers). A Display System has one or more Display Subsystems.

Display Device

See [IEC 62563-1].

Note

The definition is "specific hardware/medium used to display images presented through an analogue or digital interface".

3.19 Digital Input Values To Display Systems

Digital Driving Level (DDL)

See “Digital Driving Level (DDL)” in PS3.14 .