Electric Differential Multimedia Laboratory Bibliography
Jeffrey R. Galvin, MD, Michael P. D'Alessandro, MD, Yasuyuki
Kurihara, MD
William E. Erkonen, MD, Teresa A. Knutson, BA, David L. Lacey, MD
Peer Review Status: Externally Peer Reviewed
From the Electric Differential Multimedia Laboratory, Department of Radiology, The University of Iowa College of Medicine, Iowa City, IA 52242.Address reprint requests to J.R. Galvin, Department of Radiology, The University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242. Telephone: 319/356-7980, FAX: 319/356-2220.
Dr. D'Alessandro's present address: Department of Radiology, Children's Hospital/Harvard Medical School, 300 Longwood Ave., Boston, MA 02115.
Dr. Kurihara's present address: Department of Radiology, St. Marianna University, Kawasaki City, Japan
Abstract
Introduction
Film-based teaching files are valued assets within a radiology
department. Their value is limited, however, by poor access,
difficulty searching the file and deterioration of the films. We have
created a ubiquitous chest teaching file that can be accessed by
multiple users simultaneously both within the department and around
the world.
Methods
The chest teaching file was created using the following: 1. Internet,
the information superhighway of today; 2. World Wide Web, a public
domain software technology that organizes and links information on
the Internet; 3. Mosaic-an Internet program that allows for intuitive
access to information organized by the World Wide Web; and 4.
Inexpensive multimedia computers.
Results
Authoritative text, images and videos can be retrieved and displayed
on the majority of computers connected to the Internet.
Conclusion
This approach allows a Radiologist to access current diagnostic
information and images at the view box where it is most useful.
Introduction
The value of a film-based teaching file in radiology was quickly
recognized [7] and has been accepted as a key departmental asset [2].
The cases within the teaching file are generally stored in one
location and are organized using the American College of Radiology
(ACR) code. Variable amounts of information about the patient's
underlying predisposition, presenting symptoms, imaging findings and
the pathophysiology of the disease are included. Teaching files are
primarily used to instruct medical students and residents but they
can also be used for conference presentations, publications and
continuing medical education (CME). Considerable effort and expense
is required to create and maintain a high quality film collection
[5]. However, the effort is worthwhile since these collections are
important vehicles for increasing a radiologist's "personal database"
of clinical experience. Expert clinical reasoning is to a large
extent the process of comparing a current case to a database of
individual cases that are available in memory [8]. A teaching file
would therefore be most relevant if it were available at the view box
where it could be used to help extend one's clinical experience [4].
Unfortunately, a film-based teaching file is confined to one area,
usually remote from the view box. In addition, searching though a
film file is difficult, the films wear out over time and are easily
lost or stolen. We are, therefore, creating a ubiquitous thoracic
teaching file that is a digital representation of images, video and
text produced at the University of Iowa. This ubiquitous teaching
file is continuously available to multiple users both within our
department and throughout the world.
Methods
The technical components of the ubiquitous teaching file include 1)
the Internet, the worldwide information superhighway of today, which
we use to transmit the information in the teaching file; 2) World
Wide Web (WWW) (European Particle Physics Laboratory, Geneva,
Switzerland), an Internet database program which organizes the
information in the teaching file; 3) Wide Area Information Servers
(WAIS), an Internet program that indexes the data in the teaching
file and allows for a directed search of the information; and 4)
Mosaic, (National Center for Supercomputing Applications, Champaign,
IL) an Internet program available for all personal computers that
facilitates viewing of information organized by the World Wide Web
and indexed by Wide Area Information Servers. The thoracic teaching
file is created with a standard Macintosh (Apple Computer Inc.
Cupertino, CA) for both acquisition of media (images and video) and
to build the text files. Currently, we use a Macintosh Quadra 840 AV
with 16 megabytes of RAM and a 500 Megabyte hard drive with a direct
Ethernet connection to the Internet. The text for the thoracic
teaching file has been created by two thoracic radiologists (JRG and
YK) and one pediatric radiologist (MPD). Each disease is represented
by a separate text file with seven main headings: clinical signs and
symptoms, pathophysiology, histopathology, imaging, differential
diagnosis and key references. Multiple radiology and pathology
images, well as digital video clips, annotate the text file and are
available with a single mouse click. A variety of images are
available with each disease text file to illustrate the range of
findings and degree of severity that characterize a given disease
entity. This approach creates a more realistic view of the disease
process and contrasts with the standard "typical case" approach. The
text files are created with Microsoft Word Version 5.1 (Microsoft,
Redmond, WA). The text for 53 adult and 50 pediatric disease subjects
has been completed. The files range in size from 4 kilobytes to 7
kilobytes. Each text file is saved as plain text (also known as
ASCII) and then annotated or prepared using the Hypertext Markup
Language (HTML), which is the instruction set of the World Wide Web
(Fig.). Hypertext Markup Language uses specific "markup tags" or
instructions to tell Mosaic exactly how to display the text and where
to find the incorporated media (images, sounds, video or text) that
are linked to a particular disease text file. The computer addresses
for the linked media are called Uniform Resource Locators (URLs). Any
word processing software can be used to create HTML files. A few of
the most common ones include TeachText (Apple Computer Inc.,
Cupertino, CA), Microsoft Word and WordPerfect (WordPerfect, Orem,
UT). Images are "digitized" or brought into the computer with either
a Leafscan 35-slide scanner (Leaf Systems, Southboro, MA) or an
Imapro flatbed scanner (Imapro Corporation, Ogdensburg, NY). The
majority of our pathology images arrive in slide format. Radiographs,
computed tomographic films and other miscellaneous pictures are
digitized using the flatbed scanner. Once the images are in the
computer, we crop, caption, and label them using Adobe Photoshop
(Adobe, Mountain View, CA) which is the most time-consuming task.
Video is digitized using the VideoVision Studio board (Radius Inc.
CA) which has been added to the Macintosh computer. The digital video
is edited with Adobe Premier (Adobe, Mountain View, CA). We save all
our media in industry standard file formats: ASCII text file format
for the text, Joint Photographic Experts Group (JPEG) file format and
Graphics Interchange Format (GIF) file format for the images and
QuickTime™ file format for the videos. In addition to creating a
large version of each image, we also create a smaller picture icon or
"picon" that is embedded in the Hypertext Markup Language files. The
picon serves as a small "inline" representation or preview of the
image. These are generally 32 pixels high and must be saved in the
Graphics Interchange Format. It is important to label the media files
using a naming convention that allows you to look at the file name
and quickly understand its contents. We organize the media within the
computer's file system so that all the text files, images, video
clips, audio clips, etc., are stored in separate folders. This
facilitates the creation of links to each piece of media in the
Hypertext Markup Language documents. The completed Hypertext Markup
Language files and the related media files are transferred over a
local area network from the Macintosh to storage on a World Wide Web
server. Our World Wide Web server is currently a Macintosh Apple
WorkGroup Server 95 file server computer connected to the Internet.
It uses the UNIX operating system along with the Hypertext Transfer
Protocol Daemon World Wide Web Software (NCSA, Champaign, IL). The
text within each disease text file is indexed using Wide Area
Information Server (WAIS) software and therefore can be searched
using key words.
Results
The thoracic teaching file is currently available at The University
of Iowa in close proximity to the chest alternator. The display
station is a PowerMacintosh 7100 which has access to the Internet via
an Ethernet connection. The user locates the chest teaching file by
first launching Mosaic and typing in the address (URL) for the
Virtual Hospital (http://vh.radiology.uiowa.edu). The home page for
the Virtual Hospital is displayed and the user may then select the
teaching file category from the main menu (Fig.1 A and B). Once the
teaching file is selected, the table of contents of the thoracic
teaching file (International Thoracic Teaching Resource) is
displayed, showing all of the diseases available After clicking on
the disease of interest, the user is shown the text along with the
links to associated images. (Fig 2 A and B) These links are indicated
by underlined words and picons (Fig. 2A). The user scrolls through
the individual files by clicking on the scroll bar along the right
side of the screen. By clicking on a link, media related to the text
being read is displayed. The user may take multimedia notes by using
a word processing program that runs concurrently with Mosaic. Users
may also copy, paste and save any portion of the thoracic teaching
file for their own use and reference. However, users are not allowed
to modify the original text or images. Diseases that are part of the
differential diagnosis are included at the bottom of the file. (Fig.3
A and B) The picons are linked to related images and are also linked
back to the text file that explains those images. Key references are
displayed at the bottom. The time it takes to retrieve the text and
related images depends on the size of the file, the speed of the
network, and the network traffic at the time the file is requested.
We make the files as compact as possible to optimize viewing over the
Internet. The size of the file is controlled by the physical
dimensions of the image, the bit depth or number or greyscale range
and how the images are compressed in software. The inline images or
picons are approximately 32 kilobytes in size; full-sized images are
much larger, averaging 100-350 kilobytes. During mid-day, the text
file on Wegeners Granulomatosis takes approximately 12-50 seconds to
fill in the text and all of the radiology and pathology picons,
depending on your location within the hospital. Retrieval of the text
file alone, without the inline images, is essentially instantaneous.
Each large image requires 8-40 seconds to open again, depending on
the time of day and location within the medical center. Retrieval
speed is reduced outside of the University of Iowa Medical Center.
Attempting to access the same text file at the Children's Hospital in
Boston at mid-day (busiest time for network traffic) resulted in the
following retrieval times: 2 seconds for the text file alone without
the inline images, 15 seconds when the inline images were included,
and 60-105 seconds to access the large images.
Discussion
Our thoracic teaching file is called the International Thoracic
Teaching Resource (ITTR) and is part of project called the Virtual
Hospital (Galvin JR, The Virtual Hospital, Radiographics, in press).
The Virtual Hospital is a digital medical library, available via wide
area networks, that is being created to support rural health care
workers within the State of Iowa. The project is funded by the
National Library of Medicine, The University of Iowa Hardin Library
for the Health Sciences, The University of Iowa Hospitals and Clinics
Information Systems, Apple Computer, Inc. (Cupertino CA) and the
Department of Radiology. During the last four months over one quarter
of a million people from around the world have "logged on" to the The
Virtual Hospital. The importance of teaching files in radiology is
well accepted; however, there are a number of problems with film
based files. The disadvantages include limited access, high cost of
reproduction, films which are easily lost or damaged and a limited
ability to search through the file. One of the most significant
problems is access [3,4]. The files and images should be available at
the point of use, usually the view box. The desire to make this a
reality has driven research projects that incorporate varying
combinations of computer and network technology [1,4-6] (D'Alessandro
MP, The networked multimedia textbook, AJR, in press). Our thoracic
teaching file is based on two rapidly growing Internet standards, the
World Wide Web and Mosaic. With accepted networking standards we are
able to distribute multimedia teaching files to a variety of
inexpensive multimedia computers, not only within the hospital but
throughout the world. Mosaic software is available, within the public
domain, for Microsoft Windows (Microsoft, Redmond WA), Macintosh
(Apple Computer Inc., Cupertino CA) and X-Windows machines. Even a
VT-100 terminal connected to the Internet to can access this
information. The separation of scientific content from the
distribution hardware and software is an efficient approach that
provides cross platform functionality and obviates the need to
recreate the information in varying computer formats [4]. Digital
copies or "back-ups" of the teaching file are created at regular
intervals so that the teaching file can be restored if the original
digital data is damaged. A second problem is cost. It is estimated
that the cost of copying a 1000-case teaching file would range from
$9,000-$15,000 for the film alone [5]. Attempts to reduce the
reproduction costs and allow the teaching file a wider distribution
have led to the use of the videodisk, CD-ROM (compact disc read only
memory) and other forms of optical media. These media lower the cost
of reproduction and can be searched by computer; however, access is
still limited by the number of available copies of the teaching file
within the department. In addition, one loses the ability to update
easily. A well-managed, film-based teaching file is always evolving.
The ability to add and alter files on a daily basis is one of its key
strengths. This is lost to a significant degree when the teaching
file is published as a book or a videodisk, both of which are
expensive and time consuming to revise. The problem is not as great
with CD-ROMs since they are cheaper to recreate and a larger
percentage of the work can be managed within a radiology department.
However, problems of distribution remain with CD-ROM, and the
teaching file loses some of its vitality. Storing the teaching file
on a server computer and distributing it via the Internet allows one
to make changes that are available immediately throughout the
network. Although the network speed between institutions is still too
slow, it will certainly improve over the next 5 to 10 years.
Meanwhile, information contained in the chest teaching file can be
copied intermittently from one server to another, allowing for local
access. This process, called "mirroring," allows students in such
distant places as Osaka, Japan, to access the teaching file at the
same speed as users at the University of Iowa. The ubiquitous
teaching file allows the radiologist at the view box to search for
and retrieve authoritative information in the form of text, images
and videos. This information can now be provided by multiple
disciplines (Radiology, Pathology Surgery, and Internal Medicine,
etc.) to assist in the diagnostic process at the time of need.
Acknowledgments
We wish to acknowledge Mary Treynor Smith for her valuable assistance
in reviewing and editing this manuscript.
References
1. Apicella PL, Blaine GJ, and Jost RG. A prototype of a
high-resolution computerized radiology teaching file. J Digit Imaging
1991;4:43-50
2. Arenson RL. Teaching with computers. Radiol Clin North Am 1986;24:97-1033. Felson B and Feltham C. A simple method of information retrieval. Radiology 1972;105:315-318
4. Greenes RA. A "building block" approach to application development for education and decision support in radiology: implications for integrated clinical information systems environments. J Digit Imaging 1991;4:213-225
5. Richardson ML and Gillespy TI. An inexpensive computer-based digital imaging teaching file. AJR 1993;160:1299-1301
6. Richardson ML, Rowberg AH, Gillespy TI and Frank MS. An on-line digital internet radiology teaching file server. AJR 1994;162:1239-1242
7. Sante LR. An indexing system for the cataloguing of pathological films. From the X-Ray Department of the St. Louis City Hospital. 1929;149:162-163
8. Schmidt HG, Norman GR and Boshuizen HPA. A cognitive perspective on medical expertise: theory and implications. Acad Med 1990;65:611-621
Figure Legends
Fig. 1.-A, The "home page" of the Virtual Hospital is the first
screen that a user sees after launching Mosaic and typing in the
proper address or universal resource locator. Scrolling through the
table of contents the user can select the teaching file section with
a single mouse click. B, This screen demonstrates the title page and
the top of the table of contents for the chest teaching file (The
International Thoracic Teaching Resource)
Fig. 2.-A, Clicking on the words Chronic Eosinophilic Pneumonia in
the table of contents of the International Thoracic Teaching file
loads a text file with preview images. B, Clicking on those preview
images or picons displays larger versions of the same image.
Fig. 3.- A, The differential diagnosis list for Chronic Eosinophilic
Pneumonia is provided at the end of the text file. B, Clicking on the
preview image for Pneumocystis Carinii displays a radiograph,
computed tomographic slice and pathology image.
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