Whole Slide Imaging and telepathology
- J Galvez1
© BioMed Central 2002
Published: 1 October 2003
Accurate diagnosis of lesions in genetically engineered mice requires a level of experience and expertise that is not available in all institutions. As a result, there is an unmet demand for the services of a limited number of expert pathologists. In order to meet this demand, we have developed several electronic, web-based educational and consulting tools to expand the availability of expert pathologists.
The immediate need has been for publication quality images that are connected to a robust database. This has been accomplished using a shareware program that is connected to our SQL Mutant Mouse Pathology Archive database. This program develops Image Galleries 'on the fly' that can display still images with demographic, genetic, and diagnostic information stored in the database. The application includes a dialog box that permits the viewer and the pathologist to exchange information and comments. However, the images are limited to adynamic jpeg and tiff files that illustrate limited fields selected by the photographer and do not display or annotate the image in full context.
Whole Slide Imaging
To provide the digital view of the complete slide in context, several new technologies have been merged to the Image Archive using Whole Slide Imaging. Whole Slide images are digital images of the entire block face or slide. These digitized images are captured, compressed and viewed on any browser over the internet. The digital image allows users to view entire microscopic images at any magnification on their monitor. The images are captured with the ScanScope (AperioTech Inc., Vista, CA, USA) in approximately 3–5 min at a resolution of 50,000 dpi, producing 8–20 Gb of raw data. To make the images accessible to the community, the images are processed with the Zoomify compression algorithm which results in a 200–300 Mb image that can be viewed with a standard web browser using a Flash6 plug-in. The plug-in only downloads the pixels required to render the view requested by the user (approximately 75 kb/view).
The images can be annotated with layers that point to specific features in the image allowing users to easily navigate to selected points of interest within a slide while still being able to maneuver the entire slide. Examples of these images can be viewed online http://imagearchive.compmed.ucdavis.edu.
The full capabilities of the Zoomify system, have been exploited by combining the Whole Slide Imaging with a Telepathology Conferencing Tool that allows multiple simultaneous users to view the same slide in session becoming a virtual multi-headed microscope. A number of users can view, manipulate, and annotate a single image and share their perspective utilizing the application's voice conferencing system (voice over). A preselected Moderator controls the conference using a baton-passing utility that limits the number of users who can manipulate the image at any given time. This system allows pathologists to practice within a virtual world-wide group, gathering expert opinions from widely dispersed locations. Every investigator will have access to appropriate experts.