Study on patient dosimetry and image quality in digital mammography

Abstract

Introduction: Digital mammography present many advantages in comparison to conventional mammography, such as high dynamic range and the post-processing of acquired images. One problem is that protocols may not be optimized, resulting in higher absorbed doses to patients. The objective of this work is to evaluate image quality and to estimate mean glandular doses (MGD) in patients submitted to mammography examinations with three digital systems and one screen-film system in Recife, Brazil. Methods: To estimate the MGD, the parameters used to acquire images of 5475 patients, with ages between 40 and 64 years and compressed breasts between 2 and 9 cm, were registered. The MGD was calculated by multiplying the incident air kerma with conversion coefficients depending on the anode/filter, breast glandularity and half-value layer. The image quality evaluation of the digital systems was made using objective and subjective European criteria. Results: The results showed MGDs in the range of 0.4-10.3 mGy and the higher values were observed with digital systems. It was also observed that in the digital systems the use of compression force is not adequate and the irradiation parameters are not optimized. The images failed to reproduce the pectoral muscle and the contrast-to-noise ratio was not adequate for one system, indicating the need to improve the patient's positioning and the exposure parameters. Conclusion: It can be concluded that the use of non-optimized irradiation parameters is causing the higher doses with digital systems, highlighting the insufficient compression force.Keywords Mammography, Mean glandular dose, Image quality, Digital radiography.This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.How to cite this article: Xavier ACS, Andrade MEA, Pinto BVCC, Barros VSM, Kramer R, Khoury HJ. Study on patient dosimetry and image quality in digital mammography. Res Biomed Eng. 2017; 33(2):138-143.

Clinical image quality assessment and mean glandular dose for full field digital mammography

“…In the CC view, challenges were observed concerning the sharp reproduction of the pectoral muscle at the image margin, while in the MLO view, achieving a fully profiled nipple posed difficulties (cf table 5). These findings are consistent with literature data [31,48] and can be rooted to inadequate compression or positioning errors [49]. The assessment of the MLO view, in particular, highlighted the importance of proper positioning, as a nipple not in full profile indicated potential positioning errors, which could obscure the detection of tumour masses and microcalcifications.…”

“…Therefore, the imperative focus lies on facilities categorised in Group 2, necessitating immediate action to optimise imaging protocols. This entails the implementation of a comprehensive Quality Assurance program, continuous evaluation and protocol updates with radiologist feedback, and adherence to standards including regular audits of patient dose and IQ [31,44]. Improving IQ is pivotal for advancing early breast cancer detection, reducing false positives, and enhancing overall patient care.…”

“…Furthermore, even the vast majority of studies using subjective IQ criteria [15][16][17][18][19][20][21][22][23][24] did not address patient radiation exposure. Xavier et al estimated the mean glandular dose and evaluated the IQ, but using the old set of criteria from the European Commission (EC) [31].…”