title: Design of dual multiple aperture devices for dynamical fluence field modulated CT.
abstract: A Multiple Aperture Device (MAD) is a novel x-ray beam modulator that uses binary filtration on a fine scale to spatially modulate an x-ray beam. Using two MADs in series enables a large variety of fluence profiles by shifting the MADS relative to each other. This work details the design and control of dual MADs for a specific class of desired fluence patterns. Specifically, models of MAD operation are integrated into a best fit objective followed by CMA-ES optimization. To illustrate this framework we demonstrate the design process for an abdominal phantom with the goal of uniform detected signal. Achievable fluence profiles show good agreement with target fluence profiles, and the ability to flatten projections when a phantom is scanned is demonstrated. Simulated data reconstruction using traditional tube current modulation (TCM) and MAD filtering with TCM are investigated with the dual MAD system demonstrating more uniformity in noise and illustrating the potential for dose reduction under a maximum noise level constraint.
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Aswin John
authors.initials: AJ
authors.lastname: Mathews
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Steven
authors.initials: S
authors.lastname: Tilley
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Grace
authors.initials: G
authors.lastname: Gang
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Satomi
authors.initials: S
authors.lastname: Kawamoto
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zbijewski
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Siewerdsen
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: Reuven
authors.initials: R
authors.lastname: Levinson
authors.affiliation: Aswin John Mathews, Steven Tilley II, Grace Gang, Satomi Kawamoto, Wojciech Zbijewski, Jeffrey H. Siewerdsen and J. Webster Stayman are with the Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21212 USA. Reuven Levinson is with Philips, Haifa.
authors.forename: J
authors.initials: J
authors.lastname: Webster Stayman
keywords: Dynamic bow-tie filter; Fluence field modulation; Patient-specific CT; Radiation dose reduction; Region-of-interest CT; X-ray beam modulation