Telepathology: The Future of Pathology

With the great urban and rural divide in healthcare, telepathology can be a great asset to diagnostic healthcare

Dr Indumati Gopinathan

In today's digital world, telemedicine is an advancing science. Connecting healthcare givers across distances, telepathology is one of the significant applications of telemedicine. The telepathology services by the Armed Forces Institute of Pathology in the US is one of the best models of telepathology that many pathologists rely on. In the Indian economy, with the great urban and rural divide in healthcare, telepathology can be a great asset to diagnostic healthcare. In rural India that lack good pathology set-ups and in urban India where pathology group practice is yet to catch up, telepathology can be a well applied technological tool.

Telepathology is the electronic transmission of pathological images usually derived from microscopes, from one place to another for interpretation and diagnosis. Essentially, it involves a slide scanner, a large computer server and large bandwidth network links. The images transmitted can be still images or a video clip which again can be live or stored and forwarded transmissions. The images transmitted could be selected by the person sending them or with the advanced software, the recipient can have remote control of the microscopic stage, focusing and objectives. In fact, it is possible to digitally scan the whole slide and produce a virtual slide for actual viewing by a virtual microscope.

Teleradiology Vis-à-Vis Telepathology

Whilst teleradiology has taken off in a big way, in contrast, telepathology is still not that widespread. Multiple factors are responsible for this situation.

• Though both deal with images and not live patients, images produced in radiology are already digitised. There is no necessity to convert the image into its digital form which means there is no need to scan or photograph the image before it is electronically delivered. In contrast, in pathology the original specimen is a slide. The image essentially has to be digitised before transmission and this means a very real possibility of loss of quality.
• Teleradiology has reached a stage where international standards for image acquisitions, storage and transfer have already been set. Such standards are lacking in telepathology.
• Radiology images are viewed at a comparatively limited range of magnification whereas in histopathology, selected areas may be viewed at a very wide range of magnification, like in a light microscope. To digitise all the material on a slide at a resolution of x 1000 results in data files of differing magnitude much larger than digital radiology images.
• When image standards and technical specifications are lacking, system suppliers have no gold standard to follow and subsequently there is no guarantee of image quality.
• Radiologists are trained to interpret images and comprehend the underlying principles of digital imaging and factors influencing their quality. In contrast, pathologists have never been trained to assess digital imaging techniques for histopathology. Hence, they are less likely to recognise and correct problems related to image quality competently.

Telepathology can help pathologists in India who commonly practice in smaller labs dealing with routine histopathology or in smaller hospitals when they come across unconventional cases. Without handing over blocks, a real-time consultation with discussion can take place with telepathology, between two pathologists. This is better than a conventional consultation as the local pathologist observes and understands the diagnostic approach taken by the expert. Viewing images cuts out on the money and travel time of a pathologist.

An Effective Tool

Telepathology can have a crucial role in education and training in the following ways:

• Online cases and images are excellent tools of education, supplementing standard books.
• Video clips from case conferences can be a part of routine training.
• The virtual slide technology can reduce the number of microscopes in a class.
• Telepathology is an excellent tool to distribute material from small biopsies that defy too many replicate sections. This helps in external quality assurance. Participants can see and discuss the same images and maintain a record for future reference.

However, the expertise for diagnosing through light microscopy and tele-images need not be same. The role of image analysis and quantisation in telepathology is vital. This is especially so in certain aspects of histopathology requiring semi-quantification to asses tumour grade and dysplasia. These are subjective and poorly reproducible. Various techniques of image analysis have been attempted, but have not gained wide acceptance because of the resource implications of producing the desired digital images and their accurate measurements. The question of quality control and external quality assessment come into the fore as with any new diagnostic procedure.

Problems in Telepathology

• If used for routine workload (telemicroscopy), the problem arises if the centre lacks a pathologist who can use the facility well or is ill trained to read digital images.
• Acceptance of responsibility by the local pathologist for the final telepathology report that goes out is a point to be considered.
• Technical standards for image capture, storage and transfer need to be well set.
• While viewing distant virtual slides, the factor of time lag has to be considered which does not happen in a light microscope set up.
• Image resolutions may be inadequate for assessing nuclear chromatin pattern or glomerular pathology.
• If a lab solely relies on telepathology, there can be damaging loss of local expertise.
• Training of new pathologists can become a problem because they need to see and examine all kinds of actual specimen.
• Telepathology may prove difficult in cases of large complex specimens that need to be grossed well and dissected in person.
• When volumes of referral practice increase, the distant pathologist may find it difficult to schedule live teleconsultations without proper scheduling.
• For technicians working with an on-site pathologist, who helps solve problems on the spot, can be different from functioning with a distant pathologist. It could dampen their morale.

The writer is a Consultant Pathologist and a domain specialist and advisor for Space Telemedicine, a Chennai-based telemedicine company
Email: drindumati@gmail.com