Glenn Wachter (Research Associate) and Nancy Brown (Research Librarian), Telemedicine Research Center and Telemedicine Information Exchange, Portland, OR (wachterg@ohsu.edu; brownn@ohsu.edu; http://tie.telemed.org/), with Ace Allen, M.D.

Two years ago Telemedicine Today published its first review of teleradiology activity in the United States (Vol. 2, no. 3). We were able to identify 12 service providers doing interfacility teleradiology. In aggregate, we estimated that they interpreted about 50,000 studies in 1994. While there were certainly programs we missed, we felt that the number 50,000 was at least in the ballpark of total activity.

Today, the picture is much more complicated. There are many different ways of doing teleradiology:

• Interim (preliminary) reads, followed up later by hard-copy interpretation
• Diagnostic reads, with higher requirements for resolution and fidelity
• Picture Archiving and Communication Systems (PACS), typically deployed within single institutions
• Radiology Information Networks (RINs), the Wide Area Network equivalent of a PACS
• Teleflouroscopy, sonography, and other dynamic-imaging applications, with different technology requirements

Furthermore, teleradiology seems to have become much more widely deployed in the ensuing two years, for several reasons:

• It is the only telemedicine application that is routinely reimbursed by all carriers (including Medicare)
• The technology is well developed, even mature
• Of all specialists, radiologists are probably the least intimidated by telecommunications technology
• Rural and urban interfacility access issues persist
• The business case is becoming clearer

Working from the extensive databases at the Telemedicine Information Exchange and Telemedicine Today, we compiled a list of what we felt were the most prominent U.S.-based teleradiology groups, and surveyed them about their activities. We were most interested in groups that are doing diagnostic interfacility teleradiology, as opposed to PACS teleradiology within an institution, or interim-read telearadiology. This is largely because interim-read teleradiology to physicians’ homes, for off-hour preliminary reads, has become so common that it would be nearly impossible to ferret out all of these deployments. A survey conducted by Dr. Peter Shile of Washington University, of participants at the 1994 Radiological Society of North America (RSNA) meeting, found that 49% of the radiologists surveyed were using teleradiology, and that 88% of this use was among private practice (as opposed to University-based) radiologists. Also, we felt that diagnostic reads are a reasonable bellwether of teleradiology trends, since only these are reimbursed. We do not pretend that this is an exhaustive accounting of teleradiology service providers. However, we do feel that we’ve contacted a majority of the most significant teleradiology practices that are interpreting remote, transmitted radiographs.

Survey responses are in Table ____. Caveat: these numbers are simply those reported to us, and were not independently verified. In summary, we found:

• 3 programs were university-based; the rest were private practice groups
• 12 programs doing a significant number of interfacility diagnostic reads. One (Radiol. Assoc. of Hays) did only interim reads
• 5 programs (Marin Radiol., Radiol. Assoc. of Hays, Team Health, UCLA, and Worldcare) did cross-state teleradiology. In all of these, the radiologists were licensed in all states served
• 2 programs (Memrad, WorldCare) did international diagnostic teleradiology
• The average program interpreted about 740 studies/month (range: 50-3,330) or a bit less than 9,000/year
• In aggregrate, the 12 programs are reading about 115,000 studies/year at their current activity levels, the great majority of which are diagnostic
• No single technology or vendor is emerging as standard

In accordance with previous reports in this magazine about the most important barriers to telemedicine, two respondents noted that the biggest challenge was not the technology, but "the logistics of getting the right people to the right place at the right time." However, several others felt that technology and bandwidth issues were still primary impediments.

As we noted two years ago, the number of interfacility teleradiology reads is still minuscule relative to the total number of cases done throughout the U.S. Even if we are off by an order of magnitude -- let us say that there are 1 million diagnostic teleradiology reads/year, rather than the 100,000+ reads we’ve documented -- that still would account for less than 0.5% of all radiology traffic (which amounted to 256 million studies in 1990). The contribution of PACS-based teleradiology to the total traffic is beyond the scope of this survey. This suggests that either the rÙle of teleradiology is yet to be defined, or there is an enormous unmet need waiting to be met by entrepreneurial teleradiology providers.

Clearly, private radiology practices are finding that teleradiology can be justified from a business standpoint. Reckoning that a single radiologist normally interprets about 12,000 studies/year, it appears that at least 5 of the practices we surveyed could support a full-time teleradiologist. One practice (Memrad) could support at least three. One interim-read (thus unreimbursed) practice, Radiol. Assoc. of Hays, felt that teleradiology so improved their service that it was well justified, even in the absence of fee for service.

At recent telemedicine conferences there has been speculation, sometimes in low voices with sidelong glances, that there is a large, hidden world of telemedicine (including teleradiology) that is intentionally "flying under the radar" of the medical community. The reasoning is that these programs are avoiding the limelight because they regard their telemedicine activities as a competitive advantage, and are quietly deploying new technologies so that they can make an end-run around their rivals for managed care contracts. If this is true, our estimates of teleradiology activity could be way, way off. We frankly doubt that this is happening in any significant way, but appeal to our readers to contact us with any information about this matter, or with any other comments about or additions to this survey.