Not Your Grandfather's PACS - New Expectations for Image ...
Not Your Grandfather's PACS · 2017-03-01 · “Web-based” PACS & “remote” viewers 1990s ....
Transcript of Not Your Grandfather's PACS · 2017-03-01 · “Web-based” PACS & “remote” viewers 1990s ....
SEAAPM Symposium 2014 Not Your Grandfather's PACS New Expectations for Image Management
David Clunie ([email protected]) PixelMed Publishing
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
PACS Beginnings
l Lemke, 1979 • “A Network of Medical Workstations for
Integrated Word and Picture Communication in Medicine”
l Capp, 1981 • “Photoelectronic Radiology Department”
1982 - “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
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
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)
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
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
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
Lemke, 1979 – Ring of medical work stations (MWS’s)
Capp, 1981
DICOM Cluster or Mini-PACS
CT Modality
Laser Printer
Shared Archive
Workstation
Store
Store
Store
Q/R
Q/R
Basic PACS Components
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Monolithic + DICOM Modalities
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary
Workstation Interface
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary
DICOM Standard Interface
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM
DICOM PS3.8
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM
DIMSE/ULP
Web Access to DICOM Objects
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM WADO-URI
DICOM WS (SOAP)(IHE XDS-I)
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM
WADO-WS (XDS-I)
WADO-RS (RESTful)
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM
WADO-RS (REST)
Full Repertoire
Modality
Archive Modality
Modality
Modality
PACS +/- RIS
Manager
Workstations
Standard Boundary Standard Boundary DICOM DICOM
DIMSE/ULP WADO-URI WADO-WS (XDS-I) WADO-RS (REST)
Vendor Neutral Archive
Modality
Modality
Modality
Modality Manager
Workstations
Modality/Workstation <-> VNA
Modality
Modality
Modality
Modality Manager
Workstations
PACS <-> VNA Interface
Modality
Modality
Modality
Modality Manager
Workstations
Standard Boundary DICOM HL7 IHE
PACS <-> VNA Interface
Modality
Modality
Modality
Modality Manager
Workstations
Standard Boundary DICOM HL7 IHE ?
Multiple PACS – One Archive
PACS PACS PACS PACS
One Archive – Universal Viewer
PACS PACS
Universal (ZFP) Viewer
Universal (ZFP) Viewer
Modality
Modality
Modality
Modality Manager
Universal (ZFP) Viewer
Standard Boundary DICOM WADO-URI
WADO-RS (REST)
VNA: PACS by any other name
Modality
Modality
Modality
Modality
Universal (ZFP) Viewer
Storage Paradigms
Spinning Tape
or Optical
Jukebox Shelf
Storage Paradigms
Spinning Tape
or Optical
Jukebox Shelf
Spinning
Storage Paradigms
Spinning Tape
or Optical
Jukebox Shelf
Spinning Redundant Duplicate
Offsite
Storage Paradigms
Spinning Tape
or Optical
Jukebox Shelf
Spinning Redundant Duplicate
Offsite
Offsite
On-site
Backup
Storage Paradigms
Local Cache
Reliable “Cloud” Archive
Somebody else’s
problem
Storage Paradigms
Local Cache
Reliable “Cloud” Archive
Somebody else’s
problem
• Cost of (fast) storage • Cost of bandwidth • Local versus remote production • Local versus remote utilization
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
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
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
IHE IID – Process Flow
Image Display (ID)
Display Images
Image Display Invoker (IDI)
Invoke Image Display (RAD-106)
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 FDA-cleared 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?
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)
Imaging Object Change Management
Cross Enterprise Gateways
Multiple Image Manager/Archive
Order Placer
DSS/ Order Filler
Image Manager
Image Archive
Acquisition Modality
ADT
Order Placer
DSS/ Order Filler
Image Manager Instances Stored [RAD-70] → Image Manager Storage Commitment [RAD-71] →
Image Manager Instances Query [RAD-72] → Image Manager Instances Retrieval [RAD-73] →
Assigning Authority “Site A”
Assigning Authority “Site B”
ADT
Image Manager
Image Archive
Acquisition Modality
Image Manager
Image Archive
↑ PIX Query [ITI-9] ↓ PIX Notification [ITI-10]
Patient Identifier Cross-reference 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]
Multiple Patient Identifier Assigning Authorities
MU – Health ITSC – Image Sharing TIER 1
Exchange of Text-Based Reports
TIER 2 Exchange of Non-Radiology/
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 segment content, CDA L1, or CDA L2 + CCDA DIR
template
Without metadata: JPEG, PNG, DNG, PDF, H.264; with metadata: DICOM
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
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
Radiation Dose – Old Way – Screen Shots
DICOM CT RDSR
DICOM CT RDSR
RDSR & OCR Deployment
Modality PACS
OCR Dose Reporter
RDSR
Screen
Q/R
RDSR
Q/R
Screen RDSR RDSR
Screen
RDSR
Per-frame attributes Pixel data
Shared attributes
Enhanced Multi-frame Images
Temporal Position
Index
2
1
Trigger Delay Time
48 ms
0 ms
Space (2)
Time (1)
2 \ 1 \ 5 Dimension
Index Values
Dimension Index Pointers: 1. Temporal Position Index 2. Stack ID 3. In-Stack Position
5 1\1\5
In-Stack Position
Stack ID = 1
4 1\1\4 3 1\1\3
2 1\1\2 1 1\1\1
5 2\1\5
In-Stack Position
Stack ID = 1
4 2\1\4 3 2\1\3
2 2\1\2 1 2\1\1
PACS to PACS (or VNA) with Legacy DICOM Object Conversion
Modality
Modality
Workstations
PACS
Convert SF -> MF
Convert MF -> SF
Classic SF
Legacy Converted MF
True Enhanced MF
PACS
Convert SF -> MF
Convert MF -> SF
DICOM Whole Slide Images
Thumbnail Image
Intermediate Image Tiles
BaselineImage Tiles
Multi-frame image(single object)
Multi-frame image(single object)may include multipleZ-planes, color planes
Single frame image
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
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 20021207 27080 49 27
… … … …
Parametric Maps
Foster N L et al. Brain 2007;130:2616-2635 Meyer P T et al. J Neurol Neurosurg Psychiatry 2003;74:471-478
Label Maps
Brewer J et al. AJNR 2009; 30:578-580
Quantitative objects together
Analysis Workstation
Current DICOM
Images from Modality
DICOM Segmentation
DICOM Registration
DICOM SR
DICOM Real World Value
DICOM Parametric Map Images
PACS Store, Distribute
and Review
Previous DICOM
Images from PACS
Previous DICOM SR etc
Quantitative objects together
Analysis Workstation
Current DICOM
Images from Modality
DICOM Segmentation
DICOM Registration
DICOM SR
DICOM Real World Value
DICOM Parametric Map Images
PACS Store, Distribute
and Review
Previous DICOM
Images from PACS
Previous DICOM SR etc
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