In a PACS environment a prefetch describes the internal process where studies are retrieved from the permanent storage archive and are restored to the local cache for view. Prefetching is designed to speed up access to images by radiologists or clinicians so that a view of one patient image leads to automatic prefetching of other images which are then automatically accessible.

A typical scenario would be that when an order for a specific patient has been entered into the system, the PACS will automatically retrieve other appropriate studies of said patient. Typically, the studies are typically of the same modality or body part.

Advanced prefetching algorhythms allow for more complex rules that connect modalities or parts in appropriate ways.

Discussions between the radiologists and PACS designers/implementation team should focus on how the prefetching algorhythm should be implemented.

Prefetching in PACS environments is similar in conceptual model to software prefetching but is not a software routine but a search algorhythm for speeding access to data rather than increasing the speed of the underlying software system.

Example Systems:

• RamSoft