A zero-footprint viewer is an image viewer that runs completely in a web browser and does not require anything to be installed on the computer running it. This is in direct contrast to the “thick” or “thin” client web viewers, or dedicated viewing workstations. There are, of course, benefits to a zero-footprint viewer. Firstly, as there is nothing to install, it does not require the user to have admin-level privileges. Also, these viewers are presumed to be browser and OS agnostic. Meaning, it should run on PC or MAC; Chrome, IE, Safari, and the like. Zero-footprint viewers are now capable of displaying full DICOM image sets, as well as various levels of compression from lossless to lossy. As vendors continue to add more and more tools to these viewers, they can satisfy the needs of a much larger group of physicians. Encompassing a variety of specialties and image sets, including cardiology and visible light. The ability for physicians to view images anywhere, including on a mobile device, is huge step forward for the industry and can potentially provide dramatic improvement in patient care, as images are no longer “locked” at a specific location.
Where I diverge from trending industry-think is in the idea that every radiologist viewer should be zero-footprint. Radiology standards, when viewing and interpreting images, are necessarily high. First and foremost, when following industry standards, a radiologist requires the use of DICOM calibrated monitors. For “diagnostic” monitors there should be a QA program in place to validate the calibration of the monitor and its ability to display the full depth of data in the radiology image. In addition to the need for diagnostic quality monitors, a radiologist typically dictates into a voice recognition system to generate a report. There are indeed cloud-based dictation solutions and, while it is possible for a radiologist to type a report directly into the EMR, these are not the norm for primary interpretation. The industry dominant voice recognition system, used by the majority of radiologists, requires its application to be installed on a workstation, running windows OS. It is very difficult to have this software running on one PC but pointing to two different versions or implementations. It is in effect one dictation client per PC. Combined, these two factors generally limit radiologists, in my experience, to an average of 2-3 physical locations in which they dictate. This is important, as here is where we begin to see the technology trade-offs of having a zero-footprint viewer. First in that a web browser, such as IE or Safari, does not have a reliable way of determining how many monitors are being used on the workstation (a typical read configuration has 3 monitors) nor how to best utilize that real estate. And, second is that speed is paramount. When comparing viewers if there is a compromise between features and responsiveness to be made, most radiologists that I’ve worked with will, within reason, choose speed. The zero-footprint viewers tend to do well on a good network, but over a high latency low bandwidth network it is very difficult to provide lightning fast response times. In this type of instance, a client-based viewer can download full data sets in the background and pre-cache data for viewing, i.e. it is loading the next case. Additionally, while the zero-footprint will probably beat the client in time-to-first-image, often the client-based viewer will win during significant image manipulation. Overall, the client is more resilient to the inherent variability of a network connection. So, given that a radiologist is, more often than not, reading from a pre-defined set of locations, which require specific physical hardware in terms of monitors and a dedicated dictation application, is there a superior advantage to the radiologist in having a zero-footprint viewer? I submit that, currently, there is not one.
I believe that, as an industry, we need BOTH zero-footprint viewers of diagnostic quality, as well as client-based viewers. Currently, clients provide a rich feature set, faster manipulation and integration in a reading environment while, zero-footprint viewers provide flexibility of delivery, fast review of compressed data sets to any browser, anytime, anywhere. These are different tools for different needs. You wouldn’t try to use a screwdriver to drive a nail or vice versa.
Ultimately, the best solution will blend the advantages of both systems, depending on the needs of the user at a particular time and place.