Telecytology: Clinical applications, current challenges, and future benefits

Abstract

Telecytology is the interpretation of cytology material at a distance using digital images. For more than a decade, pioneering efforts to introduce telecytology into clinical practice have been reported. A Medline search for "telecytology" and "cytology" reveals a voluminous literature, though much of what has been published to date is based on technologies that are rapidly becoming obsolete. The technological limitations of previous techniques, including the transmission of static digital images and dynamic streaming images, have limited telecytology to minor niches. The primary problem with these technologies is that the remote viewer can only see a small fraction of the material on the original slides, introducing the possibility of diagnostic error based not only on image quality but also on image selection. Remote robotic microscopy offers one possible solution to this problem, but to date has found limited acceptance, principally attributable to slow operating times. Whole slide imaging seems to be a much more promising solution, though cytology-specific literature regarding its use is still scant. The advent of whole slide imaging opens up new possibilities for telecytology by enabling high-quality images of entire cytology specimens to be available to anyone, anywhere via the Internet. Although challenges remain, especially with regard to capturing the full microscopy experience including multiple planes of focus and sharp high-powered images, rapidly advancing technology promises to overcome these limitations. Increasing application of whole slide imaging technology in surgical pathology will undoubtedly also increase its application to cytology due to the increasing affordability and practicality of the equipment as it serves a larger number of useful roles within a pathology department. The current and expanding applications of telecytology for clinical practice, education, quality assurance, and testing will be reviewed.

Keywords: Digital images; remote microscopy; telecytology; whole-slide imaging.

Figure 1

Input devices for creating digital images: (far left) digital camera attached via adapter to a light microscope, (middle left) whole-slide scanners showing (upper) the Aperio Scanscope XT CS Scanner, scans up to 120 slides; and (lower) the Omnyx VL4 whole-slide scanner that scans up to four slides at a time and (middle right) robotic microscopes including (upper) the Nikon CoolScope II, one glass slide scanner and (lower) the Trestle 5L50, 50 slide loaders (far right) Cambridge Research and Instrumentation (CRi) Nuance multispectral imaging (MSI) camera

Figure 2

A whole-slide image (digitized slide) of signet-ring carcinoma in pleural effusion illustrating the viewer software provided by the vendor to allow for remote viewing and manipulation of images by the cytopathologist. (A) Zoom slider, (B) thumbnail image, (C) magnified field, (D) circled area is the annotation layer information used to mark up areas of interest, (E) drawing tool bar

Figure 3

Telecytology using NetCam for on-site evaluation and triaging of a cytology specimen. Case of a lymph node FNA that was suspicious for lymphoma requiring submission of the fresh sample for flow cytometric study

Figure 4

Telepathology portal used by the University of Pittsburgh Medical Center. Upper: Documents and images (static or whole slide) uploaded via the portal are available for review. Lower: Launching ImageScope viewer allows virtual slides to be viewed online