Here are the summary notes from the latest DICOM Working
Group 6 Meeting (WG-06).
WG-06 meets 5 times a year to do technical review and harmonization of the output from the 30 DICOM Working Groups.
Current progress on new DICOM supplements (new chapters to The Standard) is shown below. Also change proposals (bug fixes in The Standard) are shown grouped into voting packages (CPacks).
This Supplement defines a set of Representational State Transfer (REST) Services for interfacing with the Unified Procedure Step Services. This could be implemented as a proxy to an existing UPS service or as a web service interacting directly with a Workflow Manager.
A clarification discussion took place on when and from whom associations are opened. There are different approaches for UPS-RS user agent initiation and the DIMSE approach.
The DICOM Web service provides a RESTful interface to the UPS Sop Class and provides a set of action types. After careful consideration it was decided that the action types shall all be supported.
The supplement is agreed to go into final text and become part of the standard text.
This supplement defines use cases and storage of information related to quantitative parametric maps. In general, the term "parametric map" is loosely used to referred to any derived image whose pixel values have a quantitative meaning (e.g., CT HU versus arbitrary MR signal intensity).
Examples of parametric maps include parameters of pharmacokinetic models, such as Ktrans of the Tofts model used in DCE-MRI regional cerebral blood volume (RCBV) or flow (RCBF) used in perfusion CT normalized values based on body size, such as SUVbw used in PET diffusion parameters such as Apparent Diffusion Coefficient (ADC) used in MR DWI.
The objects described in this supplement are like secondary captures for numbers.
The remarks from the Letter Ballot request have been incorporated in the document: Consistent use of double and float Condition is necessary to make sure sending only one of pixel data, float pixel data or double float pixel data.
A discussion occurred where to add this non-mixing restriction in the text. Should general prohibition or a more specific constraint in the Parametric Map IOD as it is now. A general prohibition was agreed upon. This is more robust for display work stations.
The supplement was voted approved to be integrated in the standard as final text.
This supplement introduces the Planar MPR Volumetric Presentation State object to the standard.
The goal is to be able to present the same or close to the same volume view on imaging data (XA-3D, MR, CT enhanced objects and others) with a general volumetric presentation state object regardless of computing and displaying system and vendor. The supplement is the first of a series of supplements. The first one focuses on MPR.
A discussion occurred regarding if the creator needs to choose between cross curve animation method and multiple related presentation state method. This is similar to the decision for a creator to send information as a set of single frames or as one multi frame image.
Normally one presentation state covers on display window. This would fit with the multiple related presentation state method. The animation method would be more useful in a sequential scroll through in one window.
The working group will remove one of the methods or add normative text to guide when to use which one after internal discussions.
The working group presented the recommendations for animated presentations. The example used was cross curve. The viewing application moves the planar MPR view along a curve in the volume.
A further example was presented: The use of annotations in volume space. During an intervention trajectory planning lines representing a needle is introduced to help for further treatment. Visibility and clipping was discussed.
The supplement is approved to go out for letter ballot.
This Supplement delivers explanatory information on the usage of DICOM attributes for X-Ray 3D Angiographic Image IOD:
The set of supplements introduces the 2nd generation of radiotherapy objects to reflect the advances in modern radio therapy. Today's workflows in radiation oncology are increasingly dynamic along the whole course of treatment, requiring electronic workflow management and other objects of smaller scope than in the 1st generation objects.
The representation of an RT Prescription, which is only rudimentary available in the 1st generation objects and embedded as an extension of a RT Plan, needs its own IOD.
Other aspects like the important 3D modeling and patient position management, expandability to future treatment technologies, streamlining representation of beam and dose data also call for new approaches.
The 2nd generation objects addresses those needs by various means, e.g.:
The complete name of the new supplement is MPEG-4 AVC/H.264 Transfer Syntax.
This supplement describes two new Transfer Syntaxes to embed MPEG-4 Advanced Video Coding (AVC) / H.264 High Profile / Level 4.2 (HiP@Level4.2) and H.264 Stereo High Profile /Level 4.2 encoded pixel data in DICOM. It does not introduce any new SOP Classes or IODs.
Transfer Syntax MPEG-4 AVC High Profile will perform consistent with the ITU-T H.264 HiP@Level4.2. This will enable the storage of video files with a resolution of 1920x1080 at 50Hz/60Hz.
Transfer Syntax MPEG-4 AVC Stereo High Profile will perform consistent with the ITU-T H.264 Stereo High Profile at Level 4.2. This will enable the storage of video files where higher compression can be achieved due to inter-view prediction. An example of the use would be in binocular operational microscopy.
This proposed supplement includes Addenda to existing Parts of DICOM:
The supplement applies to all modalities in which radiographic, radiopharmaceutical or other imaging agents are introduced into a circulatory system in a controlled fashion (CT, MR, XA, NM, US).
Following are the new SOP Classes introduced to describe administration events, flows, pressure, timings, physio-chemical attributes and pharmacological attributes of the agent administration and also consumables related to the administration.
These SOP classes do not describe radioactivity or dosimetry administered.
- The Defined Substance Administration SR is for defining generic substance administration protocols for known generic study protocols.
- The Planned Substance Administration SR Storage SOP Class is intended for representing the plan or program to deliver imaging agent customized to a specific patient.
- The Performed Substance Administration SR is for reporting the actual plan or program that was used to deliver the diagnostic imaging agent during a medical imaging study.
- In addition, the Basic Performed Substance Administration provides a summarized version of the performed substance administration. This is an attribute based class instead of a SR document. The primary use of this class is for communicating administration data to a modality system during an imaging study.
A walk through with corrections and improvements of attributes, conditions and codes was performed.
The supplement stays in a draft state.
The decision was made that there will be three separate services for restful rendering.
The services are divided into three groups: DICOM Services, Rendered Services, Rendered Presentation State Service.
The services retrieve one of the following: Retrieve DICOM Study, Series and Instances, Retrieve Rendered Study, Series and Instances, Retrieve Presentation State Series or Instance.
Basic Image Review Functionality contains Layout, Tiling, Selection, Rotation by 90 degree, increments, Flip horizontal, Windowing, Zoom, Pan and Laterality Overlay
The closed issues were discussed. The point of adding vendor specific parameters was scrutinized. Both server and client should be allowed too ignore additional parameters introduced by a product implementer.
The supplement stays in a draft state.
Web Services Re-documentation is the name of the supplement which is restructuring part 18 of the DICOM standard.
A first draft of part 18 in DICOM was presented. The main idea is to harmonize with other standards through a restructuring. The use of common vocabulary is an essential goal of this effort.
The structure of the document is: