Topics for 2011/08/27 Meeting of DICOM WG-26 Anatomic Pathology

1. Topics for 2011/08/27 Meeting of DICOM WG-26 Anatomic Pathology Harry SolomonInteroperability Architect, GE Healthcare Co-Chair, HL7/DICOM Imaging Integration WG

2. Multi-spectral Blending

3. Multi-spectral imaging • Typical color image stored with RGB or YBR photometric interpretation • 3 color values / pixel /frame • Multi-spectral image stored with MONOCHROME photometric interpretation • 1 color value / pixel / frame • Multiple color planes – may be stored in single image object (WSI) • Each frame references its optical path in per-frame header 3 x 8-bit RGB n x 16-bit multi-spectral

4. Multi-Spectral Presentation State (proposed) • Selection of channels to be combined for presentation • May be from different referenced image objects – including derived images (segmentations) • May require spatial registration • Sharpening / Deconvolution (?) • Channel separation (?) • Blending parameters • Based on, or using, ICC multi-channel algorithms • Transforms to device independent color space (PCS) • Selection of display area • Graphical and textual annotations, overlays, shutters(?)

5. Multi-spectral Blending Pipeline Deconvolution ?? Tbd ?? Spatial Registration Object Sharpening Spatial Registration Derived Images (Sharpened) Derived Images (Registered) Source Images Channel Separation Channel Separation ?? Tbd ?? Real-World Value Mapping Multi-spectral Blending Presentation Statebased on ICC Derived Images (Registered,Channel separated) Display Blended Images

6. Sharpening • Input single monochrome channel • Deconvolution – can we specify parameters in a non-implementation-specific manner? • Unsuccessful in past within DICOM – see Convolution Kernel (0018,1210) • Output single monochrome channel

7. Channel separation function • N input monochrome channels • Real pixels in co-planar frames, or • Virtual pixel values (resampled) in volume defined by target Frame of Reference • Target FoR may need spatial registration to input FoR • Use same approach as for spatial registration object and blending presentation state • M output monochrome channels • Polynomial function of N inputs • In single frame of reference

8. ICC input device transformations • Different transformation types supported by ICC to transform from an input device to a standard color space (commonly referred to as Profile Connection Space, PCS) • Transformation a and b are separable, i.e. they can be defined for each color channel independently, and summing up the individual channels at the output (PCS) will give a valid result (see appendix A for mathematic clarification). For transformations c, d and e this is not possible, because values for one channel influence the transformation of the other channels, via “B” curves, and/or the CLUT. • figure taken from ICC standard : • http://www.color.org/ICC1v42_2006-05.pdf

9. Notes on pipeline • Combining steps into single object allows us to skip intermediate products – but means receiving display app must support all steps • Intermediate products can be saved without DICOM object specifying how they were derived • Too many saved intermediate products increases storage requirements

10. AP Workflow

11. DICOM Managed Workflow Concepts ORDER :A request for departmental service • PROCEDURE STEP : The smallest unit of managed work in the workflowScheduled Procedure Step: ‘A unit of work to do’Performed Procedure Step: ‘A unit of work done’ REQUESTED PROCEDURE :Unit of work resulting in one Report with associated codified, billable acts

12. CLINICIANOR REFERRING DOC:The Imaging Dept Customer RADIOLOGIST/ PATHOLOGIST : In charge of producing the Report TECHNOLOGISTIn charge of acquiring images, etc. 3 Level Workflow Structuring is User Oriented ORDER:A request for departmental service (Accession Number) REQUESTED PROCEDURE : Unit of work resulting in one Reportwith associated codified, billable acts(Requested Procedure ID) PROCEDURE STEP :The smallest unit of managed workin the workflow (modality worklist entry)

13. Pathology order Slide preparation history data LIS / APLIS Interpretation Worklist by accession Specimen accessioning data Modality Worklist Query by slide barcode Imaging task w/ slide preparation history data Imaging task completion w/ list of imagesand specimen IDs Images Images Images w/slide prep history PACS Images – X-ray, U/S, optical, etc. Anatomic Pathology Imaging Workflow Block processing / Slide preparation Workstation Gross specimen accessioning Whole Slide Scanner Surgical or biopsy procedure

14. Workflow - Orders • Pathology order from Order Placer system to Order Filler (LIS) • Based on surgical or biopsy procedure • HL7 v2.3.1 ORM/ORR – general order message (deprecated), or HL7 v2.4+ OML/ORL - laboratory order message (IHE Profile) • Patient, Visit info • Reference to Specimen and Container(s) • Reference to surgical or biopsy procedure order (not in IHE yet) • Reference to DICOM studies (diagnostic, perioperative) (not in IHE yet) • HL7 AP Workflow Project Proposal • Joint Imaging Integration / Anatomic Pathology / Orders & Observations WGs

15. Workflow – Department Procedure Steps • Requested Procedure for each separate report • Microscopy, molecular study • Conceptual Procedure Steps within Requested Procedure • Gross exam, block prep, slide prep, staining, WSI • Not all steps need to be explicitly managed by LIS • Procedure Steps associated with resources (equipment+operator) • Imaging Procedure Steps available through DICOM Modality Worklist SOP Class • Pull model interaction (query)

16. Modality Worklist • Query may be based on Container (slide) ID and Modality type • Should return one Scheduled Step for processing that slide by that equipment • Query by Accession ID, Patient ID, scheduled date, etc. may return >1 SPS • Response has Patient Demographics, Order, Requested Procedure, Scheduled Step, Protocol Code, Specimen Module • Enables automated slide scanning to fully populate image header • Protocol code allows selection of a scan configuration, possibly manufacturer-specific • Specimen Module has processing history • Processing history can be used to set up acquisition (based on stain)

17. Modality Performed Procedure Step • Status report of imaging tasks • In Progress, Completed, Discontinued (error) • LIS can manage workflow (queue next step) • Includes list of image objects • Allows LIS and PACS to track images for slides/specimens • Sent from modality to LIS, forwarded to PACS

18. DICOMModality Worklist ScheduledProcedure Step One or more series of images PerformedProcedure Step AcquisitionModality Simple Workflow Imaging Department • One Order – One Procedure – One Study – One Report ORDER A request for DepartmentalService Set of Codifiable, Billable, Acts Report Requested Procedure

19. DICOMModality Worklist ScheduledProcedure Step A Report ScheduledProcedure Step B One or more series of images One or more series of images DICOMModality Worklist PerformedProcedure Step P1 PerformedProcedure Step P2 AcquisitionModality AcquisitionModality Multiple Modality Steps Imaging Department ORDER A request for DepartmentalService Set of Codifiable, Billable, Acts Requested Procedure

20. Implementation considerations • Multiple architectural models for implementing DICOM workflow functionality on LIS and modality • Native DICOM capability built in • Facilitated by toolkits (available for all platforms - free and commercial) • Integration engine (or broker) for LIS • Typical for first generation DICOM interfaces • Database (SQL) or HL7 interface to LIS, DICOM interface to modalities • Several commercial products • Integration engine (or broker) for modality • Manages MWL/MPPS • Translates image format to DICOM

21. HL7 v2 Lab Automation • Defined in Chapter 13 • Status updates from equipment to controller • Equipment status, Specimen status, Inventory, Test settings, Log/service events • Controller may request statuses • Commands pushed from controller • Relatively low level