Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery. The Novac7 is a new linear accelerator expressly conceived for IORT that supplies electron beams at several energy, with high dose rate. These peculiar characteristics give rise to some complications with classical dosimetric techniques. In the framework of a research contract between ENEA and the Physics Department of Bologna, Italy, an original digital system has been developed to study and visualise the Novac7 electron beam in real time. The system is conceived as a grid consisting of two bundles of scintillating optical fibres (SOP) over-crossing each other, optically coupled with two arrays of photodiodes as read-out system. The problem of image reconstruction can be expressed as follows: there are only two profiles, or data arrays, which correspond respectively to the light emitted along the fibres perpendicular to the X-axis for the X-profile, and along the fibres perpendicular to the Y-axis for the Y-profile. This problem is not dissimilar to the reconstruction problem in tomography where several projections should be composed to trace them back to the original image. Unfortunately, here we have only two profiles: we have two one-dimensional profiles and are seeking one bidimensional image that could produce them. We selected a known beam image acquired by another digital instrument, then we extracted from it the two profiles simulating the acquisition arrays. Subsequently, we tested several reconstruction algorithms on these profiles, comparing the reconstructed image with the original one. We started from the simple sum algorithm until to iterative algorithms, searching the best compromise between the computational complexity and an high precision. We found that the iterative method is the best solution: it respects the geometrical characteristics and the absolute intensity values of the original image. Moreover it can reconstruct the image in a time of less than one second, a very good result.
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required. In this paper we present a CT study of an ancient large globe (diameter of about 2.2 m). We set-up an ad hoc system for the analysis of the globe in situ. The system consists of an X-ray tube, a detector made of a GOS scintillator and an EBCCD camera, the movement axes, a vertical moving axis for the tube, a horizontal-vertical axis for the detector, and a rotating platform for the globe. The investigation of the entire globe has required the acquisition of about 32000 planar images, for providing the 3D tomographic reconstruction. The analysis of the reconstructed volume has allowed to estimate the composition of the inner structure of the globe.
ABSTRACT Osteoporosis is the most common type of metabolic bone disease generating morphological ... more ABSTRACT Osteoporosis is the most common type of metabolic bone disease generating morphological alterations of the bone structure. Therefore, an intensive and accurate study of cancellous bone architecture is required to individuate the origin of the disease and to estimate its evolution. For this purpose, a specific project is in progress at the Physics Department of Bologna to carry out microtomography analysis in vitro of animal bone samples. The inspection system mainly consists of an X-ray microfocus source to irradiate the sample and of a CCD-based detector for the detection of the radiographic image. A sample with a diameter up to 30 mm and a height of 15 mm can be investigated over its whole volume. Three-dimensional images of the bone structure can be obtained with a spatial resolution variable from 30 up to few microns. A pig bone specimen has been investigated to test the equipment and to carry out intensive analysis and modeling of bone architecture. Moreover, a specific volume data processing procedure has been developed and tested to extract morphometric measurements of the bone structure.
The aim of this paper is to investigate the properties of a clinical FFDM unit (Giotto -Image MD,... more The aim of this paper is to investigate the properties of a clinical FFDM unit (Giotto -Image MD, IMS Italy). The digital detector consists of a flat panel using the amorphous selenium technology (ANRAD Corporation, Canada). The active area of the imager is 17.4 cm × 23.9 cm (2048×2816 pixels) with a pixel pitch of 85 µm. The direct conversion of X-rays into charge provides excellent imaging performance. In this work we present an objective and complete characterization of such system: detector response, MTF, NPS and DQE calculation will be presented. MTF and DQE at Nyquist frequency (5.88 lp/mm) are equal to 38% and 15%, respectively. The detector linearity is very good under the typical mammographic tested exposure conditions.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
At the Department of Physics of the University of Bologna a new intensified linear array detector... more At the Department of Physics of the University of Bologna a new intensified linear array detector is under development. The core of the system is a digital intensified CCD camera, the electron bombarded charge coupled device (EBCCD). The main innovation is a coherent rectangular-to-linear fiber optics adapter coupling the 1 in. diameter photocathode of the camera with a linear 129 mm · 1.45 mm strip of Gd 2 O 2 S:Tb. In this way a high spatial resolution over an extended length is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device to inspect a 13 cm · 18 cm area. A complete characterisation of the system has been made in terms of linearity, dynamic range, modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). At last, radiographic tests on a set of samples have been made and will be presented.
This work describes the setup of an experimental system for microtomography developed in the fram... more This work describes the setup of an experimental system for microtomography developed in the framework of a collaboration between the Physics Department of the University of Bologna (Italy) and the Geosphaera Research Center of Moscow (Russia). The main goal of this ...
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required.
this paper we modify the model to simulate price formation in a financial market. The spins are i... more this paper we modify the model to simulate price formation in a financial market. The spins are interpreted as market participants' attitude. An up-spin (S i = 1) represents a trader who is bullish and places buy orders, whereas a downspin (S i = -1) represents a trader who is bearish and places sell orders. In our model the first dynamic rule of the USDF model remains unchanged, i.e., if S i S i+1 =1 then S i-1 and S i+2 take the direction of the pair (i, i+1). This can be justified by the A Simple Model of Price Formation 5 fact that a lot of market participants are trend followers and place their orders on the basis of a local guru's opinion. However, the second dynamic rule of the USDF model has to be changed to incorporate the fact that the absence of a local guru (two neighboring spins are in di#erent directions) causes market participants to act randomly rather than make the opposite decision to his neighbor: if S i S i+1 = -1 then S i-1 and S i+2 take one of the two ...
IEEE Symposium Conference Record Nuclear Science 2004., 2004
Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery. The Novac7 is a new linear accelerator expressly conceived for IORT that supplies electron beams at several energy, with high dose rate. These peculiar characteristics give rise to some complications with classical dosimetric
IEEE Symposium Conference Record Nuclear Science 2004., 2004
Synchrotron based digital radiography and microtomography devices are powerful, non-destructive, ... more Synchrotron based digital radiography and microtomography devices are powerful, non-destructive, highresolution research tools. In this study, we present a linear system capable of a nominal spatial resolution of 22.5 micrometers over a Field-Of-View (FOV) of 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified Electron-Bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste (Italy). A monochromatic 34 keV has been used for imaging a human proximal femur, 9 cm in width, with our system. The excellent spatial resolution of the system allows the analysis of the trabecular structure of the bone over the entire FOV of about 10 cm.
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required.
In this paper, we investigate the performance of a Computer Aided Diagnosis (CAD) system for the ... more In this paper, we investigate the performance of a Computer Aided Diagnosis (CAD) system for the detection of clustered microcalcifications in mammograms. Our detection algorithm consists of the combination of two different methods. The first, based on difference-image techniques and gaussianity statistical tests, finds out the most obvious signals. The second, is able to discover more subtle microcalcifications by exploiting
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
Intraoperative radiation therapy is a special radiotherapy technique, which enables a high dose o... more Intraoperative radiation therapy is a special radiotherapy technique, which enables a high dose of radiation to be given in a single fraction during oncological surgery. The major stumbling block to the large-scale application of the technique is the transfer of the patient, with an open wound, from the operating room to the radiation therapy bunker, with the consequent organisational problems and the increased risk of infection. To overcome these limitations, in the last few years a new kind of linear accelerator, the Novac 7, conceived for direct use in the surgical room, has become available. Novac 7 can deliver electron beams of different energies (3, 5, 7 and 9 MeV), with a high dose rate (up to 20 Gy/min). The aim of this work, funded by ENEA in the framework of a research contract, is the development of an innovative system for on-line measurements of 2D dose distributions and electron beam characterisation, before radiotherapy treatment with Novac 7. The system is made up of the following components: (a) an electron-light converter; (b) a 14 bit cooled CCD camera; (c) a personal computer with an ad hoc written software for image acquisition and processing. The performances of the prototype have been characterised experimentally with different electron-light converters. Several tests have concerned the assessment of the detector response as a function of impulse number and electron beam energy. Finally, the experimental results concerning beam profiles have been compared with data acquired with other dosimetric techniques. The achieved results make it possible to say that the developed system is suitable for fast quality assurance measurements and verification of 2D dose distributions.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
State of the art in paleoanthropological and paleoprimatological research foresees the use of adv... more State of the art in paleoanthropological and paleoprimatological research foresees the use of advanced non-destructive investigative approaches. Microcomputed tomography (microCT) is a fundamental tool, since it offers the opportunity to get high quality morphological information with high spatial resolution. We carried out the set-up of an experimental microCT system able to examine paleobiological samples. The equipment can operate on small objects (size up to 3 cm) with a nominal spatial resolution of 30 lm, allowing their 3D volume reconstruction and morphometric analysis. This approach represents a forefront technique in paleobiological studies, successfully employed only in a limited number of advanced research centers. A specific program of microCT analysis has been planned on a sample of human and non-human fossil primate dentitions, in order to assess the specific nature of a number of tooth lesions (e.g. caries versus abrasion). This currently in progress experimental activity represents the first step for the set-up of a research center specifically devoted to the realization of advanced studies in the field of archaeo-paleobiology.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006
Intra Operative Radiation Therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra Operative Radiation Therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery, while reducing the exposure of normal surrounding tissue. The Novac7 is a new linear accelerator expressly conceived to perform in the operating theatre. This accelerator supplies electron beams with high dose rate (up
Synchrotron-based digital radiography and microtomography devices are powerful, nondestructive, h... more Synchrotron-based digital radiography and microtomography devices are powerful, nondestructive, high-resolution research tools. In this paper, we present a linear system with a pixel size of 22.5 m and a field-of-view (FOV) 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified electron-bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device with 18 cm travel range. The total FOV obtained this way is 13 cm long and 18 cm high. The aim of this paper is to demonstrate the feasibility of this system to investigate a large area of a bone and to calculate the appropriate histomorphometric parameters. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste, Italy. A monochromatic 34-keV beam has been used for imaging a human proximal femur, about 9 cm in width, with our system. The reconstructed images (13 cm 13 cm) were cross sections containing femoral head, femoral neck, and greater trochanter. The local variations in trabecular and cortical structure of the examined bone were clearly visible at a level not obtainable with medical CT scanners. The used spatial resolution allowed the visualization of thin trabeculae, which typically lie in a range of 100 m or lower. The quality of the reconstructed cross-section images confirmed that the system presented is a novel tool for high resolution three-dimensional (3-D) imaging of bone structure, with a pixel size over a volume of interest not achievable with conventional microCT scanners.
Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery. The Novac7 is a new linear accelerator expressly conceived for IORT that supplies electron beams at several energy, with high dose rate. These peculiar characteristics give rise to some complications with classical dosimetric techniques. In the framework of a research contract between ENEA and the Physics Department of Bologna, Italy, an original digital system has been developed to study and visualise the Novac7 electron beam in real time. The system is conceived as a grid consisting of two bundles of scintillating optical fibres (SOP) over-crossing each other, optically coupled with two arrays of photodiodes as read-out system. The problem of image reconstruction can be expressed as follows: there are only two profiles, or data arrays, which correspond respectively to the light emitted along the fibres perpendicular to the X-axis for the X-profile, and along the fibres perpendicular to the Y-axis for the Y-profile. This problem is not dissimilar to the reconstruction problem in tomography where several projections should be composed to trace them back to the original image. Unfortunately, here we have only two profiles: we have two one-dimensional profiles and are seeking one bidimensional image that could produce them. We selected a known beam image acquired by another digital instrument, then we extracted from it the two profiles simulating the acquisition arrays. Subsequently, we tested several reconstruction algorithms on these profiles, comparing the reconstructed image with the original one. We started from the simple sum algorithm until to iterative algorithms, searching the best compromise between the computational complexity and an high precision. We found that the iterative method is the best solution: it respects the geometrical characteristics and the absolute intensity values of the original image. Moreover it can reconstruct the image in a time of less than one second, a very good result.
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required. In this paper we present a CT study of an ancient large globe (diameter of about 2.2 m). We set-up an ad hoc system for the analysis of the globe in situ. The system consists of an X-ray tube, a detector made of a GOS scintillator and an EBCCD camera, the movement axes, a vertical moving axis for the tube, a horizontal-vertical axis for the detector, and a rotating platform for the globe. The investigation of the entire globe has required the acquisition of about 32000 planar images, for providing the 3D tomographic reconstruction. The analysis of the reconstructed volume has allowed to estimate the composition of the inner structure of the globe.
ABSTRACT Osteoporosis is the most common type of metabolic bone disease generating morphological ... more ABSTRACT Osteoporosis is the most common type of metabolic bone disease generating morphological alterations of the bone structure. Therefore, an intensive and accurate study of cancellous bone architecture is required to individuate the origin of the disease and to estimate its evolution. For this purpose, a specific project is in progress at the Physics Department of Bologna to carry out microtomography analysis in vitro of animal bone samples. The inspection system mainly consists of an X-ray microfocus source to irradiate the sample and of a CCD-based detector for the detection of the radiographic image. A sample with a diameter up to 30 mm and a height of 15 mm can be investigated over its whole volume. Three-dimensional images of the bone structure can be obtained with a spatial resolution variable from 30 up to few microns. A pig bone specimen has been investigated to test the equipment and to carry out intensive analysis and modeling of bone architecture. Moreover, a specific volume data processing procedure has been developed and tested to extract morphometric measurements of the bone structure.
The aim of this paper is to investigate the properties of a clinical FFDM unit (Giotto -Image MD,... more The aim of this paper is to investigate the properties of a clinical FFDM unit (Giotto -Image MD, IMS Italy). The digital detector consists of a flat panel using the amorphous selenium technology (ANRAD Corporation, Canada). The active area of the imager is 17.4 cm × 23.9 cm (2048×2816 pixels) with a pixel pitch of 85 µm. The direct conversion of X-rays into charge provides excellent imaging performance. In this work we present an objective and complete characterization of such system: detector response, MTF, NPS and DQE calculation will be presented. MTF and DQE at Nyquist frequency (5.88 lp/mm) are equal to 38% and 15%, respectively. The detector linearity is very good under the typical mammographic tested exposure conditions.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
At the Department of Physics of the University of Bologna a new intensified linear array detector... more At the Department of Physics of the University of Bologna a new intensified linear array detector is under development. The core of the system is a digital intensified CCD camera, the electron bombarded charge coupled device (EBCCD). The main innovation is a coherent rectangular-to-linear fiber optics adapter coupling the 1 in. diameter photocathode of the camera with a linear 129 mm · 1.45 mm strip of Gd 2 O 2 S:Tb. In this way a high spatial resolution over an extended length is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device to inspect a 13 cm · 18 cm area. A complete characterisation of the system has been made in terms of linearity, dynamic range, modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). At last, radiographic tests on a set of samples have been made and will be presented.
This work describes the setup of an experimental system for microtomography developed in the fram... more This work describes the setup of an experimental system for microtomography developed in the framework of a collaboration between the Physics Department of the University of Bologna (Italy) and the Geosphaera Research Center of Moscow (Russia). The main goal of this ...
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required.
this paper we modify the model to simulate price formation in a financial market. The spins are i... more this paper we modify the model to simulate price formation in a financial market. The spins are interpreted as market participants' attitude. An up-spin (S i = 1) represents a trader who is bullish and places buy orders, whereas a downspin (S i = -1) represents a trader who is bearish and places sell orders. In our model the first dynamic rule of the USDF model remains unchanged, i.e., if S i S i+1 =1 then S i-1 and S i+2 take the direction of the pair (i, i+1). This can be justified by the A Simple Model of Price Formation 5 fact that a lot of market participants are trend followers and place their orders on the basis of a local guru's opinion. However, the second dynamic rule of the USDF model has to be changed to incorporate the fact that the absence of a local guru (two neighboring spins are in di#erent directions) causes market participants to act randomly rather than make the opposite decision to his neighbor: if S i S i+1 = -1 then S i-1 and S i+2 take one of the two ...
IEEE Symposium Conference Record Nuclear Science 2004., 2004
Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra operative radiation therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery. The Novac7 is a new linear accelerator expressly conceived for IORT that supplies electron beams at several energy, with high dose rate. These peculiar characteristics give rise to some complications with classical dosimetric
IEEE Symposium Conference Record Nuclear Science 2004., 2004
Synchrotron based digital radiography and microtomography devices are powerful, non-destructive, ... more Synchrotron based digital radiography and microtomography devices are powerful, non-destructive, highresolution research tools. In this study, we present a linear system capable of a nominal spatial resolution of 22.5 micrometers over a Field-Of-View (FOV) of 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified Electron-Bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste (Italy). A monochromatic 34 keV has been used for imaging a human proximal femur, 9 cm in width, with our system. The excellent spatial resolution of the system allows the analysis of the trabecular structure of the bone over the entire FOV of about 10 cm.
Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of... more Computed Tomography (CT) is one of the principal non-invasive techniques for the investigation of the inner structure of works of art. The main advantage of using CT is that it provides high resolution 3D information of the analyzed object. CT of large objects can be hampered by the long time needed and by the difficulties regarding the experimental arrangements required.
In this paper, we investigate the performance of a Computer Aided Diagnosis (CAD) system for the ... more In this paper, we investigate the performance of a Computer Aided Diagnosis (CAD) system for the detection of clustered microcalcifications in mammograms. Our detection algorithm consists of the combination of two different methods. The first, based on difference-image techniques and gaussianity statistical tests, finds out the most obvious signals. The second, is able to discover more subtle microcalcifications by exploiting
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
Intraoperative radiation therapy is a special radiotherapy technique, which enables a high dose o... more Intraoperative radiation therapy is a special radiotherapy technique, which enables a high dose of radiation to be given in a single fraction during oncological surgery. The major stumbling block to the large-scale application of the technique is the transfer of the patient, with an open wound, from the operating room to the radiation therapy bunker, with the consequent organisational problems and the increased risk of infection. To overcome these limitations, in the last few years a new kind of linear accelerator, the Novac 7, conceived for direct use in the surgical room, has become available. Novac 7 can deliver electron beams of different energies (3, 5, 7 and 9 MeV), with a high dose rate (up to 20 Gy/min). The aim of this work, funded by ENEA in the framework of a research contract, is the development of an innovative system for on-line measurements of 2D dose distributions and electron beam characterisation, before radiotherapy treatment with Novac 7. The system is made up of the following components: (a) an electron-light converter; (b) a 14 bit cooled CCD camera; (c) a personal computer with an ad hoc written software for image acquisition and processing. The performances of the prototype have been characterised experimentally with different electron-light converters. Several tests have concerned the assessment of the detector response as a function of impulse number and electron beam energy. Finally, the experimental results concerning beam profiles have been compared with data acquired with other dosimetric techniques. The achieved results make it possible to say that the developed system is suitable for fast quality assurance measurements and verification of 2D dose distributions.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2004
State of the art in paleoanthropological and paleoprimatological research foresees the use of adv... more State of the art in paleoanthropological and paleoprimatological research foresees the use of advanced non-destructive investigative approaches. Microcomputed tomography (microCT) is a fundamental tool, since it offers the opportunity to get high quality morphological information with high spatial resolution. We carried out the set-up of an experimental microCT system able to examine paleobiological samples. The equipment can operate on small objects (size up to 3 cm) with a nominal spatial resolution of 30 lm, allowing their 3D volume reconstruction and morphometric analysis. This approach represents a forefront technique in paleobiological studies, successfully employed only in a limited number of advanced research centers. A specific program of microCT analysis has been planned on a sample of human and non-human fossil primate dentitions, in order to assess the specific nature of a number of tooth lesions (e.g. caries versus abrasion). This currently in progress experimental activity represents the first step for the set-up of a research center specifically devoted to the realization of advanced studies in the field of archaeo-paleobiology.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006
Intra Operative Radiation Therapy (IORT) is a technique based on delivery of a high dose of ionis... more Intra Operative Radiation Therapy (IORT) is a technique based on delivery of a high dose of ionising radiation to the cancer tissue, after tumour ablation, during surgery, while reducing the exposure of normal surrounding tissue. The Novac7 is a new linear accelerator expressly conceived to perform in the operating theatre. This accelerator supplies electron beams with high dose rate (up
Synchrotron-based digital radiography and microtomography devices are powerful, nondestructive, h... more Synchrotron-based digital radiography and microtomography devices are powerful, nondestructive, high-resolution research tools. In this paper, we present a linear system with a pixel size of 22.5 m and a field-of-view (FOV) 13 cm long and about 1 mm high. The system is composed of a linear converter GOS screen coupled to an intensified electron-bombarded CCD (EBCCD) camera, by means of a rectangular-to-linear fiber optic adapter. This optical guide is composed of seven bundles, each one transporting light in a coherent way to preserve spatial information. In this way, a high spatial resolution over an extended FOV is obtained. The detector works as an X-ray scanner by means of a high-precision translation mechanical device with 18 cm travel range. The total FOV obtained this way is 13 cm long and 18 cm high. The aim of this paper is to demonstrate the feasibility of this system to investigate a large area of a bone and to calculate the appropriate histomorphometric parameters. Here we present an investigation gained at ELETTRA synchrotron facility at Trieste, Italy. A monochromatic 34-keV beam has been used for imaging a human proximal femur, about 9 cm in width, with our system. The reconstructed images (13 cm 13 cm) were cross sections containing femoral head, femoral neck, and greater trochanter. The local variations in trabecular and cortical structure of the examined bone were clearly visible at a level not obtainable with medical CT scanners. The used spatial resolution allowed the visualization of thin trabeculae, which typically lie in a range of 100 m or lower. The quality of the reconstructed cross-section images confirmed that the system presented is a novel tool for high resolution three-dimensional (3-D) imaging of bone structure, with a pixel size over a volume of interest not achievable with conventional microCT scanners.
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Papers by Davide Romani