Материал: part03

A Composite Information Object Definitions​ (Normative)​

A.1 Elements of An Information Object Definition​

Each Composite Information Object Definition is composed of the following Sections​

a.​IOD Description​

b.​IOD Entity-Relationship Model​

c.​IOD Module Table​

d.​Optionally, a Functional Group Macros Table used by the Multi-frame Functional Groups Module​

Section A.1.1, Section A.1.2 and Section A.1.3 define the requirements of a) through d) above.​

A.1.1 IOD Description​

This Section provides a brief description of the IOD. Specifically, this description includes:​

•​The Real-World Object that is represented by the IOD​

•​Information as to the scope of the represented object if appropriate​

A.1.2 IOD Entity-Relationship Model​

This Section of an IOD provides the Entity-Relationship (E-R) Model that depicts the relationships of the components or Information​ Entities (IE) of the specified IOD. It forms an IOD specific information model. This E-R model provides the complete context of how​ the Composite Instance information shall be interpreted when a Composite Instance is exchanged between two DICOM Application​ Entities; in particular, an IOD will specify a single IE at the level below the Series IE.​

EventhoughCompositeInstancesareencodedasdiscreteindividualcomponents,eachCompositeInstanceIODE-RModelrequires​ that all Composite Instances that are part of a specific Study shall share the same context. That is, all Composite Instances within a​ specific Patient Study share the same Patient and Study information; all Composite Instances within the same Series share the same​ Series information; etc.​

Figure A.1-1 is the DICOM Composite Instance IOD Information Model. It applies to all Patient-related Composite Instance IODs​ definedinAnnexA.However,asubsetofthismodelmaybespecifiedbyeachindividualCompositeInstanceIODtoaccuratelydefine​ the context for specific Composite Instance exchange.​

The sub-sections of this Section describe the Information Entities (IE) that comprise the Composite Instance IODs defined in this​ Annex.​

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Patient

1 is the subject of

Figure A.1-1. DICOM Composite Instance IOD Information Model​

A.1.2.1 Patient IE​

The Patient IE defines the characteristics of a Patient who is the subject of one or more medical Studies.​

Note​

A Patient may be a human or an animal.​

The Patient IE is modality independent.​

A.1.2.2 Study IE​

The Study IE defines the characteristics of a medical Study performed on a Patient. A Study is a collection of one or more Series of​ medical images, presentation states, and/or SR documents that are logically related for the purpose of diagnosing a Patient. Each​ Study is associated with exactly one Patient.​

A Study may includeComposite Instances that are created by asingle modality,multiplemodalities or bymultiple devicesofthe same​ modality.​

The Study IE is modality independent.​

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A.1.2.3 Series IE​

The Series IE defines the Attributes that are used to group Composite Instances into distinct logical sets. Each Series is associated​ with exactly one Study.​

The following criteria group Composite Instances into a specific Series:​

a.​All Composite Instances within a Series must be of the same modality​

b.​Each Series may be associated with exactly one Frame of Reference IE, and if so associated all Composite Instances within the​ Series shall be spatially or temporally related to each other​

c.​All Composite Instances within the Series shall be created by the same equipment; therefore, each Series is associated with​ exactly one Equipment IE​

d.​All Composite Instances within a Series shall have the same Series information​

Presentation States shall be grouped into Series without Images (i.e., in a different Series from the Series containing the Images to​ which they refer).​

Note​

TheSeriescontainingGrayscale,ColorandPseudo-ColorSoftcopyPresentationStatesandtheSeriescontainingtheImages​ to which they refer are both contained within the same Study, except for Blended Presentation States, which may refer to​ images from different Studies.​

Waveforms shall be grouped into Series without Images. A Frame of Reference IE may apply to both Waveform Series and Image​ Series.​

SR Documents shall be grouped into Series without Images. The Frame of Reference IE may apply to SR Document Series, for SR​ Documentsthatcontain3DspatialcoordinatesrelativetooneormorespatialFramesofReference,ortemporalcoordinatesthatrequire​ a temporal Frame of Reference.​

A.1.2.4 Equipment IE​

The Equipment IE describes the particular device that produced the Series of Composite Instances. A device may produce one or​ more Series within a Study. The Equipment IE does not describe the data acquisition or image creation Attributes used to generate​ the Composite Instances within a Series. These Attributes are described in the Composite Instance specific IEs (e.g., the Image IE).​

A.1.2.5 Frame of Reference IE​

The Frame of Reference IE identifies the coordinate system that conveys spatial and/or temporal information of Composite Instances​

in a Series.​

When present, a Frame of Reference IE may be related to one or more Series. In this case, it provides the ability to spatially or tem-​ porally relate multiple Series to each other. In such cases, the Series may share the UID of the Frame of Reference, or alternatively,​ a Registration SOP Instance may specify the spatial relationship explicitly, as a spatial transformation. A Frame of Reference IE may​ also spatially register a Frame of Reference to an atlas.​

A.1.2.6 Image IE​

The Image IE defines the Attributes that describe the pixel data of an image. The pixel data may be generated as a direct result of​ Patient scanning (termed an Original Image) or the pixel data may be derived from the pixel data of one or more other images (termed​ a Derived Image). An image is defined by its image plane, pixel data characteristics, gray scale and/or color mapping characteristics​ and modality specific characteristics (acquisition parameters and image creation information).​

An image is related to a single Series within a single Study.​

The pixel data within an Image IE may be represented as a single frame of pixels or as multiple frames of pixel data. The frames of​ a Multi-frame image (a cine run or the slices of a volume) are sequentially ordered and share a number of common properties. A few​

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Attributes may vary between frames (e.g., Time, Angular Displacement, Slice Increment). All common Image IE Attributes refer to​ the first frame of a multiple frame image.​

Overlay, Modality and Value of Interest Lookup Table and Real World Value Mapping data may be included within an Image IE only​ if this information is directly associated with the image.​

A.1.2.6.1 Overlay Data​

Overlay data represents graphics or text in a bit-map format, and is used to indicate such items as region of interest, reference marks​ and annotations.​

A.1.2.6.2 Modality LUT Data​

Modality LUT data describes the transformation of manufacturer dependent pixel values into pixel values that are manufacturer inde-​ pendent(e.g.,HounsfieldunitsforCT,OpticalDensityforfilmdigitizers,etc.).Thetransformationmaybelinear,describedbyRescale​ Slope and Rescale Intercept, or non-linear, described by a Lookup Table (LUT).​

A.1.2.6.3 Value of Interest LUT Data​

The Value of Interest (VOI) LUT data describes the transformation of the modality pixel values into pixel values that are meaningful​ for print, display, etc. This transformation is applied after any Modality LUT. The transformation may be linear, described by Window​ Center and Window Width, or non-linear, described by a Lookup Table. A non-linear interpretation of Window Center and Window​ Width may be defined by VOI LUT Function.​

A.1.2.6.4 Real World Value Mapping Data​

The Real World Value Mapping data describes the transformation of the image pixel values into real world values in defined units.​ There may be multiple transformations, each scoped by a range of input pixel values. Each transformation may be linear, described​ by Slope and Intercept, or non-linear, described by a Lookup Table.​

A.1.2.7 Overlay IE​

Retired. See PS3.3-2016a.​

Note​

Overlays were previously modeled as independent Information Entities; in the current model they are considered Attributes​ within the Image IE or Presentation State IE. See A.1.2.6.1.​

A.1.2.8 Curve IE​

Retired. See PS3.3-2004.​

A.1.2.9 Modality LUT IE​

Retired. See PS3.3-2016a.​

Note​

Modality LUTs were previously modeled as independent Information Entities; in the current model they are considered At-​ tributes within the Image IE or Presentation State IE. See A.1.2.6.2.​

A.1.2.10 VOI LUT IE​

Retired. See PS3.3-2016a.​

Note​

VOI LUTs were previously modeled as independent Information Entities; in the current model they are considered Attributes​ within the Image IE or Presentation State IE. See A.1.2.6.3.​

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A.1.2.11 Presentation State IE​

The Presentation State IE defines how a referenced image (or images) will be presented (e.g., displayed) in a device independent​ grayscale space (i.e., in P-Values) or color space (i.e., in PCS-values), and what graphical annotations and spatial and grayscale​ contrast transformations will be applied to the referenced image pixel data.​

Overlay, Modality LUT, and VOI LUT data (see A.1.2.6.1, A.1.2.6.2, and A.1.2.6.3) may be included within a Presentation State IE if​ this information is to be applied to the referenced image(s).​

A.1.2.12 Waveform IE​

The Waveform IE represents a multi-channel time-based digitized waveform. The waveform consists of measurements of some​ physical qualities (e.g., electrical voltage, pressure, gas concentration, or sound), sampled at constant time intervals. The measured​ qualities may originate, for example, in any of the following sources:​

a.​the anatomy of the Patient,​

b.​therapeutic equipment (e.g., a cardiac pacing signal or a radio frequency ablation signal),​

c.​equipment for diagnostic synchronization (e.g., a clock or timing signal used between distinct devices),​

d.​the physician's voice (e.g., a dictated report).​

The sample data within a Waveform IE may represent one or more acquired channels. Several signal channels acquired at the same​ sampling rate can be multiplexed (by interleaving samples) in a single multiplex group. (see also Annex C “Waveforms (Informative)”​ in PS3.17.)​

A.1.2.13 SR Document IE​

The SR Document IE defines the Attributes that describe the content of an SR Document. These include semantic context as well​ as Attributes related to document completion, verification and other characteristics. An SR Document SOP Instance is related to a​ single Series within a single Study.​

A.1.2.14 Spectroscopy IE​

The Spectroscopy IE defines the Attributes that describe the data of a spectroscopy acquisition created by a magnetic resonance​ spectroscopy device.​

A.1.2.15 Raw Data IE​

The Raw Data IE defines the Attributes that describe a collection of data that may be used for further processing to produce image​ data or other data.​

Note​

For example, raw data may be used with CT and MR systems to reconstruct sets of images or for MR to reconstruct spec-​ troscopic data. The format of the raw data is vendor specific.​

A.1.2.16 Encapsulated Document IE​

The Encapsulated Document IE defines the Attributes that describe the content of a non-DICOM formatted document that is encap-​ sulated in a DICOM Attribute. These include Attributes related to document origin, title, and other characteristics. An Encapsulated​ Document SOP Instance is related to a single Series within a single Study.​

A.1.2.17 Real World Value Mapping IE​

The Real World Value Mapping IE defines the Attributes that describe the mapping of stored pixel data to Real World values (see​ A.1.2.6.4).​

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