It has long been the dream of forward-looking radiologists that advanced technology would one day replace the most common medical imaging detector, X-ray film. Although X-ray film produces high quality images, it is an imaging modality which, in the electronic age, has become antiquated. After exposure, for example, X-ray film must be developed, which is precious time lost in emergency situations. Film has a low dynamic range, which makes under- and over-exposure a common experience, and which requires re-takes. Also, medical X-ray films must, by law, be stored for a period from three to seven years. As such, hospital administrators must lease warehouses for film storage, at great expense.

What is needed is an electronic imager of medical X-rays. At electronic speeds, an image may be displayed instantaneously upon exposure. With high dynamic range, under- and over-exposure can be virtually eliminated. With image data in electronic form, optical juke boxes may replace warehouses as storage facilities. Also, a means to capture X-ray images electronically creates new opportunities. Via modern telecommunications technology, images taken in remote areas by general practitioners may be transmitted to expert radiologists in metropolitan areas for expert advice. Sophisticated pattern recognition algorithms could allow computer diagnosis of disease.

In recent years, a new technology has emerged which has the potential to produce the desired electronic imager of X-rays. Known as amorphous silicon technology, it is the same technology which is used to make flat panel displays for computer notebooks. This technology holds not only the promise to replace X-ray film, it also has the potential to replace another medical imaging device, the fluoroscope.

Applications for amorphous silicon X-ray imaging technology also extend beyond the medical arena. The technology is also useful for industrial non-destructive test applications.

Dr. M. D. Wright, Varian Associates, Inc., will describe this new technology at the May 13 meeting of the Oakland - East Bay Chapter of the Nuclear and Plasma Science Society. The physics of the technology will be discussed, and a prototype imaging system which is currently under development will be described. Information regarding the commercialization of this technology will also be presented.

Dr. Wright received his bachelor of science degree from the Department of Physics at the University of Redlands in 1974. He received his doctorate degree from the Department of Applied Physics at Stanford University in 1981.

While at Stanford, Dr. Wright studied laser physics. Dr. Wright took his first position of employment at Philips Research Laboratory, Sunnyvale, where he investigated silicon device physics topics. In 1984 Dr. Wright moved to Varian's corporate research center. In 1987 he became the technical leader of a team developing an aluminum gallium arsenide charge-coupled device for an imaging application. In 1990 Dr. Wright began his research in the area of amorphous silicon medical imagers. Dr. Wright is currently Advanced Development Manager at Varian Imaging Products, a new business unit at Varian.

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24-13 map
From highway 24 or 13, take the Berkeley/Tunnel Road/13 exit. Tunnel Road becomes Ashby past the Claremont Hotel. Turn right at the traffic light at College Ave (at the Wells Fargo Bank). Turn right at the traffic light at Durant (one-way street located one block before College Ave ends at the UC campus). At the end of Durant (one block), turn left onto Piedmont, which becomes Gayley Road. Turn right at the traffic light at Hearst at the northeast corner of the campus. Hearst becomes Cyclotron Road. At the LBL guard station the guard can give you instructions to Building 2, Room 100B.

Alternative route from 24-13 (Green line on map; shorter, but through residential neighborhood): On Ashby, turn right at Claremont Ave. (at gas station; second traffic light after main entrance to Claremont Hotel). Immediately bear left around the "island", with the restaurant on it. You will find yourself driving through a wrought iron and brick gateway if you have performed this maneuver properly. Proceed to the end of the street to a forced left turn onto Derby at the UC-Clark Kerr campus. Turn right at Warring at the southwest corner of the campus. After two blocks, follow the road as it bears to the left to join Piedmont Ave at the traffic light (stay in the right lane on Piedmont to avoid a forced left turn at Haste). Continue along Piedmont until it becomes Gayley Road and proceed as described in the previous paragraph.