Consistent Presentation of Images Integration Profile Charles Parisot GE Medical Systems IT Planning and Technical Radiology Committees

IHE Integration profiles Patient Informa-tion Reconci-liation , Scheduled Workflow Charge Posting Reporting Workflow Presentation of Grouped Procedures - Post-Processing Workflow Consistent Presentation of Images Evidence Documents Key Image Notes Simple Image and Numeric Reports Access to Radiology Information Basic Security HIMSS/RSNA April 2003 Workshop

The Grayscale Consistency Problem: The appearance of grayscale images displayed on different types of softcopy display devices or printed on different types of hardcopy output devices is in general inconsistent and at times may impact clinical perception HIMSS/RSNA April 2003 Workshop

Problems of Inconsistency VOI chosen on one display device Rendered on another with different display Mass expected to be seen is no longer seen mass visible mass invisible Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Problems of Inconsistency 0.5 1.0 Not all display levels are perceivable on all devices 1.5 3.0 Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Problems of Inconsistency 0.5 1.0 Not all display levels are perceivable on all devices 1.5 3.0 Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Problems of Inconsistency Laser Printer Digital Modality Printed images don’t look like displayed images Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Causes of Inconsistency Display devices vary in the maximum luminance they can produce Display CRT vs. film on a light box is an extreme example 1.0 .66 Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Consistent Presentation of Images IHE Objectives Consistent distribution of Images across the healthcare enterprise : Consistency among Hardcopy Images Printed on different Printers (from different Vendors). Consistency among Softcopy Images view on different display devices (from different Vendors). Consistency among Hardcopy and Softcopy Image view The cost effective solution to ensure that image quality is maintained across different monitors and film producing devices. HIMSS/RSNA April 2003 Workshop

Consistent Presentation of Images Requires: Calibration of the Softcopy Display and the Hardcopy Output Devices using DICOM Grayscale Standard Display Function Creating Hardcopy Output Using DICOM Basic Print with Presentation LUT Support Preserving/Using the Softcopy Display Viewing Parameters in the DICOM Grayscale Softcopy Presentation State Cal Hard Soft HIMSS/RSNA April 2003 Workshop

Achieve Grayscale Consistency in Hardcopy Output and Softcopy Viewing The DICOM Standard Defines: A standard curve, the Grayscale Standard Display Function (GSDF), against which different types of display and hardcopy output devices should be calibrated Cal Devices Have to Be Properly Calibrated HIMSS/RSNA April 2003 Workshop

Grayscale Standard Display Function DICOM GSDF .01 .1 1 10 100 1000 200 400 600 800 Grayscale Standard Display Function JND Index Monitors Film preserves the human perceptual response based on eye contrast sensitivity Mapping of the P-values to the view luminance or optical density value HIMSS/RSNA April 2003 Workshop Slide Provided by David Clunie

Perceptual Linearization Cal Perceptual Linearization .01 .1 1 10 100 1000 200 400 600 800 Grayscale Standard Display Function JND Index Despite different change in absolute luminance Same number of Just Noticeable Difference == Same perceived contrast Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Printer Calibration Tools (Densitometer) HIMSS/RSNA April 2003 Workshop

Display Calibration Tools (Photometer) HIMSS/RSNA April 2003 Workshop

Monitor Characteristic Curve Cal Monitor Characteristic Curve Monitor Characteristic Curve 100 10 0.1 Ambient Light 0.01 50 100 150 200 250 300 Digital Driving Level Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Standard Display Function Cal Standard Display Function .01 .1 1 10 100 1000 200 400 600 800 Grayscale Standard Display Function JND Index Monitor’s Capability Jmax == P-Value of 2n-1 Jmin == P-Value of 0 Minimum Luminance + Ambient Light Maximum Luminance Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Standardizing a Display Cal Standardizing a Display 0.1 1 10 100 50 150 200 250 DDL or P-Values Standard Characteristic Curve Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

To Achieve Consistent Presentation of Images, the DICOM Standard Defines: Hard Basic Print Management with Presentation Look Up Table, for controlling the consistent appearance of preformatted images on printed output HIMSS/RSNA April 2003 Workshop

Basic Print Request with Presentation LUT Composer Server DICOM Film Session N-CREATE Print Composer DICOM Presentation LUT N-CREATE Print Request Print Presentation LUT DICOM Film Box N-CREATE DICOM Image Box N-SET DICOM Film Box N-ACTION DICOM Film Session N-ACTION Print Server Print Status (DICOM N-EVENT-REPORT) Hard Printer Status HIMSS/RSNA April 2003 Workshop

Basic Print Request with Presentation LUT Print Composer – A system that generates DICOM print requests as a DICOM Print SCU. Print composer has to apply image processing manipulations, and requests to Print server will specify P-Values in the form of a Presentation Look-Up Table (Presentation LUT) or implicitly by Presentation LUT Shape. Print Server – A system that accepts and processes DICOM print requests as a DICOM Print SCP and performs image rendering on hardcopy media. The system must support pixel rendering to optical density according to the DICOM Grayscale Standard Display Function. Hard HIMSS/RSNA April 2003 Workshop

To Achieve Consistent Presentation of Images, the DICOM Standard Defines: Soft Grayscale Softcopy Presentation State (GSPS): an object for storing and communicating the parameters that describe how an image or set of images should be displayed. A GSPS object contains references to the images it applies to, and the transformations (grayscale transformations, shutter transformation, image annotation, spatial transformations, and displayed area annotation) that should be applied when the images are presented on a softcopy display, or printed on film. HIMSS/RSNA April 2003 Workshop

Reporting Radiologist Consistent Presentation of Images Referring Physician or Reviewing Radiologist Reporting Radiologist Area Of Interest Annotate Achieving Consistent Presentation Area Of Interest Soft Presentation State Presentation LUT Zoom Grayscale Standard Flip Window Level Original Image Without Consistent Presentation HIMSS/RSNA April 2003 Workshop

DICOM Grayscale Image Transformation Model Soft T r a n s f o m t i V O I L U ( S u b c ) M k d l y A g e h p D . Presentation LUT Transformation Window/Level or VOI LUT Rescale Slope/Intercept or Modality LUT Original Image Display P-Values Grayscale Transformations Shutter, Annotation and Spatial Transformations e HIMSS/RSNA April 2003 Workshop 10

GSPS Stored, and Query/Retrieve GSPS Image Creator Modality Presentation State Stored 9 Acquisition Modality Creator Presentation 19 Display Query Presentation State 15 Retrieve 17 Archive IHE Transaction - an Acquisition Modality or Image Creator Actor sends a DICOM GSPS C-STORE request to an Image Archive Actor IHE Transaction - an Image Display Actor issues a C-FIND request to an Image Manager Actor IHE Transaction - an Image Display Actor issues a C-MOVE request to an Image Archive Actor Soft HIMSS/RSNA April 2003 Workshop

IHE Year 4: Presentation State Specific Query Matching and Return Keys Soft Attribute Name Tag Query Keys Matching Query Keys Return SCU SCP SCU SCP Presentation Label (0070,0080) O O R+ R+ Presentation Description (0070,0081) O O O R+ Presentation Creation Date (0070,0082) O O R+ R+ Presentation Creation Time (0070,0083) O O R+ R+ Presentation Creator’s Name (0070,0084) O O R+ R+ Referenced Series Sequence (0008,1115) O O R+ R+ > Series Instance UID (0020,000E) O O O R+ > Referenced Image Sequence (0008,1140) O O O R+ >> Referenced SOP Class UID (0008,1150) O O O R+ >> Referenced SOP Instance UID (0008,1155) O O O R+ HIMSS/RSNA April 2003 Workshop

Consistent Presentation of Images Acquire Print Display Slide Provided by David Clunie HIMSS/RSNA April 2003 Workshop

Documents Available On the Web at: Questions? Documents Available On the Web at: www.rsna.org/IHE HIMSS/RSNA April 2003 Workshop