Presentation of CAD/Annotations/Markups - Detailed Proposal

1. Proposed Workitem:

• Proposal Editor: Michael Planchart/Peter Maton
• Profile Editor:
• Domain: Radiology

Summary

PACS image viewing workstations utilize inconsistent means to display Chest CAD/Annotations/Markups.

DICOM has defined the Chest CAD SR to convey the detection and analysis results of a chest CAD device. If PACS image viewing workstation software developing companies had a "one-way" approach defined through an IHE harmonization profile it would be easier for them to be encouraged to adopt it. A Presentation of CAD/Annotations/Markups Profile would require compliant workstations to consume the Chest CAD SR to toggle on/off the markups.

Healthcare providers are showing continued interest in the use of CAD to improve the detection of cancer nodules and other abnormalities in Chest X-Rays.

DICOM offers so many different approaches to the presentation of CAD/Annotations/Markups that has caused each vendor to implement it in various ways and often interpreting differently the same standard. By means of an IHE harmonization profile they would have one defined way of

2. The Problem

CAD and clinical processing applications create processed images with annotations/markups. Different products are using different mechanisms for the markup, e.g.:

• burned into the DICOM image,

• encoded in the image overlay,

• encoded in separate presentation state graphics,

• encoded in a separate SR,

• rendered onto the image in a separate JPEG

With so many mechanisms, display systems support some of them poorly or not at all, so workflow is disrupted and key information may be inaccessible. The variability also makes it very difficult to create robust hanging protocols.

Of all the methods available the DICOM Structured Report (SR) is the preferred one and by industry-wide consensus, to contain the encoded markups.

3. Key Use Case

• DR/CR Chest X-Ray Lung CAD:

Chest X-Ray Lung CAD devices process the digital images of AP/PA projections (frontal chest) obtained from the DR/CR modalities in order to detect nodules or abnormalities and to identify and mark the coordinates of the regions of interest (ROI).

The CAD processed output shall be delivered as a DICOM Chest CAD SR SOP Class to the PACS server.

The PACS image viewing workstation shall provide the means of toggling on off the markers atop the source image. The markers should be off by default on the PACS viewing workstation. The SR should be independently toggled from other overlays.

4. Standards & Systems

• DICOM – Chest CAD SR SOP Class

5. Technical Approach

<This section can be very short but include as much detail as you like. The Technical Committee will flesh it out when doing the effort estimation.>

<Outline how the standards could be used/refined to solve the problems in the Use Cases. The Technical Committee will be responsible for the full design and may choose to take a different approach, but a sample design is a good indication of feasibility.>

<If a phased approach would make sense indicate some logical phases. This may be because standards are evolving, because the problem is too big to solve at once, or because there are unknowns that won’t be resolved soon.>

Existing actors

<Indicate what existing actors could be used or might be affected by the profile.>

New actors

• DR/CR Modalities
• Chest CAD Device
• PACS
• PACS Image Viewing Workstation

Existing transactions

<Indicate how existing transactions might be used or might need to be extended.>

New transactions (standards used)

<Describe possible new transactions (indicating what standards would likely be used for each. Transaction diagrams are very helpful here. Feel free to go into as much detail as seems useful.>

Impact on existing integration profiles

<Indicate how existing profiles might need to be modified.>

New integration profiles needed

<Indicate what new profile(s) might need to be created.>

Breakdown of tasks that need to be accomplished

<A list of tasks would be helpful for the technical committee who will have to estimate the effort required to design, review and implement the profile.>

6. Support & Resources

<List groups that have expressed support for the proposal and resources that would be available to accomplish the tasks listed above.>

7. Risks

<List technical or political risks that will need to be considered to successfully field the profile.>

8. Open Issues

<Point out any key issues or design problems. This will be helpful for estimating the amount of work and demonstrates thought has already gone into the candidate profile.>

9. Tech Cmte Evaluation

<The technical committee will use this area to record details of the effort estimation, etc.>

Effort Evaluation (as a % of Tech Cmte Bandwidth):

• 35% for ...

Responses to Issues:

See italics in Risk and Open Issue sections

Candidate Editor:

TBA