Virtual microscopy:applications to hematology.
Virtual microscopy is the simulation of microscopy over a computer network. A virtual slide is a giant digital image file of a glass slide that can be displayed, panned, zoomed, and focused in a virtual slide viewer on a computer screen. Virtual slides represent a revolutionary advance over glass slides. They are easy to file, store, retrieve, annotate, and mark and can be preserved indefinitely. Furthermore, they are easy to duplicate and distribute and can be integrated into electronic patient records. Large virtual slides can be readily transmitted to users over a standard broadband connection. With the recent introduction of viewers that can focus virtual slides, virtual microscopy can simulate all the functions of real microscopy. Virtual microscopy has significant advantages over real microscopy in education and in proficiency testing. In education, virtual microscopy enables "anytime, anywhere" learning and has been favorably received by students and teachers. In proficiency surveys, all users view the same image, virtual slides are easy to distribute, and the slides do not deteriorate. Potential applications for hematology proficiency surveys include blood and bone marrow morphology, differential cell counts, cytochemistry and immunocytochemistry, detection of malarial parasites, and other tests. Virtual microscopy enables proficiency surveys of critical clinical parameters, such as the bone marrow blast count, and implementation of "locate and identify" exercises. It is conceivable that with the next generation of technological developments, virtual microscopy can be extended to diagnostic applications. Important goals are to minimize slide file size without loss of relevant detail, to establish diagnostic equivalence, and to automate virtual slide capture with high throughput for integration into laboratory information systems. Key factors that will drive implementation include user-friendliness, cost, data storage requirements, and throughput speed. Implementation may have constructive effects on teaching and learning, the peer-to-peer consultative process, and diagnostic accuracy and performance.