Program Information
Average Glandular Dose (AGD) Measurement of GE Contrast-Enhanced Spectral Mammography (CESM) Using a ACR Mammography Accreditation Phantom
Y Liang1*, A Dutta1 , (1) Columbia University Medical Center, New York, NY
Presentations
SU-D-204-4 (Sunday, July 12, 2015) 2:05 PM - 3:00 PM Room: 204
Purpose:To investigate a practical approach to measure the average glandular dose (AGD) for GE Contrast-Enhanced Spectral Mammography (CESM) using a ACR mammography accreditation phantom
Methods:This study used a GE Senographe Essential unit with SenoBright CESM, a Gammex ACR mammography accreditation phantom, an Unfors RaySafe X2 mammography detector, and a Radcal 10x9-6M ion chamber. Five AUTO CESM exposures were done on the ACR phantom with 5 daN compression to select the target/filter combination, kVp, and mAs. These techniques were used for the following manual CESM exposures, and the regular mammography to simulate the low energy exposure of a CESM run. Both Unfors and Radcal detectors are positioned near the phantom as the regular AGD measurement of mammography. The unfors detector measured the high energy exposure of the CESM run directly. The Radcal detector was set to accumulated mode and measured the total output from a CESM run. For Radcal, the high energy exposure was determined by subtracting the output of the regular mammography which simulated the low energy run of CESM from the total output. We also measured the HVLs of the low and high energy exposure respectively. The measured entrance skin air Kerma was then converted to the AGD using two methods: one was based on the tables provided by GE; the other was introduced by D R Dance and K C Young (2014).
Results:The AGD from the AUTO CESM on a ACR mammography phantom is approximately 1.75 mGy, 13.5% higher than that of the regular CNT AUTO mode, and 94% higher than that of the regular STD AUTO mode of this GE unit. The high energy exposure contributes about 18% of the total AGD. The AGD results from two methods are agreed to each other within 2%.
Conclusion:We provide a practical approach to measure the AGD of GE CESM.
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