CDMAM in digital mammography: contrast threshold measurements, achievable values and relation with dose

Abstract

The main goal of this study is to characterize threshold contrast values and average glandular dose (AGD) in mammography exams, as well as their relationship with acceptable (minimum quality values) and achievable values (desirable quality values) from the fourth edition of the EUREF protocol. Therefore, data from 84 mammography units of 6 different manufactures and 15 different models was gathered across Portugal during 2020 and 2021. The contrast measurements were obtained with a CDMAM 4.0 phantom. Within the tested units, 6 failed to comply with the acceptable EUREF values for threshold contrast and 5% achieved all levels of desirable contrast. Only 3% of the units presented values above an AGD achievable level of 2.4 mGy, for an equivalent breast thickness of 60 mm. As these acceptable and achievable values are used as a guideline for the setup of dose and image quality of mammography units, the obtained results demonstrate that clinical images are being produced with an AGD much lower than the achievable dose values. As a result, contrast threshold values are close to the minimum quality values which could result in images with lower diagnostic data, compromising the justification of X-ray exams. Results proved that there is a possibility for an AGD increase, aiming achievable image standards. Greater levels of radiation dose correlated with better image quality and consequently higher diagnostic confidence could be consistent with the optimization principle for radiation protection.

The human dimension: the Bernard Wheatley Award for 2023

“…Although constraining radiation doses received in medical diagnosis is important, where imaging modalities are used, the benefits of reducing doses have to be considered against the need to achieve adequate image quality. Trindade and Barreira (2023) examined this issue in the context of digital mammography using data from 84 mammography units from six different manufacturers comprising 15 different models. Amongst the tested units, six failed to comply with guidelines for acceptable performance.…”

“…Amongst the tested units, six failed to comply with guidelines for acceptable performance. Trindade and Barreira (2023) observed that many images were being produced with average glandular doses of less than the achievable glandular dose of 2.4 mGy. They concluded that their results show that it would be appropriate to increase the average glandular dose in many cases to achieve better image quality.…”