Program Information
A Systematic Approach for Testing the Performance of Primary Diagnostic Monitors
A Ruuge*, Y Erdi , Memorial Sloan Kettering Cancer Center, New York, NY
Presentations
WE-RAM1-GePD-IT-1 (Wednesday, August 2, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Theater
Purpose: In our work we evaluated the change of primary diagnostic monitor (PDM) characteristics, in two consecutive years, measured by an external calibrated photometer.
Methods: Thirty two PDMs (BARCO) were included in our analysis. Monitors were located at radiology physicians’ offices and radiology reading rooms. All PDMs were equipped with the manufacturer’s built-in photometers and connected to BarcoMediCalQA web service for manual and automatic quality control measurements. All monitors were warmed up for at least 30 minutes before the luminance measurements. TG-18 test patterns and external photometer (RaySafe Solo Light) were used to measure the luminance values. Maximum luminance Lmax (all white), minimum luminance Lmin (all black), luminance ratio (Lmax/Lmin), luminance uniformity and Grayscale Standard Display Function (GSDF) calibration were used to evaluate the PDM performance. Measured and calculated PDM performance parameters were compared via the Wilcoxon signed-rank test.
Results: Comparison of the of the QA measurement results for the same monitors performed in a two year period showed that 13 PDMs showed decrease in Lmax and 19 PDMs showed an increase in Lmax. Maximum decrease was 40.9cd/m² or 10.1%. Maximum increase was 45.1cd/m² or 10.2%. The mean change in: Lmax was 3.4 ± 3.8%; Lmin was 8.1 ± 11.9%; GSDF maximum deviation from expected contrast response was 22.5 ± 20.1% and luminance uniformity was 22.1 ± 20.0%. Wilcoxon signed-rank test results for: Lmin (p-value=0.7636); Lmax (p-value=0.1827); Luminance uniformity (p-value=0.07792) and GSDF (p-value=0.01956) showed that the two year change in each PDM performance parameter was not statistically significant.
Conclusion: Although it is expected PDM luminance values to decrease over time, we found more PDMs with increased luminance. However, the change in luminance and other parameters were not statistically significant. This is probably due to the twice a year calibration of the monitors and shows the importance of the QC program.
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