Troubleshooting

Agfa employs two system administrators to work from 8 a.m. until 5 p.m. Monday through Friday onsite at the Vienna General. The company has guaranteed 99.9% uptime for the PACS.

One of the main complaints the administrators encounter is the slow speed of image retrieval. An unplanned request for an image (i.e., not part of the prefetching workflow) can take five to 10 minutes to fulfill.

Current RAID capacity in the radiology department is 1.3 TB, which equates to just four to six weeks' worth of images held online. Older images are stored on magneto optical disk (MOD). Plans to extend the short-term archiving capacity, previously prohibitively expensive, are under consideration.

Imaging exams generate an average of 30 GB of data per day (10 TB per year). This compares with just 10 GB per day two and a half years ago, when project planning for the Impax PACS started. Much of the blame is attributed to exams performed on multidetector-row CT (MDCT) scanners. Four of the seven CT scanners at Vienna General use MDCT technology. The radiology department is also in the process of installing a new 16-slice MDCT scanner, which will undoubtedly increase the data generated still further.

Comments:

"If you use an MDCT unit, perhaps a four-row or a six-row scanner, you have to deal with about 2500 images. But I only need about 200 images to do the report. I have suggested that we only send reformatted images to the PACS. Most of my colleagues do not like this idea at the moment, but I think this will change over time. If you do a study, you can keep all of the images on a CD-ROM in your room. It is not necessary to put all the data into the PACS. This, of course, is the reason why the system sometimes is slow."
Dr. Viktor Metz, professor of radiology, Vienna General Hospital