Image Display Systems Optimizing the Environment

1. Image Display SystemsOptimizing the Environment Stephen G Davies Consultant Radiologist Royal Glamorgan Hospital

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

3. Radiologist reporting • Heat • Desking • Seating • Noise • Light

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

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

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

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

8. Radiographer viewing • Heat output • Room layout

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

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

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