[Conception and data transfer analysis of an open-source digital image archive designed for radiology]

[PACS: acceptance by orthopedic surgeons]

PURPOSE

The goal of the study was to evaluate the acceptance of a web-based picture archiving and communication system (PACS) by orthopedic surgeons 1 year after implementation.

MATERIALS AND METHODS

One year after the implementation of a web-based PACS all physicians were surveyed with a standardized questionnaire. Questions included: speed of PACS, quality of clinicoradiological meetings, quality of monitors, PACS training, and performance. Data were evaluated separately for the Department of Orthopedic Surgery and the reference group of all other physicians.

RESULTS

Among the respondents, 92% of the orthopedic surgeons stated there was a reduction of time required to receive images, and 64% concluded that patient care was faster. Archived images were received in less than 5 min in 82% after PACS and in 8% before PACS. The clinicoradiological meetings improved with PACS in 100% due to beamer presentation. All would recommend a PACS. The equipment to view images in the operating theater was assessed as being good or very good by 83%; monitor quality was judged better for the outpatient clinics (100% good or very good). Conventional radiograms were missed at the ward rounds by 56%. Training for PACS was considered sufficient by 67%, and 15% asked for refresher courses. In the reference group 60% asked for refresher courses. In the comparison of orthopedic surgeons with the reference group PACS was judged better especially concerning the viewing software and quality of monitors.

CONCLUSION

There is an over all acceptance of PACS by physicians outside the radiology department. The availability of images was not only facilitated it was faster as well. However, the quality of monitors in the operating theater should be improved. To achieve sustained success of PACS consistent training on PACS and its features is necessary. Conventional radiograms were often missed at the ward rounds.

Hard disk online caches in picture archiving and communication systems archives: how big is beautiful?

The objective of our study was to support algorithmic recommendations for the appropriate sizing of picture archiving and communication system (PACS) caches. For a large PACS installation, a detailed analysis of current radiographic (CR), CT and MRI studies (n=400 consecutive studies, respectively) was performed. In this process every available prior examination was also considered. A new algorithmic procedure for appropriate sizing of PACS caches was developed and applied to the given cache implementation. The number of all priors was 7.6+/-12.3. Of them, 61% were relevant priors with an average age of 203+/-385 days. A basic cache (BC) that covers 12 months of current imaging results in a pre-fetching quote of 15.4% (8.6% for 24 months). In the PACS installation examined, a minimal threefold increase in cache capacity was recommended. Studies that are retrieved, prior to viewing, from the long-term archive require additional space in the extended cache (EC). An intimate and mutual interaction between hospital information system (HIS), radiology information system (RIS) and PACS minimizes this requirement and increases the time during which actual image material from the BC is available online. A basic cache size covering actual imaging of 12 months up to 24 months is recommended. The parameters governing the individual dimensions of both cache spaces and a mathematical algorithm are demonstrated.

[PACS: storage and retrieval of digital radiological image data]

BACKGROUND

Efficient handling of both picture archiving and retrieval is a crucial factor when new PACS installations as well as technical upgrades are planned.

MATERIALS AND METHODS

For a large PACS installation for 200 actual studies, the number, modality,and body region of available priors were evaluated. In addition, image access time of 100 CT studies from hard disk (RAID), magneto-optic disk (MOD), and tape archives (TAPE) were accessed.

RESULTS

For current examinations priors existed in 61.1% with an averaged quantity of 7.7 studies. Thereof 56.3% were within 0-3 months, 84.9% within 12 months, 91.7% within 24 months, and 96.2% within 36 months. On average, access to images from the hard disk cache was more than 100 times faster then from MOD or TAPE.

CONCLUSION

Since only PACS RAID provides online image access, at least current imaging of the past 12 months should be available from cache. An accurate prefetching mechanism facilitates effective use of the expensive online cache area. For that, however, close interaction of PACS, RIS, and KIS is an indispensable prerequisite.