Материал: part03

- Standard -​

C.8.24.3.1 Pixel Representation​

Pixel Representation (0028,0103) is specified to be Type 1 with the constraint that VR for all the pixel data will always be unsigned​ (US) and not signed (SS).​

Enumerated Values:​

0000H​unsigned integer​

Note​

Thereal-worldvaluesthatareinherentlysigned(e.g.,FlowVelocity,TissueVelocity,Variance)arerepresentedasunsigned,​ unitless pixel values and may be mapped to signed real-world quantities via the Real World Value Mapping Macro.​

C.8.24.3.2 Image Type​

C.8.24.3.2.1 Pixel Data Characteristics​

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.1. No additional requirements or​ Enumerated Values.​

C.8.24.3.2.2 Patient Examination Characteristics​

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.2. No additional requirements or​ Enumerated Values.​

C.8.24.3.2.3 Image Flavor​

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.3. No additional requirements or​ Defined Terms.​

C.8.24.3.2.4 Derived Pixel Contrast​

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in Section C.8.16.1.4. No additional requirements or​ Defined Terms.​

C.8.24.3.3 Dimension Organization Type​

Dimension Organization Type (0020,9311) specifies the general structure of the image. The concept of "multi-frame dimensions" as​ specifiedbytheDimensionIndexSequence(0020,9222)andper-frameDimensionIndexValues(0020,9157)shallbeusedtospecify​ the relationships of frames within that general structure.​

If Dimension Organization Type (0020,9311) has values of 3D or 3D_TEMPORAL, then the Dimension Index Sequence (0020,9222)​ shall have exactly three Items, with the dimension values described in Table C.8.24.3.3-1.​

Table C.8.24.3.3-1. Dimension Definition for US Acquisition 3D Images​

- Standard -​

The Dimension Index Values (0020,9157) corresponding to these dimension variables positively associate frames with different Data​ Type values at the same spatial and temporal position. Figure C.8.24.3.3-1 illustrates the use of Dimensions to associate frames with​ temporal, spatial, and Data Type dimensions.​

These Dimension values shall be used even if there is only one possible value for a Dimension.​

Note​

For example, if Dimension Organization Type (0020,9311) has the value 3D, the temporal position dimension is present and​ the dimension index of the temporal Attribute is the same in every frame of the image. Similarly, if the Data Type Attribute​ isintheSharedFunctionalGroupandallframesintheobjectareofDataTypeTISSUE_INTENSITY,theDataTypedimension​ is present and the dimension index of the Data Type dimension is the same in every frame of the image.​

Each plane in the volume consists of one or more frames each with a distinct value of Data Type (0018,9808). Adjacent planes in the​ volume shall be equally spaced in the Z direction.​

Each frame comprising a volume shall have the same value of the temporal dimension Attribute. Any appropriate physiological event​ temporal Attribute may be used to specify the temporal position. If there is no specific physiological event to which the temporal pos-​ ition of frames is referenced, then Temporal Position Time Offset (0020,930D) in the Temporal Position Sequence (0020,9310) may​ beusedasthetemporaldimensionAttribute.Ifallframesareatthesametemporalposition,anytemporalAttributemaybereferenced.​

Note​

For example, the Attribute specifying temporal position of frames may be any appropriate temporal Attribute, such as Nom-​ inalCardiacTriggerDelayTime(0020,9153)orNominalPercentageofCardiacPhase(0020,9241)intheCardiacSynchron-​ ization Sequence (0018,9118) if the temporal position of frames is referenced to the cardiac R-wave, or Nominal Respiratory​ TriggerDelayTime(0020,9255)orNominalPercentageofRespiratoryPhase(0020,9245)intheRespiratorySynchronization​ Sequence (0020,9253) if the temporal position of frames is referenced to the latest inspiration maximum.​

- Standard -​

Figure C.8.24.3.3-1. Dimension Organization Type Frame Relationships​

C.8.24.3.4 Transducer Description​

Thefollowingelementstogetherdescribethetypeoftransducerusedtoacquiretheimage.Thesearecharacteristicsofthetransducer​ itself rather than its specific use in the acquisition of this image. In other words, these Attribute values are determined from the con-​ struction and design of the transducer and a given transducer generally has the same values of these Attributes in every image it is​ used to create.​

•​Transducer Scan Pattern Code Sequence (0018,9809)​

The shape of the acoustic scan field the transducer is capable of.​

•​Transducer Geometry Code Sequence (0018,980D)​

The physical scan aperture from which acoustic pulses are emitted and received.​

•​Transducer Beam Steering Code Sequence (0018,980E)​

The method used to steer acoustic beam.​

•​Transducer Application Code Sequence (0018,980F)​

The placement on the subject for which the transducer is designed.​

EachprobemodelhasauniquesetofvaluesoftheseAttributes.Forexample,thesesampleprobeshavethefollowingcharacteristics,​ which are encoded in the Attributes above:​

Table C.8.24.3.4-1. Sample Transducer Characteristics​

- Standard -​

See Section C.8.5.6.1.25​

C.8.24.5 Excluded Intervals Module​

The Excluded Intervals Module indicates those periods within Acquisition Duration (0018,9073) during which no volume acquisition​ takes place. It provides information not available at the frame level or image level, since individual frames of the volume may have​ been built-up over a time period within which some intervals were excluded from acquisition. Further, it provides information that is​ not specific to associated waveform objects since the fact that volume acquisition was excluded during these intervals is a character-​ istic of the volume, not the associated waveform(s), see Figure C.8.24.5-1. Table C.8.24.5-1 specifies the Attributes of the Excluded​ Intervals Module.​

Note​

For example, if the imaging device performing a gated volume acquisition excludes volume data acquired during an ectopic​ beat, the Excluded Intervals Attributes would be used to mark this interval in an associated physio waveform display.​

- Standard -​