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Proceedings Paper

Optical compensation device for chest film radiography
Author(s): Robert G. Gould; Bruce H. Hasegawa; Sherman E. DeForest; Gregory W. Schmidt; Richard G. Hier
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Paper Abstract

Although chest radiography is the most commonly performed radiographic examination and one of the most valuable and cost-effective studies in medicine it suffers from relatively high error rates in both missing pathology and false positive interpretations. Detectability of lung nodules and other structures in underpenetrated regions of the chest film can be improved by both exposure and optical compensation but current compensation systems require major capital cost or a significant change in normal clinical practice. A new optical compensation system called the " Intelligent X-Ray Illuminator" (IXI) automatically and virtually instantaneously generates a patient-specific optical unsharp mask that is projected directly on a radiograph. When a radiograph is placed on the IXI which looks much like a conventional viewbox it acquires a low-resolution electronic image of this film from which the film transmission is derived. The transmission information is inverted and blurred in an image processor to form an unsharp mask which is fed into a spatial light modulator (SLM) placed between a light source and the radiograph. The SLM tailors the viewbox luminance by decreasing illumination to underexposed (i. e. transmissive) areas of the radiograph presenting the observer with an optically unsharp-masked image. The IXI uses the original radiograph and will allow it to be viewed on demand with conventional (uniform illumination. Potentially the IXI could introduce the known beneficial aspects of optical unsharp masking into radiology at low capital

Paper Details

Date Published: 1 July 1990
PDF: 14 pages
Proc. SPIE 1233, Medical Imaging IV: Image Processing, (1 July 1990); doi: 10.1117/12.18917
Show Author Affiliations
Robert G. Gould, Univ. of California/San Francisco (United States)
Bruce H. Hasegawa, Univ. of California/San Francisco (United States)
Sherman E. DeForest, DigiVision, Inc. (United States)
Gregory W. Schmidt, DigiVision, Inc. (United States)
Richard G. Hier, DigiVision, Inc. (United States)

Published in SPIE Proceedings Vol. 1233:
Medical Imaging IV: Image Processing
Murray H. Loew, Editor(s)

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