What product is affected?
ClearCanvas Workstation v.1.5 of the ClearCanvas RIS/PACS v.1.5
What is the issue?
The Polygonal ROI tool reports:
- An incorrect area, mean and standard deviation for all complex polygons (i.e., polygons which cross over on themselves).
- An incorrect mean and standard deviation for all simple polygons (i.e., polygons which do not cross over on themselves).
We have determined that the magnitude of the error is unpredictable and cannot be reliably quantified. It is potentially different each time a polygonal ROI is drawn.
What is the scope of this issue?
The defect is limited to the Polygonal ROI tool. All other measurement tools, including linear measurements and elliptical and rectangular ROIs have been verified to report correct values. Note also that the area of simple polygons is correctly computed.
What do I need to do?
Because the mean and standard deviation of polygonal ROIs is sometimes used for diagnostic purposes,
we recommend that the Polygonal ROI tool not be used until a service pack has been issued. There is no workaround. This corrective action should be communicated to all users of ClearCanvas Workstation 1.5 at your institution. If you wish to disable the Polygonal ROI tool, please follow the instructions in this
appendix.
What is ClearCanvas doing to address this issue?
Firstly, out of an abundance of caution, we have elected to temporarily remove ClearCanvas Workstation 1.5 from our website so that new users will not be affected by the issue. While this may seem extreme, it reflects our deep commitment to our users and to our quality process. Even though our products are freely available, we recognize the impact that they can have on patient care. Because of that, we take quality very seriously.
Secondly, we are currently working on a service pack to correct the issue. We expect to make this service pack available within a week of the issue date of this bulletin.
Thirdly, we are reviewing and improving our internal processes to reduce the likelihood of similar issues occurring in the future. Amongst other things, this includes augmenting our unit and regression test suites.