title: [PACS: storage and retrieval of digital radiological image data].
abstract: BACKGROUND
  Efficient handling of both picture archiving and retrieval is a crucial factor when new PACS installations as well as technical upgrades are planned.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institut für Klinische Radiologie, Klinikum der Universität Muenchen. Stefan.Wirth@med.uni-muenchen.de
authors.forename: S
authors.initials: S
authors.lastname: Wirth
authors.forename: M
authors.initials: M
authors.lastname: Treitl
authors.forename: S
authors.initials: S
authors.lastname: Villain
authors.forename: A
authors.initials: A
authors.lastname: Lucke
authors.forename: S
authors.initials: S
authors.lastname: Nissen-Meyer
authors.forename: I
authors.initials: I
authors.lastname: Mittermaier
authors.forename: K-J
authors.initials: KJ
authors.lastname: Pfeifer
authors.forename: M
authors.initials: M
authors.lastname: Reiser
mesh_terms: D003628:Database Management Systems; D016208:Databases, Factual; D019033:Delivery of Health Care, Integrated / Q000379:methods / Q000458:organization & administration; D005858:Germany; D033181:Information Dissemination / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D020407:Internet; D016347:Medical Records Systems, Computerized; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D011873:Radiology Information Systems; D012815:Signal Processing, Computer-Assisted; D018511:Systems Integration; D013673:Technology Assessment, Biomedical; D014584:User-Computer Interface