Extra patient movement during mammographic imaging : an experimental study
Ma, WK, Brettle, D, Howard, D, Kelly, J, Millington, S and Hogg, P 2014, 'Extra patient movement during mammographic imaging : an experimental study' , British Journal of Radiology, 87 (1044) .
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Objectives: To determine if movement external to the patient occurring during mammography may be a source of image blur. Methods: Four mammography machines with seven flexible and nine fixed paddles were evaluated. In the first stage, movement at the paddle was measured mechanically using two calibrated linear potentiometers. A deformable breast phantom was used to mimic a female breast. For each paddle, the movement in millimeters and change in compression force in Newton was recorded at 0.5 and 1 second intervals respectively for 40 seconds with the phantom in an initially compressed state under a load of 80N. In the second stage, clinical audit on 28 females was conducted on one mammography machine with the 18x24cm and 24x29cm flexible paddles. Results: Movement at the paddle followed an exponential decay with a settling period of approximately 40 seconds. The compression force readings for both fixed and flexible paddles decreased exponentially with time while fixed paddles have a larger drop in compression force than flexible paddles. There is a linear relationship between movement at the paddle and change in compression force. Conclusions: Movement measured at the paddle during an exposure can be represented by a second order system. The amount of extra-patient movement during the actual exposure can be estimated using the linear relationship between movement at the paddle and the change in compression force. Advances in knowledge: This research provides a possible explanation to mammography image blurring caused by extra patient movement and proposes a theoretical model to analyze the movement.
|Themes:||Health and Wellbeing|
|Schools:||Schools > School of Health Sciences > Centre for Health Sciences Research|
|Journal or Publication Title:||British Journal of Radiology|
|Publisher:||British Institute of Radiology|
|Funders:||Non funded research|
|Depositing User:||P Hogg|
|Date Deposited:||09 Jan 2015 16:31|
|Last Modified:||21 Mar 2016 15:16|
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