Image Display Systems Optimizing the Environment Stephen G Davies Consultant Radiologist Royal Glamorgan Hospital

PACS Image viewing Radiologist reporting room Radiologist reporting room Radiographer quality control station Radiographer quality control station Clinic viewing in wards and clinics Clinic viewing in wards and clinics

Radiologist reporting Heat Heat Desking Desking Seating Seating Noise Noise Light Light

Perception factors Spatial and contrast resolution of the display device Spatial and contrast resolution of the display device Brightness and luminance of the monitor Brightness and luminance of the monitor Extraneous light in the reading room Extraneous light in the reading room Displayed field size; magnification and zoom Displayed field size; magnification and zoom Signal to noise of the displayed image Signal to noise of the displayed image

Extraneous light Significant effect on performance of viewers Significant effect on performance of viewers Decreases the perceived object contrast – reducing the detection of the object Decreases the perceived object contrast – reducing the detection of the object More significant in a PACS environment More significant in a PACS environment Low luminance levels of monitors compared with viewboxes (6:1) Low luminance levels of monitors compared with viewboxes (6:1) Increasing luminance increases contrast sensitivity Increasing luminance increases contrast sensitivity Effect more marked in the low luminance range Effect more marked in the low luminance range

Radiologist reporting Lighting conditions Lighting conditions No standards No standards General principles General principles Control Control Ambient light levels Ambient light levels Consider all tasks e.g. reading Consider all tasks e.g. reading Reflected light Reflected light

Radiographer quality control Lighting conditions Lighting conditions Just as important as for radiologist reporting quality control of images Just as important as for radiologist reporting quality control of images Also need to read clinical request for verification Also need to read clinical request for verification

Radiographer viewing Heat output Heat output Room layout Room layout

Clinical viewing Significant challenge Significant challenge Lighting a key issue Lighting a key issue Bright for clinical examination Bright for clinical examination Dim for image viewing Dim for image viewing

Clinical Viewing Desk space is at a premium Desk space is at a premium Theatres a special case Theatres a special case Flat screen monitors Flat screen monitors

Summary Ambient lighting conditions pose the greatest challenge to display systems at present Ambient lighting conditions pose the greatest challenge to display systems at present Heat and desk space are becoming less important Heat and desk space are becoming less important