In 1986, Ronald S. Weinstein M.D., an academic pathologist, coined the word telepathology. In an editorial published in a medical journal, Weinstein outlined what actions would need to be taken in order for remote pathology diagnostic services to be developed. The first scientific paper to be published on robotic telepathology was authored by Weinstein and his collaborators. In addition, he was the first to be granted U.S. patents for telepathology diagnostic networks and robotic telepathology systems. Many know Dr. Weinstein as the father of telepathology. In 1989 in Norway, Nordrum and Eide instituted the first clinical telepathology service that was actually sustainable. Decades later, it is still in operation. Thousands of patients in Asia, Europe and North America have benefited from numerous clinical telepathology services.
Telepathology has been used successfully for many different applications, including histopathology tissue diagnoses being rendered from a distance. In developed countries, digital pathology imaging, which includes virtual microscopy, is preferred. However, in some developing countries, analogy telepathology imaging still is used in patient services.
Telepathology System Types
There are three major types of telepathology systems: virtual slide systems, real-time systems and image-based systems.
The main benefits to static image systems are that they are the most usable and reasonably priced systems. They do have one significant drawback which is that only a selected subset in the microscopic fields can be captured to evaluate off-site.
Virtual slides and real-time robotic microscopic systems provide an opportunity for the consultant pathologist to evaluate entire histopathology slides from a distance. When it comes to a real-time system, a motorized microscope that is robotically controlled is actively operated by the consultant from a distant site. He is able to change the field of view, magnification, illumination and focus at will. For robotic microscopy, either a digital video camera or analog video camera can be used. There is another type of real-time microscopy that involves using a high resolution video camera that is mounted onto a path lab microscope. Live digital video of slides is sent to a large computer monitor that is located in the remote location of the pathologist. Encrypted store-and-forward software is used to send the data. On both ends of the video conference there are echo-cancelling microphones which make it possible for the pathologist to communicate with the individual who is moving the slides underneath the microscope.
Automated digital slide scanners are used by virtual slide systems to create digital image files of a complete glass slide. The file then gets stored onto a computer server which can be navigated using a browser over the Internet from a distance. For virtual microscopy, digital imaging is needed.
Although higher diagnostic accuracy is offered by virtual slide and real-time systems compared to static-image telepathology, each does have drawbacks. A real-time system will perform at its best over a local area network (LAN). However, if use at times of high network traffic or if the Internet is being used as a backbone, performance might suffer. Expense can be a problem with both virtual slide and real-time system, since they both can be quite expensive. For telepathology services, virtual slide telepathology is becoming the technology of choice. However, currently virtual high throughput slide scanners (those that produce one or more virtual slide per minute) are quite expensive. Virtual slide digital files are also fairly large. They often are larger than one gigabyte. It can be cumbersome to simultaneously store and retrieve large amounts of telepathology whole-slide files. In the clinical laboratory, this can pose some workflow challenges.
Telepathology Uses And Benefits
Currently telepathology is being used for numerous clinical applications. These include research, competency assessment, education, subspecialty expert pathology diagnoses, second opinion diagnoses, primary histopathology diagnoses and the diagnosis of frozen section specimens. Telepathology benefits include being able to provide off-site pathologists with immediate access to perform quick frozen section diagnoses. Having direct access to a dermatopathologist, neuropathologist, renal pathologist or other subspecialty pathologist for an immediate consultation is another benefit of telepathology.