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Purpose: The purpose of this work is to compare two methods of artifact spread function (ASF) estimation in digital breast tomosynthesis (DBT) and study the feasibility of a task-based ASF estimation. Methods: A homogeneous PMMA phantom with two aluminum spheres with size 0.5mm and 1.0mm was scanned on Siemens Inspiration, Giotto Class and Hologic Dimensions DBT systems. The ASF curves were estimated using a standard method from average pixel values from the DBT planes. A physical phantom with anthropomorphic features, including microcalcification simulating particles of average diameter 0.24 mm and a 3.0mm mass-like lesion, was also scanned on the same DBT systems. The in-focus and out-of-focus planes were read with a newly developed model observer in order to assess target detectability through the different slices and calculate task-based ASF curves for each DBT system. The corresponding curves for the standard sphere and the task-based methods were compared. Results: The ASF curves for the smaller targets, i.e. the 0.24 mm microcalcification particles and 0.5 mm aluminum sphere, were found to match closely, despite the size difference and the ASF curves for the larger targets. The propagation across planes for the 3.0mm mass-like lesion and the 1.0mm aluminum sphere did not match. Conclusions: The task-based ASF estimation gives better clinical relevance to the artifact spread estimation. The ASF of 0.5mm aluminum sphere calculated with the standard method can approximate the ASF of calcification cluster in a background with anthropomorphic properties.
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