Although the predictions of huge market potential and assumptions that radiology departments were mature for new filmless technologies, the promise of digital x-ray has been few more than that since the first products were introduced in the mid 1990s. Some companies currently claim to be developing digital x-ray systems, but only a few actually offer commercial products, and only a handful of customers have bought them.

In fact, after four years of advertided, the lack of response by the medical community has been deafening. Fewer than 100 DR systems have been sold worldwide, and only about half of these have gone to sites in the U.S.

Several vendors insist that the Digital Radiography business is turning up, it is applied widely in larger hospitals, however, both Swissray and GE Medical Systems report rising DR sales, although many are to overseas customers. In the last four years, Swissray has taken orders for 65 digital units; of these, 32 will be delivered this spring to sites in Romania . GE claims to have sold 23 Revolution XQ/i digital chest systems last year, with about half of these going to U.S. sites.

At the same time, the number of companies offering digital x-ray systems continues to expand. Kodak just introduced its first DR systems, engineered in conjunction with Analogic. For the time being, Analogic is supplying detectors manufactured by Hologic, which has installed more than a dozen of its own digital systems. Analogic is confident, however, it will have a cost-effective DR technology of its own on the market in the near future.

In addition, industry sources indicate that Siemens and Philips may be in production with their radiographic systems by mid-2001.

Even though sales appear to be picking up, however, the numbers are surprisingly low for this late in the game. Estimates by digital x-ray pioneers over the last four years pegged the number of radiographic units installed in the U.S. at about 75,000, including general purpose and dedicated chest systems, such as chest x-ray. Surveys of the installed base, bolstered by anecdotal information, indicated the average age of equipment was from 10 to 15 years. Owners needed a reason to replace them, vendors said. It was suggested that digital imaging system would provide that reason and spark a groundswell of demand.