RESUMO
OBJECTIVE: Blurred images in full-field digital mammography 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. This study assesses the visual detection of blurring on a 2.3-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. METHODS: 28 observers assessed 120 images for blurring; 20 images had no blurring present, whereas 100 images 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. χ2 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. The angular size for 0.2- to 1-mm motion varied from 55 to 275 arc s. 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 [χ2 (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 ≤2.3 MP are not suitable for technical review of full-field digital mammography images for the detection of blur. Advances in knowledge: This research proposes the first observer standard for the visual detection of blurring.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mamografia/métodos , Mama/diagnóstico por imagem , Feminino , Humanos , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Reino UnidoRESUMO
PURPOSE: Breast density categorization consistency is important when performing research, and minimization of interoperator and intraoperator variability is essential. This research aimed to validate a set of mammography images for visual breast density estimation to achieve consistency in future research projects and to determine observer performance. METHODS: Using the Breast Imaging Reporting and Data System (BI-RADS) as the visual grading scale, 50 mammography images were scored for density grade by 8 observers. RESULTS: Six of 8 observers achieved near-complete intraobserver agreement (kappa > 0.81). Strong agreement among observers (kappa = 0.61-0.8) was found in 10 of 28 paired observation episodes on the first iteration and 12 of 28 on the second. No observers demonstrated a delta variance above 1. Fleiss' kappa was used to evaluate concordance among all observers on the first and second iterations (first iteration, 0.64; second iteration, 0.56). DISCUSSION: This research illustrates the difficulties of comparing observer visual performance scores because differences can exist when studies are repeated by and among individuals. CONCLUSION: We confirmed that the 50 images were suitable for research purposes. Some variability existed among observers; however, overall density classification agreement was strong. Future research should include repeating this study with digitally acquired images.