- Email: [email protected]
Mammography compression force readings
Radiography 19 (2013) 280
Contents lists available at SciVerse ScienceDirect
Radiography journal homepage: www.elsevier.com/locate/radi
Letter to the Editor
Mammography compression force readings Dear Sir, We would like to point out some observations made recently in an experiment and then ask a question of your readers. We have just completed a multicentre study which required us to record compression force readouts from mammography machines (43 paddles on 14 machines). The compression force readings were taken over a 40 s period during which the compression paddle ‘relaxed’. The object being compressed was a deformable breast phantom. On conducting the experiment we noted that some machines gave compression force readouts in Newtons and some in deca Newtons, this can be seen on Figs. 1 and 2. For machines giving readouts in Newtons (Fig. 1) we realized that practitioners could adjust their compression force to be accurate and consistent over time. By contrast for machines giving readouts in deca Newtons we noted that there could be up to 10 N error between what the machine displays and what is actually applied; this could be either an under- or overestimate. This error could have consequences for compression force consistency between and within screening rounds (eg left versus right breast) and the patient’s experience (eg discomfort). We wondered how practitioners using machines with deca Newton readouts minimize the potential for the potential 10 N error; equally we wondered if those using machines with Newton
Figure 2. The change of compression force in deca Newtons against time for a 18 24 cm flexible paddle.
readouts find the compression force easy to reproduce within (eg left versus right) and between screening rounds. Yours sincerely Wang Kei Ma*, Peter Hogg Department of Radiography, University of Salford, Salford M6 6PU, United Kingdom Judith Kelly, Sara Millington Breast Imaging Unit, Countess of Chester Hospital, Chester CH2 1UL, United Kingdom E-mail addresses: [email protected] (J. Kelly); [email protected] (S. Millington) * Corresponding author. Directorate of Radiography, Room L608, Allerton Building, Salford M5 4WT, United Kingdom. Tel.: þ44 7424221947. E-mail addresses: [email protected] (W.K. Ma); [email protected] (P. Hogg)
Figure 1. The change of compression force in Newtons against time for a 18 24 cm flexible paddle.
1078-8174/$ – see front matter Ó 2013 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.radi.2013.02.001
11 February 2013 Available online 9 March 2013
Contents lists available at SciVerse ScienceDirect
Radiography journal homepage: www.elsevier.com/locate/radi
Letter to the Editor
Mammography compression force readings Dear Sir, We would like to point out some observations made recently in an experiment and then ask a question of your readers. We have just completed a multicentre study which required us to record compression force readouts from mammography machines (43 paddles on 14 machines). The compression force readings were taken over a 40 s period during which the compression paddle ‘relaxed’. The object being compressed was a deformable breast phantom. On conducting the experiment we noted that some machines gave compression force readouts in Newtons and some in deca Newtons, this can be seen on Figs. 1 and 2. For machines giving readouts in Newtons (Fig. 1) we realized that practitioners could adjust their compression force to be accurate and consistent over time. By contrast for machines giving readouts in deca Newtons we noted that there could be up to 10 N error between what the machine displays and what is actually applied; this could be either an under- or overestimate. This error could have consequences for compression force consistency between and within screening rounds (eg left versus right breast) and the patient’s experience (eg discomfort). We wondered how practitioners using machines with deca Newton readouts minimize the potential for the potential 10 N error; equally we wondered if those using machines with Newton
Figure 2. The change of compression force in deca Newtons against time for a 18 24 cm flexible paddle.
readouts find the compression force easy to reproduce within (eg left versus right) and between screening rounds. Yours sincerely Wang Kei Ma*, Peter Hogg Department of Radiography, University of Salford, Salford M6 6PU, United Kingdom Judith Kelly, Sara Millington Breast Imaging Unit, Countess of Chester Hospital, Chester CH2 1UL, United Kingdom E-mail addresses: [email protected] (J. Kelly); [email protected] (S. Millington) * Corresponding author. Directorate of Radiography, Room L608, Allerton Building, Salford M5 4WT, United Kingdom. Tel.: þ44 7424221947. E-mail addresses: [email protected] (W.K. Ma); [email protected] (P. Hogg)
Figure 1. The change of compression force in Newtons against time for a 18 24 cm flexible paddle.
1078-8174/$ – see front matter Ó 2013 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.radi.2013.02.001
11 February 2013 Available online 9 March 2013