Monte Carlo simulation of inverse geometry x-ray fluoroscopy using a modified MC-GPU framework

David L Dunkerley; Michael T. Tomkowiak; Jordan M. Slagowski; B McCabe; Tobias Funk; Michael A. Speidel

doi:10.1117/12.2081684

Monte Carlo simulation of inverse geometry x-ray fluoroscopy using a modified MC-GPU framework

Published on Mar 18, 2015in Proceedings of SPIE

· DOI :10.1117/12.2081684

David L Dunkerley29

Estimated H-index: 29

(UW: University of Wisconsin-Madison), Michael T. Tomkowiak7

Estimated H-index: 7

(UW: University of Wisconsin-Madison)+ 3 AuthorsMichael A. Speidel11

Estimated H-index: 11

(UW: University of Wisconsin-Madison)

Sources

Abstract

Scanning-Beam Digital X-ray (SBDX) is a technology for low-dose fluoroscopy that employs inverse geometry x-ray beam scanning. To assist with rapid modeling of inverse geometry x-ray systems, we have developed a Monte Carlo (MC) simulation tool based on the MC-GPU framework. MC-GPU version 1.3 was modified to implement a 2D array of focal spot positions on a plane, with individually adjustable x-ray outputs, each producing a narrow x-ray beam directed toward a stationary photon-counting detector array. Geometric accuracy and blurring behavior in tomosynthesis reconstructions were evaluated from simulated images of a 3D arrangement of spheres. The artifact spread function from simulation agreed with experiment to within 1.6% (rRMSD). Detected x-ray scatter fraction was simulated for two SBDX detector geometries and compared to experiments. For the current SBDX prototype (10.6 cm wide by 5.3 cm tall detector), x-ray scatter fraction measured 2.8-6.4% (18.6-31.5 cm acrylic, 100 kV), versus 2.2-5.0% in MC simulation. Experimental trends in scatter versus detector size and phantom thickness were observed in simulation. For dose evaluation, an anthropomorphic phantom was imaged using regular and regional adaptive exposure (RAE) scanning. The reduction in kerma-area-product resulting from RAE scanning was 45% in radiochromic film measurements, versus 46% in simulation. The integral kerma calculated from TLD measurement points within the phantom was 57% lower when using RAE, versus 61% lower in simulation. This MC tool may be used to estimate tomographic blur, detected scatter, and dose distributions when developing inverse geometry x-ray systems.

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Mar 18, 2015·Proceedings of SPIE

#1Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11

#2Michael T. Tomkowiak (UW: University of Wisconsin-Madison)H-Index: 7

Last. Tobias FunkH-Index: 10

view all 8 authors...

Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system for low dose cardiac imaging. The use of a narrow scanned x-ray beam in SBDX reduces detected x-ray scatter and improves dose efficiency, however the tight beam collimation also limits the maximum achievable x-ray fluence. To increase the fluence available for imaging, we have constructed a new SBDX prototype with a wider x-ray beam, larger-area detector, and new real-time image reconstructor. Imaging is performed with ...more

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The scanning-beam digital x-ray (SBDX) system has been developed for fluoroscopic imaging using an inverse x-ray imaging geometry. The SBDX system consists of a large-area x-ray source with a multihole collimator and a small detector. The goal of this study was to build a Monte Carlo (MC) model of the SBDX source as a useful tool for optimization of the SBDX imaging system in terms of its hardware components and imaging parameters. The MC model of the source was built in the EGSnrc/BEAMnrc code ...more

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view all 4 authors...

Purpose: Scanning beam digital x-ray (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis at multiple planes. This study describes a tomosynthesis-based method for 3D tracking of high-contrast objects and present the first experimental investigation of cardiac catheter tracking using a prototype SBDX system. Methods: The 3D tracking algorithm utilizes the stack of regularly spaced tomosynthetic planes that are g...more

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Mar 4, 2010·Proceedings of SPIE

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