Add an indicator to the study list which indicates if a study has been downloaded to the local cache, add a button to pre-fetch or clear
Waiting for images and their associated metadata to load is one of the most significant issues with the OHIF viewer. For some large studies it can take several minutes for the data to transfer -- disrupting review, validation, and reporting -- and frustrating users. In ad-hoc testing, we've been told by members of some care teams that the viewer is "too slow and we will not use it." This particularly applies to large CT and X-ray studies.
OHIF uses session storage to cache for searches and series that have been downloaded to the local machine. That capability could be extended to help improve the perceived performance of the viewer. Proposed changes:
- Extend caching to use both local storage in addition to session storage. The current session storage used by OHIF resets when the page is refreshed. That works for studies that have been passively loaded and the user may not want to preserve between sessions. There are however, studies that the user might want to explicitly transfer to the local machine for review (or to work with offline). If the caching system in OHIF were extended to use both the local storage and session storage, a user could queue multiple studies to download in the background. After download, loading the data from local storage would be near instant.
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Add controls which allow for the user to manage local storage. One of the frustrating aspects of the current caching system, is there is no way to control which studies are cached or to refresh data in the cache. Adding controls to allow download (or to clear) a study from the local storage would solve this issue.
- Study list: add indicator showing whether a study is available locally (and if it is downloading, show progress)
- Viewer: add a button indicating the data is stored locally and allowing the user to delete it from the local cache