Pitfalls abound when extending PACS to areas outside radiology

IT vendors are agog about opportunities inherent in the creation of electronic medical records. Going digital can boost efficiency and reduce medical errors, according to proponents, to say nothing about the sales potential of implementing such comprehensive networks. Integration of radiology with other disciplines that involve images is drawing increasing interest, as synergies in technology become apparent. But the ability to network other "-ologies," especially those dependent on images, may not be as easy as it looks.

In a presentation at the Symposium for Computer Applications in Radiology meeting in May, Barry R. Wiggs, Ph.D., a product manager for McKesson Information Systems, described issues affecting the expansion of PACS to other -ologies.

In their efforts to expand a PACS at the University of Wisconsin to include gastroenterology, Wiggs and colleagues had little trouble devising a system to capture endoscopic cine clips. But when they hooked the network up to the university's PACS, other systems linked to the PACS began slowing down or crashing. A lack of bandwidth limited the number of gastroenterologists who could simultaneously access the data. Four of them simultaneously collecting and saving their cine exams threw the PACS into a dither.

Bringing pathologists into the network created a similar potential for chaos. The challenge came mostly from the enormous volume of data.

A pathology department can produce 300 million slides per year, with images achieving better than 0.1-micron resolution.

Small images may be 30,000 x 40,000 pixels, but larger ones may be 1.4 million x 1.7 million pixels. Image sizes range from 3 to 37.5 GB per frame with 70:1 compression. The extraordinary number and size of some images put the efforts of a radiology department, equipped even with the most advanced multislice CT scanners, to shame.

Other challenges accompanying PACS expansion involve data not commonly found in radiology. Ear, nose, and throat physicians, like pathologists, generate enormous amounts of visual data, but they have the additional requirement of synching audio data with their 200 video frames per second. Maintaining true color fidelity is another requirement for some specialists, whereas it has not been a worry for radiologists, who deal mostly with gray-scale images.

Interfaces designed to meet each specialty's unique needs will be necessary if PACS is to expand beyond radiology, Wiggs said. Some considerations that will not be easily addressed by interfaces relate to the very essence of the specialty, the foundation for its practice.

When radiologists schedule scans, they use a modality work list. Other specialists often order tests after they schedule patients, an entirely different approach. Accommodating these and other inconsistencies among specialists will be possible only if the different thinking processes of these are somehow consolidated into the function of the PACS.