Image Viewer > Administration > System Configuration

File Store

You can change the location of the file store, which is where all the DICOM images for patient imaging studies are saved when they are imported or received over the network. Simply type in the location or click Browse to select a folder.

In order to apply a change to the file store, the local service must be stopped. If the service is still running, you will be unable to apply the change without stopping the local service via the link that appears in the bottom right corner.

If you try to apply your change while the service is still running, a validation icon will appear next to the file store location (right) explaining the problem.

Once the changes are successfully applied, you should restart the service; the "Stop Local Service" link will have changed to "Start Local Service". Note that you can always start or stop the local service later via Tools > Service.

There are 3 typical reasons for changing the file store location:

1.	You want to use a dedicated drive (usually large capacity) to store studies.

2.	You have studies (or a file store) from a previous installation.

3.	You wish to move the existing studies because you are running out of disk space.

In any case, if the previous file store had studies in it, or the new file store already does, you must re-index the file store. Otherwise, you will encounter errors in viewing or otherwise working with studies. See Re-indexing the File Store for more details.

If you are simply moving the existing studies, you must move the contents of the old file store to the new location manually before starting the service; Workstation does not do this automatically. In this case, re-indexing is not necessary, provided the new file store location was empty before you moved the existing studies.

Important Note

If the old file store location had studies in it, or the new one already does, you must re-index the file store. Otherwise, you will encounter errors in viewing or otherwise working with studies. See Re-indexing the File Store for more details.

Maximum Disk Usage

As Workstation's file store fills up with studies, disk space would eventually be exhausted if there were no safeguards in place, which could cause instability in the entire system, including the computer's operating system. Because of this, Workstation will stop importing or receiving studies when the maximum disk usage is met or exceeded; by default, the maximum usage is 95% of the total disk space.

When this happens, the meter in the Activity Monitor dashboard will turn red. Hovering over the warning message will explain the problem. Any work items that add files to the file store (Receive, Import) will fail, as shown below.

Also, a warning alert will be shown, and will continue to be shown whenever Workstation starts up until the problem is dealt with.

To fix the problem, you can:

1.	Manually delete studies that no longer need to be stored.

2.	Configure Automatic Study Deletion (discussed below).

3.	Move/change the file store location (discussed above).

4.	Increase the maximum disk usage; this will only fix the problem temporarily.

Once you have fixed the problem, there may be failed work items in the Activity Monitor (as shown above) that did not complete successfully, which means that there may be partial studies in the local store, which could lead to patient misdiagnosis due to incomplete information. You should restart any failed work items that may not have completed successfully, and ensure all studies are imported/received completely.

In the case of an unsolicited receive (e.g. incoming auto-route or send from another device) that has failed, these operations cannot be restarted from the Activity Monitor; they must be restarted from the originating device. ClearCanvas ImageServer will automatically retry send operations that fail, but you should still verify that new work items appear (and succeed) for each affected study.

Important Notes

When the maximum disk usage is exceeded, there may be failed work items in the Activity Monitor that did not complete successfully, which means that there may be partial studies in the local store, which could lead to patient misdiagnosis due to incomplete information. You should restart any failed work items that may not have completed successfully, and ensure all studies are imported/received completely.

Automatic Study Deletion

You can configure Workstation to automatically delete studies a specified period of time after receipt/import. By default, this option is turned off because Workstation cannot make any assumptions about how long studies must be kept, as regulations vary from region to region. Also, Workstation, although not intended to be used as a permanent archive, could be used as one, and you may want to keep all the studies without ever deleting any. Here are some common use cases for study deletion:

•

Review Workstation: Workstation is used by a radiologist to review patient studies that are either retrieved or auto-routed to Workstation. In this situation, because studies are likely being stored elsewhere permanently (PACS), they can be safely purged from Workstation, say 2 weeks after receipt/import.

•	QA Station: studies are sent to Workstation for a technologist to review before manually sending them on to a radiologists' review workstation. In this case it may be appropriate to delete studies after a very short time, say 2 days.

•	Permanent Archive: in this situation, studies would never be permanently deleted. Because Workstation uses a lightweight database, it is highly recommended that it not be used in this way.

Configuring study deletion is simple; just check the box to enable it and select a number of minutes/hours/days/weeks for which to keep studies after they have been received/imported.

Note: the local service must be running to apply the changes; a "Start Local Service" link will appear, as discussed above (File Store).

Once the changes are accepted, the deletion time for each local study will be recalculated. The Delete On column in My Studies will show the date and/or time the study will be automatically deleted, according to the following rules:

1.	If the deletion date is several days in the future, only the deletion date is shown (e.g. "20-Aug-2012").

2.	If the deletion time is approaching, "Tomorrow" or "Today" is shown, followed by the deletion time (e.g. "Tomorrow 11:45").

3.	If the deletion time is past, "Past Due" will be shown.

If you later choose to modify or even disable study deletion, the deletion time(s) will again be recalculated.

Technical Note

The file store location and automatic study deletion must be configured separately. This is because each requires the local service to be in a different state (e.g. started or stopped) in order to be applied. When you change either one, the other will immediately become disabled, and a message will appear in the bottom left corner.