1991

Imaging the Future


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One picture is worth a thousand words. That ancient proverb is especially apt in the field of medicine, where the x-ray image has become a standard diagnostic tool. But today, thanks to new imaging technologies such as ultrasound, magnetic resonance imaging, and x-ray computed tomography (CT or "cat" scans), the number of medical images generated in the clinical environment is exploding. Distribution and storage of such images has become a major issue for the nation's health care system.

Instead of just single pictures, doctors must now process thousands of images. A typical CT or MRI exam generates from 20 to 100 images each, corresponding to a series of cross-sectional slices through the patient's body that are used to piece together an understanding of the three-dimensional structures and processes inside the patient. In a typical 600-bed hospital, some 250,000 x-rays, 425,000 CT images, 225,000 MRI images, 150,000 ultrasounds, and 100,000 images from nuclear medicine studies are generated during the course of a single year—more than one million images in all for just one hospital.footnote 1 And these numbers are expected to grow in the future.

A Picture Archiving and Communication System, or PACS, provides a computerized way to collect, interpret, distribute, and store such images. A PACS can handle images in electronic format, offering a potentially more efficient and less expensive way to manage this type of diagnostic information. One picture may be worth a thousand words, but millions of pictures are not worth nearly as much without one PACS.

The research of UW professor Yongmin Kim on Picture Archiving and Communications Systems has led to the first such system in the world being implemented at Madigan Army Medical Center in Tacoma, Washington. The Madigan system has been used clinically since March 1992 and has been used hospital-wide since spring of 1995. This $250-million project is the first of many installations to come, since the U.S. Army decided in 1991 to place PACS systems in all of the major military hospitals in the U.S.

As a professor of electrical engineering and adjunct professor of bioengineering, radiology, and computer science and engineering at the UW, Kim is actively engaged in a wide range of research projects relating to image processing, from PACS and telemedicine to multimedia and computer graphics. Multimedia refers to the fusion of text, graphics, images, sound, animation, and video in a computer-based format.

In telemedicine, health care professionals are linked over a computer network. Using cutting-edge computing and communications technologies, they can carry out a videoconference, where audio and visual images of participants are transmitted in real time, while they share and explore medical data such as charts, x-rays, and other medical images. Kim has worked closely with the U.S. military to establish telemedicine systems in military and federal medical treatment facilities around the Puget Sound area.

In addition to Madigan Army Medical Center, facilities involved in the telemedicine project include Bremerton Naval Hospital, Oak Harbor Naval Hospital, and the Veteran's Administration Hospitals in Seattle and in American Lake. Feasibility of the system was successfully demonstrated on January 13, 1995, when the UW and Madigan were able to transfer x-ray, MRI, and ultrasound images interactively, using two MediaStation 5000 image processing boards developed in Kim's lab, linked with a wide-bandwidth phone line provided by U S West Communications. As a result of this successful demonstration, telemedicine systems are slated to be installed in the Puget Sound military and federal hospitals in 1996. Telemedicine coupled with PACS offers a more efficient and inexpensive way for health care professionals to conference, even over long distances. Remote collection and/or interpretation of medical data becomes possible. The technology facilitates the sharing of medical data, and fast, inexpensive access to medical images. And it holds promise for improving delivery of health care services to rural areas.

The heart of the telemedicine demonstration was the MediaStation 5000 (MS5000), a lightning-fast, high-resolution digital computing system that will allow users of even relatively low-end microcomputers to process video and high-quality audio information. The system uses the Texas Instruments Multimedia Video Processor chip, developed by TI with participation of Kim's group.

Capabilities of the MS5000 plug-in board allow video to be displayed independently of any image-processing operations being performed at the same time. The system represents a breakthrough for a wide range of multimedia applications, including desktop multimedia authoring and publishing, videoconferencing, video-on-demand (digitized motion pictures coming into the home over the cable system), and interactive television. The MS5000 technology was licensed to Redmond-based Precision Digital Images in February 1994, as well as to other companies outside Washington State.

A prolific inventor, Kim and his group have made 17 invention disclosures to the UW's Office of Technology Transfer over the years. Ten commercial licenses have been signed for technologies transferred over the past eight years alone. For example, Kim has been working with Siemens Medical Systems Ultrasound Group in Issaquah, Washington, since 1991. His patented invention for an ultrasound image processor forms part of Siemens' new ultrasound systems, introduced in 1996.

Kim co-founded the Seattle-based optical imaging company Optimedx, Inc. in 1992. The company is developing an imaging system to assist surgeons in visualizing the boundaries of tumors during surgical operations. In January 1995, Kim established the UW Image Computing Library Consortium to provide an efficient and flexible library of image processing algorithms. Currently, seven companies sponsor the effort. And in addition to his normal undergraduate and graduate teaching duties, he has taught many continuing education courses on image processing, advanced microprocessor system design, digital electronics, and multimedia systems; his courses have been attended by hundreds of engineers from the Pacific Northwest.


  1. "Requirements for Picture Archiving and Communications," IEEE Engineering in Medicine and Biology, March 1993, p. 62.

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