Dicom News

January 2014 Bjoern.Nolte@siemens.com

Here are the summary notes from the latest Dicom Working Group 6 Meeting. The progress of all 30 working groups and the state of Dicom supplements (new chapters to the standard) and change proposals (bug fixes in the standard) are reflected.

Volumetric Presentation

Sup 156 Revisit planned for April 2014
Still in concept discussion phase

The supplement has been renamed from multi dimensional presentation state to Volumetric presentation state.

Further, to reduce complexity and speed up the release of the most important part and to gain feedback from implementors, the supplement has been broken down into three separate parts:

  • Planar MPR Volumetric Presentation State
  • Curved MPR
  • Volume Rendering
This supplement will address the first part of the three.

The following assumptions are currently made for this supplement.

It is implementation specific how styles are defined for charachters and annotations as this makes a more consistent user experience.

There is no guidance in the supplement how views are layed out in comparision with other displayed views on the display device. A single Presentation State instance may describe a collection of views if they originate from the same geometric description.

Annotations are always linked to clinical context.

Further a discussion took place regarding if style information to text and line attributes should be part of the standard. It was decided to note this as an open question for public comment.

The document is still in the concept discussion.

View details »

Dicom in XML

Dicom source converted to XML Revisit in June 2014 Part 3 and 16 are prototyped (50% completeness of standard)

David Clunie gave an introductory talk about the result and current state of the transformation of the Dicom 2013 Word format into XML.

In the PDF version derived from the XML content the table of content is with hyperlinks and there are bookmarks. The text is "jumpable". If the user clicks somewhere then the user is taken to the definition.

Part 3 and Part 16 have been partly converted as proof of concept. Especially complicated was to get tables and images right.

The biggest tooling problem was to render the PDF well from Docbook and the templates used.

Equation rendering is still an open issue. The content is work in progress and should not be used for reference. Further work is necessary with cross linking and verifying the content and transformation from MS Word.

A current goal is to get to quarterly releases of the standard.

View details DOCX format»

View details HTML format »

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Web Technology

Working Group 27, not yet as supplements or Change Proposals These extensions of the standard are paramount for interacting with IT

The most important work item for WG27 is to redocument part 18 of the DICOM standard as many newly released supplements kame changes necessary.

J. Philbin highlighted the draft Work Item: The revised Part 18 would have no semantics changes. It would be reorganized for clarity, simplicity, and brevity. Terminology would be unified and use the terminology in the Revised HTTP/1.1 standard.

The following initial decsions have been made:

Initial decisions:

  • Use header fields or resources rather than query parameters.
  • Use media type parameters for transfer syntax and quality factors.
  • Rendering query parameters apply to all objects specified by the request.
  • All RS payloads are multipart
  • Include anonymize parameter and add preferred pseudonym de-identify.
  • The server will return window/level in the part headers of bulk data.
  • Use QIDO or metadata to determine the values of needed fields before rendering and use of RetrieveURL to match the content location of the part containing the image.
  • Use the DICOM presentation pipeline to determine how the image is rendered based on the parameters.
  • Allow bulk data to contain rendered images.
  • Interface for DICOM UPS, Unified Procedure Step. The API proposal contains POST (service, workitem) (modelled after C-Create, N-Action), GET (C-Find),PUT (N-Action). The services are modeled after STOW and QIDO.
  • Results are in XML or JSON format.

X-Ray 3D info annex

Sup 167 Revisit planned for April 2014 Still in concept discussion phase

This Supplement delivers explanatory information on the usage of DICOM attributes for X-Ray 3D Angiographic Image IOD.

The detailed purpose can be summarized as follows:

  • Give more information beyond the definitions in PS 3.3 (detailed text vs. scenarios, examples, drawings, etc.);
  • Identify scenarios where the X-Ray 3D Angiographic Image will be applied;
  • Indicate restrictions on the applicable scenarios (defined terms recommended, values ranges, recommended presence of attributes);
  • Promote usage of Type 3 attributes under particular scenarios;
  • Assess the applicability for some conditional attributes under particular scenarios;
  • Ensure that the introduction of private attributes is a "last resort only" situation.

Some of the concepts described in this Supplement are common to any X-Ray 3D cone-beam reconstruction modality, although the application cases only apply to X-Ray 3D Angiographic SOP Class.

A discussion took place on how to create 3D instances. Should one 3D reconstruction be stored in one X-Ray 3D angiography instance? A proposal came up to merge the reconstruction and the volume into one.

A longer discussion took place on how to best visualize how all the time related attributes work: Frame duration, acquisition duration and when to measure Datetime etc. Diagrams from Part 3 of the standard were scrutinized to use as models for this supplement.

Further changes are planned within the WG2 with a revisit later on in WG6.

View details »

Frame of reference

Future CPs
Preparation for one or more larger change proposals

A white paper was presented which contains issues with the current usage of Frame of Reference and proposals how to improve the handling.

The presenter urged interested to read the text before the next meeting. The purpose is to improve the reliability of frame of reference.

A patient is put in a CT twice, the same frame of reference is used in both cases (which is wrong as the patient has a slightly new position during the second scan). The scenario above is a typical case when a first scan was not good enough. The frame of reference is reused. Then during radio therapy or surgery the wrong spatial information will be used.

The white paper describes typical problems and proposes some solutions. The consuming application can validate that the frame of reference is correct. Registration and timing can be used for validation.

View details »


Information only
Informal discussion

A meeting was held for the Dicos Standard to learn from Dicom regarding how raw data is utilized in Dicom.

DICOS is the little sister standard from DICOM. It standardizes how luggage and persons are checked for threats with XRay in airports.

There are two types of scans done: person whole body and luggage. The goal is to validate that the systems at airports are finding threats.

There are different ways of doing this:

  • Having algorithms on the scanning systems testing if the scanners are finding what they should find.
  • Retrieving data from the scanners and to analyze them somewhere else.

One model used today is for the regulator to interact with the few vendors on the market. The regulator uses a threat finding validator, which interacts with the main vendors' equipment. They validator has become blue prints of the few vendors interfaces.

The main obstacle is to retrieve the vast amount of real time data from the scanners at the many airports and to check the data in one central location. The regulator wants to keep the algorithm secret. If the algorithm was public, it would be easier to circumvent it.

Hence the requirement is to do real time validation. The goal is to standardize how raw CT data is structured in Dicom for CT scanned luggage.

Contrast Inj. SR

Sup 164 Revisit planned for April 2014 Close to ready for Public Comment

The author S. Balasubramanian asked for advice on specific ways to specify attributes, conditions and explaining text on selected paragraphs of the supplement.

Missing modules were added to the IOD definition in a new section, Substance Administration: Interventional module, Enhanced PET and Enhanced Contrast/Bolus to cover possible workflows and codes describing important properties of the workflows.

Further discussions took place on how to make query retrieve more effective.

The working group will revisit WG6 in April 2014.

View details »

2nd Gen RT

Sup 147 Revisit planned for April 2014 Close to ready for Public Comment

The document was further scrutinized regarding consistency and definitions on control points, sub control points and meter sets. Many cleanups were made.

The supplement will be revisited in April 2014.

View details »

Breast Projection XR

Sup 165
Final Text

No further changes. The supplement is now a part of the standard.

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Display Parameters

Sup 124 Revisit planned for April 2014
Ready for Letter Ballot

A walkthrough of the open issues was the proposed form to work on this supplement during the meeting.

A longer discussion took place regarding how computer tablets should be handled within the example of Display System SOP.

A further discussion took place on test patterns, specifically how to document if a test pattern image has the right bit depths and resolution for the display. Minor updates throughout tables and with attributes were discussed and performed.

This supplement was voted as approved for Letter Ballot.

View details »

Dose SR

Sup 159
Final text

The complete name is "Radiopharmaceutical Radiation Dose Reporting"

This supplement was voted as approved for Final Text. It is now a part of the standard.

View details »

Echocardiography Report

Sup 169 Revisit planned for April 2014
Early content

This supplement to the DICOM Standard introduces a simplified SR template for Adult Echocardiography measurements.

It provides similar content to that of TID 5200 while addressing details that were the source of interoperability issues; in particular, varying degrees and patterns of pre- and post-coordination, multiple codes for the same concept and numerous optional descriptive modifiers.

Input from European Association of Electrocardiography is requested.

This supplement is still in an early phase.

View details »

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