Evidence map›Paper›PMID 30506056›Full record

ArticleConference proceedings. International Conference on Image Formation in X-Ray Computed Tomography2018

Implementation and Assessment of Dynamic Fluence Field Modulation with Multiple Aperture Devices.

Grace J Gang, Andrew Mao, Jeffrey H Siewerdsen, J Webster Stayman

Abstract read
In one paragraph

Article in Conference proceedings. International Conference on Image Formation in X-Ray Computed Tomography, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Volume-of-interest Imaging Using Multiple Aperture Devices.Proceedings of SPIE--the International Society for Optical Engineering · 2019
    Article
  2. Dynamic fluence field modulation for miscentered patients in computed tomography.Journal of medical imaging (Bellingham, Wash.) · 2018
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Grace J GangDepartment of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA (grace.j.gang@jhu.edu, amao@jhu.edu, web.stayman@jhu.edu, jeff.siewerdsen@jhu.edu).
Andrew MaoDepartment of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA (grace.j.gang@jhu.edu, amao@jhu.edu, web.stayman@jhu.edu, jeff.siewerdsen@jhu.edu).
Jeffrey H SiewerdsenDepartment of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA (grace.j.gang@jhu.edu, amao@jhu.edu, web.stayman@jhu.edu, jeff.siewerdsen@jhu.edu).
J Webster StaymanDepartment of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA (grace.j.gang@jhu.edu, amao@jhu.edu, web.stayman@jhu.edu, jeff.siewerdsen@jhu.edu).

Funding

Task-driven dynamic beam modulation for high-performance,low-dose CT.U01EB018758 · NIBIB · JOHNS HOPKINS UNIVERSITY · PI STAYMAN, JOSEPH WEBSTER · 2014 to 2017
$2.6M
NIBIB NIH HHS U01 EB018758
6 · The paper itself

Abstract

This work reports experimental results of dynamic fluence field modulation (FFM) using a dual multiple aperture devices (MAD) system. MAD filters use Moiré patterns produced by relative motions between two sets of thin, highly attenuating tungsten bars of varying widths and spacings. Each MAD was affixed to a linear actuator and installed on an experimental cone-beam CT bench. Phantom-specific FFM profiles were designed based on a flatness and minimum mean variance objectives and realized through a combination of MAD translations and pulse width modulation at a constant tube current. To properly correct for gains associated with the MAD filters, a correction algorithm was designed to account for focal spot shifts during scanning, as well as spectral effects from incomplete blockage of x-rays by the tungsten bars. The FFM designs were demonstrated in an elliptical phantom (25.8×14.1 cm). Variance and noise power spectrum (NPS) analysis was performed on the resulting reconstructions. While conventionalgain correction produced reconstructions with high frequency ring artifacts in axial slices, the proposed correction algorithm effectively removed such artifacts while preserving phantom details. Fluence field designs for the elliptical phantom were achievedusing relative MAD motions over a 0.44 mm range, and measured beam profiles closely approximated the theoretically computed target profiles. The noise properties of the resulting reconstructions behave as expected: a flat detected fluence criterion yields nearly isotropic NPS and more homogeneous variance across the reconstruction as compared to an unmodulated scan; the minimum mean variance FFM results in lower mean variance compared to both the unmodulated and flat-field patterns at approximately matched total bare-beam fluence. These results suggest that a dual-MAD CT is an effective approach to provide fluence and image quality control and that can potentially accommodate a wide range of phantoms and design objectives.

Indexed as

correctionsdynamic fluence field modulationimage qualitymultiple aperture device

Identifiers

PMID30506056
PMCPMC6261319

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.