Consistent Presentation of Images Profile IHE North America Webinar Series 2008 Chris Lindop IHE Radiology GE Healthcare

2 Consistent Presentation of Images Use Case Print Composer Print Grayscale Images Provide Consistent Imaging Viewing on Different Display and Print Devices Laser Imagers Imaging Diagnostics Display Workstations Imaging Diagnostics Display Workstations Display Grayscale Images

3 Consistent Presentation of Images Value proposition Resolve the Grayscale Consistency Problem The Visual Appearance of grayscale images displayed or printed on different devices is in general inconsistent and may impact the clinical Diagnostics Reading The cost effective solution to ensure that image quality is maintained across different monitors and film producing devices

4 Problems of Display Inconsistency mass visiblemass invisible VOI chosen on one display device Rendered on another with different display Mass expected to be seen is no longer seen Slide Provided by David Clunie

5 Inconsistency in Display Luminance range Not all display levels are perceivable on all devices Slide Provided by David Clunie

6 Inconsistency in Display Luminance range Not all display levels are perceivable on all devices

7 Hardcopy-Softcopy Inconsistency Digital Modality Laser Printer Printed images don’t look like displayed images

8 Causes of Inconsistency Display devices vary in the maximum luminance they can produce Display CRT Luminance vs. Film Optical Density on a light box is an extreme example

9 Consistent Presentation of Images Scope 1.Consistent distribution of Images across the healthcare enterprise -Consistency among Hardcopy Images Printed on different Printers -Consistency among Softcopy Images view on different Display devices -Consistency among Hardcopy and Softcopy Image view 2. Maintain and Improve Image Quality - Calibrating the Display/Print Device - Use Presentation State for Display and Presentation (P-Val) LUT for Print. 3. Improve Throughput -Preserve the Display Setup parameters in the Presentation State -Apply the Presentation State automatically before the Images Display

10 DISPLAY Image Archive Image Manager Image Display Image Creator Present. State Stored Q /R Presentation Sates Images Stored Present. State Stored Acquisition Modality PRINTING Print Server Print Request with Presentation LUT Print Composer Consistent Appearance of Images: – –Display Devices – –Printed Output Consistent Presentation of Images Transaction Diagram

11 Consistent Presentation of Images DICOM Standard Used: Calibration of the Softcopy Display and the Hardcopy Output Devices using DICOM Grayscale Standard Display Function (GSDF) Creating Hardcopy Output Using DICOM Basic Print with Presentation LUT (P-LUT) Support Preserving/Using the Softcopy Display Viewing Parameters in the DICOM Grayscale Softcopy Presentation State (GSPS) container Cal Hard Soft

12 Consistent Presentation of Images Standardizing/Calibrating Device 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 – Adjust their Characteristic Curve to the GSDF curve. Cal Devices Have to Be Properly Calibrated

13 Standardizing a Display/Print Device to GSDF Curve Cal DDL or P-Values Standard Characteristic Curve

14 Consistent Presentation of Images Images Printed, the DICOM Standard Defines:   Basic Print Management with Presentation Look Up Table, for controlling the consistent appearance of preformatted images on printed output Hard

15 Basic Print Request with Presentation LUT Actors Print Composer Print Server DICOM Film Session N-CREATE DICOM Film Box N-CREATE DICOM Image Box N-SET DICOM Film Box N-ACTION DICOM Film Session N-ACTION Print Status (DICOM N-EVENT-REPORT) DICOM Presentation LUT N-CREATE Print Composer Print Server Print Request Printer Status Hard Print Presentation LUT

16 Actors: 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

17 Consistent Presentation of Images Preserving Display Parameters: 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. Soft

18 Consistent Presentation of Images Reporting Radiologist Referring Physician or Reviewing Radiologist Presentation State Presentation LUT Grayscale Standard Original ImageWindow LevelFlip Zoom Area Of Interest Annotate Without Consistent Presentation Achieving Consistent Presentation Area Of Interest Soft

19 DICOM Grayscale Image Transformation Model e Transformation VOI LUT (Subtraction) Mask Modality LUT Transformation Annotation Image Transformation ShutterSpatial Transformation Annotation Disp. Area Presentation LUT 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 Soft

20 Consistent Presentation of Images Actors: Grayscale Softcopy Presentation State (GSPS) Image Acquisition / Evidence Creator   Creates Images with GSPS Objects and Store them on Image Manager/Image Archive Image Manager /Image Archive   Store and Query & Retrieve Images with GSPS Objects Image Display   Query & Retrieve Images with GSPS Objects and Apply the GSPS on the Images

21 Acquire DisplayPrint Consistent Presentation of Images

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