Can static telepathology be a trusted method for the communication of pathological information? The Image Pyramid

Abstract

AIMS: Although various telepathology techniques have recently been developed globally to enable telecommunication in pathology, pathologists seem to have reservations about implementing cyber age tools in professional practice. Static telepathology (ST) is easy and inexpensive but most of the methods used have been biased due to the low explicit/implicit ratio of transferred information. Our object was to develop a method of ST, which make the technique less biased. METHODS: Digital images of cytological and histopathological samples were captured with a bright field transmitted light microscope. Static images were stored on a hard disk and transferred to various remote locations via a local network, connected to the Internet. To determine the degree of bias of ST method, ratio of explicit/implicit information /REI/ has been calculated. RESULTS: The degree of bias of transferred digital images strongly depends on both the size of the image and numerical aperture of the objective lenses used to capture the image. Using images with a resolution of 800 x 800 pixels REI of small biopsies was approximately 1:1 when they were captured with an objective lens at a magnification of X10. However, REI of a section with an area typical of that used for pathological diagnosis (approx. 1x1 cm) captured at the same magnification proved to be only 0.01. We found that increasing the magnification of the objective lens used to capture the image, the REI decreased significantly. Although it is possible to increase the resolution of digital images by capturing them with high-resolution cameras or by the use of a slide scanner, this is not always helpful. We recommend, that hierarchic arrangements of digital images captured in the “x, y” and “z” planes and presented in the form of an image pyramid may ameliorate some of the difficulties associated with static digital image transfer. CONCLUSION: Storage and transfer of digital images enable complex information exchange using Internet protocols. ST methods are inexpensive and broadly accessible. The use of the image pyramid system can reduce the degree of bias significantly. It seems to be a useful method for expert discussions, consultations, archiving and education.