In-concatenation Total Number Attribute
| Tag | (0020,9163) |
|---|---|
| Type | Optional (3) |
| Keyword | InConcatenationTotalNumber |
| Value Multiplicity | 1 |
| Value Representation | Unsigned Short (US) |
The number of SOP Instances sharing the same Concatenation UID.
If present, shall have a value greater than one, unless an IOD overrides this constraint to enumerate a value of 1 to prevent the use of Concatenations (e.g., see Section C.8.17.7 and Section C.8.17.16).
Section C.8.17.7
C.8.17.7 Ophthalmic Tomography Image Module
Table C.8.17.7-1 specifies the Attributes of the Ophthalmic Tomography Image Module, which describe an Image produced by Ophthalmic Tomography imaging modalities.
Table C.8.17.7-1. Ophthalmic Tomography Image Module Attributes
|
Attribute Name |
Tag |
Type |
Attribute Description |
|---|---|---|---|
|
Ophthalmic Volumetric Properties Flag |
(0022,1622) |
1C |
Whether this SOP Instance is suitable for OCT volumetric processing. Required if this SOP Instance is suitable for OCT volumetric processing. May be present otherwise. Enumerated Values:
|
|
Image Type |
(0008,0008) |
1 |
Image identification characteristics. See Section C.7.6.1.1.2 for Enumerated Values and Defined Terms and further explanation. |
|
Samples Per Pixel |
(0028,0002) |
1 |
Number of samples (planes) in this image. See Section C.7.6.3.1.1 for further explanation. Enumerated Values:
|
|
Acquisition DateTime |
(0008,002A) |
1 |
The date and time that the acquisition of data started. NoteThe synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800). |
|
Acquisition Duration |
(0018,9073) |
1C |
The scan time in seconds used to create all frames of an Ophthalmic Tomography image. Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise. |
|
Acquisition Number |
(0020,0012) |
1 |
A number identifying the single continuous gathering of data over a period of time that resulted in this image. |
|
Photometric Interpretation |
(0028,0004) |
1 |
Specifies the intended interpretation of the pixel data. Enumerated Values:
|
|
Pixel Representation |
(0028,0103) |
1 |
Data representation of pixel samples. Enumerated Values:
|
|
Bits Allocated |
(0028,0100) |
1 |
Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Enumerated Values:
|
|
Bits Stored |
(0028,0101) |
1 |
Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. Enumerated Values:
|
|
High Bit |
(0028,0102) |
1 |
Most significant bit for pixel sample data. Each sample shall have the same high bit. High Bit (0028,0102) shall be one less than Bits Stored. |
|
Presentation LUT Shape |
(2050,0020) |
1 |
Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values:
|
|
Lossy Image Compression |
(0028,2110) |
1 |
Specifies whether an Image has undergone lossy compression (at a point in its lifetime). Enumerated Values:
Once this value has been set to "01" it shall not be reset. See Section C.7.6.1.1.5. |
|
Lossy Image Compression Ratio |
(0028,2112) |
1C |
Describes the approximate lossy compression ratio(s) that have been applied to this image. Required if Lossy Image Compression (0028,2110) is "01". |
|
Lossy Image Compression Method |
(0028,2114) |
1C |
A label for the lossy compression method(s) that have been applied to this image. Required if Lossy Image Compression (0028,2110) is "01". |
|
Burned In Annotation |
(0028,0301) |
1 |
Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values:
|
|
Recognizable Visual Features |
(0028,0302) |
3 |
Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values:
If this Attribute is absent, then the image may or may not contain recognizable visual features. |
|
Concatenation Frame Offset Number |
(0020,9228) |
1 |
Offset of the first frame in a multi-frame image of a concatenation. Enumerated Values:
|
|
In-concatenation Number |
(0020,9162) |
1 |
Identifier for one SOP Instance belonging to a concatenation. Enumerated Values:
|
|
In-concatenation Total Number |
(0020,9163) |
1 |
The number of SOP Instances sharing the same Concatenation UID (0020,9161). See Section C.8.17.16.3 for further explanation. Enumerated Values:
|
|
Image Comments |
(0020,4000) |
3 |
User-defined comments about the image. |
The value constraints on Concatenation Frame Offset Number (0020,9228), In-concatenation Number (0020,9162), and In-concatenation Total Number (0020,9163) have the effect of preventing the use of concatenations.
The Attribute Ophthalmic Volumetric Properties Flag (0022,1622) is YES when the Ophthalmic Tomography Image Storage SOP Instance encodes volumetric spatial information (e.g. Frame of Reference, Pixel Measures, Plane Orientation, Plane Position, etc.). For example, ophthalmic tomography volumetric information is required when implementations encode Surface Segmentation SOP Instance(s) (e.g., surface segmentation is applied to the structural OCT volume to delineate the anatomical boundaries) and/or an Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Storage SOP Instance (e.g., angiographic (blood flow) volume information) based upon the volumetric Ophthalmic Tomography Image Storage SOP Instance.
Section C.8.17.16
C.8.17.16 Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Image Module
Table C.8.17.16-1 specifies the Attributes of the Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Image Module.
Table C.8.17.16-1. Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Image Module Attributes
|
Attribute Name |
Tag |
Type |
Attribute Description |
|---|---|---|---|
|
Image Type |
(0008,0008) |
1 |
Image identification characteristics. Enumerated Values for Value 1:
Enumerated Values for Value 2:
|
|
Instance Number |
(0020,0013) |
1 |
A number that identifies this SOP Instance. |
|
Content Time |
(0008,0033) |
1 |
The time the image pixel data creation started. |
|
Content Date |
(0008,0023) |
1 |
The date the image pixel data creation started. |
|
Bits Allocated |
(0028,0100) |
1 |
Number of bits allocated for each pixel sample. Enumerated Values:
|
|
Bits Stored |
(0028,0101) |
1 |
Number of bits stored for each pixel sample. |
|
High Bit |
(0028,0102) |
1 |
Most significant bit for pixel sample data. Shall be one less than the value in Bits Stored (0028,0101). |
|
Samples per Pixel |
(0028,0002) |
1 |
Number of samples (planes) in this image. Enumerated Values:
|
|
Photometric Interpretation |
(0028,0004) |
1 |
Specifies the intended interpretation of the pixel data. Enumerated Value: MONOCHOME2 |
|
Pixel Representation |
(0028,0103) |
1 |
Data representation of pixel samples. Enumerated Values: 1 |
|
Presentation LUT Shape |
(2050,0020) |
1 |
Specifies an identity transformation for the Presentation LUT such that the output of all grayscale transformations are defined to be in P-Values. Enumerated Values:
|
|
Lossy Image Compression |
(0028,2110) |
1 |
Specifies whether an Image has undergone lossy compression (at a point in its lifetime), or is derived from lossy compressed images. Enumerated Values:
Once this value has been set to "01" it shall not be reset. See Section C.8.32.2.1 and Section C.7.6.1.1.5. |
|
Lossy Image Compression Ratio |
(0028,2112) |
1C |
Describes the approximate lossy compression ratio(s) that have been applied to this image. Required if present in the source images or this IOD Instance has been compressed. |
|
Lossy Image Compression Method |
(0028,2114) |
1C |
A label for the lossy compression method(s) that have been applied to this image. Required if present in the source images or this IOD Instance has been compressed. See Section C.8.32.2.1. |
|
Burned In Annotation |
(0028,0301) |
1 |
Indicates whether or not image contains sufficient burned in annotation to identify the patient and date the image was acquired. Enumerated Values:
|
|
Recognizable Visual Features |
(0028,0302) |
1 |
Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values:
|
|
Acquisition Method Algorithm Sequence |
(0022,1423) |
1 |
Software algorithm used by the acquisition method. Only a single Item shall be included in this Sequence. |
|
>Include Table 10-19 “Algorithm Identification Macro Attributes” |
For Algorithm Family Code Sequence (0066,002F) BCID 4270 “OCT-A Processing Algorithm Family”. |
||
|
OCT B-scan Analysis Acquisition Parameters Sequence |
(0022,1640) |
1 |
Conveys raw data parameters captured during the B-scan acquisition process. One or more Items are permitted in this Sequence. More than one Item indicates that multiple scan patterns have been used to acquire the raw data. See Section C.8.17.16.2 for further explanation. |
|
>Scan Pattern Type Code Sequence |
(0022,1618) |
1 |
The scan pattern type used to generate this SOP Instance. Only a single Item shall be included in this Sequence. |
|
>Number Of B-scans Per Frame |
(0022,1642) |
1 |
The number of B-scans performed at the same spatial location (B-scan slab). See Section C.8.17.16.2 for further explanation. |
|
>B-scan Slab Thickness |
(0022,1643) |
1 |
Nominal thickness of each B-scan slab, in mm. See Section C.8.17.16.2 for further explanation. |
|
>Distance Between B-scan Slabs |
(0022,1644) |
1 |
Nominal distance between adjacent B-scan slabs, in mm. See Section C.8.17.16.2 for further explanation. |
|
>B-scan Cycle Time |
(0022,1645) |
1C |
Nominal time (in msec) between individual B-scans. See Section C.8.17.16.1.1 for further explanation. Required if B-scan Cycle Time Vector (0022,1646) is absent. |
|
>B-scan Cycle Time Vector |
(0022,1646) |
1C |
An array that contains the real time increments (in msec) between B-scans. See Section C.8.17.16.1.1 for further explanation. Required if B-scan Cycle Time (0022,1645) is absent. Notescan time + latency between B-scans |
|
>A-scan Rate |
(0022,1649) |
3 |
Frequency, in kHz, of the A-scan used to acquire the raw image data. |
|
>B-scan Rate |
(0022,1650) |
3 |
Frequency, in Hz, of the B-scan used to acquire the raw image data. |
|
Concatenation Frame Offset Number |
(0020,9228) |
1 |
Offset of the first frame in a multi-frame image of a concatenation. Enumerated Values:
|
|
In-concatenation Number |
(0020,9162) |
1 |
Identifier for one SOP Instance belonging to a concatenation. Enumerated Values:
|
|
In-concatenation Total Number |
(0020,9163) |
1 |
The number of SOP Instances sharing the same Concatenation UID (0020,9161). See Section C.8.17.16.3 for further explanation. Enumerated Values:
|
|
Image Comments |
(0020,4000) |
3 |
User-defined comments about the image. |
C.8.17.16.1 Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Image Module Attribute Descriptions
C.8.17.16.1.1 B-scan Cycle Time and B-scan Cycle Time Vector
The B-scan Cycle Time (0022,1645) is the nominal scan time (in milliseconds) plus the latency between the individual repeats of the B-scan at the same location. The B-scan Cycle Time Vector can be used if the time for the repeats are not uniform. Either the B-scan Cycle Time (0022,1645) or the B-scan Cycle Time Vector (0022,1646) are required.
B-scan Cycle Time shall be used in the following manner to calculate 'the relative time' for each B-scan:
-
B-scan Cycle 'Relative Time' (n) = B-scan Cycle Delay + B-scan Cycle Time * (n-1)
where:
-
n = number of B-scan cycles within the frame and the first B-scan number is one
Note
When there is only one B-scan present, B-scan Cycle Time (0022,1645) may have either a value of 0, or a nominal value that would apply if there were multiple B-scans.
B-scan Cycle Time Vector (0022,1646) is an array that contains the time increments (in milliseconds) between the nth B-scan cycle and the previous B-scan cycle for a frame. The first B-scan cycle always has a time increment of 0. The B-scan Cycle Time Vector shall be used in the following manner to calculate 'relative time' T(n)for B-scan Cycle n:
where Δti is the ith B-scan Cycle Time Vector component.
C.8.17.16.2 Ophthalmic Optical Coherence Tomography B-scan Volume Analysis Acquisition Parameters Expected Use
The acquisition technique of ophthalmic tomography B-scan volume analysis (e.g., OCT angiography blood flow information) is based on the same mechanism as used for ophthalmic tomography images. Therefore, B-scans are used for individual image frames of the acquired volume. The frames of the resulting volume are calculated based on a number of repeated B-scans at the same spatial location. So the frame of an Ophthalmic Tomography B-scan Volume Analysis SOP Instance is not a B-scan, but a data aggregation of B-scans from the raw data of the acquisition.
To convey the information about the acquisition of the raw data, which are not typically in the scope of DICOM, the OCT B-scan Analysis Acquisition Parameters Sequence (0022,1640) is used. The parameters are provided for the user to assess the quality of the resulting B-scan volume analysis as well as to provide a means to compare volumes created by different devices. Furthermore the user is able to identify if a vendor-recommended protocol has been used to acquire the raw data.
The OCT B-scan Analysis Acquisition Parameters Sequence contains at least one Item. It can contain more than one if multiple scan patterns have been used to acquire the raw data and are used to calculate the volume data.
Number of B-scans Per Frame (0022,1642) can be used to provide an indication about the resulting image quality. In principal, the more B-scans averaged the better but as a high number of scans slows down the acquisition process, the resulting data becomes prone to noise introduced by eye movements, which are not related to blood flow. Furthermore, the number of B-scans averaged can be used to determine whether the acquisition was based on a vendor-specific protocol, or if the user changed the protocol.
The B-scan Slab Thickness (0022,1643) and Distance Between B-scan Slabs (0022,1644) provide information about the density of the sampling pattern used to acquire the volume data. The calculation of the volume (Ophthalmic Tomography B-scan Volume Analysis SOP Instance) is based on this information.
C.8.17.16.3 Data Subsets
Applications may find it useful to break up an OPT image or B-scan volume into multiple data subsets. There are two mechanisms in DICOM to achieve this: Concatenations and Multiple SOP Instances.
Concatenations are not permitted in the Ophthalmic Tomography Image and Ophthalmic Optical Coherence Tomography B-scan Volume Analysis IODs.
However, an OPT image or a B-scan volume can be encoded in multiple SOP Instances. For example:
-
All frames of the volume are collected and transmitted in one multi-frame SOP Instance (e.g., one SOP Instance with 30 frames).
-
Each frame of the volume is transmitted in one SOP Instance where the number of frames is equal to one (e.g., 30 SOP Instances with 1 frame each).
-
The frames in the volume are transmitted in multiple SOP Instances (e.g., 3 SOP Instances with 10 frames each).