Материал: part03

The physical units for the real world values obtained from the Sequence Item are given by the Measurement Units Code Sequence​ (0040,08EA).​

The quantity that the real world values represent may be described by the Quantity Definition Sequence (0040,9220), which consists​ of a list of name-value pairs, in which the coded concept name specifies what aspect of the physical quantity is being described.​

Note​

1.​For example, Relative Regional Blood Flow may be described by units and quantity as follows:​

•​Measurement Units Code Sequence (0040,08EA) = ({ratio}, UCUM, "ratio")​

•​Quantity Definition Sequence (0040,9220):​

•​(246205007, SCT, "Quantity") = (126397, DCM, "Relative Regional Blood Flow")​

Additionalinformationabouthowtherelativebloodflowwasderived,e.g.,thereferenceregionused,canalsobeencoded​ as name-value pairs in the Quantity Definition Sequence (0040,9220). See the example in Annex EEEE “Encoding​ Diffusion Model Parameters for Parametric Maps and ROI Measurements (Informative)” in PS3.17.​

2.​For example, the Apparent Diffusion Coefficient (ADC) may be described by units and quantity as follows:​

•​Measurement Units Code Sequence (0040,08EA) = (mm2/s, UCUM, "mm2/s")​

•​Quantity Definition Sequence (0040,9220):​

•​(246205007, SCT, "Quantity") = (113041, DCM, "Apparent Diffusion Coefficient")​

Additional information about how the ADC was derived, e.g., the model used, method of fitting and acquisition b-values​ used, can also be encoded as name-value pairs in the Quantity Definition Sequence (0040,9220). Other diffusion​ models and quantities are also defined. See the example in Annex EEEE “Encoding Diffusion Model Parameters for​ Parametric Maps and ROI Measurements (Informative)” in PS3.17.​

The Quantity Definition Sequence (0040,9220) describes only the stored pixel values that are mapped using the Real World Values​ Mapping, and does not describe derived values from multiple pixels to which the Real World Values Mapping applies.​

Note​

I.e., the mapping is a "point" operation, and as a consequence various modifiers that might be applied to a group of pixels,​ such as in an ROI, should not be used. E.g., an ROI encoded in a Structured Report using TID 1419 "ROI Measurements"​ mightbethemeanormaximumvalue(e.g.,SUVbwmeanorSUVbwmax),andbeencodedwith(121401,DCM,"Derivation")​ = (373098007, SCT, "Mean") or (56851009, SCT, "Maximum"), respectively. These would not be appropriate to use within​ Quantity Definition Sequence (0040,9220), unless the individual pixel values were themselves derived in such a manner,​ e.g., when multiple images are averaged together. Thus the Content Items used in an SR to describe an ROI might be a​ superset of the name-value pairs used in Quantity Definition Sequence (0040,9220).​

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No real-world values

Real World Value Intercept (0040,9224)

Figure C.7.6.16-7. Example of mapping stored values to real world values​

C.7.6.16.2.12 Contrast/Bolus Usage Macro​

Table C.7.16-13 specifies the Attributes of the Contrast/Bolus Usage Macro.​

Table C.7.16-13. Contrast/Bolus Usage Macro Attributes​

YES​

NO​

May only be zero length if the acquisition device is not capable of​ detecting the presence of this contrast agent in the frame.​

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PRE_CONTRAST​

POST_CONTRAST​

IMMEDIATE​

DYNAMIC​

STEADY_STATE​

DELAYED​

ARTERIAL​

CAPILLARY​

VENOUS​

PORTAL_VENOUS​

Required if Contrast/Bolus Administration Route Sequence (0018,0014)​ for the Contrast/Bolus Agent Number (0018,9337) defined in the​ Contrast/Bolus Agent Sequence (0018,0012) is (47625008, SCT,​ "Intravenous route") or (47625008, SCT, "Intravenous route"); may be​ present otherwise.​

C.7.6.16.2.13 Pixel Intensity Relationship LUT Macro​

Table C.7.6.16-14 specifies the Attributes of the Pixel Intensity Relationship LUT Functional Group Macro.​

Table C.7.6.16-14. Pixel Intensity Relationship LUT Macro Attributes​

Defined Terms:​

TO_LOG​

TO_LINEAR​

C.7.6.16.2.13.1 Pixel Intensity Relationship LUT​

The purpose of this Pixel Intensity Relationship LUT Sequence is to provide information to recalculate the pixel values proportional​ to the X-Ray beam intensity from the stored pixel values. It is intended to be used by any application that needs transformed pixel​ values (e.g., scaled back to acquired pixel values) pixel values for further processing and not as replacement of the Modality LUT in​ the display pipeline, see Figure C.7.6.16-7a.​

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Figure C.7.6.16-7a. Purpose of Pixel Intensity Relationship LUT​

C.7.6.16.2.13.2 Pixel Intensity Relationship LUT Data Attribute​

The number of bits in LUT Data (0028,3006) may be different from the value of Bit Stored (0028,0101) Attribute.​

C.7.6.16.2.14 Frame Pixel Shift Macro​

Table C.7.6.16-15 specifies the Attributes of the Frame Pixel Shift Functional Group Macro.​

Table C.7.6.16-15. Frame Pixel Shift Macro Attributes​

Note​

If no pixel shift has to be applied a pair of zero values should​ be specified.​

See Section C.7.6.10.1.2.​

C.7.6.16.2.14.1 Subtraction Item ID Description​

SubtractionItemID(0028,9416)specifiestheIDofasubtractionoperationtowhichtheMaskSub-pixelShift(0028,6114)isassociated.​ The Subtraction Item ID is also present in the Mask Subtraction Sequence (0028,6100) to allow this association.​

When used as per-frame Macro, the Subtraction Item ID (0028,9416) allows to specify different values of Mask Sub-pixel Shift​ (0028,6114) individually frame by frame, and relate them to a single Item of the Mask Subtraction Sequence (0028,6100).​

Note​

There is no restriction in the number of Subtraction Item ID's associated to each contrast frame. The same contrast frame​ may be present in several Items of the Mask Subtraction Sequence, each Item having a different value of Subtraction Item​ ID.​

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When used as shared Macro, the Subtraction Item ID (0028,9416) allows to specify one or more values of Mask Sub-pixel Shift that​ will be applied to all the frames of the Multi-frame image.​

Note​

Example of usage of Subtraction Item ID in a per-frame Macro, see Figure C.7.6.16-8:​

In this example of Multi-frame Image with 3 frames, one Mask Frame (i.e., Frame 1) is applied to the next two frames of the​ Multi-frame image (i.e., Frames 2 and 3). Therefore, there is only one Item in the Mask Subtraction Sequence, containing​ its own Subtraction Item ID value (i.e., 100). The Frame Pixel Shift Macro allows to define a Mask Sub-Pixel Shift different​ for each contrast frame.​

First Frame Subtracted: Subtraction of Frame 1 (Mask) to Frame 2, with Sub-Pixel Shift 1.3\2.4​

Second Frame Subtracted: Subtraction of Frame 1 (Mask) to Frame 3, with Sub-Pixel Shift 1.9\3.0​

Figure C.7.6.16-8. Example of usage of Subtraction Item ID in a per-frame Macro​

C.7.6.16.2.15 Patient Orientation in Frame Macro​

Table C.7.6.16-16 specifies the Attributes of the Patient Orientation in Frame Functional Group Macro.​

Table C.7.6.16-16. Patient Orientation in Frame Macro Attributes​

C.7.6.16.2.16 Frame Display Shutter​

Table C.7.6.16-17 specifies the Attributes of the Frame Display Shutter Functional Group Macro.​

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