Prefetch filters


 

When opening a study, data downloads from the server to the workstation. On a slow or busy network, downloading while you wait results in poor performance. You can set up your workstation to download selected studies to your workstation before you open them.  When you go to open the study, it loads quickly from the local cache.

 

User Prefetching

When prefetching is enabled, the workstation automatically downloads the studies defined on the user prefetch worklist. To define a prefetch worklist,

  1. Create a filter identifying what you want downloaded to your workstation.

  2. Scroll to the bottom of the worklist.

  3. Select Prefetch from the options under Save List As.

  4. Click Save.

Thumbnail Prefetching

Prefetch all the image data to a workstation may result in unnecessary network traffic.  A second prefetch filter exists for downloading just the thumbnail information to the workstation, especially for studies with many small images or studies you may want to preview before downloading.  Thumbnails consist of subsampled images and all the study information.  Prefetching this to the workstation speeds up the study loading process, but doesn't require as much workstation disk space.  To set up the thumbnail prefetch filter,

  1. Create a filter identifying what you want to download to your workstation

  2. Scroll to the bottom of the worklist.

  3. Select Prefetch Thumbnails from the options under Save List As.

  4. Click Save.

Prefetching is enabled from the Customize Settings panel in the viewer.  The viewer’s prefetch setting controls both normal and thumbnail prefetch filters. For details, refer to the eRAD PACS Viewer manual.

 

Workstation Prefetching

Workstation prefetching is equivalent to user and thumbnail prefetching, except the action is independent of a user's account.  Instead, a worklist filter is defined and the workstation prefetches the data independent of a user account.  To set up a workstation prefetch filter,

  1. Create a filter identifying what you want to download to a specific workstation.

  2. Go to the Other Lists page, and click the Forward column for the filter.

  3. Click on Enable.

  4. Set the schedule time.

  5. Select the workstation from the Targets list.

  6. Check the Updates box if you want subsequent updates to go to the workstation.

  7. Check the Thumbnail Only box if you want thumbnail prefetching only.

  8. Click on Configure.