Digital images produced in the pathology laboratory today are most commonly used for education, consultation and quality assurance purposes. This will soon change as newer technologies - for both acquiring and managing the images - are welcomed into pathology. Clinicians forecast that the adoption of digital imaging will not only improve diagnosis and patient care, but facilitate the integration of images in pathology reports and electronic medical records as well as advance telepathology.

Digital imaging in anatomic pathology and the clinical lab is becoming more widespread as community hospitals, academic medical centers and industrial laboratories move to incorporate the technology into their pathology practice. The benefits include instant online access to images, telepathology and the integration of images into pathology reports and electronic medical records (EMRs). The new systems also reduce costs and improve the efficiency of departmental workflow.

But there have been and remain a few bridges to cross on the road to digital conversion. Before pathology information system (PIS) vendors began offering add-on imaging modules, many digital imaging efforts in pathology grew out of customized solutions. Additionally, pathology cases are not digital from their inception. Scanning entire microscopic slides - similar to digitizing x-rays in radiology - is not a mature technology. Pathologists today produce images of gross specimens and microscopic slides using a digital camera. The images are loaded onto a PC, stored on a hard drive and usually discarded after a certain period of time.

But once a healthcare organization decides to utilize digital imaging in pathology, it's a whole different ballgame. A number of issues and questions must be addressed from the start:

• How will this change workflow?
• At a departmental level, how much storage will be devoted to the system?
• Will the digital image of the slide become a permanent part of the patient's record?
• How much integration will be involved between pathology and other departments?

ACQUIRING THE IMAGE

When a digital image is captured in pathology using a camera on a microscope, it is saved temporarily as a data file. The static image is usually JPEG compressed and on average between 150 and 250 kilobytes. Static images can be transferred within a department to specialists and consultants for secondary review. With the appropriate equipment and credentialing, the images also can be sent via the internet to a remote viewing station for consultation for telepathology.

Capturing a digital image can be a rather laborious process. "It is up to the pathologist to choose the field that represents the pathologic findings," says Walter Henricks, MD, director of laboratory information services at the Cleveland Clinic and president of the Association for Pathology Informatics (API). "Someone has to take the time to select the field and capture the image. That's not part of routine microscopic work right now. Typical workflow includes looking at the slide, dictating the report and moving on to the next case. To get that into a digital image, I need to find the field that represents what I want to show, select the correct focus, select the correct magnification and select the correct picture and do something with that picture."

Virtual microscopy - a new technology - automatically converts entire glass slides into a series of digital images. Whole slide images are in the range of megabytes and gigabytes, says Michael Becich, MD, PhD, professor of pathology at the UPMC Health System-Shadyside, part of the University of Pittsburgh Medical System, and founder of InterScope Technologies, Wexford, Pa., a provider of high-speed automated digital imaging systems.

The goal of virtual microscopy is to scan every slide and present the pathologist the image on a computer monitor rather than have him or her manipulate glass slides. While the slide is still produced in the regular laboratory, it gets loaded onto an imaging robot (such as InterScope's new Xcellascan Slide Scanning Station that can automatically load 500 slides at a time). Using an optical light source and a robotic device that scans the anatomic pathology slide, a digital image is produced (at roughly five minutes per one square centimeter of material on a slide). That time will be reduced to under a minute, Becich says, which will facilitate virtual microscopy's ability to handle the clinical workload of a pathology department.

Whole slide imaging is already underway at UPMC, Becich says, and it is used in the medical division teaching laboratories and for training pathology residents. "We are also moving toward the first clinical trial using the imager for primary diagnosis in response to a Food and Drug Administration request," he notes.

Bruce Friedman, MD, professor of pathology at the University of Michigan Medical School, views virtual microscopy as rapidly approaching practical technology. And the benefits? "You can have a central processing lab receiving the tissue and producing the paraffin sections and then pathologists in multiple hospitals as part of a health system can review different slides [remotely]," says Friedman. "Also, then there is a stored digital image that could be kept theoretically forever."


AN IMAGE IS WORTH A THOUSAND WORDS

Image management in pathology is evolving. It promises to be the area in which the most technological improvements will occur over the next couple of years, says Mark Tuthill, MD, division head of pathology informatics at Henry Ford Health System in Detroit. "There needs to be a way to manage the images and integrate them into the workflow of a hospital," explains Tuthill. "There are two pieces to this: an image storage system and the attachment of an image to a pathological report. We are working hard to develop systems so that the images can be stored in a system that allows them to be easily connected to the surgical pathology report and then for that report to be distributed to the clinicians."

The value of including images in pathological reports is questioned by some, but advocates of the technology say it aids diagnosis and improves patient care. An image is worth a thousand words, says Tuthill, and both clinicians and patients will benefit from it.

The pathology department at Henry Ford uses digital imaging predominantly in anatomic pathology photo documentation. It is performed and stored on an ad hoc basis. "We are working with industry partners to change our processes to a completely digitally based imaging and workflow process, including dedicated gross workstations for doing gross imaging and dedicated microscopes for doing microscopic imaging," notes Tuthill. "Both of the systems, since they are able to serve the image streams up into internet browsers, will be able to support telepathology.

"The next phase is to integrate the storage of those images with our local image storage system. Finally, we will integrate that storage system with our reporting system so we are able to deliver an efficiently created, image-enhanced pathology report."


TYING IT ALL TOGETHER

The Department of Pathology at Brigham & Women's Hospital in Boston eventually will provide radiologists, surgeons and specialists enterprise access to pathology data, including images. Currently, only pathologists have access to digital images and they are used exclusively for teaching and medical conferences. This will change when the hospital implements a new pathology information system called Tamtron PowerPath (from Impac Medical Systems). "When we capture an image, it will be associated with the actual case information and will reside in the same database as the case information," says David Weinberg, MD, PhD, director of pathology information technology at Brigham & Women's Hospital, which is part of Partners Healthcare. "Right now, pathology is an isolated system, but that is eventually going to change."

PowerPath's image management module offers the ability to capture and associate images directly to a case. Images may be used for purposes such as inclusion on a patient's report, educational conferences, publications, or as a teaching tool. Other companies that provide PIS with similar anatomic image management capabilities include Misys Healthcare Systems (CoPathPlus) and Computer Trust Corp. (WinSURGE). The newer systems help streamline data so that the integration of systems from different departments may some day be a reality.

"We are in discussion [with radiology] about incorporating pathology images in the PACS network so they can be distributed over the [web] viewers," says Weinberg. "In the same way that people bring up radiology images, they will be able to bring up pathology images throughout the medical center. Also, Partners has a web-based EMR that includes radiological images. Eventually, we would like them to bring up with pathology images as well."

Cleveland's Henricks forsees the eventual incorporation of pathology images into the facility's EMR. "We have an EMR system in place and in which we send all of our pathology results," explains Henricks. "But incorporating images into the reports and integrating them with EMRs poses a bit of a challenge. Even if we had images stored with cases in our pathology laboratory information system, we could not send them to the other information systems through current interfaces. In addition, EMR systems are not always able to accommodate pathology images in a way that is user friendly."

One way that images may be tied to the EMR is through a hyperlink connected to an image server. "However, that is changing rapidly and it will not be long until EMR systems can more usefully accommodate pathology images," continues Henricks. "That is where you get into the potential integration of radiology and pathology image storage management. With an enterprise-level image management system, images potentially could be fed by the pathology system, radiology images are fed by the radiology system, and the EMR then hits up against that enterprise-wide image management system to display the images."


CONCLUSION

In a timeline depicting the inclusion of informatics in medicine, pathology would fall years behind more image-intensive specialties such as radiology. Pathologists live by the glass slide. But in the last decade, more and more clinicians have been taking electronic images of slides in one form or another. The next step is managing and storing these files so that they can be included in reports, sent over the internet for remote reading and incorporated into EMRs and PACS. In addition, standards for digital imaging in pathology and proper ways in which to annotate them also will be needed to accelerate the widespread adoption of these new technologies and sharing of the images.

Remote Link-ups for the Lab

Telepathology is not as widely used as teleradiology, but improvements in digital imaging technology are helping to fuel its acceptance in hospitals, laboratories and pathology practices nationwide. Today, telepathology is generally used for second opinion and education purposes in areas such as breast pathology, cytopathology, dermatopathology, neuropathology and hematology.

The University of Michigan Medical School recently installed Trestle Holdings Corp.'s MedMicro telepathology system. Clinicians there are validating the technology "to attain a comfort level with the system and assure diagnostic accuracy," says Richard Lieberman, MD, clinical assistant professor of pathology and Ob/Gyn at the facility.

The system includes a digital microscope networked to a remote PC running MedMicro. The remote pathologist controls the microscope from anywhere using MedMicro Viewer software. As the image appears on the computer screen in real-time, the clinician can use a number of navigation tools to help render a diagnosis.

MedMicro is being implemented onsite at U of M for optional use in real-time second opinions for frozen section diagnosis in the operating rooms in the main hospital. "What usually happens is I get a page indicating that the OR wants me to look at a frozen section," explains Leiberman. "Right now, I have to walk over to the main OR and the surgeons sometimes have to wait an additional 10 to 15 minutes for the consultation. Telepathology will allow me to pop the image up on my computer and look at the slide in real-time with the pathologist in the frozen section room."

Leiberman notes that additional uses of the system may include pre-transplant viability assessment - where on-call pathologists will have the capability to review slides even though they are not at the hospital at the time when the patient is to undergo surgery - and remote consultation, by pathologists and specialists located anywhere in the world.