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Medical Image Display. Bradley Hemminger School of Information and Library Science Department of Radiology, University of North Carolina, Chapel Hill http://ils.unc.edu/bmh bmh@ils.unc.edu. Medical Image Display. Digital Values + Human Observer Observer makes decisions
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Medical Image Display Bradley Hemminger School of Information and Library Science Department of Radiology, University of North Carolina, Chapel Hill http://ils.unc.edu/bmh bmh@ils.unc.edu
Medical Image Display • Digital Values + Human Observer • Observer makes decisions • Decisions affect patient care/treatment • Results in different patient outcomes.
Basic Perception Issues • Color or Grey Scale to Use? • Standardizing the Grey Scale • Perceptual Linearization • Different types of Displays (CRT, flat panel) • Calibration
Consistent Grayscale: Acquire Display Print Slide courtesy of David Clunie, ComView
Image Presentation Integrity • Goal: Images look the same independent of the display system or method used to present the images. • DICOM Standards supporting this: • - Grayscale Standard Display Function • - Softcopy Presentation State Storage • AAPM guidelines • - Display Quality for Electronic Displays
Display Display Modality Perceptual Linearization Ambient Light Perception of Contrast By Human Visual System
Display Card Values (0-255, 0-1023) Laser Printer Values (0-255, 0-4095) Display Card Computer Analog Voltage Luminance on Monitor or through film on Lightbox Computer Digital Values (0-255, 0-4095, ... 0-65535) Perceived Brightness by human observer
Computer Characteristic Curve Display Card CSF Contrast Sensitivity Function (CSF) Transfer function describing the change in luminance required to see a contrast threshold at a given luminance level.
Image Display and Interaction • Single Images • Alternators • Hanging Protocols • Staged Interactions (Mammo Screening) • Studying Users to optimize CHI.
Image Enhancement • Intensity Windowing • Unsharp Masking • AHE • MUSICA
Novel Display technologies • Cine/stack • “3D” • Virtual reality • Fusion