Blurred digital mammography images : an analysis of technical recall and observer detection performance

Ma, WK; Kelly, J; Millington, S; Hilton, B; Borgan, R; Aspin, R; Lanca, C; Hogg, P

Abstract

Background: Blurred images in Full Field Digital Mammography (FFDM) are a problem in the UK Breast Screening Programme. Technical recalls may be due to blurring not being seen on lower resolution monitors used for review.
Objectives: This study assesses the visual detection of blurring on a 2.3 megapixel (MP) monitor and a 5 MP report grade monitor and proposes an observer standard for the visual detection of blurring on a 5 MP reporting grade monitor.
Method: Twenty-eight observers assessed 120 images for blurring; 20 had no blurring present whilst 100 had blurring imposed through mathematical simulation at 0.2, 0.4, 0.6, 0.8 and 1.0 mm levels of motion. Technical recall rate for both monitors and angular size at each level of motion were calculated. Chi-squared (X2) tests were used to test whether significant differences in blurring detection existed between 2.3 and 5 MP monitors.
Results: The technical recall rate for 2.3 and 5 MP monitors are 20.3 % and 9.1% respectively. Angular size for 0.2 to 1 mm motion varied from 55 to 275 arc seconds. The minimum amount of motion for visual detection of blurring in this study is 0.4 mm. For 0.2 mm simulated motion, there was no significant difference X2 (1, N=1095) =1.61, p=0.20) in blurring detection between the 2.3 and 5 MP monitors.

Conclusion: According to this study monitors equal or below 2.3 MP are not suitable for technical review of FFDM images for the detection of blur.
Advances in knowledge: This research proposes the first observer standard for the visual detection of blurring.
Key words: Simulated motion; technical recall; monitor resolution; observer standard; blurring detection

Citation

Ma, W., Kelly, J., Millington, S., Hilton, B., Borgan, R., Aspin, R., …Hogg, P. (2017). Blurred digital mammography images : an analysis of technical recall and observer detection performance. British Journal of Radiology, 90(1071), 20160271. https://doi.org/10.1259/bjr.20160271

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2017
• Online Publication Date: Mar 3, 2017
• Publication Date: Mar 3, 2017
• Deposit Date: Jan 30, 2017
• Publicly Available Date: Jan 30, 2018
• Journal: British Journal of Radiology
• Print ISSN: 0007-1285
• Electronic ISSN: 1748-880X
• Publisher: British Institute of Radiology
• Volume: 90
• Issue: 1071
• Pages: 20160271
• DOI: https://doi.org/10.1259/bjr.20160271
• Publisher URL: http://dx.doi.org/10.1259/bjr.20160271
• Related Public URLs: http://www.bir.org.uk/publications/journals/