Evaluation of Digital Mammography Device Quality Control Measurements and Image Quality

• Main Authors: Rukiye Şanlı, Özcan Gündoğdu
• Format: Article
• Language: English
• Published: Kocaeli University 2018-09-01
• Series: Kocaeli Üniversitesi Sağlık Bilimleri Dergisi
• Subjects: PMMA; CNR; AGD; ImageJ; Pro-Mam; full field digital mammography; dijital mamografi cihazı
• Online Access: http://dergipark.org.tr/kusbed/issue/39194/455426?publisher=kocaeli

Objective: In this study, we aimed to establish a standard protocol of measurements by taking quality control tests belonging to digital mammography devices widely used in our country. Breast cancer occurs in glandular tissue. For this reason, it is necessary to measure the mean glandular tissue value and follow the standard values. The accuracy of  the system has been tested  by considering whether the values specified are within the acceptable limit values specified by the EUREF standard. Performing quality control tests periodically will increase the quality of the image and reduce patient doses by minimizing repetitive work. Methods: The measurements were performed on a Fujifilm Amulet Innovality digital mammography system. Contrast detail Pro-Mamphantomand Pro-Mam software to simulate different breast tissues for measurements, Ray SafeXi detector for dosimetry, MTF test for image qualities, Image J software was used to measure the average pixel and standard deviation of the pattern the image. The PMMA phantoms of different thicknesses have the mean glandular tissue change (AGD), contrast-to-noiseratio (CNR), figure of merit (FOM) values and modular transfer function (MTF), detective quantum efficiency (DQE) and noise power spectrum (NPS) graphics are compared. HVL and CNR values of W/Rh filter and W/Al filter are compared. Results: The mean glandular dose was measured  as 0.92 mGy on a 45 mm PMMA plate in normal dose mode. When the W/Rh filter is used, the Contrast Noise Ratio (CNR) is 5.1, while the W/Al filter is 4.5. The FOM value with a 45 mm PMMA plate at 26 kVp was measured as 42.905 with the W/Rh filter. When there is a W/Al filter, it is measured as 50.115. Conclusion: The average glandular dose at 45 mm to the EUREF standard should be less than 2.5 mGy, the measured values are within the limit values. Breast dose, air kerma and AGD values increased while CNR and FOM values decreased with increasing breast thickness. When W/Rh filter is used, HVL, FOM and CNR values are higher because the X rays are more cured. Thus, it has been determined that it is possible to obtain a better image quality at a lower dose in the W/Rh combination.