Материал: part03

10.33.1 Conceptual Volume Macro Attribute Descriptions​

10.33.1.1 Equivalent Conceptual Volumes​

Conceptual Volumes can be declared to be equivalent to other Conceptual Volumes. In such cases, the Equivalent Conceptual​ Volumes Sequence (3010,000A) is used in derived SOP instances which are aware of other SOP instances defining a semantically​ equivalent volume, but using different Conceptual Volume UIDs (3010,0006).​

10.33.1.2 Derivation Conceptual Volume Sequence​

The Derivation Conceptual Volume Sequence (3010,0014) may be used to describe how a Conceptual Volume is derived from one​ or more other Conceptual Volumes in cases where it may not be possible to describe the method of the derivation completely. Since​ the Conceptual Volume cannot be mathematically constructed from a derivation description, it will be defined explicitly by a segment-​ ation.​

The specification of derivation is different from combining Conceptual Volumes as defined in Section 10.34 “Conceptual Volume​ Segmentation Reference and Combination Macro”.​

10.34 Conceptual Volume Segmentation Reference and Combination Macro​

This Macro allows the combination of Conceptual Volumes as constituents of a combined volume. A representative example is to​ have the Left Lung and the Right Lung segmented, and then to declare the Lungs as a combined Conceptual Volume, for which​ prescription constraints can be defined.​

The Macro also allows reference to RT Segment Annotation SOP instances, which contain a segmented representation of the Con-​ ceptual Volume. At the invocation of this Macro it is declared, whether this segmented representation is required or not.​

Figure 10.34-1. Conceptual Volume References​

Figure 10.34-1 describes an RT Physician Intent Instance where Conceptual Volumes "Lung, left" and "Lung, right" are referenced,​ but not defined. In this example, the RT Segmentation Annotation Instances then define the volumetric information of the Conceptual​ Volumes by referencing a specific segment of a Segmentation Instance and a specific ROI in an RT Structure Set Instance.​

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RT Physician Intent

Conceptual Volume

“Lung”

Figure 10.34-2. Conceptual Volume Combination References​

Figure 10.34-1 describes an RT Physician Intent Instance defining Conceptual Volumes "Lung, left" and "Lung, right" and Conceptual​ Volume "Lung" as a combination of the first two without a direct reference to a volume definition.​

Table 10.34-1. Conceptual Volume Segmentation Reference And Combination Macro Attributes​

If this Conceptual Volume orginated in the current SOP Instance,​ thenthereferencedSOPInstanceUIDisthecurrentSOPInstance​ UID.​

Only a single Item shall be included in this Sequence.​

>>IncludeTable10-11“SOPInstanceReferenceMacroAttributes”​

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Only a single Item shall be included in this Sequence.​

See Section 10.34.1.3.​

(3010,0010) equals YES and Conceptual Volume Combination​ Flag Indicator (3010,000E) equals NO.​

Only a single Item shall be included in this Sequence.​

See Section 10.34.1.4.​

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In the segment Item referenced, the Direct Segment Reference​

Sequence (3010,0023) shall be present.​

10.34.1 Conceptual Volume Segmentation Reference and Combination Macro Attribute De-​ scription​

10.34.1.1 Conceptual Volume Combination Expression​

For Conceptual Volumes specified as a combination of other Conceptual Volumes, the combination logic is specified by the text string​ value of the Conceptual Volume Combination Expression (3010,000C).​

A nested list notation is used to apply geometric operators to a set of Conceptual Volumes.​

The first element of the list shall be one of the following geometric operators:​

INTERSECTION​geometric intersection of two or more arguments​

NEGATION​ geometric inverse of a single argument​

SUBTRACTION​geometric subtraction of second argument from the first​

Note​

The result of a NEGATION operation is well-defined only if used as an operand to an INTERSECTION. NEGATION without​ context to an INTERSECTION results in an infinite Volume.​

Subsequent elements shall specify arguments of the geometric operator. An argument is either a Conceptual Volume Constituent​ Index (3010,000D) value (i.e., positive integer) or a parenthesized list of operations.​

The grammar for the Conceptual Volume Combination Expression (<sexpr>) is shown below in BNF (Backus Naur Form) :​

Examples:​

- Standard -​

(1)(2)

Figure 10.34.1.1-1. Conceptual Volume Example of Union of Disjoint Volumes​

Conceptual Volume Combination Expression (3010,000C):​ (UNION 1 2)​

Items in Conceptual Volume Constituent Sequence (3010,0008):​

Table 10.34.1.1-1. Conceptual Volume Example of Union of Disjoint Volumes​

Figure 10.34.1.1-2. Conceptual Volume Example of Union of Non-disjoint Volumes​

Conceptual Volume Combination Expression (3010,000C):​

(UNION 1 2)​

Items in Conceptual Volume Constituent Sequence (3010,0008) :​

Table 10.34.1.1-2. Conceptual Volume Example of Union of non-disjoint Volumes​

- Standard -​