Luca Brombal - Academia.edu (original) (raw)
Papers by Luca Brombal
Journal of Instrumentation, 2020
X-Ray Phase-Contrast Tomography, 2020
A Phase-Contrast breast CT facility based on a high-resolution CdTe photon-counting detector is u... more A Phase-Contrast breast CT facility based on a high-resolution CdTe photon-counting detector is under development at Elettra, the Italian Synchrotron Radiation (SR) facility in Trieste. The CT system exploits propagation-based phasecontrast imaging and phase-retrieval algorithm. The voxel size is 57×57×50 μm3 and the delivered MGDs, about 5 mGy, are comparable with clinical breast CT systems. In the present contribution, the comparisons between histological breast cancers and full breast CT images are presented from samples of breast mastectomy. The high resolution of the breast CT images and low noise due to the phase contrast allow a very fine matching between x-ray CT and histology at acceptable delivered doses.
A program devoted to perform the first in-vivo monochromatic breast computed tomography (BCT) is ... more A program devoted to perform the first in-vivo monochromatic breast computed tomography (BCT) is ongoing at the Elettra Synchrotron Facility. Since the synchrotron radiation provides high energy resolution and spatial coherence, phase-contrast (PhC) imaging techniques can be used. The latest high resolution BCT acquisitions of breast specimens, obtained with the propagation-based PhC approach, are herein presented as part of a wider framework, devoted to the optimization of acquisition and reconstruction parameters towards the clinical exam. Images are acquired with a state-of-the-art dead-time-free single-photon-counting CdTe detector with a 60 µm pixel size. The samples are imaged at 32 and 38 keV in continuous rotating mode, delivering 5-20 mGy of mean glandular dose (MGD). Contrast-to-noise ratio (CNR) and spatial resolution performances are evaluated for both absorption and phase-retrieved images considering tumor/adipose tissue interfaces. We discuss two different phase-retrie...
Phase-based (PB) x-ray imaging (XRI) methods have grown in importance over recent years, and it c... more Phase-based (PB) x-ray imaging (XRI) methods have grown in importance over recent years, and it can probably be argued that the majority of micro-CT experiments at synchrotrons include phase effects in some form or fashion. A comparable if not higher level of interest has consequently arisen with regards to the translation of PB XRI into lab-based CT and micro-CT system, where however things have been moving more slowly, and the opposite is probably true i.e. most acquisitions are currently non-PB. The reasons for this are multiple and varied, but the key ones may be attributable to setup complexity and to the necessity to move optical elements during acquisitions, limits in spatial resolution, and excessively long acquisition times. In the imaging of biological tissues, especially in vivo, excessive delivered dose can pose an additional concern. Based on the acceptance that a “one size fits all solution” probably does not exist, and that most real world applications typically do no...
Journal of Instrumentation
Journal of Instrumentation
We report on the application of the multi-aperture analyser X-ray Phase-Contrast imaging (XPCI) t... more We report on the application of the multi-aperture analyser X-ray Phase-Contrast imaging (XPCI) technique to the three-dimensional imaging of breast tissue samples. The experiment was conducted at the SYRMEP beamline (Elettra synchrotron, Italy) with a monochromatic X-ray beam. Along with the presentation of the methodology and resulting images, the potential extension of this approach to enable in-vivo applications at acceptable doses is discussed. K : Inspection with x-rays, X-ray mammography, X-ray radiography and digital radiography (DR) 1Corresponding author. 3 Results and Discussion 3 4 Conclusion 4
Physica Medica
Purpose Breast Computed Tomography (CT) is a dedicated 3D imaging modality that provides a comple... more Purpose Breast Computed Tomography (CT) is a dedicated 3D imaging modality that provides a complete volumetric reconstruction of the uncompressed organ, thus matching a high image quality with an acceptable delivered dose. The SYRMA-3D collaboration is developing the first clinical trial of phase-contrast breast CT with synchrotron radiation at the Elettra synchrotron facility in Trieste. We present a proposal for a Quality Control (QC) protocol, including a custom made QC phantom that was designed and built by the laboratories of the University of Ferrara. Methods The synchrotron beam is monochromatic in the energy range 8.5–40 keV. The images were acquired with a photon counting detector placed at about 2 m from the organ, so as to generate a phase contrast signal. The QC phantom consists of a water filled PMMA cylinder, hung from the patient support through the breast aperture. It contains several inserts that allow measurements of geometric alignment, reconstruction uniformity and linearity, low and high contrast resolution. Results CT images of the phantom were acquired at several beam energies within the range of interest, to explore the energy dependence of the results. Uniformity and linearity appeared to be preserved by the reconstruction for all energies. Conversely, low contrast details exhibited a more pronounced dependence on the energy choice. Finally, the visibility of high contrast details was always found above acceptance levels. Conclusions The main goal of the study was to verify the compatibility of the QC phantom with the experimental environment of the SYRMA-3D project, and to test the validity and feasibility of the proposed QC protocol. With minimal modifications, they proved viable instruments to perform the necessary quality assessments for the innovative diagnostic device developed by the SYRMA-3D collaboration.
Journal of Instrumentation
SYRMA-3D (SYnchrotron Radiation MAmmography 3D) aims to develop a breast CT system based on monoc... more SYRMA-3D (SYnchrotron Radiation MAmmography 3D) aims to develop a breast CT system based on monochromatic synchrotron radiation and a single photon counting detector (PIXIRAD-8) with CdTe sensor. Due to the demanding requests on high contrast resolution and low dose, images in breast CT are particularly sensitive to small imperfections of the flat field correction applied before the CT reconstruction. Detectors based on high Z crystal sensors show inhomogeneous pixels gain, which depends on the time from the switching-on of the high voltage polarization. This effect has been studied in our CdTe detector with the purpose of develop an effective flat field correction procedure. In the PIXIRAD-8 detector, the time-dependent inhomogeneities of the flat field signal appear to be local, small and systematically reproducible, with the exception of the pixels on the sensors edges.
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)
Journal of Instrumentation, 2020
X-Ray Phase-Contrast Tomography, 2020
A Phase-Contrast breast CT facility based on a high-resolution CdTe photon-counting detector is u... more A Phase-Contrast breast CT facility based on a high-resolution CdTe photon-counting detector is under development at Elettra, the Italian Synchrotron Radiation (SR) facility in Trieste. The CT system exploits propagation-based phasecontrast imaging and phase-retrieval algorithm. The voxel size is 57×57×50 μm3 and the delivered MGDs, about 5 mGy, are comparable with clinical breast CT systems. In the present contribution, the comparisons between histological breast cancers and full breast CT images are presented from samples of breast mastectomy. The high resolution of the breast CT images and low noise due to the phase contrast allow a very fine matching between x-ray CT and histology at acceptable delivered doses.
A program devoted to perform the first in-vivo monochromatic breast computed tomography (BCT) is ... more A program devoted to perform the first in-vivo monochromatic breast computed tomography (BCT) is ongoing at the Elettra Synchrotron Facility. Since the synchrotron radiation provides high energy resolution and spatial coherence, phase-contrast (PhC) imaging techniques can be used. The latest high resolution BCT acquisitions of breast specimens, obtained with the propagation-based PhC approach, are herein presented as part of a wider framework, devoted to the optimization of acquisition and reconstruction parameters towards the clinical exam. Images are acquired with a state-of-the-art dead-time-free single-photon-counting CdTe detector with a 60 µm pixel size. The samples are imaged at 32 and 38 keV in continuous rotating mode, delivering 5-20 mGy of mean glandular dose (MGD). Contrast-to-noise ratio (CNR) and spatial resolution performances are evaluated for both absorption and phase-retrieved images considering tumor/adipose tissue interfaces. We discuss two different phase-retrie...
Phase-based (PB) x-ray imaging (XRI) methods have grown in importance over recent years, and it c... more Phase-based (PB) x-ray imaging (XRI) methods have grown in importance over recent years, and it can probably be argued that the majority of micro-CT experiments at synchrotrons include phase effects in some form or fashion. A comparable if not higher level of interest has consequently arisen with regards to the translation of PB XRI into lab-based CT and micro-CT system, where however things have been moving more slowly, and the opposite is probably true i.e. most acquisitions are currently non-PB. The reasons for this are multiple and varied, but the key ones may be attributable to setup complexity and to the necessity to move optical elements during acquisitions, limits in spatial resolution, and excessively long acquisition times. In the imaging of biological tissues, especially in vivo, excessive delivered dose can pose an additional concern. Based on the acceptance that a “one size fits all solution” probably does not exist, and that most real world applications typically do no...
Journal of Instrumentation
Journal of Instrumentation
We report on the application of the multi-aperture analyser X-ray Phase-Contrast imaging (XPCI) t... more We report on the application of the multi-aperture analyser X-ray Phase-Contrast imaging (XPCI) technique to the three-dimensional imaging of breast tissue samples. The experiment was conducted at the SYRMEP beamline (Elettra synchrotron, Italy) with a monochromatic X-ray beam. Along with the presentation of the methodology and resulting images, the potential extension of this approach to enable in-vivo applications at acceptable doses is discussed. K : Inspection with x-rays, X-ray mammography, X-ray radiography and digital radiography (DR) 1Corresponding author. 3 Results and Discussion 3 4 Conclusion 4
Physica Medica
Purpose Breast Computed Tomography (CT) is a dedicated 3D imaging modality that provides a comple... more Purpose Breast Computed Tomography (CT) is a dedicated 3D imaging modality that provides a complete volumetric reconstruction of the uncompressed organ, thus matching a high image quality with an acceptable delivered dose. The SYRMA-3D collaboration is developing the first clinical trial of phase-contrast breast CT with synchrotron radiation at the Elettra synchrotron facility in Trieste. We present a proposal for a Quality Control (QC) protocol, including a custom made QC phantom that was designed and built by the laboratories of the University of Ferrara. Methods The synchrotron beam is monochromatic in the energy range 8.5–40 keV. The images were acquired with a photon counting detector placed at about 2 m from the organ, so as to generate a phase contrast signal. The QC phantom consists of a water filled PMMA cylinder, hung from the patient support through the breast aperture. It contains several inserts that allow measurements of geometric alignment, reconstruction uniformity and linearity, low and high contrast resolution. Results CT images of the phantom were acquired at several beam energies within the range of interest, to explore the energy dependence of the results. Uniformity and linearity appeared to be preserved by the reconstruction for all energies. Conversely, low contrast details exhibited a more pronounced dependence on the energy choice. Finally, the visibility of high contrast details was always found above acceptance levels. Conclusions The main goal of the study was to verify the compatibility of the QC phantom with the experimental environment of the SYRMA-3D project, and to test the validity and feasibility of the proposed QC protocol. With minimal modifications, they proved viable instruments to perform the necessary quality assessments for the innovative diagnostic device developed by the SYRMA-3D collaboration.
Journal of Instrumentation
SYRMA-3D (SYnchrotron Radiation MAmmography 3D) aims to develop a breast CT system based on monoc... more SYRMA-3D (SYnchrotron Radiation MAmmography 3D) aims to develop a breast CT system based on monochromatic synchrotron radiation and a single photon counting detector (PIXIRAD-8) with CdTe sensor. Due to the demanding requests on high contrast resolution and low dose, images in breast CT are particularly sensitive to small imperfections of the flat field correction applied before the CT reconstruction. Detectors based on high Z crystal sensors show inhomogeneous pixels gain, which depends on the time from the switching-on of the high voltage polarization. This effect has been studied in our CdTe detector with the purpose of develop an effective flat field correction procedure. In the PIXIRAD-8 detector, the time-dependent inhomogeneities of the flat field signal appear to be local, small and systematically reproducible, with the exception of the pixels on the sensors edges.
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)