what’s new in dicom robert horn, agfa healthcare (chair wg 6) presented by bas revet, philips...

What’s New in DICOM

Robert Horn, Agfa Healthcare (Chair WG 6)

Presented by Bas Revet, Philips HealthcareSPIE 2009

2What's new in DICOM - RSNA 2008

• DICOM is the International Standard for Medical Imaging and related information: – images, – waveforms,– derived measurements and assessments,– image presentation controls,– and workflow management in the

imaging department

Published as NEMA PS3 and as ISO 12052


Agenda

• The DICOM Change Process• Images• Image Processing & Reporting• Workflow• Specialties• Get Involved!


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 2008– Available free at DICOM web site

Highlighted CPs

• CP-874 (October 2008, this affects everything that uses ionizing radiation)– Radiation Dose reporting (jumbo patch)

• Extensive clarifications to dose reporting, based on IHE review and early implementation efforts.

• Will be required for IHE Radiation Dose reports.

• Veterinary Extensions (public comment, noteworthy as probably the largest page count for this year)– Species extension CP-918– View codes for quadrupeds CP-919

• The other 100+ are all important within their domain.


Images

Information Object Definitions

and Image Access


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 141 Enhanced MR Color (Letter Ballot)– Sup 139 Enhanced XA/XRF Informative Annex (Public

Comment 2008)– Sup 43 Enhanced Ultrasound (in Public Comment) – Sup 125 Breast Tomosynthesis (Adopted August 2008)– Sup 117 Enhanced PET (Adopted January 2008)– Sup 110 Ophthalmic Coherence Tomography (Adopted

August 2007)– Sup 116 3-D X-ray (Adopted January 2007)– Sup 83 Enhanced XA/XRF Image (Adopted 2004)– Sup 58 Enhanced CT (Adopted 2003)– Sup 49 Multiframe MR (Adopted 2001)


Single-frame to MultiFrame

N Objects, N Headers

N Frames, One Header

Pixel dataDimension dataPer-frame headerFixed Header


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



…..

Item n (Frame n)




Item 2 (Frame 2)


…..

…..

…..

…..

> Functional Group K


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 multi-frame 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 UIDSecond Ballot round, January 2009


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

Preparing for Ballot

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


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 +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)


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

Adopted June 2008

More video transfer syntaxes

• MPEG-2 (Supplement 137, Adopted 2009) – Hi-def formats (e.g., BluRay)– Hi-def TV shapes and frame rates– Output format for many current Hi-def cameras– DICOM size limit corresponds to 15-30 minutes of

video per SOP instance.

• MPEG-4 (soon)– Higher compression ratio than MPEG-2– Higher computational requirements than MPEG-2

• These will be available for any image modality, although visible light is the expected type.


Image Processing & Reporting

Segmentation, Registration, Structured

Reporting


Sup 132 Surface Segmentation

• Derived image object– Uses the new surface representation

sequence• Multiple segments per object

– Each segment linked to a categorization– Each segment is a surface, which may have

viewing hint.• Surfaces are always 3-D• 3-D segmentation is typically in same

Frame of Reference as source image• Surface Display methods are not

specified, although display hints can be conveyed.

Adopted August 2008


Surface Segmentation

• Actual object contains digital parameters of a surface mesh.

• Display can be shaded image, or any other kind of user interface.


Structured Reporting

• Additional Templates for standard SR SOP Classes– Sup 129 Cardiac Electrophysiology (in

Public Comment) – Sup 128 Cardiac Stress Testing (Final Text

– Codes provided October 2008)

• Templates for specialty SR SOP Classes– Sup 126 Colon CAD (in preparation)

– Sup 130 Ophthalmic Refractive SR (Adopted January 2008)

– Sup 127 CT Radiation Dose (Adopted October 2007)

• Harmonization with HL7– Sup 114 DICOM Encapsulation of CDA

Documents (Adopted January 2007)


Workflow

Substance Administration, Unified Worklist, RT Workflow,

Specimen Identification


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


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


• Biomed engineering– Supp 124 Communication of Display Parameters (in

preparation)– Administrative support for automated and remote

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 (Final Text, October 2008) – Captured screen layout of multiple images (with

presentation states) for dental series, radiology conference, etc.

Specialties


Get Involved!

• Get the DICOM Standard (free!)– http://dicom.nema.org/dicom/2008/

• 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

• Build the new DICOM capabilities into your products– Your URL here!

what’s new in dicom robert horn, agfa healthcare (chair wg 6) presented by bas revet, philips...

Documents

dicom rsna

functional group attributes

functional group c item

sequence of functional

frame headerwhats new

dicom web site whats

new image iodssup

image accesswhats new