The image pyramid system--an unbiased, inexpensive and broadly accessible method of telepathology.

Although computerised information technology, including the Internet is broadly used and globally accessible it is still not a significant form of professional communications in diagnostic histopathology. The high cost of interactive dynamic telepathology systems makes their use limited outside the richest economies. In contrast static telepathology systems are relatively cheap but in practice their information content can be heavily biased by the choice of images sent by the consulting pathologist. The degree of this bias may be regarded simply as the amount of information transferred to a remote location expressed as a percentage of the total information present in the histological sample. We refer to this as the percentage of explicit versus implicit information. Another major source of bias may be found in the information transmitted in written or verbal discussion with a remote consultant. We have developed a system of static telepathology, the image pyramid, which attempts to minimise bias by transferring all of the information in a section to the consultant. It is inexpensive and should prove to be widely accessible.