Dual-energy contrast enhanced digital mammography: theoretical and experimental study of optimal monoenergetic beam parameters using synchrotron radiation

Abstract

Dual-energy imaging with the injection of an iodinated contrast medium has the potential to depict cancers in the breast, by the demonstration of tumour angiogenesis and the suppression of the breast structure noise. The present study investigates the optimum monoenergetic beam parameters for this application. First, a theoretical study of the beam parameters was performed to find the best compromise between the quality of the dualenergy recombined image and the patient dose. The result of this analysis was then validated by phantom experiments using synchrotron monoenergetic radiation at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). For an average breast of 5cm thickness and 50% glandularity, the theoretical simulations show an optimum at 20 keV for the low energy and 34 keV for the high energy, for a CsI detector of a standard mammography system. The SDNR variations with the low energy, the high energy or the dose repartition are very similar between the measurements on images acquired with synchrotron radiation and the simulated values. This ensures the accuracy of our theoretical optimization and the validity of the optimal beam parameters found in this study. The aim of this work is to demonstrate the potential of Dual-Energy CEDM (Contrast Enhanced Digital Mammography) with ideal monoenergetic sources, in order to provide an indicator of how to shape the polyenergetic spectra produced with classical X-ray sources for this application.

Investigation of test methods for QC in dual-energy based contrast-enhanced digital mammography systems: I. Iodine signal testing

“…The CEM image can then be produced via a weighted logarithmic subtraction of the LE and HE images, yielding an image of the iodine uptake, while anatomical background structures are cancelled. Algorithms can go beyond a simple weighted subtraction (Puong et al 2009, Contillo et al 2015 and therefore the iodine image is referred to as the 'recombined image' in this text. The clinical feasibility of CEM was demonstrated in the early 2000s (Lewin et al 2003, Dromain et al 2004, followed by US Premarket Notification (510(k)) for a device in 2011 (GE Healthcare 2011).…”

Multiple energy synchrotron biomedical imaging system

“…As earlier mentioned, the interest in MEI is not only with conventional x-ray sources but also with a synchrotron x-ray source. Some examples of synchrotron based MEI systems that have been developed are: multiple energy CT (MECT) for imaging of the human head and neck (Wu et al 1995, Ren et al 1999; Dual-energy imaging systems for various types of angiography including human coronary angiography (Suortti 1993, Dix et al 1996, Arfelli 2000, Elleaume et al 2000, Schültke et al 2010, contrast enhanced digital mammography (Puong et al 2009); and a Spectral K-edge subtraction imaging system (Zhu et al 2014) developed for biomedical imaging applications at the Canadian Light Source (CLS). At synchrotron facilities, monochromators made of silicon (Si) crystals are mostly used in the x-ray region of synchrotron radiation due to the favourable properties of Si (Suortti andSchulze 1995, Shastri et al 2002), its availability as a perfect or dislocation free crystal of large size, as well as good thermal and mechanical properties.…”

A scatter correction method for dual-energy digital mammography: Monte Carlo simulation

“…100 × 100 μm 2 for each pixel) was placed right after the bottom of phantom. For easy implementation, we made use of the monochromatic x-ray energies [38,39] with 18 keV for LE imaging and 36 keV for HE imaging. To save simulating time, we applied Richardson-Lucy fitting algorithm [40] to process the raw scatter data.…”