What’s New in DICOM Harry Solomon, GE Healthcare RSNA 2007.
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Transcript of What’s New in DICOM Harry Solomon, GE Healthcare RSNA 2007.
What’s New in DICOM
Harry Solomon, GE HealthcareRSNA 2007
2What's new in DICOM - RSNA 2007
DICOM is the International Standard for Medical Imaging and related information: images, waveforms, derived measurements and assessments, image presentation control, and workflow management for the imaging department
Published as NEMA PS3 and as ISO 12052
3What's new in DICOM - RSNA 2007
Agenda
• The DICOM Change Process• Images• Image Processing & Reporting• Workflow• Specialties• Get Involved!
4What's new in DICOM - RSNA 2007
The DICOM Change Process
• Continuous process for evolution of the standard– It’s just “DICOM”, not DICOM 3.0, 3.1, etc.– Conformance is to SOP Classes, not to a ‘version’ of the
Standard
• Change Proposals for minor corrections– About 100 / year – Anybody can submit
• Supplements for major changes – new object types, services, compression schemes– About 10 / year– Require Work Item approved by DICOM Standards
Committee
• Consolidated edition published every year– Most recently, January 2007– Available free at DICOM web site
Images
Information Object Definitions
and Image Access
6What's new in DICOM - RSNA 2007
Multiframe Images
• Multiframe objects to support 1000+ slice studies– Image header supports functional group
attributes changing during acquisition– Dimensions allow multiple views of data
• Common structure used for all new image IODs– Sup 110 Ophthalmic Coherence Tomography
(Adopted August 2007)– Sup 116 3-D X-ray (Adopted January 2007)– Sup 117 Enhanced PET (in Letter Ballot)
– Sup 43 Enhanced Ultrasound (in Public Comment)
– Sup 125 Breast Tomosynthesis (in Public Comment)
7What's new in DICOM - RSNA 2007
Single-frame to MultiFrame
N Objects, N Headers
N Frames, One Header
Pixel dataDimension dataPer-frame headerFixed Header
8What's new in DICOM - RSNA 2007
The Per-Frame Header
Other attributes
Per-frame Functional Groups Sequence
Shared Functional Groups Sequence
> Functional Group A
> Functional Group B
> Functional Group M
…..
Other attributes
Functional Groups with attributes constant
for all frames
Item 1 (Frame 1) Sequence of
Functional Groups for each individual frame
Pixel Data
Frame 1
Frame 2
Frame n
…..
> Functional Group C
> Functional Group B
> Functional Group M
…..
Item n (Frame n)
> Functional Group C
> Functional Group B
> Functional Group M
Item 2 (Frame 2)
> Functional Group C
…..
…..
…..
…..
> Functional Group K
9What's new in DICOM - RSNA 2007
Sup 119 Frame Level Retrieve
• If we have 1000+ slice image objects, how do we access the slice identified in the report as the Key Image?– Or, how to access a short video clip of a long endoscopy
video image object?– Many similar use cases needing one frame or a small
subset of frames from large multiframe image– Purpose of retrieval may not be diagnostic; compression
OK
• Proposed new Retrieve SOP Classes for subsets of frames– Request can include a preferred transfer syntax (i.e., type
of compression)– Returned object is a derived image with the requested
subset of frames, but with a different Instance UIDIn Public Comment
10What's new in DICOM - RSNA 2007
Sup 43 Enhanced Ultrasound
• Pixel frames may represent tissue, velocity, variance or power
• Multiple frames (up to 3) must be blended for proper display
• Enhanced blending pipeline required to render images
In Public Comment
Data Frame Modality
LUT (identity)
VOI LUT(optional)
PrimaryRGBAPalette
Color LUT
(optional)
Data Frame
Data Frame Modality
LUT (identity)
VOI LUT(optional)
SecondaryRGBAPalette
Color LUT
(optional)
OpacityLUT
(optional)
RGB
ProfileConnection
Space Transformation
RGB
ICC Input Profile
Real World Value Mapping
Real World Value Mapping
Presentation LUT
(identity)
Gray Scale Output asP-Values
Color Output as
PCS-Values
RGB (Input 1)
Real World Value +Units
Alpha 1
Alpha 2
RGB
RGB (Input 1)
Real World Value Mapping
Real World Value +Units
Alpha, Beta(Constants)
RGB (Input 2)
Convert to RGB (R=B=G)
Blending Operation
Multiply inputs and add the result
(Alpha 1) x Input 1 +
(Alpha 2) x Input 2
CLAMP
OR
OR
Alpha
(1-Alpha), Alpha
Alpha
MSB’s
LSB’s
Alpha,BetaLUT
outputs
OR
Modality LUT
(identity)
VOI LUT(optional)
Image Processing & Reporting
Segmentation, Registration, Structured
Reporting
12What's new in DICOM - RSNA 2007
Sup 111 Segmentation Image
• Derived image object– Multiframe, using functional group mechanism
• Multiple segments per object– Each segment linked to a categorization– Pixels show presence of category at pixel location– Binary (1-bit/pixel) or fractional (probability or
occupancy)
• Segments can be 2-D or 3-D• 3-D segmentation is typically in same
Frame of Reference as source image• Segments can be displayed as overlays on
source image Adopted August 2006
13What's new in DICOM - RSNA 2007
Segmentation Example
Segment Sequence
Other attributes
Item 1 (Segment 1)
Pixel Data
Frame 1
Frame 2
Frame 4
Item 2 (Segment 2)
Segment Number = 1
Segment Name = White Matter
Segment Category = Brain
Segment Type = White Matter
Segment Number = 2
Segment Name = Grey Matter
Segment Category = Brain
Segment Type = Grey Matter
Per-frame Functional Groups Sequence
Item 1 (Frame 1)
Segment Identification Sequence
Referenced Segment Number = 2
Segment Identification Sequence
Item 1
Item 2 (Frame 2)
Referenced Segment Number = 3
Segment Identification Sequence
Item 1
Item 3 (Frame 3)
Frame 3
Shared Functional Groups Sequence
Item 1 (Shared – all frames)
Derivation Image Sequence
Item 3 (Segment 3)
Segment Number = 3
Segment Name = Lesion Part 1
Segment Category = Brain
Segment Type = Lesion
Item 4 (Segment 4) Segment Number = 4
Segment Name = Lesion Part 2
Segment Category = Brain
Segment Type = Lesion
Referenced Segment Number = 4
Segment Identification Sequence
Item 1
Item 4 (Frame 4)
Referenced Segment Number = 1
Item 1
Item 1
Reference to source image (external object)
14What's new in DICOM - RSNA 2007
Sup 132 Surface Segmentation
• Work in progress – just released for Public Comment
• Segmentation using 3-D surface mesh (rather than voxel volume)
• First use of mesh technology in DICOM– Will also be used for future volumetric work,
including implant specification and surgical planning
In Public Comment
15What's new in DICOM - RSNA 2007
Sup 112 Deformable Spatial
Registration
• Composite Object that supports multi-image alignment
• 3 step algorithm– Pre-deformation matrix transform – Deformation using 3D grid of 3D deformation
vectors– Post-deformation matrix transform
• Facilitates further image processing, especially multi-modality image fusion and image pasting applications
Adopted August 2006
16What's new in DICOM - RSNA 2007
Structured Reporting
• Additional Templates for standard SR SOP Classes– Sup 128 Cardiac Stress Testing (Frozen Draft –
passed Ballot, awaiting final SNOMED and IEEE codes)– Sup 129 Cardiac Electrophysiology (in Public
Comment)
• Templates for specialty SR SOP Classes– Sup 127 CT Radiation Dose (Adopted October
2007)– Sup 130 Ophthalmic Refractive SR (in Letter
Ballot)– Sup 126 Colon CAD (in preparation)
• Harmonization with HL7– Sup 114 DICOM Encapsulation of CDA
Documents (Adopted January 2007)
Workflow
Substance Administration, Unified Worklist, RT Workflow,
Specimen Identification
18What's new in DICOM - RSNA 2007
Sup 107 Substance Administration
• Patient safety issue – “five rights” checking for contrast agents– Point of use verification for substances often “out of the
loop” of hospital pharmacy systems
• Three new DICOM services– Typically Modality as SCU interacting with HIS via gateway
SCP
• Query: Look up product characteristics – Given a barcode ID (from contrast agent bottle), get name,
active ingredient, concentration, etc.
• Query: Get substance administration approval– Based on agent, patient, route of administration; get
approval or warnings
• Report contrast used to HIS Medication Administration Record
Adopted January 2007
19What's new in DICOM - RSNA 2007
Sup 96 Unified Procedure Steps
• Simplification and merger of Worklist Management and Performed Procedure Steps – 1:1 relationship between scheduled and performed
steps– A single IOD that combines attributes of both – C-FIND to query worklists– N-CREATE to create new scheduled procedure steps– N-GET/N-SET to update – N-EVENT-REPORT to monitor and report progress
• Intended to meet the needs of– Radiation Therapy Scheduling and Monitoring– Scheduling and Monitoring CAD systems– Proposed new scheduling activities
Frozen Draft for Trial Implementation
20What's new in DICOM - RSNA 2007
Sup 74 Radiotherapy Worklist
• Supports automated worklist management and machine parameter verification for the integration of multi-system radiation therapy planning and treatment
• First usage of Unified Procedure Step• Also defines three new objects / SOP Classes
– RT Beams Delivery Instruction (Composite)– RT Conventional Machine Verification (Normalized)– RT Ion Machine Verification (Normalized)
• Real implementation and evaluation needed – in conjunction with IHE Radiation Oncology
Frozen Draft for Trial Implementation
21What's new in DICOM - RSNA 2007
Sup 122 Specimen Identification
• Support for pathology lab workflow, specimen-based imaging– Gross specimens, blocks, vials, slides– Image-guided biopsy samples
• Retires current Specimen Identification Module, adds new Specimen Module at image level of hierarchy– May affect applications that implement current Module
(if any)
• Update to Modality Worklist to allow Specimen Module– Enables automated slide scanning devices to fully
populate header
• Update to Modality Performed Procedure Step to identify imaged specimen– Allows LIS to track images for specimens
In Public Comment
22What's new in DICOM - RSNA 2007
• Biomed engineering– Supp 124 Communication of Display Parameters
(in preparation)– Administrative support for monitor calibration
• Research / Biomarkers– Supp 118 Application Hosting (in preparation)– Image analysis programs run on any workstation
• Surgery– Sup 131 Implant Description (in preparation) – Supports 3D model of bone-mountable implants
• Dentistry / Radiology– Sup 123 Structured Display (in preparation) – Captured screen layout of multiple images (with
presentation states) for dental series, radiology conference, etc.
Specialties
23What's new in DICOM - RSNA 2007
Get Involved!• Get the DICOM Standard (free!)
– http://dicom.nema.org/medical/dicom/2007/ (annual issue)– ftp://dicom.nema.org/medical/dicom/final (changes between
issues)• Ask questions/discuss on the DICOM Newsgroup
– http://groups.google.com/group/comp.protocols.dicom• Respond to Supplements released for Public Comment
– http://www.dclunie.com/dicom-status/status.html• Submit Change Proposals
– mailto:[email protected] • Join a DICOM Working Group
– See list in http://medical.nema.org/dicom/geninfo/Strategy.pdf
• Attend the DICOM International Conference and Seminar, Chengdu, China, April 8-10, 2008– http://dicom.nema.org/Dicom/DCS-2008/
• Build the new DICOM capabilities into your products– Your URL here!