Magazine article Information Today

Exploring the Web for Medical Images

Magazine article Information Today

Exploring the Web for Medical Images

Article excerpt

With the arrival of the World Wide Web to the online scene in 1994, Internet traffic surged into the dynamic growth phase that continues today. What is the link between the Web and the dramatic increase in Net usage? I believe there are two principal factors. The first is ease of access to information-point and click means you no longer have to be a UNIX guru to harvest the information bounty on the Net. The second, and equally important, is the graphical nature of the Web and HTML. While it is clearly the quest for information that is the primary driving force behind the success of the Internet, it is the Web's rich visual landscape that encourages neophytes to explore and that keeps serious browsing enjoyable for the veteran.

We all prefer to have our information delivered in a way that is pleasing to the eye. This preference goes beyond the use of colors, fonts, tables, and icons when building Web pages. It also includes our desire for pictures to illustrate concepts and information.

Access to graphics, then, is one of the reasons for the popularity of the Web, and pictures are among the most popular resources on the Internet. In medicine, the value of pictures goes beyond interest and entertainment: They are often critical to the information being conveyed. The Web provides an unprecedented environment for discovering, learning from, and sharing instructional medical graphics.

Searching for Images with AltaVista

So, as promised in the last column, I'll close out this ongoing tutorial about using search engines to unearth medical resources with a look at medical images on the Internet. Of the many available search engines, the only one I'm familiar with that allows you to search specifically for images is AltaVista. This is convenient for those readers who have followed the column, because the search will build on some of the concepts and syntax covered previously (see Information Today, May 1997, p.16).

For a sample search, I picked a medical topic from a timely National Public Radio feature that aired as I began this column. The topic is the growing problem of fungal infections in immunocompromised hosts, specifically, Cryptococcus neoformans.

Before searching for images of cryptococcus, I first searched for all pages discussing the organism, just to get an idea of how much on the topic might be found on the Web. To ensure that I caught all the possible variants (e.g., cryptococci, cryptococcal, etc.), I used the "*" character to truncate the search term. So, using "cryptococc*" (the quotes are just for print clarity; don't use quotes in the search itself), I found about 2,000 related pages.

To look for images of cryptococcus, AltaVista has provided an image search format that you enter on their simple (default) search page. To restrict your search to images, use the search term format, image:keyword:jpg. The search term in this instance is "image:cryptococc* :jpg" (again, don't use the quotes). On my results list I get a single listing (http:/bio AIDS.html), which shows several micrographs of the organism.

The search functioned excellently. The only problem is the very brief results list. The brevity illustrates an important limitation of looking for images with search engines. I know from browsing the results of my initial search for cryptococcus that there are some terrific cryptococcus images at several Web pages that don't show up in the results above. For example, PathWeb contains several images of the organism (the direct URL to the cryptococcus images is http://pathweb.pds. htm).

These images didn't turn up with the search:keyword:jpg command because they are in a different image format, namely, GIF. The search:keyword:jpg command only locates images formatted with the JPEG (.jpg) image compression standard. The images at PathWeb are in GIF format, a standard that is far more common on the Web than JPEG. …

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