C.7.6.16.2 Common Functional Group Macros

The following sections contain Functional Group macros common to more than one IOD specification.

Note: The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e. the macro is part of the Shared Functional Groups Sequence) the phrase "this frame" in the attribute description shall be interpreted to mean "for all frames".

C.7.6.16.2.1 Pixel Measures Macro

Table C.7.6.16-2 specifies the attributes of the Pixel Measures Functional Group macro.

Table C.7.6.16-2PIXEL MEASURES MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Pixel Measures Sequence (0028,9110) 1 Identifies the physical characteristics of the pixels of this frame. Only a single Item shall be included in this sequence.
>Pixel Spacing (0028,0030) 1C Physical distance in the imaging target (patient, specimen, or phantom) between the centers of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See 10.7.1.3 for further explanation of the value order. Note: In the case of CT images with an Acquisition Type (0018,9302) of CONSTANT_ANGLE, the pixel spacing is that in a plane normal to the central ray of the diverging X-Ray beam as it passes through the data collection center. Required if Volumetric Properties (0008,9206) is other than DISTORTED or SAMPLED. May be present otherwise.
>Slice Thickness (0018,0050) 1C Nominal reconstructed slice thickness (for tomographic imaging) or depth of field (for optical non-tomographic imaging), in mm. See C.7.6.16.2.3.1 for further explanation. Note: Depth of field may be an extended depth of field created by focus stacking (see C.8.12.4). Required if Volumetric Properties (0008,9206) is VOLUME or SAMPLED. May be present otherwise.

C.7.6.16.2.2 Frame Content Macro

Table C.7.6.16-3 specifies the attributes of the Frame Content Functional Group macro.

This Functional Group Macro may only be part of the Per-frame Functional Groups Sequence (5200,9230) attribute.

Table C.7.6.16-3FRAME CONTENT MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame Content Sequence (0020,9111) 1 Identifies general characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Acquisition Number (0020,9156) 3 A number identifying the single continuous gathering of data over a period of time that resulted in this frame.
>Frame Reference DateTime (0018,9151) 1C The point in time that is most representative of when data was acquired for this frame. See C.7.6.16.2.2.1 and C.7.6.16.2.2.2 for further explanation. Note: The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800). Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Frame Acquisition DateTime (0018,9074) 1C The date and time that the acquisition of data that resulted in this frame started. See C.7.6.16.2.2.1 for further explanation. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Frame Acquisition Duration (0018,9220) 1C The actual amount of time [in milliseconds] that was used to acquire data for this frame. See C.7.6.16.2.2.1 and C.7.6.16.2.2.3 for further explanation. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Cardiac Cycle Position (0018,9236) 3 Description of the position in the cardiac cycle that is most representative of this frame. Defined Terms: END_SYSTOLE END_DIASTOLE UNDETERMINED
>Respiratory Cycle Position (0018,9214) 3 Description of the position in the respiratory cycle that is most representative of this frame. Defined Terms: START _RESPIR END_RESPIR UNDETERMINED
>Dimension Index Values (0020,9157) 1C Contains the values of the indices defined in the Dimension Index Sequence (0020,9222) for this multi-frame header frame. The number of values is equal to the number of Items of the Dimension Index Sequence and shall be applied in the same order. See section C.7.6.17.1 for a description. Required if the value of the Dimension Index Sequence (0020,9222) exists.
>Temporal Position Index (0020,9128) 1C Ordinal number (starting from 1) of the frame in the set of frames with different temporal positions. Required if the value of SOP Class UID (0008,0016) equals “1.2.840.10008.5.1.4.1.1.130”. May be present otherwise. See C.7.6.16.2.2.6.
>Stack ID (0020,9056) 1C Identification of a group of frames, with different positions and/or orientations that belong together, within a dimension organization. See C.7.6.16.2.2.4 for further explanation. Required if the value of SOP Class UID (0008,0016) equals “1.2.840.10008.5.1.4.1.1.130”. May be present otherwise. See C.7.6.16.2.2.7.
>In-Stack Position Number (0020,9057) 1C The ordinal number of a frame in a group of frames, with the same Stack ID Required if Stack ID (0020,9056) is present. See section C.7.6.16.2.2.4 for further explanation.
>Frame Comments (0020,9158) 3 User-defined comments about the frame.
>Frame Label (0020,9453) 3 Label corresponding to a specific dimension index value. Selected from a set of dimension values defined by the application. This attribute may be referenced by the Dimension Index Pointer (0020,9165) attribute in the Multi-frame Dimension Module. See C.7.6.16.2.2.5 for further explanation.

C.7.6.16.2.2.1 Timing Parameter Relationships

Figure C.7.6.16-2 shows the relationships among the various timing parameters used.

[pic]

Figure C.7.6.16-2Relationship of Timing Related Attributes

C.7.6.16.2.2.2 Frame Reference DateTime

The Frame Reference DateTime (0018,9151) is used to indicate the point in time that is most representative for that specific frame.

Notes: 1. For example, in the case of MR it might be the time of acquisition of the data for the k y =0 line in k-space (the central Fourier segment).

2. For cardiac gated acquisitions the choice of the Frame Reference DateTime (0018,9151) is influenced by the Nominal Cardiac Trigger Delay Time (0020,9153). For respiratory gated acquisitions the choice of the Frame Reference DateTime (0018,9151) is influenced by the Nominal Respiratory Trigger Delay Time (0020,9255).

C.7.6.16.2.2.3 Frame Acquisition Duration

The Frame Acquisition Duration (0018,9220) is used to indicate the duration of the acquisition related to this frame.

For SOP Instances or Concatenations of the Enhanced PET Image Storage SOP Class (1.2.840.10008.5.1.4.1.1.130) the Frame Acquisition Duration (0018,9220) is the sum of the portion of each cycle during which data contributing to this frame has actually been acquired for all of the cardiac or respiratory cycles of a gated acquisition (i.e. if Cardiac Synchronization Technique (0018,9037) equals other than NONE, and/or if Respiratory Motion Compensation Technique (0018,9170) equals other than NONE).

C.7.6.16.2.2.4 Concatenations and Stacks

Due to implementation specific reasons (such as maximum object size) the information of a multi-frame image may be split into more than one SOP Instance. These SOP Instances form together a Concatenation. This is a group of SOP Instances within a Series that is uniquely identified by the Concatenation UID (0020,9161).

The Dimension Index Sequence (0020,9222) for each SOP Instance with the same Concatenation UID (0020,9161) shall contain exactly the same tags and values.

In a Concatenation the Dimension Index Sequence (0020,9222) items of the Shared Functional Groups (5200,9229) shall be identical and have the same values for all individual SOP Instances. The items of the Per-frame Functional Groups (5200,9230) shall be identical for all individual SOP Instances but the values may change per frame. For all other Attributes of all the Modules of the IOD, the same Attributes shall be present and the values shall be identical, with the exception of the following Attributes:

Note: The intent of Concatenations is to split what might have been encoded in a single SOP Instance into smaller fragments for more convenient storage or transmission. All the multiple SOP Instances of a Concatenation should be able to be assembled into a valid single SOP Instance. Hence it is not permitted to change such Attributes as Photometric Interpretation (0028,0004), Rows (0028,0010), Columns (0028,0011), etc.

Stacks describe application-specific groups of frames that have a geometric relationship. Stacks have a Stack ID (0020,9056) that contains a descriptive name that identifies the stack. A Stack ID (0020,9056) may be re-used in another SOP Instance even outside a concatenation. The value of Stack ID (0020,9056) is unique within the scope of a particular Dimension Organization UID (0020,9164) if present, otherwise it is unique within the scope of a particular Concatenation UID (0020,9161). See Figure C7.6.16-3 for an example.

[pic] Figure C.7.6.16-3 Identifying attributes for Concatenation, SOP Instances, Frames and Stacks

Each frame in a stack has an In-Stack Position Number (0020,9057) that is the ordinal number (starting from 1) of the frame within the set of frames with the same Stack ID (0020,9056), see Figure C.7.6.16-4 for an example.

[pic]

Figure C.7.6.16-4 Example of multiple stacks

In order to allow interoperable operations on stacks, 2 different frames with the same Stack ID (0020,9056) can only have the same In-Stack Position Number (0020,9057) if they have the same values for the following attributes:

  1. Dimension Organization UID (0020,9164) or if absent Concatenation UID (0020,9161) to qualify the Stack ID

  2. Image Position (Patient) (0020,0032)

  3. Image Orientation (Patient) (0020,0037)

  4. Rows (0028,0010) ( first value of Pixel Spacing (0028,0030) (= field of view in the row direction)

  5. Columns (0028,0011) ( second value of Pixel Spacing (0028,0030) (= field of view in the column direction)

  6. Slice Thickness (0018,0050)

C.7.6.16.2.2.5 Frame Label

The Frame Label attribute (0020,9453) can be used to label frames that need to be handled as a group in application. The Dimension Index Pointer (0020,9165) from the Dimension Module may point to this attribute if it is the base of a dimension.

C.7.6.16.2.2.6 Temporal Position Index and Stack ID in PET images

For PET Dynamic images, i.e. images in which Image Type (0008,0008) Value 3 is DYNAMIC, Temporal Position Index is used to distinguish between the multiple acquisitions of the same anatomical area. Similarly, the frames that result from one acquisition over the anatomic area shall be contained in one stack. Thus, for Dynamic images, Temporal Position Index (0020,9128), Stack ID (0020,9056), and In-Stack Position Number (0020,9057) shall be used as three of the dimensions of the image, in that order.

Figure C.7.6.16-4b describes the usage for a PET dynamic image.

[pic]

Figure C.7.6.16-4bPET dynamic frame organization

C.7.6.16.2.2.7 Stack ID usage in PET static, whole body and gated images

For static and whole body PET images, a single Stack ID (0020,9056) is used to group all of the transverse slices over the entire imaged volume together. That is, a single Stack ID (0020,9056) is used no matter how many acquisition bed positions are involved. In-Stack Position Number (0020,9057) is then used as the spatial dimension index. When rectangular sagittal, coronal or oblique images are created from these, a single Stack ID (0020,9056) is again used.

Similarly, in cardiac or respiratory gated images, the entire volume is again identified by a single Stack ID (0020,9056), and In-Stack Position Number (0020,9057) is the spatial dimension index. The time dimension is indicated by one of the timing attributes, such as trigger delay time or respiratory phase.

C.7.6.16.2.3 Plane Position (Patient) Macro

Table C.7.6.16-4 specifies the attributes of the Plane Position (Patient) Functional Group macro.

Table C.7.6.16-4PLANE POSITION (PATIENT) MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Plane Position Sequence (0020,9113) 1 Identifies the position of the plane of this frame. Only a single Item shall be included in this sequence.
>Image Position (Patient) (0020,0032) 1C The x, y, and z coordinates of the upper left hand corner (center of the first voxel transmitted) of the frame, in mm. See C.7.6.2.1.1 and C.7.6.16.2.3.1 for further explanation. Note: In the case of CT images with an Acquisition Type (0018,9302) of CONSTANT_ANGLE the image plane is defined to pass through the data collection center and be normal to the central ray of the diverging X-Ray beam. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Volumetric Properties (0008,9206) of this frame is other than DISTORTED, may be present otherwise.

C.7.6.16.2.3.1 Position and Orientation for SAMPLED Frames

In the case of Volumetric Properties (0008,9206) having a value of SAMPLED, the Image Position (0020,0032), Image Orientation (0020,0037) and Slice Thickness (0018,0050) shall represent the volume from which the frame was derived based on the orientation of the sampling performed.

Note: For example in the case of MAX_IP:

The Image Orientation shall be the direction of the ray used for projection of the center of the plane.

The image position shall contain the x, y, and z coordinates of the intersection of the mid-plane of the sampled volume with the ray used to project the upper left hand corner of the frame.

The Slice Thickness shall contain the distance that the ray used for projection of the center of the plane traveled through the volume.

C.7.6.16.2.4 Plane Orientation (Patient) Macro

Table C.7.6.16-5 specifies the attributes of the Plane Orientation (Patient) Functional Group macro.

Table C.7.6.16-5PLANE ORIENTATION (PATIENT) MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Plane Orientation Sequence (0020,9116) 1 Identifies orientation of the plane of this frame. Only a single Item shall be included in this sequence.
>Image Orientation (Patient) (0020,0037) 1C The direction cosines of the first row and the first column with respect to the patient. See C.7.6.2.1.1 and C.7.6.16.2.3.1 for further explanation. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Volumetric Properties (0008,9206) of this frame is other than DISTORTED. May be present otherwise.

C.7.6.16.2.5 Referenced Image Macro

Table C.7.6.16-6 specifies the attributes of the Referenced Image Functional Group macro.

Table C.7.6.16-6REFERENCED IMAGE MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Referenced Image Sequence (0008,1140) 2 The set of images or other composite SOP Instances used to plan the acquisition, if any, and other significant related images. See Section C.7.6.16.2.5.1 for further explanation. Zero or more Items shall be included in this Sequence.
>Include ‘Image SOP Instance Reference Macro’ Table 10-3
>Purpose of Reference Code Sequence (0040,A170) 1 Describes the purpose for which the reference is made. Only a single Item shall be included in this sequence. See C.7.6.16.2.5.1 for further explanation.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Defined CID 7201.

C.7.6.16.2.5.1 Use of Referenced Image Macro

Referenced Image Sequence (0008,1140) shall be used to identify other data objects used to plan the acquisition of this image. Instances referenced for this purpose shall have the same Frame of Reference UID (0020,0052) as this image. For each Item that contains such a reference, the value of the Purpose of Reference Code Sequence (0040,A170) shall be (”121311”, DCM, ”Localizer"). Applications can use the Referenced Image Sequence (0008,1140) in combination with data in Plane Position (Patient) and Plane Orientation (Patient) Macros to provide projections of the position of an image with respect to the referenced image.

The Referenced Image Sequence (0008,1140) may also be present when references to other images (or frames within other images) are required for other reasons, as specified by Purpose of Reference Code Sequence (0040,A170).

Note: An Image may contain references to itself (e.g. to other frames within itself).

C.7.6.16.2.6 Derivation Image Macro

Table C.7.6.16-7 specifies the attributes of the Derivation Image Functional Group macro.

Table C.7.6.16-7DERIVATION IMAGE MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Derivation Image Sequence (0008,9124) 2 The set of Images or other composite SOP Instances that were used to derive this frame. Zero or more Items shall be included in this Sequence.
>Derivation Description (0008,2111) 3 A text description of how this frame data was derived. See C.7.6.1.1.3 for further explanation.
>Derivation Code Sequence (0008,9215) 1 A coded description of how this frame was derived. See C.7.6.1.1.3 for further explanation. One or more Items shall be included in this Sequence. More than one Item indicates that successive derivation steps have been applied.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Defined CID 7203.
>Source Image Sequence (0008,2112) 2 The set of Images or other Composite SOP Instances that were used to derive this frame. Zero or more Items shall be included in this Sequence. See C.7.6.1.1.4 for further explanation.
>>Include ‘Image SOP Instance Reference Macro’ Table 10-3
>>Purpose of Reference Code Sequence (0040,A170) 1 Describes the purpose for which the reference is made, that is what role the source image or frame played in the derivation of this image or frame. Only a single Item shall be included in this sequence.
>>>Include ‘Code Sequence Macro’ Table 8.8-1 Defined CID 7202.

C.7.6.16.2.7 Cardiac Synchronization Macro

Table C.7.6.16-8 specifies the attributes of the Cardiac Synchronization Functional Group macro.

Table C.7.6.16-8CARDIAC SYNCHRONIZATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Cardiac Synchronization Sequence (0018,9118) 1 Sequence that describes the frame specific cardiac synchronization parameters. Only a single Item shall be included in this sequence.
>Nominal Percentage of Cardiac Phase (0020,9241) 1C The nominal time relative to the preceding R peak divided by the nominal R-R interval multiplied by 100. Required if used as a dimension index, may be present otherwise.
>Nominal Cardiac Trigger Delay Time (0020,9153) 1 The nominal time in ms from the time of the previous R-peak to the value of the Frame Reference DateTime (0018,9151) expressed as a positive value. See C.7.6.16.2.7.1 for further explanation.
>Actual Cardiac Trigger Delay Time (0020,9252) 1C The actual time in ms from the time of the previous R-peak to the value of the Frame Reference DateTime (0018,9151) expressed as a positive value . See C.7.6.16.2.7.1 for further explanation. Required if Intervals Acquired (0018,1083) is present and has a value of 1. May be present otherwise.
>Nominal Cardiac Trigger Time Prior to R-peak (0020,9154) 3 The nominal time in ms from the time of the next R-peak to the value of the Frame Reference DateTime (0018,9151) expressed as a negative value. See C.7.6.16.2.7.1 for further explanation.
>Actual Cardiac Trigger Time Prior to R-peak (0020,9155) 3 The actual time in ms from the time of the next R-peak to the value of the Frame Reference DateTime (0018,9151) expressed as a negative value. See C.7.6.16.2.7.1 for further explanation.
>Intervals Acquired (0018,1083) 3 Number of R-R intervals acquired.
>Intervals Rejected (0018,1084) 3 Number of R-R intervals rejected.
>Heart Rate (0018,1088) 3 Average number of heart beats per minute for the collection period for this frame. This shall include all accepted beats as well as rejected beats. Note: During prolonged acquisitions the average heart rate may differ from the reciprocal of the nominal R-R interval.
>R-R Interval Time Nominal (0020,9251) 1C Nominal R-peak - R-peak interval time in ms for the cardiac cycle used for the acquisition of this frame. See C.7.6.16.2.7.1 for further explanation. Required if Cardiac Synchronization Technique (0018,9037) equals other than NONE or REALTIME. May be present otherwise.
>Low R-R Value (0018,1081) 3 R-R interval low limit for beat rejection, in ms.
>High R-R Value (0018,1082) 3 R-R interval high limit for beat rejection, in ms.

C.7.6.16.2.7.1 Relationship of Cardiac Timing Attributes

The Nominal Cardiac Trigger Delay Time (0020,9153) is the nominal trigger delay time in ms from the previous R-peak to the value of the Frame Reference DateTime (0018,9151). When frames are acquired with prospective gating, that is, the data acquisition actually begins in response to a timed delay from the R-peak, it may be that Actual Cardiac Trigger Delay Time (0020,9252) and the Nominal Cardiac Trigger Delay Time (0020,9153) have the same value.

However, when frames are the result of retrospective gating, that is, the data is continuously acquired and then later compared with a simultaneously acquired ECG waveform and fitted into time slots corresponding to nominal phases of the cardiac cycle, then Nominal Cardiac Trigger Delay Time (0020,9153) and the Actual Cardiac Trigger Delay Time (0020,9252) may have different values. When applicable the same is valid for the Nominal Cardiac Trigger Time Prior to R-peak (0020,9154) and the Actual Cardiac Trigger Time Prior to R-peak (0020,9155) attributes.

When multiple cardiac cycles are averaged together, then the Low R-R Value (0018,1081), and High R-R Value (0018,1082) are an average of the cardiac cycles that were accepted in the frame.

Note: For cardiac gated acquisitions the choice of the Frame Reference DateTime (0018,9151) is influenced by the Nominal Cardiac Trigger Delay Time (0020,9153). For respiratory gated acquisitions the choice of the Frame Reference DateTime (0018,9151) is influenced by the Nominal Respiratory Trigger Delay Time (0020,9255).

Figure C.7.6.16-5a depicts the usage.

[pic]

Figure C.7.6.16-5aCardiac Timing Tags

Nominal Cardiac Trigger Time Prior to R-peak (0020,9154) and the Actual Cardiac Trigger Time Prior to R-peak (0020,9155) attributes can be used to store a time of the next R-peak to the value of the Frame Reference DateTime (0018,9151) expressed as a negative value. In this case the Actual Cardiac Trigger Delay Time (0020,9252), when present, and the Nominal Cardiac Trigger Delay Time (0020,9153) shall contain a value calculated based on the R-R interval applicable for this frame. See Figure C.7.6.16-5b.

[pic]

Figure C.7.6.16-5bCardiac Timing Relationships

Note: Specifying the time interval prior to the R-peak is relevant for applications such as capturing P- and Q-wave related morphology.

C.7.6.16.2.8 Frame Anatomy Macro

Table C.7.6.16-9 specifies the attributes of the Frame Anatomy Functional Group macro.

Table C.7.6.16-9FRAME ANATOMY MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame Anatomy Sequence (0020,9071) 1 Identifies anatomic characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Laterality (0020,9072) 1 Laterality of (possibly paired) body parts (as described in Anatomic Region Sequence (0008,2218)) examined. Enumerated Values: R = right L = left U = unpaired B = both left and right Note: This Attribute is mandatory, in order to ensure that frames may be positioned correctly relative to one another for display. Shall be consistent with any laterality information contained in Primary Anatomic Structure Modifier Sequence (0008,2230), if present.
>Include 'General Anatomy Mandatory Macro' Table 10-5 Defined Context ID for the Anatomic Region Sequence (0008,2218) is 4030. Defined Context ID for Anatomic Region Modifier Sequence (0008,2220) and Primary Anatomic Structure Modifier Sequence (0008,2230) is 2.

C.7.6.16.2.9 Pixel Value Transformation Macro

Table C.7.6.16-10 specifies the attributes of the Pixel Value Transformation Functional Group macro.

Note: This Macro is equivalent with the Modality LUT transformation in non Multi-frame IODs.

Table C.7.6.16-10PIXEL VALUE TRANSFORMATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Pixel Value Transformation Sequence (0028,9145) 1 Contains the attributes involved in the transformation of stored pixel values. Only a single Item shall be included in this sequence.
>Rescale Intercept (0028,1052) 1 The value b in relationship between stored values (SV) and the output units. Output units = m*SV + b.
>Rescale Slope (0028,1053) 1 m in the equation specified by Rescale Intercept (0028,1052).
>Rescale Type (0028,1054) 1 Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). See C.11.1.1.2 for further explanation. Enumerated Value: US = Unspecified if Modality (0008,0060) equals MR or PT.

Note: Window Center (0028,1050) and Window Width (0028,1051) are applied after Rescale Slope (0028,1053) and Rescale Intercept (0028,1054) have been applied to Stored Pixel Values, see C.11.2.1.2.

C.7.6.16.2.9b Identity Pixel Value Transformation Macro

Table C.7.6.16-10b specifies the attributes of the Identity Pixel Value Transformation Functional Group macro.

Note: This Macro constrains the Modality LUT Transformation step in the grayscale rendering pipleine to be an identity transformation.

Table C.7.6.16-10bIDENTITY PIXEL VALUE TRANSFORMATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Pixel Value Transformation Sequence (0028,9145) 1 Contains the attributes involved in the transformation of stored pixel values. Only a single Item shall be included in this sequence.
>Rescale Intercept (0028,1052) 1 The value b in relationship between stored values (SV) and the output units. Output units = m*SV + b. Enumerated Value: 0
>Rescale Slope (0028,1053) 1 m in the equation specified by Rescale Intercept (0028,1052). Enumerated Value: 1
>Rescale Type (0028,1054) 1 Specifies the output units of Rescale Slope (0028,1053) and Rescale Intercept (0028,1052). See C.11.1.1.2 for further explanation. Enumerated Value: US - Unspecified

C.7.6.16.2.10 Frame VOI LUT Macro

Table C.7.6.16-11 specifies the attributes of the Frame VOI LUT Functional Group macro.

Table C.7.6.16-11FRAME VOI LUT MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame VOI LUT Sequence (0028,9132) 1 Window Center and Width values applied to the frame. Only a single item is permitted in this sequence.
>Window Center (0028,1050) 1 Window Center for display. See C.11.2.1.2 for further explanation.
>Window Width (0028,1051) 1 Window Width for display. See C.11.2.1.2 for further explanation.
>Window Center & Width Explanation (0028,1055) 3 Explanation of the Window Center and Width. Defined Terms for CT: BRAIN SOFT_TISSUE LUNG BONE
>VOI LUT Function (0028,1056) 3 Describes a VOI LUT function to apply to the values of Window Center (0028,1050) and Window Width (0028,1051). See C.11.2.1.3 for further explanation. Defined terms: LINEAR SIGMOID When this attribute is not present, the interpretation of the values of Window Center (0028,1050) and Window Width (0028,1051) is linear as in C.11.2.1.2.

C.7.6.16.2.10b Frame VOI LUT With LUT Macro

Table C.7.6.16-11b specifies the attributes of the Frame VOI LUT With LUT Functional Group macro. This macro contains one or more sets of linear or sigmoid window values and/or one or more sets of lookup tables.

Table C.7.6.16-11bFRAME VOI LUT WITH LUT MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame VOI LUT Sequence (0028,9132) 1 The VOI LUT transformations applied to this frame. Only a single item is permitted in this sequence.
>Include VOI LUT Macro Table C.11-2b

C.7.6.16.2.11 Real World Value Mapping Macro

Table C.7.6.16-12 specifies the attributes of the Real World Value Mapping Functional Group macro.

Table C.7.6.16-12REAL WORLD VALUE MAPPING MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Real World Value Mapping Sequence (0040,9096) 1 The mapping of stored values to associated real world values. One or more Items shall be included in this sequence.
>Real World Value First Value Mapped (0040,9216) 1 Specifies the first stored value mapped for the Real Word Value Intercept (0040,9224) and Real World Value Slope (0040,9225) or Real World Value LUT (0040,9212) of this Item. See C.7.6.16.2.11.1 for further explanation.
>Real World Value Last Value Mapped (0040,9211) 1 Specifies the last stored value mapped for the Real Word Value Intercept (0040,9224) and Real World Value Slope (0040,9225) or Real World Value LUT (0040,9212) of this Item. See C.7.6.16.2.11.1 for further explanation.
>Real World Value Intercept (0040,9224) 1C The Intercept value in relationship between stored values (SV) and the real world values. See section C.7.6.16.2.11.2 for further explanation. Required if Real World Value LUT Data (0040,9212) is not present.
>Real World Value Slope (0040,9225) 1C The Slope value in relationship between stored values (SV) and the real world values. See section C.7.6.16.2.11.2 for further explanation. Required if Real World Value LUT Data (0040,9212) is not present.
>Real World Value LUT Data (0040,9212) 1C LUT Data in this Sequence. Required if Real World Value Intercept (0040,9224) is not present.
>LUT Explanation (0028,3003) 1 Free form text explanation of the meaning of the transformation in this Item.
>LUT Label (0040,9210) 1 Label that is used to identify the transformation of this Item.
>Measurement Units Code Sequence (0040,08EA) 1 Units of measurement. Only a single Item shall be included in this sequence. See C.7.6.16.2.11.1 for further explanation.
>>Include Code Sequence Macro Table 8.8-1 Defined CID 82, or as specified in the macro invocation.

C.7.6.16.2.11.1 Real World Value representation

C.7.6.16.2.11.1.1 Real World Value Mapping Sequence

The items in the Real World Value Mapping Sequence (0040,9096) may be used to translate stored values into real world values when there is such a relationship. The Real World Value Mapping Sequence (0040,9096) is independent of the Modality LUT (or Pixel Value Transformation Macro), as illustrated in Figure C.7.6.16-6.

Each item specifies the range of stored values as well as the associated mapping function. Each item can specify either a linear mapping, using Real World Value Slope (0040,9225) and Real World Value Intercept (0040,9224), or a non-linear mapping using Real World Value LUT Data (0040,9212). More than one Real World Value Mapping Item is allowed.

The range of stored pixel values specified by different Real Value World Mapping Sequence (0040,9096) Items can overlap (as illustrated in the example in Figure C.7.6.16-7).

[pic]

Figure C.7.6.16-6The Real World Value LUT and the Image Viewing pipeline

Note: For example, MR images may contain data that is not only the result of the physical/chemical properties of the scanned anatomy, but may also contain information that is representing real world values, such as, temperature [in degrees C], flow [in l/min], speed [in m/sec], relative activity [in %], relative contrast enhancement [in %], diffusion [in sec/mm2], etc.

In some cases the conversion from Stored Values to Real World Values can be linear (through "slope" and "intercept") or non-linear (through look-up tables).

Both transformation methods can be applied to one range of stored values. Overlapped ranges might be used for different representations such as log versus linear scales or for different representations in units such as cm/sec versus mm/sec. Alternative methods can be identified by the labels assigned to the transformations.

C.7.6.16.2.11.1.2 Real World Values Mapping Sequence Attributes

The Real World Value First Value Mapped (0040,9216) and Real World Value Last Value Mapped (0040,9211) Attributes describe the range of stored pixel values that are mapped by the Sequence Item. Stored pixel values less than the first value mapped, or greater than the last value mapped have no real value attached.

When the Real World Value Intercept (0040,9224) and Real World Value Slope (0040,9225) attributes are supplied, the stored value (SV) is converted to a real world value (RV) using the equation:

RV = (Real World Value Slope) * SV + Real World Value Intercept

When the Real World Value LUT Data (0040,9212) attribute is supplied, Real World Values are obtained via a lookup operation. The stored pixel value of the first value mapped is mapped to the first entry in the LUT Data. Subsequent stored pixel values are mapped to the subsequent entries in the LUT Data up to a stored pixel value equal to the last value mapped.

The number of entries in the LUT data is given by:

Number of entries = Real World Value Last Value Mapped- Real World Value First Value Mapped + 1

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

[pic]

Figure C.7.6.16-7Example 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.7.16-13CONTRAST/BOLUS USAGE MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Contrast/Bolus Usage Sequence (0018,9341) 1 Contains the attributes describing the use of contrast for this frame. One or more Items shall be included in this sequence.
>Contrast/Bolus Agent Number (0018,9337) 1 Identifying number corresponding to the agent described in the Enhanced Contrast/Bolus Module.
>Contrast/Bolus Agent Administered (0018,9342) 1 The administration of the selected agent had begun by the time this frame was acquired. Enumerated Values: YES NO
>Contrast/Bolus Agent Detected (0018,9343) 2 The selected agent was detected in the frame. Enumerated Values: 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.
>Contrast/Bolus Agent Phase (0018,9344) 2C Nominal phase of intravenous contrast administration. Defined terms: 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 (G-D101, SRT, “Intravenous route”) or (G-D101, SNM3, “Intravenous route”); may be present otherwise. Note: SRT is the preferred designator for SNOMED, but SNM3 is allowed for backward compatibility. See PS3.16.

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.7.6.16-14PIXEL INTENSITY RELATIONSHIP LUT MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Pixel Intensity Relationship LUT Sequence (0028,9422) 1 Defines a sequence of Pixel Intensity Relationship LUTs. One or more items shall be included in this sequence. At least one item with LUT Function (0028,9474) equals TO_LINEAR LUT shall be present if Pixel Intensity Relationship (0028,1040) equals LOG. Only a single item with LUT Function (0028,9474) equals TO_LINEAR LUT shall be present.
>LUT Descriptor (0028,3002) 1 Specifies the format of the LUT Data in this Sequence. See C.11.1.1 and C.7.6.16.2.13.1 for further explanation.
>LUT Data (0028,3006) 1 LUT Data in this Sequence.
>LUT Function (0028,9474) 1 The transformation function this LUT applies to the stored pixel values. 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.7.6.16-7.

[pic]

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

C.7.6.16.2.13.2 Pixel Intensity Relationship LUT Data Attribute

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

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.7.6.16-15FRAME PIXEL SHIFT MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame Pixel Shift Sequence (0028,9415) 1 Sequence containing the pixel shift for a number of masks for this frame. One or more items shall be included in this sequence.
>Subtraction Item ID (0028,9416) 1 Identifier of the Subtraction Item in the Mask Subtraction Sequence (0028,6100) to which this pixel shift is associated. See C.7.6.16.2.14.1.
>Mask Sub-pixel Shift (0028,6114) 1 A pair of floating point numbers specifying the fractional vertical [adjacent row spacing] and horizontal [adjacent column spacing] pixel shift applied to the mask before subtracting it from this contrast frame. 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

Subtraction Item ID (0028,9416) specifies the ID of a subtraction operation to which the Mask Sub-pixel Shift (0028,6114) is associated. 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.

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

[pic]

Figure C.7.6.16-8Example 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.7.6.16-16PATIENT ORIENTATION IN FRAME MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Patient Orientation in Frame Sequence (0020,9450) 1 Sequence containing the row and column directions for this frame in the patient. Only a single Item shall be included in this sequence.
>Patient Orientation (0020,0020) 1 Patient direction of the rows and columns of this frame. See C.7.6.1.1.1 for further explanation.

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.

Table C.7.6.16-17FRAME DISPLAY SHUTTER MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Frame Display Shutter Sequence (0018,9472) 1 Sequence containing the display shutter parameters for this frame. Only a single Item shall be included in this sequence.
>Include ‘Display Shutter Macro’ Table C.7-17A.

C.7.6.16.2.17 Respiratory Synchronization Macro

Table C.7.6.16-18 specifies the attributes of the Respiratory Synchronization Functional Group macro.

Table C.7.6.16-18RESPIRATORY SYNCHRONIZATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Respiratory Synchronization Sequence (0020,9253) 1 Sequence that describes the frame specific respiratory synchronization parameters. Only a single Item shall be included in this sequence.
>Respiratory Interval Time (0020,9254) 1C Measured interval time in ms from maximum respiration peak to the next peak for the respiratory cycle in which this frame occurs. See C.7.6.16.2.17.1 for further explanation. Required if Respiratory Motion Compensation Technique (0018,9170) equals other than NONE or REALTIME and Respiratory Trigger Type (0020,9250) is absent or has a value of TIME or BOTH.
>Nominal Percentage of Respiratory Phase (0020,9245) 1C The nominal time relative to the preceding respiratory inspiration maximum divided by the nominal respiratory interval multiplied by 100. Required if used as a dimension index, may be present otherwise.
>Nominal Respiratory Trigger Delay Time (0020,9255) 1 The nominal time in ms from the beginning of the respiratory interval to the value of the Frame Reference DateTime (0018,9151). See C.7.6.16.2.17.1 for further explanation.
>Actual Respiratory Trigger Delay Time (0020,9257) 1C The actual time in ms from the beginning of the respiratory interval to the value of the Frame Reference DateTime (0018,9151). See C.7.6.16.2.17.1 for further explanation. Required if Respiratory Trigger Type (0020,9250) is TIME or BOTH.
>Starting Respiratory Amplitude (0020,9246) 1C Nominal amplitude of the respiratory signal at which the acquisition of data for this frame begins, in percent of the nominal maximum value (which represents maximum inspiration). Required if Respiratory Trigger Type (0020,9250) is AMPLITUDE or BOTH.
>Starting Respiratory Phase (0020,9247) 1C The phase of respiration at which the Starting Respiratory Amplitude (0020,9246) was measured. Enumerated Value: INSPIRATION MAXIMUM EXPIRATION MINIMUM Required if Starting Respiratory Amplitude (0020,9246) is present.
>Ending Respiratory Amplitude (0020,9248) 1C Nominal amplitude of the respiratory signal at which the acquisition of data for this frame ends, in percent of the nominal maximum value (which represents maximum inspiration). Required if Respiratory Trigger Type (0020,9250) is AMPLITUDE or BOTH.
>Ending Respiratory Phase (0020,9249) 1C The phase of respiration at which the Ending Respiratory Amplitude (0020,9248) was measured. Enumerated Value: INSPIRATION MAXIMUM EXPIRATION MINIMUM Required if Ending Respiratory Amplitude (0020,9248) is present.

C.7.6.16.2.17.1 Relationship of Respiratory Timing Attributes

For time based respiratory gating, the Nominal Respiratory Trigger Delay Time (0020,9255) is the prescribed trigger delay time in ms from the previous Respiratory-peak to the value of the Frame Reference DateTime (0018,9151). When frames are acquired with prospective gating, that is, the data acquisition actually begins in response to a timed delay from the Respiratory trigger, it may be that Actual Respiratory Trigger Delay Time (0020,9257) and the Nominal Respiratory Trigger Delay Time (0020,9255) have the same value.

However, when frames are the result of retrospective gating, that is, the data is continuously acquired and then later compared with a simultaneously acquired respiratory waveform and fitted into bins corresponding to nominal phases of the respiratory cycle, then Nominal Respiratory Trigger Delay Time (0020,9255) and the Actual Respiratory Trigger Delay Time (0020,9257) may have different values.

Figure C.7.6.16-9a and C.7.6.16-9b depict the usage.

[pic]

Figure C.7.6.16-9aRespiratory Timing Tags

[pic]

Figure C.7.6.16-9bRelationship of Respiratory Amplitude Attributes

C.7.6.16.2.18 Irradiation Event Identification Macro

Table C.7.6.16-19 specifies the attributes containing the Irradiation Event Identification Functional Group macro.

Table C.7.6.16-19IRRADIATION EVENT IDENTIFICATION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Irradiation Event Identification Sequence (0018,9477) 1 Sequence containing the Irradiation Event Identification for this frame. Only a single Item shall be included in this sequence.
>Irradiation Event UID (0008,3010) 1 Unique identification of the irradiation event(s) associated with the acquisition of this image.

C.7.6.16.2.19 Radiopharmaceutical Usage Macro

Table C.7.6.16.2-20 specifies the attributes of the Radiopharmaceutical Usage Functional Group macro.

Table C.7.6.16.2-20RADIOPHARMACEUTICAL USAGE MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Radiopharmaceutical Usage Sequence (0018,9737) 1 One or more Items shall be included in this sequence.
>Radiopharmaceutical Agent Number (0018,9729) 1 Identifying number corresponding to the radiopharmaceutical described in the Enhanced PET Isotope Module.

C.7.6.16.2.20 Patient Physiological State Macro

Table C.7.6.16.2-21 specifies the attributes of the Patient Physiological State Functional Group Macro, which describes the physiological state of the patient.

Table C.7.6.16.2-21PATIENT PHYSIOLOGICAL STATE MACRO

Attribute Name Tag Type Attribute Description
Patient Physiological State Sequence (0018,9771) 1 Contains the attributes describing the physiological sate of the patient for this frame. Only a single Item shall be included in this sequence.
>Patient Physiological State Code Sequence (0018,9772) 1 The physiological state of the patient. Only a single Item shall be included in this sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Defined CID 3101

C.7.6.16.2.21 Plane Position (Volume) Macro

Table C.7.6.16.2.21-1 specifies the attributes of the Plane Position (Volume) Functional Group macro.

Table C.7.6.16.2.21-1PLANE POSITION (VOLUME) MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Plane Position (Volume) Sequence (0020,930E) 1 Identifies the position of the plane of this frame. Only a single Item shall be included in this sequence.
>Image Position (Volume) (0020,9301) 1 The x, y, and z coordinates, in mm, of the upper left hand corner (center of the first voxel transmitted) of the plane in the Volume Frame of Reference.

C.7.6.16.2.22 Plane Orientation (Volume) Macro

Table C.7.6.16.2.22-1 specifies the attributes of the Plane Orientation (Volume) Functional Group macro.

Table C.7.6.16.2.22-1PLANE ORIENTATION (VOLUME) MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Plane Orientation (Volume) Sequence (0020,930F) 1 Identifies orientation of the plane of this frame. Only a single Item shall be included in this sequence.
>Image Orientation (Volume) (0020,9302) 1 The direction cosines of the first row and the first column of the frame with respect to the Volume Frame of Reference.

C.7.6.16.2.23 Temporal Position Macro

Table C.7.6.16.2.23-1 specifies the attributes of the Temporal Position Functional Group macro.

Table C.7.6.16.2.23-1TEMPORAL POSITION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
Temporal Position Sequence (0020,9310) 1 Identifies the temporal position of the plane of this frame. Only a single Item shall be included in this sequence.
>Temporal Position Time Offset (0020,930D) 1 Time offset of the frame in the set of frames with different temporal positions, in seconds.

C.7.6.16.2.24 Image Data Type Macro

Table C.7.6.16.2.24-1 specifies the attributes of the Image Data Type Functional Group macro.

Table C.7.6.16.2.24-1 IMAGE DATA TYPE MACRO

Attribute Name Tag Type Attribute Description
Image Data Type Sequence (0018,9807) 1 Identifies the data type characteristics of this frame. Only a single Item shall be included in this sequence.
>Data Type (0018,9808) 1 Identification of the data type of a frame. See C.7.6.16.2.24.1 for Defined Terms and further explanation.
>Aliased Data Type (0018,980B) 1 Indicates whether this data type is “aliased”. Enumerated Values: YES = data are aliased values NO = data are not aliased values See C.7.6.16.2.24.2 for further explanation.

C.7.6.16.2.24.1 Data Type

Data Type (0018,9808) indicates the data type of an image frame. Table C.7.6.16.2.24.1-1 lists Defined Terms for this value.

Table C.7.6.16.2.24.1-1

DATA TYPE DEFINED TERMS

Defined Term Name Defined Term Description
TISSUE_INTENSITY Tissue intensity typically displayed as grayscale (e.g. B-mode)
TISSUE_VELOCITY Velocity (Doppler shifts) of tissue
FLOW_VELOCITY Velocity (Doppler shifts) of blood flow
FLOW_POWER Power contained in the Doppler signal
FLOW_VARIANCE Statistical variance of blood velocity relative to mean
ELASTICITY Scalar value related to the elastic properties of the tissue
PERFUSION Scalar value related to the volume of blood perfusing into tissue
SOUND_SPEED Speed of sound in tissue
ATTENUATION Reduction in strength of ultrasound signal as the wave traverses through the medium

C.7.6.16.2.24.2 Aliased Data Type

Some data types require special treatment when interpolating data values whose type is “aliased”, such as FLOW_VELOCITY when derived from discrete data samples as is done for PW Doppler or sampled CW Doppler. Values of these types are “cyclical” in that the maximum value should be considered adjacent to the minumum value in any interpolation algorithm. Aliased Data Type (0018,980B) indicates whether modular arithmetic is necessary for the associated data type.

Note: For example, when Data Type (0018,9808) is FLOW_VELOCITY, Aliased Data Type (0018,980B) should be set to YES indicating that an interpolation algorithm should support aliased data. When several FLOW_VELOCITY values near the maximum or minimum are interpolated, this algorithm should produce a value near the maximum or minimum. It would be incorrect to use an interpolation algorithm such as the arithmetic mean, which would erroneously produce a result near the mid-point of the range.