Computed tomography (CT) scanner daily quality assurance (QA) is essential in ensuring patient safety and optimal image quality.

For Siemens, scanners perform self-tests using the manufacturer’s water phantom; the phantom is scanned in air with fixed parameters in both Head and Body mode. Regions of interest (ROIs) are positioned in the centre and periphery of the phantom, and measurements are made of noise, uniformity, and CT number of water over a number of slices.

If any result in the ROIs measured exceed the tolerance, the overall result of the daily QA is a fail. The scanner displays only a pass or fail message to the operator, however stores detailed PDFs of raw results on the system for each run of the tests.

The aim was to develop an in-house software to extract the results from the PDF files, and collate and analyse them. The output should be useful to both:

• CT superintendents - presented with graphical overview of scanner performance as well as key performance indicators, such as how often QA is performed, how often it failed and whether it was successfully repeated if so, to aid with department compliance.
• Medical Physics – raw data for analysis of trends and further manipulation.