At the USCAP 2017 conference in San Antonio, I had a chance to try out the Precipoint M8 (http://www.precipoint.com/m8-microscope), which is a combined microscope and slide scanner. It is an entirely new concept and is the only example I am aware of on the market. It starts by scanning a low-power overview of the slide after which the user can zoom in and examine the slide at higher power. As the user zooms in or pans around, the M8 quickly scans multiple fields of view and stitches them together on the screen. Since the slide remains on the stage, the user can adjust the focus (unlike other whole slide imagers which scan at a single focal plane typically). Using a large high-resolution monitor, one essentially has a much larger field of view than one would have with a regular microscope without loss of z-axis information. The user can also scan the entire slide or a specific area of the slide to be stored as a file.
A critic’s first response might be, “Why would you want a real time slide scanner when you can just scan the slides in advance with a whole slide imager?” I would suggest 3 responses:
1. A real time slide scanner such as the M8 allows the user to adjust the focus continuously. Although other slide scanners are starting to provide the option of scanning in 2 or more predetermined focal planes, discrete planes of focus inherently provide less information than exists on an actual slide with several microns worth of continuous z-axis information.
2. Scanning the slides in advance means the physical slides are delivered to the pathologist later. When my department at UPMC was trying out the Omnyx system during pilot testing, most of us felt that we needed to still examine the original slides to make sure we weren’t missing information that was lost by scanning only a single focal plane. Of course we examined the original slides anyway since digital pathology was not and still is not FDA approved for primary diagnosis, but most of us felt that we still would have liked to examine the original slides even if we were not required to. Therefore, we felt like there was little to gain by trying to interpret whole slide images and were discouraged that we received our slide later.
3. Accessing previously scanned whole slide images requires downloading them from a server, which can incur a delay depending on the available bandwidth at one’s institution.
Now the M8 isn’t better than a microscope in every way. With a microscope, the user experiences no delay when changing the magnification or panning the image, even though the field of view is smaller. It is interesting to wonder how much faster this technology can theoretically be pushed – if the delay in filling in those squares on the screen can be reduced to the point where it is no longer perceptible. Then I would consider ditching my microscope (if the price is right).