The Medicine Behind the Image DICOM Display Update: Color Presentation States Hanging Protocols Dr....

The

Medicine Behind the

ImageDICOM Display Update: DICOM Display Update:

Color Presentation Color Presentation StatesStates

Hanging ProtocolsHanging Protocols

Dr. David A. Clunie, MB.,BS., FRACR

Chief Technology Officer

Princeton Radiology Pharmaceutical Research

OverviewOverview

• Review of Grayscale Presentation State

• Color Presentation States– Color Consistency

– Presentation States applied to Color Images

– Color Blending - CT-PET fusion

• Hanging Protocols

Distributed Image Distributed Image ConsistencyConsistency

Digital ModalityDigital Modality

WorkstationWorkstation

Laser PrinterLaser Printer


Identical perceived contrast

Spatial Spatial TransformationsTransformations

Original ImageOriginal Image

Entire Image SelectedEntire Image Selected

Transformed ImageTransformed Image

Scale To FitScale To FitFlip HorizontalFlip Horizontal

Spatial Spatial TransformationsTransformations


Part of Image SelectedPart of Image Selected



Transformation & Transformation & AnnotationAnnotation


Part of Image SelectedPart of Image Selected



Mass behind heartMass behind heart

Mass behind heartMass behind heart

In this example,- text annotation is specified by image relative visible anchor point- the circle is a separate image relative graphic annotation

In this example,- text annotation is specified by image relative visible anchor point- the circle is a separate image relative graphic annotation

Limitations of Limitations of Grayscale Presentation Grayscale Presentation

StatesStates

• Apply to grayscale images– no means to specify spatial transformations or graphic

annotations for color images

• Only grayscale consistency– standard display function defined only for luminance

• No pseudo-color capability

• No blending or fusion capability




PrinterPrinter


Different perceived color




PrinterPrinter


Identical perceived color

True and Pseudo-ColorTrue and Pseudo-Color

Goals for ColorGoals for Color

• Color consistency– standard function

– defined for image output space of existing color images

• Transformation and annotation pipeline

• Pseudo-color for grayscale images

• Blending of grayscale images– alpha blending function

– colorizing superimposed image

Standard Color SpaceStandard Color Space

• GSDF filled a void

• Color consistency already standardized

• ICC - International Color Consortium

• Graphics and pre-press industry

• CIE Colorimetry

• Profiles of input and output devices

• COTS color management software handles conversion

• Perceptual rendering intent

Three New SOP ClassesThree New SOP Classes

• Color Presentation State• Pseudo-Color Presentation State• Blending Presentation State

• ICC Profile– Defines output of all color presentation states– Optionally present in all color images

• PCS-Values (analogous to grayscale P-Values)– Profile Connection Space (CIELAB or CIEXYZ)

CommonalityCommonality

• All presentation states share identical– Spatial transformation pipeline

– Graphic and text annotation pipeline

• Choice of output space– P-Values for grayscale

– PCS-Values for color and pseudo-color and blending

Old Grayscale PipelineOld Grayscale Pipeline

Rescale Slope/Intercept Window or VOI LUT

Presentation LUT

Grayscale Stored Pixel

Values

Modality LUT

Transformation

Mask Subtraction

VOI LUT Transformation

Presentation LUT

Transformation P-Values

Device Independen t

Values


Presentation LUT


Values

Modality LUT

Transformation

Mask Subtraction


Presentation LUT


Device Independen t

Values

Grayscale & Color Grayscale & Color PipelinePipeline


Presentation LUT


Values

Modality LUT

Transformation

Mask Subtraction


Presentation LUT


Pseudo Color

Palette Color LUT

Transformation

True Color Stored Pixel

Values

Profile Connection

Space Transformation

PCS-Values

Device Independen t

Values

Palette Color LUT

Transformation

Indexed Color Stored Pixel

Values

ICC Input Profile


Presentation LUT


Values

Modality LUT

Transformation

Mask Subtraction


Presentation LUT


Pseudo Color

Palette Color LUT

Transformation

True Color Stored Pixel

Values

Profile Connection


PCS-Values

Device Independen t

Values

Palette Color LUT

Transformation

Indexed Color Stored Pixel

Values

ICC Input Profile

Common Spatial & Common Spatial & Annotation PipelineAnnotation Pipeline

Device Independent

Values

Spatial Transformation

Displayed Area Relative

Annotation

Display

Shutter Transformation

Image Relative

Annotation

Device Independent

Values

Spatial Transformation

Displayed Area Relative

Annotation

Display

Shutter Transformation

Image Relative

Annotation

Blending PipelineBlending Pipeline


Underlying Image


Values

Modality LUT

Transformation


Pseudo Color

Palette Color LUT

Transformation

Profile Connection


PCS-Values

Device Independen t

Values

ICC Input Profile

Superimposed Image


Values

Modality LUT

Transformation


Blending Operation

Relative Opacity


Underlying Image


Values

Modality LUT

Transformation


Pseudo Color

Palette Color LUT

Transformation

Profile Connection


PCS-Values

Device Independen t

Values

ICC Input Profile

Superimposed Image


Values

Modality LUT

Transformation


Blending Operation

Relative Opacity

Blending for CT-PETBlending for CT-PET

selectsuperimposed

selectunderlying


selectsuperimposed

[register]select

underlying


selectsuperimposed

[register]

resample

selectunderlying


selectsuperimposed

[register]

resamplewithin slices

selectunderlying


selectsuperimposed

[register]


[between slices]

selectunderlying


selectsuperimposed

[register]


[between slices]

selectunderlying

rescale andwindow


selectsuperimposed

[register]


[between slices]

selectunderlying

rescale andwindow

pseudo-color


selectsuperimposed

[register]


[between slices]

selectunderlying

rescale andwindow

blend

pseudo-color

Color - ConclusionColor - Conclusion

• Color consistency using industry standard

• Transformation/annotation for color images

• Exchange of pseudo-color information

• Support for specifying sets of images to be blended, and how to blend (but not register or resample) them

OverviewOverview

• Review of Grayscale Presentation State

• Color Presentation States– Color Consistency

– Presentation States applied to Color Images

– Color Blending - CT-PET fusion

• Hanging Protocols


• “Default display protocols”

• A set of instructions

• How to layout a class of images for display

• Order, orientation, windowing, processing

• Not specific to a particular patient’s images

• Hence a protocol, not a presentation state


New Study

OldLateral

NewLateral

NewFrontal

NewTownes

L L L L

FFFF

Old Study

Hanging Protocol GoalsHanging Protocol Goals

• Encode– Applicability of protocol (type of display & images)– Selection of images– Display of selected images

• Store centrally, retrieve and exchange– Persistent composite objects– Query, retrieval and media encoding

• Vendor neutrality– Interchange between sites, PACS and workstations– Survive upgrades and replacements– “Public” library of “good” hanging protocols ?

New Information ModelNew Information Model

• Required for storage and query/retrieval

• No Patient/Study/Series hierarchy

• New Storage Service Class

• New Query Model

• Still C-STORE, C-FIND, C-MOVE

Using a Hanging Using a Hanging ProtocolProtocol

• Given a current exam (e.g. reading worklist)• Find potentially applicable protocols• Retrieve them from archive• Select one from those available• Select image +/- other studies to which it

applies• Display selected images as instructed

Finding a ProtocolFinding a Protocol

• Definition Module– Name, description, level, creator, creation datetime– Modality, anatomy, laterality– Procedure, reason for procedure– Number of priors

• Environment Module– Number of screens– Size(s) of screens– Color or grayscale bit depth

Selecting ImagesSelecting Images

• Definition of “image sets”• By attribute values

– Specific attributes, e.g. Modality, Anatomy

– Specific values, e.g, CT, Chest

– Supports all VRs, coded sequences, private elements and multi-frame functional groups

• By time– Relative time (today, yesterday, within last week)

– Abstract priors (last, oldest, pre-operative, etc.)

Successful SelectionSuccessful Selection

• All hanging protocols depend on consistent and reliable (and standard) information being present in the images

• DICOM Hanging Protocols don’t solve this integration problem

• Ideally - modality inserts correct anatomy and procedure and reason and orientation codes, and uses standard technique descriptions

• Worst case (typically?) - modality protocol (or operator) inserts recognizable Series Description

Information for Information for HangingHanging

Modality: MammographyAnatomic Region: BreastImage Laterality: LView Code: Medio-Lateral ObliquePatient Orientation: A\FR

Anterior

FootRight

L

PriorsPriors

• Concept of the “current” study required• Protocol chooses priors based on

– Relative time– Abstract temporal ranges (previous, last, etc.)– Abstract coded descriptions (“pre-operative”)

• Does NOT specify how to find them or get them• May have been pushed, may need a query• May be hard to find by abstract descriptions• Creative use of queries or out-of-band information

Mapping to Image Mapping to Image BoxesBoxes

• Image Sets are mapped to Image Boxes• Image Box types

– Tiled (e.g. 3x4)

– Stack (single image paged manually)

– Cine (time-based play back)

– Processed (e.g. MPR, 3D)

– Single (e.g. a place for a report or waveform)

• Specify– Scrolling mode

– Playback rate

Mapping to Image Mapping to Image BoxesBoxes

• Filtering– By attribute, or abstract, e.g. “category” of “image plane” “axial”

• Sorting– By attribute, or abstract, e.g. “along axis” “increasing”

• Orientation– E.g. rotate/flip until row left column posterior (L\P)

• Annotation– Patient demographics, technique and graphics on or off

Processing & Processing & PresentationPresentation

• Reformatting, e.g., MPR, 3D, slab• Thickness, interval• View direction, e.g., axial, sagittal, coronal• Type, e.g., MIP, surface, volume• VOI Type (windowing), e.g., brain, bone• Pseudo-color type, e.g., hot iron• Invert grayscale• True size• Synchronized scrolling (by Display Set number)• Navigation and localization

Display of Image BoxesDisplay of Image Boxes

• Entire display environment from 0,0 to 1,1

• Individual screens are not distinguished

(0.0, 0.0)

(1.0, 1.0)

1024 pixels

1024 pixels

2560 pixels

2048 pixels

(0.33, 1.0)

(1.0, 0.0)

(0.0, 0.4)

(0.33, 0.0)

(0.0, 0.0)

(1.0, 1.0)

1024

1024

2560

2048

DS 6: MPRCOR

DS 8: AXIAL

DS 7: MPR SAG

DS 9: 3D VOL

DS 10: AXIAL

Display of Image BoxesDisplay of Image Boxes

• Image Sets displayed in Image Boxes

• Image Boxes rendered at relative location

Hanging Protocols - Hanging Protocols - ConclusionConclusion

• Interchangeable• Vendor neutral• Multi-modality• Support selection of priors• Full richness of current display modes• Flexible• Extensible

• Non-trivial to implement and retrofit• Dependent on reliable image attributes

The Medicine Behind the Image DICOM Display Update: Color Presentation States Hanging Protocols Dr....

Documents

Transcript of The Medicine Behind the Image DICOM Display Update: Color Presentation States Hanging Protocols Dr....