Affiliation:
1. 1 Particle Acceleration Physics and Technology Division, National Centre for Nuclear Research (NCNR) , Poland
2. 2 Medical Physics Department , Maria Sklodowska-Curie National Research Institute of Oncology (MSCNRIO) , Poland
Abstract
Abstract
Introduction: Early detection of breast cancer requires high-quality mammographic images that have been made possible by the introduction of new technologies, such as full-field digital mammography (FFDM). In this new study, we perform extended measurements to calculate effective detective quantum efficiency (eDQE) and introduce effective noise equivalent quanta (eNEQ). Our aim was to show how these two metrics relate to the image quality of two digital mammography systems.
Material and methods: Measurements were performed for a Siemens Mammomat Inspiration and a GE Senographe Pristina system. Each was equipped with an automatic exposure control (AEC) for use in a clinical setting. We used a polymethyl methacrylate (PMMA) phantom at thicknesses of 20, 30, 40 and 70 mm to cover the range of scatter conditions expected in mammography, with and without an anti-scatter grid. The Siemens system had an a-Se detector, and the GE system had an indirect-conversion detector. Measurements of Kerma were performed with Piranha Black 657 meter (RTI Electronics AB). The majority of our calculations were automated, using a modified version of our software.
Results: For the two mammographic systems evaluated, we characterized physical quality parameters, such as effective modulation transfer function (eMTF), effective normalized noise power spectrum (eNNPS), eDQE and eNEQ for a wide range of exposures, phantom thicknesses, with and without an anti-scatter grid. Results are presented as a function of spatial frequency. A contrast-detail analysis was performed with a CDMAM 3.4 phantom with dedicated software (CDMAM analysis 1.5.5, NCCPM) and a set of different PMMA phantoms.
Conclusions: We successfully demonstrated that the eNEQ metric can be used as a new option to evaluate image quality for images taken with and without a grid and with phantoms of different thicknesses for the Siemens and GE systems. These results were consistent with the results obtained from CDMAM.
Reference21 articles.
1. https://profilaktykaraka.pib-nio.pl/kontrola-jakosci/, in Polish, access: May 2023
2. Wysocka-Rabin A, Dobrzyńska M, Pasicz K, Skrzyński W, Fabiszewska E. Determination of DQE as a quantitative assessment of detectors in digital mammography: Measurements and calculation in practice. Pol J Med Phys Eng. 2021;27(3):223-232. https://doi.org/10.2478/pjmpe-2021-0027
3. Dobrzyńska M, Wysocka-Rabin A, Fabiszewska E, Pasicz K, Skrzyński W. New Software for DQE Calculation in Digital Mammography Compliant with IEC 62220–1-2. J Dig Imag 2022;35(5):1069-1078. https://doi.org/10.1007/s10278-021-00546-y
4. Van Engen R, Young K, Bosmans H, Thijssen H. The European protocol for the quality control of the physical and technical aspect of mammography screening, Luxembourg. 2006
5. Young K, Johnson B, Bosmans H, Van Engen R. Development of minimum standards for image quality and dose in digital mammography. In: Proceedings of the 7th International Workshop on Digital Mammography, 2005, 149-154.