Integrating the Healthcare Enterprise

1. Integrating the Healthcare Enterprise What’s New in DICOM Robert Horn AGFA Healthcare

2. Significant Extensions to DICOM • Upgrades to existing modalities • Additions of new modality objects • Safety and Security • User Interface support • Coordination with other standards • Compression improvements

3. Upgrading Modalities • First, MR • Then, CT • Now, XA/XRF • Continues use of multi-frame with functional group macros to capture more frame to frame relationships than just time. • Concatenations for improved network performance and streaming • Incorporate standard DICOM attributes to describe the new information gathered by modern XA and XRF equipment. • (See the CT/MR demonstration for an illustration of the improvements provided by the multi-frame objects with functional group descriptions.)

4. Ion Therapy • A new SOP class to describe the use of ion beam radiation therapy machines. • Extensive detail on beam setting options • Enhancements to patient position and fixation devices that will be retrofitted to other therapy systems. • Fits into the therapy workflows already defined for other kinds of radiation therapy machines.

5. Radiation Dose • A structured report to describe the radiation dose from various forms of projection X-ray devices: CR, DX, Angiography, Flouroscopy, etc. • Three levels of detail for the description • Based on recent IEC recommendations for reporting radiation dose • Addition of CTDIvol information to both the old and the new CT objects. • More extensive structured report, like that for projection radiography, awaits agreed recommendations from the CT radiation dose experts.

6. Radiation dose (contd) • Patient records reports are not defined. The structured report describes the dose from each individual irradiation event so that overall patient dose can be analyzed. • Radiation dose reports can describe any irradiation event, and need not correspond to diagnostic studies.

7. CT/MR CardiovascularReport • An evidence document that captures measurement data derived from either CT or MR observations of the cardiovascular system. • The report incorporates; • Patient characteristics • Relevant images references • Procedure summaries • Automatically as well as manually detected findings • Information about the progress of finding properties over time (by comparison with predecessor preceding reports) • Observational Conclusions

8. Real World Mapping • The relationship between pixel data values and real world values is not generally specified in DICOM. (The relationship of pixel values to Hounsfield units in CT is an exception.) • The real world value mapping object is used to describe the relationship between pixel data values and some real world characteristic such as glucose density. • This is particularly useful for specifying relationships between PET pixel values and real world measurements.

9. Color Presentation State • This object serves two purposes: • Providing a color equivalent to the Grayscale Presentation State, • Providing color image fusion descriptions, e.g., for PET/CT image fusion display. • Color Presentation State incorporates • Color consistency based upon ICC color standards, instead of the DICOM grayscale standard in Part 14. • Other presentation facilities are the same as the grayscale presentation state. Geometric corrections, shutters, etc. are provided.

10. Color Calibration • Color calibration of displays is more complex and subjective than grayscale calibration. • Most displays incorporate a nominal ICC profile based on product design. • More precise calibration tools do exist, generally from the printing and publishing vendors. • There is no established degree of calibration need based on ROC or other clinical trials. • There is much more human and environmental variation in color display sensitivity.

11. Image Fusion • The CPS object can specify: • One grayscale object to be presented as the grayscale background, • One grayscale object to be presented using color coding as a semi-transparent overlay, • The color coding to be used for the overlay object, • Geometric translations, shutters, etc. for the two objects like the grayscale presentation state object. • This enables PET/CT image fusion as well as many other possible fusions of grayscale images.

12. Hanging Protocol • DICOM Hanging Protocols • Save Hanging Protocols on a PACS Archive • Search for Hanging Protocols by name, level (single user, user group, site, manufacturer), user identification code, modality, anatomy, and laterality. • Allow automatic hanging of image sets to occur for all studies on workstations with sufficiently compatible capabilities by matching against user or site defined Hanging Protocols. This includes supporting automatic hanging when the user reads from different but similar workstation types. • Capturing the details of a specific display, e.g., for tutorial purposes, will be handled by a different but similar SOP class.

13. JPIP • A transfer syntax is defined for supporting the JPEG Progressive Interactive Protocol. • This syntax is intended for supporting interactive access to large images or over slower links, and is not well suited to transfer of complete images with full fidelity.

14. JPEG 2000 Multi-component • This is an additional compression method that gains better compression for multi-slice images. The compression algorithm incorporates knowledge of pixel values from adjacent slices.

15. User Identity Support • DICOM Association Negotiation incorporates the ability to convey current user information. This may be used for purposes such as audit trail and access control. The methods currently described are: • Simple username • Username with password • Kerberos • (under discussion) SAML

16. Digital Signatures for SR • A means of signing all or only selected portions of any SR or SR-like object is defined. • DICOM is not specifying the rules for when objects should be signed or why. It is enabling a variety of different workflows that need digital signatures.

17. PDF Encapsulation • PDF files can be encapsulated into a DICOM wrapper, similar to a secondary capture object. • No restrictions on the PDF contents, although some PDF features such as dynamic content are discouraged. • Expected uses • Scan and capture existing documents into PDF, and archive onto a PACS for query like any other image. • Direct generation of PDF from retrofits to existing software, such as PDF printer drivers, and subsequent addition of DICOM demographic information.

18. HL7 References • As part of ongoing coordination efforts, there are standard attributes and rules for referring to HL7 CDA documents from within DICOM objects.

19. Retirement • When features are retired from DICOM it means: • We remove them from the subsequent publications of the standard, so old versions of the standard should be archived. • We stop maintaining those features for fixing problems or coordinating additions to the standard. • Features are retired because: • They are not being used • They might be redundant with existing or new objects • They are not recommended for implementation by new products.

20. Retirement (contd) • Retirement candidates are: • Basic Study Content Notification • Detached Patient Management • Detached Study and Study Component Management • Detached Results and Interpretation Management • Print Queue Management • Stored Print • Standalone Overlays, Curves, VOI LUT and Modality LUT Storage • Multi-Referenced File Directory Record, and TOPIC • Floppy disk and obsolete MOD formats and profiles • Patient Study Only Query • Curves • Print Overlay • Overlays in images in high bits

21. New efforts • Image Library • Veterinary extensions • Enhancements to Query and Retrieve • Very Large Images