What is the minimum amount of simulated breast movement required for visual detection of blurring : An exploratory investigation?

Ma, WK; Aspin, R; Hogg, P; Kelly, J; Millington, S

Abstract

Background: Image blurring in mammography can cause significant image degradation and interpretational problems. A potential source is due to paddle movement during image formation. Paddle movement has been shown to be as much as 1.5mm. No study has yet been performed to determine how much motion would be noticeable, visually.
Objectives: To determine the minimum amount of simulated breast movement at which blurring can be detected visually.
Method: 25 artefact free mammogram images were selected. Mathematical simulation software was created to mimic the effect of blurring produced by breast movement during exposure. Motion simulation was imposed to 15 levels, from 0.1mm to 1.5mm stepping through 0.1mm increments. 15 degraded images and 1 without blurring were de-identified, randomized and assessed on a blinded basis by two clinical experts to determine presence or absence of blurring. Statistical testing was carried out to determine the consistency between the two observers.
Results: The probability of simulated blurred image detection is highest for the Gaussian method and lowest for soft edged mask estimation.
Conclusion: The amount of simulated breast movement at which blurring can be detected visually for Gaussian blur, hard edge mask estimation, and soft edge mask estimation are 0.4mm, 0.8mm and 0.7mm respectively. Cohen's Kappa for all the levels of simulated blurring is 0.689 (p<0.05).
Advances in knowledge: This research establishes the concept of using probability to represent visual detection of blurring rather than defining a hard cut-off level.

Citation

Ma, W., Aspin, R., Hogg, P., Kelly, J., & Millington, S. (2015). What is the minimum amount of simulated breast movement required for visual detection of blurring : An exploratory investigation?. British Journal of Radiology, 88(1052), https://doi.org/10.1259/bjr.20150126

• Journal Article Type: Article
• Acceptance Date: May 26, 2015
• Online Publication Date: Jun 25, 2015
• Publication Date: Aug 1, 2015
• Deposit Date: Jul 7, 2015
• Journal: British Journal of Radiology
• Print ISSN: 0007-1285
• Electronic ISSN: 1748-880X
• Publisher: British Institute of Radiology
• Peer Reviewed: Peer Reviewed
• Volume: 88
• Issue: 1052
• DOI: https://doi.org/10.1259/bjr.20150126
• Publisher URL: http://dx.doi.org/10.1259/bjr.20150126
• Related Public URLs: http://www.birpublications.org/toc/bjr/current