Advancements towards the implementation of clinical phase-contrast breast computed tomography at Elettra

Abstract

Breast computed tomography (BCT) is an emerging application of X‐ray tomography in radiological practice. A few clinical prototypes are under evaluation in hospitals and new systems are under development aiming at improving spatial and contrast resolution and reducing delivered dose. At the same time, synchrotron‐radiation phase‐contrast mammography has been demonstrated to offer substantial advantages when compared with conventional mammography. At Elettra, the Italian synchrotron radiation facility, a clinical program of phase‐contrast BCT based on the free‐space propagation approach is under development. In this paper, full‐volume breast samples imaged with a beam energy of 32 keV delivering a mean glandular dose of 5 mGy are presented. The whole acquisition setup mimics a clinical study in order to evaluate its feasibility in terms of acquisition time and image quality. Acquisitions are performed using a high‐resolution CdTe photon‐counting detector and the projection data are processed via a phase‐retrieval algorithm. Tomographic reconstructions are compared with conventional mammographic images acquired prior to surgery and with histologic examinations. Results indicate that BCT with monochromatic beam and free‐space propagation phase‐contrast imaging provide relevant three‐dimensional insights of breast morphology at clinically acceptable doses and scan times.

Propagation‐based x‐ray phase‐contrast tomography of mastectomy samples using synchrotron radiation

“…The assessment results by the imaging experts and radiologists were found to be generally consistent with the objective measurements of SNR and spatial resolution in the reconstructed CT slices of mastectomy samples. These results constitute part of the systematic research that our collaborative team has been conducting with the goal of developing medical breast cancer imaging facilities at the Australian Synchrotron in Melbourne, Australia, and at Elettra Synchrotron in Trieste, Italy …”

“…These results constitute part of the systematic research that our collaborative team has was assessed as having higher quality, even though the measured signal-to-noise-ratio and spatial resolution were apparently better in image (a) (see Table II) been conducting with the goal of developing medical breast cancer imaging facilities at the Australian Synchrotron in Melbourne, Australia, and at Elettra Synchrotron in Trieste, Italy. 11,15,25,27,40…”

Radiochromic film dosimetry in synchrotron radiation breast computed tomography: a phantom study

“…The tomographic setup of the SYRMA-3D project is hosted at the SYRMEP beamline at the Elettra SR facility (Longo et al, 2016(Longo et al, , 2019. The patient lies in a prone position, with one of her uncompressed pendant breasts inserted into a circular opening of the patient support, which can fully rotate around a vertical axis and translate in the vertical direction, using a dedicated control system.…”

“…Breast imaging with SR may also be compatible with K-edge subtraction imaging with iodine contrast medium (Thomlinson et al, 2018) for enhanced visibility of tumor masses. Phase-contrast breast CT with SR employs a parallel, coherent, monoenergetic beam of X-ray photons with the patient in a prone position on a rotating and vertically translating patient support (Longo et al, 2016(Longo et al, , 2019Brombal et al, 2019;Sarno et al, 2016aSarno et al, , 2017aDelogu et al, 2017;Taba et al, 2018). Optimal conditions for propagationbased phase-contrast imaging are obtained by using a large source-object distance and by positioning the (photon counting) imaging detector at a distance up to several metres from the vertical axis of rotation (Brombal et al, 2018), where the breast is pendant from an aperture in the patient support.…”

A phase-retrieval toolbox for X-ray holography and tomography

“…High resolution at the nanoscale is achieved by focusing SR to a secondary source and then exploiting the cone-beam geometry (Mokso et al, 2007;Bartels et al, 2015) and the Fresnel scaling theorem (Paganin, 2006). A wide range of dedicated beamlines are now available for parallel-beam PBI (see, for example, Weitkamp et al, 2010;Longo et al, 2019;Wang et al, 2001;Schell et al, 2013) as well as -at a somewhat smaller scale and numberfor cone-beam PBI based on nano-focused undulator radiation (da Silva et al, 2017;Wilde et al, 2016;Lovric et al, 2016;Salditt et al, 2015). In addition, a new generation of microfocus X-ray sources, with increased flux and improved spatial coherence (Hemberg et al, 2003), has enabled the implementation of PBI and computed tomography at the micrometre scale (microCT) in the laboratory (Bartels et al, 2013;Vå gberg et al, 2015;Larsson et al, 2016).…”