Not Your Grandfather's PACS

Transcription

1 SEAAPM Symposium 2014 Not Your Grandfather's PACS New Expectations for Image Management David Clunie PixelMed Publishing

2 PACS Learning Objectives l Understand the tradition roles, challenges and limitations of departmental, enterprise and cross-enterprise PACS l Identify contemporary forces impinging on PACS choice, migration, design and deployment, including IS consolidation, EHR integration, provider and patient access, advanced quantitative applications, and document integration l Discuss alternatives to traditional PACS, including the role of Vendor-Neutral Archives and Universal Zero Footprint Viewers, "deconstruction", and other buzzwords of choice l Review the role of DICOM and IHE standards (or not) in this evolution

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8 PACS Beginnings l Lemke, 1979 A Network of Medical Workstations for Integrated Word and Picture Communication in Medicine l Capp, 1981 Photoelectronic Radiology Department

9 The year of the PACS l First International Conference and Workshop on Picture Archiving and Communications Systems, SPIE, Newport Beach l First International Symposium on PACS and PHD (Personal Health Data), Japan Association of Medical Imaging Technology

10 What does PACS mean? l Physics and Astronomy Classification Scheme l Political Action Committee(s) l Pan-American Climate Studies l Picture Archiving and Communication System

11 What has PACS meant? l Multi-modality digital acquisition l Storage (current, archival, local, off-site) l Distribution, locally and remotely l Display (diagnostic and review) l Reporting creation, distribution, storage l Workflow management l Integration with other information (systems)

12 What did PACS mean in 1982? l Pretty much the same l Less ambitious in scope l Not all modalities (CR not yet available) l More emphasis on storage, transfer and display than workflow l No standards, but recognition of the need for them l Relatively impractical given technology of the day l A grand vision for the future

13 What does PACS mean today? l Multi-modality digital acquisition l Storage (current, archival, local, off-site) l Distribution, locally and remotely l Display (diagnostic and review) l Reporting creation, distribution, storage l Workflow management l Integration with other information (systems) l Enterprise wide (multi-specialty) l EHR Integration l Access on mobile devices

14 Infrastructural trends l Home grown components, all local l Commercial purchase monolithic solution l Commoditization all vendors similar l Factor out network and storage (NAS, SAN) l Sharing enterprise IT infrastructure l Workstation -> PC -> Web browser viewer l Proprietary -> DICOM -> HTTP protocols l Factor out archive (VNA) & viewer l Zero footprint universal viewers

15 Lemke, 1979 Ring of medical work stations (MWS s)

16 Capp, 1981

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18 DICOM Cluster or Mini-PACS Print Store Q/R Print Store Laser Printer CT Workstation Store Q/R Shared Archive

19 Basic PACS Components PACS +/- RIS Archive Workstations Manager

20 Monolithic + DICOM Modalities Standard Boundary PACS +/- RIS Archive Workstations Manager

21 Workstation Interface Standard Boundary Standard Boundary PACS +/- RIS Archive Workstations Manager

22 DICOM Standard Interface DICOM Standard Boundary DICOM Standard Boundary PACS +/- RIS Archive Workstations Manager

23 DICOM PS3.8 DICOM Standard Boundary DICOM Standard Boundary DIMSE/ULP PACS +/- RIS Archive Workstations Manager

24 Web Access to DICOM Objects DICOM Standard Boundary Standard Boundary DICOM WADO-URI PACS +/- RIS Archive Workstations Manager

25 DICOM WS (SOAP)(IHE XDS-I) DICOM Standard Boundary DICOM Standard Boundary WADO-WS (XDS-I) PACS +/- RIS Archive Workstations Manager

26 WADO-RS (RESTful) DICOM Standard Boundary PACS +/- RIS DICOM Standard Boundary WADO-RS (REST) Archive Workstations Manager

27 Full Repertoire DICOM DICOM Standard Boundary Standard Boundary PACS +/- RIS DIMSE/ULP WADO-URI WADO-WS (XDS-I) WADO-RS (REST) Archive Workstations Manager

28 Vendor Neutral Archive Workstations Manager

29 /Workstation <-> VNA Workstations Manager

30 PACS <-> VNA Interface IHE HL7 DICOM Standard Boundary Workstations Manager

31 PACS <-> VNA Interface? IHE HL7 DICOM Standard Boundary Workstations Manager

32 Multiple PACS One Archive PACS PACS PACS PACS

33 One Archive Universal Viewer Universal (ZFP) Viewer PACS PACS

34 Universal (ZFP) Viewer DICOM WADO-URI Standard Boundary WADO-RS (REST) Universal (ZFP) Viewer Manager

35 VNA: PACS by any other name Universal (ZFP) Viewer

36 Storage Paradigms Spinning Tape or Optical Jukebox Shelf

37 Storage Paradigms Spinning Tape or Optical Jukebox Shelf Spinning

38 Storage Paradigms Spinning Tape or Optical Jukebox Shelf Spinning Redundant Duplicate Offsite

39 Storage Paradigms Spinning Tape or Optical Jukebox Shelf Spinning Redundant Duplicate Offsite Offsite Backup On-site

40 Storage Paradigms Local Cache Reliable Cloud Archive Somebody else s problem

41 Storage Paradigms Cost of (fast) storage Cost of bandwidth Local versus remote production Local versus remote utilization Local Cache Reliable Cloud Archive Somebody else s problem

42 Zero Footprint Universal Viewer l Web browser viewer for all types of users l Zero footprint No helper apps, plugins, applets, Flash or SilverLight Not even any JavaScript???? l Absolute zero HTML pre-5, frames, tables, images l Almost zero JavaScript +/- HTML5 Canvas l Pretending to be zero Flash (etc.) dependency l Not zero at all just fine for many deployments l Thick client spawned by browser (or EHR app ) l Web-based PACS & remote viewers 1990s

43 EHRs and Images l EHR vendors do NOT want to store images l Separation of requestor from performer EHR/PHR/etc. user requests viewing of study PACS/VNA/etc. actually performs it l A link - very common proprietary pattern e.g., encrypted URLs identify, authorize, time-limited n:m permutations of requestor/performer to customize l Storing fully qualified links (URLs) go stale l Common identifiers, dates, etc. more reliable l IHE Invoke Image Display (IID) profile (new) standard display request now only n+m permutations

44 IHE Invoke Image Display l A minimalist means of image-enabling non-image-aware systems l Uses simplest available HTTP-based request l Supports patient and study level invocation l Usable with or without a priori knowledge of individual study identifiers l Requires servers to provide at request of the user interactive viewing review or diagnostic quality key images only l Independent of how/where server gets/stores the images l Any mutually agreed HTTP security mechanism

45 IHE IID Process Flow Image Display Invoker (IDI) Image Display (ID) Invoke Image Display (RAD-106) Display Images

46 Mobile Device Considerations l Relatively limited memory/cpu/network bandwidth l Assuming that mobile devices are used only for low quality use cases is not valid e.g., are now some FDAcleared mobile apps l RESTful versus SOAP for protocol l JSON versus XML for meta data l Not all browsers HTML5/Canvas yet l New crop of MHD standards mirroring XDS l Payload: DICOM v. JPEG v. proprietary l Protocol: DICOM v. WADO v. proprietary l Viewing environment and display quality (FDA) l One day all viewing will be on mobile devices?

47 Special Considerations l Change management deletion, correction life cycle management (purge, expire) IHE Imaging Object Change Management (IOCM) l Cross-enterprise protocol (DICOM, WADO, XDS-I.b) payload (DICOM images) identifiers (patient ID, accession#), codes PACS <-> PACS, PACS <-> central repository IHE Multiple Image Manager Archive (MIMA)

48 Imaging Object Change Management

49 Cross Enterprise Gateways

50 Multiple Image Manager/Archive Patient Identifier Crossreference Manager Image Manager Instances Stored [RAD-70] Image Manager Storage Commitment [RAD-71] Image Manager Instances Query [RAD-72] Image Manager Instances Retrieval [RAD-73] PIX Query [ITI-9] PIX Notification [ITI-10] Image Manager Image Archive Image Manager Instances Stored [RAD-70] Image Manager Storage Commitment [RAD-71] Image Manager Instances Query [RAD-72] Image Manager Instances Retrieval [RAD-73] Image Manager Image Archive Image Manager Image Archive Acquisition Acquisition Order Placer DSS/ Order Filler DSS/ Order Filler Order Placer ADT Assigning Authority Site A ADT Assigning Authority Site B Multiple Patient Identifier Assigning Authorities

51 MU Health ITSC Image Sharing TIER 1 TIER 2 Exchange of Text-Based Exchange of Non-Radiology/ Reports Cardiology Images TIER 3 Exchange of Radiology/ Cardiology Images - Full Study TIER 4 Exchange of Radiology/ Cardiology Images- Key Images CONTENT Plain text +/- structured headings, scanned/ rendered document "Clinical Capture" images with or without metadata Complete set of images of diagnos<c quality IHE Key Image Note (KIN) and images referenced therein ENCODING PDF, HL7 2.x OBX Without metadata: JPEG, PNG, segment content, CDA L1, DNG, PDF, H.264; with or CDA L2 + CCDA DIR metadata: DICOM template DICOM (object appropriate to modality) VOCABULARY LOINC to describe study/ procedure, LOINC for structured headings LOINC to describe study/ procedure (in DICOM header/ XDS metadata) LOINC to describe study/ procedure LOINC to describe study/ procedure, DICOM DCID 7010 for <tles PUSH HL7 V2 ORU/MDM MLLP over VPN/TLS, DIRECT SMTP or XDR preferred DIRECT SMTP or XDR, DICOM DIMSE/ULP or STOW over VPN/TLS, IHE XDR- I DICOM DIMSE/ULP or STOW over VPN/TLS, IHE XDR- I DICOM DIMSE/ULP or STOW over VPN/TLS, IHE XDR- I PULL IHE XDS IHE XDS- I, DICOM WADO- URI or WADO- RS over VPN/TLS IHE XDS- I, DICOM WADO- URI or WADO- RS over VPN/TLS IHE XDS- I, DICOM WADO- URI or WADO- RS over VPN/TLS VIEW IHE IID, else pull (WADO- URI+/- XDS- I for rendered JPEGs when sufficient) IHE IID, else pull (WADO- URI+/- XDS- I for rendered JPEGs when sufficient

52 New(er) DICOM Objects l Images for new modalities ophthalmology, Whole Slide Imaging (WSI), l Better images for existing modalities enhanced multi-frame & legacy conversion l Images for derived stuff pretty pictures (screenshots), parametric maps, segmentations l Non-images annotations, measurements, ROIs, fiducials, registrations presentation states and structured reports key images (key object selection) radiotherapy stuff Radiation Dose SR (RDSR), Radiopharmaceutical Dose (RRD) l Encapsulated stuff PDF, CDA

53 Radiation Dose Old Way Screen Shots

54 DICOM CT RDSR

55 DICOM CT RDSR

56 RDSR & OCR Deployment Screen RDSR PACS Q/R Screen Q/R Screen RDSR RDSR RDSR OCR RDSR Dose Reporter

57 Enhanced Multi-frame Images Shared attributes Per-frame attributes Pixel data

58 Trigger Delay Time Temporal Position Index Stack ID = 1 2 \ 1 \ 5 Dimension Index Values 48 ms 2 In-Stack Position 5 2\1\5 4 2\1\4 3 2\1\3 2 2\1\2 1 2\1\1 Stack ID = 1 Dimension Index Pointers: 1. Temporal Position Index 2. Stack ID 3. In-Stack Position Time (1) 0 ms 1 In-Stack Position 5 1\1\5 4 1\1\4 3 1\1\3 2 1\1\2 1 1\1\1 Space (2)

59 PACS to PACS (or VNA) with Legacy DICOM Object Conversion PACS PACS Convert SF -> MF Convert SF -> MF Classic SF Legacy Converted MF True Enhanced MF Convert MF -> SF Convert MF -> SF Workstations

60 DICOM Whole Slide Images Thumbnail Image Single frame image Intermediate Image Tiles Multi-frame image (single object) Baseline Image Tiles Multi-frame image (single object) may include multiple Z-planes, color planes

61 Quantification Considerations l Increasingly an area of attention for some advanced imaging applications l Increasingly important applications tumor response assessment, neurodegenerative disease, etc. not just research & clinical trials, but clinical care l Not novel, just not widely used/available Lemke 1979 paper described segmentation and lateral ventricle volume determination l Many PACS still fail to provide more than basic measurements

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63 DICOM encoding of ROIs l Private elements evil & must be stopped l Curves in image weak semantics, old, retired l Overlays in image weak semantics l Presentation States weak semantics, PACS favorite l Structured Reports best choice, but more work l RT Structure Sets coordinates only l Segmentations per-voxel ROIs; use with SR Date Volume Auto LD Auto SD

64 Parametric Maps Foster N L et al. Brain 2007;130: Meyer P T et al. J Neurol Neurosurg Psychiatry 2003;74:

65 Label Maps Brewer J et al. AJNR 2009; 30:

66 Quantitative objects together DICOM Segmentation Previous DICOM SR etc DICOM Registration Current DICOM Images from Analysis Workstation DICOM SR PACS Store, Distribute and Review DICOM Real World Value Previous DICOM Images from PACS DICOM Parametric Map Images

67 Quantitative objects together DICOM Segmentation Previous DICOM SR etc DICOM Registration Current DICOM Images from Analysis Workstation DICOM SR PACS Store, Distribute and Review DICOM Real World Value Previous DICOM Images from PACS DICOM Parametric Map Images

68 Final thoughts l Patient versus provider access just another universal viewer client access through portal rather than EHR l Universal viewers really as capable as specialty workstations? union of all previously implemented features? l Reality check most sites running an obsolete PACS version migration (vendor/architecture change) is painful VNAs need migration too