Topics in this article include:
- Introduction
- Reference File Selection
- Adding Reference File Tests
- Generating Reference Files
- Adding Reference Files to Your Schedule
Introduction
Various factors including scan parameters and artifacts can lead to the misidentification of ROIs in Planar kV and MV imaging tests. The image below shows a case in which the boundaries of a Sun Nuclear planar imaging phantom are misidentified (as shown in the green outline), as well as the kV imaging ROIs themselves (outlined in red).
This article discusses a method for establishing a reference file that can be assigned to these tests, specifically to correctly locate the ROIs for each imaging test. The failure to correctly identify the phantom outline is an issue that should be referred directly to support.
Note: the processes in this article are identical for either SNC kV or MV and Doselab kV or MV Planar Imaging tests. The graphics below illustrate the specific use-case for addressing a SNC Planar kV test, but the example can be extended to any of these four tests.
Reference File Selection
You will need to find a test that has run successfully. By looking at historical reports, you can open the thumbnail image that the analysis has chosen to perform the tests.
Clicking this thumbnail will open a larger image, with which you can visually verify the correct ROI selection. Pay close attention not only to the shape and size of the ROIs, but also to the numerical orientation relative to your phantom’s documented references.
Be sure that any image chosen matches the phantom placement and orientation that you will be using going forward.
When you have confirmed the proper ROI selection, you will use this image file to create a set of reference files that will be saved in the analysis template.
Download the image by clicking the download icon, shown below.
Adding Reference File Tests
In your Planar kV or MV template, you will need to add the two specific tests that will generate and display the required reference files. First, find the template that will run the required kV or MV Imaging test. Per the image below, modify this template to add the tests.
Continue through the opening page.
Now select the two tests circled in the image below by checking each box. You will see the tests populate in the pane to the right as they are selected.
Generating Reference Files
To generate the reference files, run a new QA with the image file containing the correct ROIs. This new QA will output the two files required for proper ROI identification. Click each file name to download the .mat and .json files.
Once the reference files are downloaded, the image file may be removed from the new QA. Additionally you may also want to remove the Processed Reference Image and Processed ROI JSON test from your template.
Adding Reference Files to Your Schedule
Now modify your Planar kV or MV schedule to include the reference files. Navigate to Manage - Schedule Configurations, and find the schedule your QA uses. Click the pencil icon to edit the schedule.
Click the pencil icon to edit the Image Processing section, per the image below. Notice in the current settings, there are no reference files present in this schedule.
Finally, choose the .mat and .json files from your downloads, and upload them here.
Save to finish the process.