Sup243
Label Map Segmentation
This Supplement describes addition of a Label Map
Segmentation IOD to DICOM to encode classification of
entities.
Currently, the DICOM standard supports an IOD and SOP
Class for pixel- or voxel-based segmentation encoding (as distinct
from the representation of segmented objects as surfaces in the
surface segmentation and encapsulated 3D object IODs and SOP Classes),
in which each segmented property is represented as a binary bit plane
(or an 8 bit probabilistic or occupancy value).
While this allows for overlapping of segments, it is
inefficient and difficult to encode large numbers of
non-overlapping segmentations, as they require non-trivial
processing both to extract from the bit plane encoded
data, to assure there is no overlap, and to convert to the
label map form that is very commonly used internally and
persistently for clinical applications.
The current DICOM bit-plane-based segmentation methods
have proven to be awkward both for 3D cross-sectional
imaging applications when there are very large numbers of
slices and/or structures, and for whole slide microscopy
imaging, when there are very large numbers of tiles and/or
property classes.
They are also typically large and sparse and should
compress well but there are very few single bit
compression schemes supported by the standard and they do
not do well with these types of images.
This Supplement defines a label map segmentation enhanced
multi-frame IOD that specifies a data structure that
provides, for each pixel or voxel in 2D, 3D or tiled
pyramidal space, an index value conveying the
non-overlapping segment for each pixel.
Existing data elements for describing segmentations are
reused where appropriate.
Bit depth is sufficient (8, 16) to encode large numbers of
segments but allow for more compact encoding.
The existing palette color photometric interpretation may
be used (instead of monochrome) if colors are to be
suggested, to leverage the widespread implementations in
toolkits, and to allow for the use of existing lossless
com- pression schemes.
Segment properties are conveyed in the existing segment
description structure so as to be compatible with the
existing bit plane segment descriptions.
Re-using the segment description does not prevent the use
of separately encoded or well- known DICOM color palette
objects.
The scope is confined to label maps for "classes" (what
"class" a segment represents) but not "instances' (which
"instance" of a "class" is represented), where classes and
instances are separately communicated by the pixel value
(e.g., if one wants to individually identify nuclei rather
than treat them all as being of one class).
This might be the subject of a future extension.
The scope is confined to a single label map, which does
not allow for overlap of different segments.
If overlapping of multiple label maps is required,
separate SOP Instances may be created.
Issues related to the efficient representation (or
avoidance) of the Per-Frame Functional Group Sequence (in
which, for every frame, the Referenced Segment Number is
specified) are out of scope, and may be addressed in a
separate Supplement or CP if necessary.
This supplement was voted ready as final text and is
incorporated in publication 2024d.
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Sup242
Ultrasound Fetal Cardiac SR Extensions
This supplement to the DICOM Standard introduces new SR
template content to address fetal cardiac assessments in
echo reports.
Current clinical practice and technology for fetal cardiac assessments
using ultrasound have progressed since Sup78 was published, which
introduced TID 5220 "Pediatric, Fetal and Congenital Cardiac
Ultrasound Reports" and sub-template TID 5228 "Cardiac Ultrasound
Fetal Measurement Section".
Practice now includes many more measurements beyond visual
assessment. For example, additions will address:
- measurements of the ventricles, atria, septa and valves,
- measurements of fetal arrhythmia and hemodynamics,
- assessment of the fetal cardiovascular profile score (CVPS)
Many measurements described for pediatric echo are also potentially relevant for fetal echo, particularly at later stages of fetal development.
To that end, TID 5221 is now included in TID 5228, making any of those measurements readily available as needed and appropriate.
Also, CID 12279, which is titled Cardiac Ultrasound Fetal General Measurement, is pruned here based on usage experience to list just general fetal measurements that are specifically relevant to cardiac fetal ultrasound.
CID 12005 Fetal Biometry Measurement already covers fetal measurements relevant to a non-cardiac fetal ultrasound. Since CID 12279 is extensible, any existing implementations with unexpected usages will not be invalidated.
This supplement was voted ready as final text and is incorporated in publication 2024d.
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Sup240
Heightmap Segmentation
This Supplement introduces a new Heightmap Segmentation IOD and SOP
Class.
Heightmaps in computer graphics are defined as a two-dimensional
raster image used to store surface elevations that can later be
applied to a three-dimensional object.
In its DICOM use, heightmap is a type of segmentation using a 2D set
of pixels to identify a surface in the 3D volume of a referenced
multi-frame image.
In the degenerate case, it can identify the intersection of a surface
with a single image plane, i.e., a 1D raster for a 2D object.
The Heightmap Segmentation IOD follows the current enhanced
multi-frame image data architecture.
For data management purposes, e.g., with Media Exchange, Heightmap
Segmentation SOP Instances may be treated similarly to other
segmentation images.
While intended to be broadly applicable for a variety of medical
imaging domains, the initial use case is in ophthalmic tomography
(OPT) for representing segmentation of retinal layers.
Further description of Heightmap Segmentation is found in the proposed
informative annex to PS3.17.
This Supplement also revises the current Ophthalmic Optical Coherence
Tomography En Face Image IOD, which had required use of Surface
Segmentation SOP Instances to specify a retinal layer, to allow use of
any type of segmentation SOP Instances, including Heightmap
Segmentation or other (including future) SOP Classes.
The reference to the segmentation object in the En Face Image object
enables traceability of the processing steps that produced the
image. It is not necessarily the case that a receiving application
could reproduce the En Face Image from the original source Ophthalmic
Tomography Image(s) and the referenced segmentation object(s).
This supplement was voted ready as final text and is
incorporated in publication 2024d.
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Sup232
JPEG XL
This supplement adds lossless, JPEG recompression and
general JPEG XL Transfer Syntaxes.
JPEG XL has the following desirable features:
- JPEG XL has demonstrated improved compression of color images
- Existing Baseline JPEG images can be transcoded without additional loss to smaller JPEG XL images (particularly useful for WSI)
- Supports multi-frame encoding more effectively than animated gif, the only other multiframe rendered format
- JPEG XL has both lossless and lossy modes that can be natively displayed in some browsers
- Has flexible encoding options (including > 8 bits, single bit)
JPEG XL is also added to the set of rendered formats for DICOMweb.
- It avoids the need to transcode into JPEG
- Performance is adequate even with WASM based decoders
This supplement was voted ready as final text and is incorporated in publication 2024d.
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Sup228
DICOMweb API for Server Volumetric Rendering
This supplement introduces Volumetric Rendering web
services and a Volumetric Rendering Protocol IOD to
enable Volume Rendering (VR), Maximum Intensity
Projection (MIP), and Multiplanar Planar Rendering
(MPR) without having to specify the numerous and
complex parameters required to do so.
Web services enable a user agent to initiate
server-side 3D volumetric rendering by specifying
Query Parameters and/or referencing a Volumetric
Rendering Protocol, or a Volumetric Presentation
State.
The Resources introduced in the Supplement derive
Query Parameters from Volumetric Presentation State
attributes while maintaining alignment with current
DICOMweb Studies Rendered Resources.
The Volumetric Rendering Protocol IOD is a
Non-Patient Instance within the Defined Procedure
Protocol IOD family.
Its primary function is to facilitate the creation
of predefined renderings, by establishing criteria
and organizing image set inputs for rendering, and
specifying Volumetric Rendering parameters, such as
rendering algorithms, geometry, color, shading, and
lighting.
This supplement was voted ready as final text and is
incorporated in publication 2024d.
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Sup244
Frame Deflate Transfer Syntax
This Supplement adds a new Transfer Syntax primarily for
single bit segmentation encoding, which is otherwise not
well supported.
There is a need to be able to store and transfer encoded
single frames (such as for DICOMweb) rather than the
entire dataset for those applications where only selected
frames of a multi-frame object are required (such as for
selected tiles at selected resolutions for whole slide
images that have been segmented, or multi-organ
segmentations of large volumetric CT or MR
datasets).
Currently, the DICOM standard supports a means of single
bit representation of binary segmentations with a Bits
Stored and Bits Al- located of 1, and these can grow
extremely large, especially when segmenting at the full
resolution of the underlying image (e.g., for whole slide
imaging).
If compressed, they need to be mathematically reversibly
(losslessly) compressed. The existing Deflate Transfer
Syntax (algorithm used in zip and gzip) is reasonably
effective, but applies to the entire data set (including
the "metadata" and all the frames treated as a single
stream).
Frame-based pixel data compression schemes currently in
the standard generally do not support single-bit, with the
exception of RLE and J2K (CP 2301), neither of which
achieves as high a compression ratio as Deflate does for
segmentation data.
Other alternative lossless compression codecs designed for
single bit use (such as for fax using CCITT Group 4 (ITU-T
T.6), JBIG, or JBIG2) were considered, which though they
compress more effectively, were not considered widely
enough supported to justify the complexity for this use
case at this time. Other general purpose compressors do
slightly better than Deflate, but again, not so much
better that they justify their addition to the standard at
this time, though they may be considered in future if
other use cases justify them.
This supplement was voted to be ready to go out for
Letter Ballot.
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Sup236
Waveform Presentation State
This supplement introduces Service Classes for
storage and exchange of presentation information for
DICOM waveform objects by adding a Waveform
Presentation State IOD. The Waveform Presentation
State object stores the display montages,
i.e. calculative combinations of recorded channels,
display filter and other display properties as well
as arbitrary Annotations.
This supplement adds
- a new Waveform Presentation State IE.
- a SOP Class to store Waveform Presentation States and the related Modules.
In cardiology, technicians annotate previously recorded waveforms (e.g. from home monitoring Holter ECG) and highlights areas of interest. This information is essential input for the cardiologist who reviews the ECG and finally provides the report.
This supplement was voted to be ready to go out for Letter Ballot.
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Sup245
RDSR Informative Annex
This Supplement provides explanatory information on
the creation and usage of RDSR (traditional and
enhanced) within Angiography, Mammography,
Radiography, CT, Dentistry modalities etc.
This supplement excludes Radiopharmaceutical and
Patient Radiation Dose SR.
Given the modality-specific content definition of
the RDSR, and the many different types of system
configurations existing in the field, it becomes
challenging for the manufacturers to have a clear
understanding of the precise requirements for each
type of device.
The purpose of this supplement can be summarized as
follows:
- Give more information beyond the definitions
in PS 3.16: describe real-world scenarios of
typical equipment configurations, provide
examples and encoding guidelines;
- Indicate restrictions on the applicable
scenarios (defined terms recommended, values
ranges, recommended presence of Content
Items);
- Promote usage of optional Content Items
under particular scenarios;
- Assess the applicability for some
conditional Content Items under particular
scenarios;
The scope of the proposed Supplement includes:
- An overview of the landscape of different
modalities and types of equipment
configuration, from simple legacy CR to
modern integrated Angio equipment.
- Guidance on how to use the different TIDs
and Content Items depending on the modality,
equipment types and configurations.
This supplement will be further presented and
discussed in the base standard group before going
out for Public Comments.
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Sup241
Structural Heart SR Template
This supplement introduces SR templates for
Structural Heart Procedures.
These procedures involve interventions aimed at
addressing various conditions or abnormalities
affecting the structures of the heart, excluding the
coronary arteries.
Unlike open-heart surgery, these interventions are
characterized by their minimally invasive nature or
catheter-based approach.
Periprocedural imaging follows a consistent pattern
of three phases: pre-operative assessment,
intraprocedural assessment, and follow-up.
Throughout all three phases, echocardiography
emerges as the primary imaging modality.
X-ray angiography is predominantly utilized for
intraprocedural guidance.
CT may also find application in the pre-operative
assessment and follow-up.
The templates proposed in the supplement are based
the Simplified Adult Echocardiography Templates
(root TID 5300), modified to support multimodality
image acquisition.
Structural Heart Procedures include:
- TAVI: Transcatheter Aortic Valve implantation
- TAVR: Transcatheter Aortic Valve Replacement
- TTVP: Transcatheter Tricuspid Valve Procedure
- TTVR: Transcatheter Tricuspid Valve Repair
- TEER: Transcatheter Edge-to-Edge Repair
- TMVr: Transcatheter Mitral Leaflet Clip Procedure
- TMVR: Transcatheter Mitral Valve Replacement
- LAAC: Left Atrial Appendage Closure
This supplement will be further presented and discussed in the base standard group before going out for Public Comments.
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Sup246
DICOMWeb Modality Services
The DICOMweb Modality Services extends the
existing DICOMweb services, mimicking the Modality
Worklist (MWL) and Modality Performed Procedure Step
(MPPS) services that are already available in
DIMSE.
It has been designed with the intention of facilitating
proxies from/to DIMSE to/from DICOMweb Modality
Services.
This supplement describes the way to perform modality
services MWL and MPPS based on DICOM-web's UPS-RS.
This supplement will be further presented and
discussed in WG06 before going out for Public
Comments.
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