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X-ray Computed Tomography (X-ray CT) is a sophisticated non-destructive imaging technique to investigate structures and materials of complex objects, and its application can answer many conservation and restoration questions. However, for Cultural Heritage investigations, medical CT scanners are not optimized for many case-studies: These instruments are designed for the human body, are not flexible and are difficult to use in situ. To overcome these limitations and to safely investigate works of art on site&mdash, in a restoration laboratory or in a museum&mdash, the X-ray Tomography Laboratory of the University of Bologna designed several CT systems. Here we present two of these facilities and the results of important measurement campaigns performed in situ. The first instrument, light and flexible, is designed to investigate medium-size objects with a resolution of a few tens of microns and was used for the CT analysis of several Japanese theater masks belonging to the collection of the &ldquo, L. Pigorini&rdquo, Museum (Rome). The second is designed to analyze larger objects, up to 200 cm and was used to investigate the collection of the so-called &ldquo, Statue Vestite&rdquo, (devotional dressed statues) of the Diocesan Museum of Massa.

Since 2018, a scientific research project, the “Lilybaeum Project”, is being carried out by a collaboration of physicists and archaeologists. The goal is to apply forefront analysis techniques to the investigation of archaeological artefacts, both in situ and in the laboratory. The first case study presented in this paper concerns the original investigation through X-ray computed tomography of a collection of objects from the Regional Archaeological Museum of Lilybaeum, in Marsala, Italy. In addition to a very significant collection of clay jars mostly from children's graves of the ancient Lilybaeum necropolis, an unprecedented analysis of wooden planks belonging to the only existing wreck of a Punic Ship kept in the Museum is presented.

We present the results of the broad scientific investigation campaign of an important Celestial globe by Vincenzo Coronelli, part of the Marciana National Library collection (Venice). Coronelli was one of the finest globe-makers and cartographers of the 17th century and he manufactured a large number of Terrestrial and Celestial globes of different sizes, such as the two impressive and entirely manuscript 4-meter globes commissioned for Louis XIV. Using multiple techniques, we studied the materials and the construction techniques of the first printed reproduction of the French Celestial globe, donated to the Serenissima Republic in 1689 and still in Venice. We present and discuss the results of the multispectral imaging analysis, of the chemical investigations X-ray Fluorescence (XRF), Scanning electron microscopy - Energy Dispersive X-ray Spectrometry (SEM-EDS) and Fourier Transform Infrared spectroscopy (FT-IR) and of the stratigraphic analysis by polarised-light microscopy. Moreover, we explain in detail the results of the X-ray tomographic analysis performed in situ. Thanks to this comprehensive campaign, we examined the production process of this unique globe, from the pigment to the woodworking approach of the Master globe-maker Coronelli.

Dynamic AngioThermography (DATG) is a contact-plate technique capable of producing a digital representation of breast vascularity. The inception and growth of a tumor are associated with neoangenesis, which may result in a demonstrable alteration in the regional blood flow, while in normal health conditions the vascularity remains unchanged throughout life. DATG, if included in the clinical evaluation for breast cancer, could potentially improve the accuracy of the diagnosis of this disease. Conventional DATG is limited, however, in that it is a projection (i.e. two-dimensional) imaging technique that does not provide any information on the depth and its effect on the pattern of the perfusion revealed by this technique. In fact, the blood pattern is detected by projecting temperature signals on the plate, thus acquiring a digital two-dimensional image. In this article we propose a new approach for extracting information on depth through the inversion of the Fourier heat equation. The idea is to extract the information along the third axis while acquiring and analyzing the temporal sequence during the process of image formation. The method implemented has been tested on a dedicated "electric phantom" and in one in vivo experiment. In spite of the limits of these preliminary tests, the experimental results have shown that this method makes it possible to obtain a 3D representation of the vascularity. Although it appears to be promising, further validation and characterization of our technique are required.

A seashell dump from the site of San Vincenzo (Stromboli, Aeolian islands, Italy) was studied using an interdisciplinary approach to identify the type of molluscs and the formation process of the deposit, with the aim of reconstructing the most important cultural and social aspects of the meal. A large village occupied Stromboli during the Early and Middle Bronze Age. The village, at least during its later phases, had a modular topographical structure made up of rectangular enclosures with imposing stone elements at the corners. A large pit filled almost exclusively with marine shells was found near one of these stones and by an enclosure wall at the southernmost edge of the village. A sample of the deposit where the shells are embedded in their originally sandy matrix was extracted, investigated by means of CT scanning and reconstructed in 3D, confirming deposition after a single discard event. Radiometric, stratigraphic, typological and archaeometric data indicate that the meal was consumed contemporaneously with the beginning of interactions with the Mycenaeans, and discharged in a specific location possibly marking a major topographical transformation. The quantity of molluscs consumed was reconstructed experimentally by comparing the ancient record with the corresponding quantity of meat provided by contemporary animals collected as a specimen from the rocky shores of the island. Shell deposits of the Mediterranean Bronze Age have been rarely studied in such detail and this case study may reveal forms of ancient communal consumption of such food at the beginning of the Middle Bronze Age, and therefore important feasting contexts in which ancient communities materially interacted and exchanged information.

In consequence of the increasing request of on-site analysis the availability of portable systems for imaging paintings and other works of art has become really an issue for cultural heritage investigation. In many cases, authorities do not allow to transport paintings and works of art outside museums because of their value. We thus developed and used successfully a transportable X-ray Computed Tomography (CT) system that the operators can transport in a regular van and then mount inside museums or conservation centers. The system is composed of spare components that have to be properly mounted and carefully aligned in order to perform the radiographic or tomographic analysis. The basic elements are a 200 kV X-ray tube and a 12×12 cm2 flat-panel detector. With this system, it is possible to scan painting and works of art up to 1.5 × 1.5 m2 of size thanks to three mechanical translation axes. In the tomographic mode, a rotating platform provides high-resolution rotation of the object carrying up to 50 kg in weight. The operators control all the components of the system with a remote connection computer at a safe distance. In the present work, we report details about the development of this transportable X-ray CT system, we describe how it operates and the technical solutions we used and we show examples of application to real case studies with their specificity.

PURPOSE: The temporal bone includes several important structures of the human body, some of which are smaller than 1 mm. The aim of this study is to demonstrate the feasibility of a computed tomography system capable of providing 3-dimensional images of the inner ear with low doses and a spatial resolution adequate for providing the surgeon with good guidance. METHODS: A laboratory prototype, based on a CMOS Hamamatsu model C10900D detector, was set up, and several tomographic tests were carried out on 2 dedicated phantoms. RESULTS: The proposed system is able to achieve a 150-μm spatial resolution (5% of modulation transfer function) with a voxel size of 88 μm, with an acceptable contrast and an estimated effective dose ranging from 1/20 up to 1/100 of the mean effective dose reported in literature for head computed tomography. CONCLUSION: The new tomographic system has shown excellent characteristics and proves suitable for the imaging of the inner ear. In particular, this prototype requires very low radiation doses.

In this paper, we describe the work done in order to run the CT 3-D reconstruction algorithm on the 120 GB raw data from the more than 25\thinspace000 radiographs acquired from the Kongo Rikishi (XIII century) Japanese wooden statue. The work was done using the Microsoft (Redmond) HPC cluster and then on a local cluster at the INFN of Bologna. A speed-up factor of 75 was reached.

The technique of High Dose Rate Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately after the removal of a cancerous mass, where the same incision is used to focalize the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a target volume whose extension and depth will be determined directly during the operation. Because of this peculiar characteristics, until now there is not a dosimetric system able to detect the electron beam giving at once a realtime response and an extensive spatial measure of the absorbed dose. Within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics), we proposed a new system to overcome the problems, Dosiort. The final set-up is a solid phantom having a density approximately 1 g/cm 3 with sensitive layers of scintillating fibres at fixed positions in a calorimetric configuration for the containment of electrons of energy 4-12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (energy, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: percentage Depth Dose; beam profiles; isodose curves; values of dose per MU. In this work we present the results obtained by using two orthogonal layers of the calorimetric phantom Dosiort, in particular we report the measurement of the dynamic range of the read-out system and the first qualitative study of the results which can be extracted from the measurements taken in a test beam.

The technique of High Dose Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately following the removal of a cancerous mass, where the same incision is used to direct the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a target volume whose extension and depths will be determined directly during the operation. Since the possibility of devising a treatment plan using a TPS (Treatment Planning System) is not available, it is necessary to know the physical and geometric characteristics of the beam. Defining the physical characteristics of the beam entails both measuring the delivered dose and defining (monitoring) procedures. In any case a much higher dose will be released than occurs with conventional external accelerators. The ionization chamber recommended by the standard protocols for radiotherapy cannot be used because of the ion recombination inside the gas. In this work we propose the use of a calorimetric phantom, the Dosiort, to measure the beam properties. We describe the main characteristics and some preliminary results of the Dosiort System, which is proposed within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics). The set-up is a solid phantom of density approaching 1 g/cm3 with sensitive layers of scintillating fibres at fixed a position in a calorimetric configuration for the containment of electrons of energy 4-12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (energy, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: Percentage Depth Dose; Beam profiles; Isodose curves; Values of dose for MU.

Objectives The aim of this study is to investigate the effect of head motion on the reconstruction image quality in relation to patient positioning in dental cone-beam computed tomography (CBCT) systems. This study should be intended as the first step to evaluate the effect of the head movements also in more stringent conditions.

An X-ray computed tomography (CT) model based on the GEANT4 Monte Carlo code was developed for simulation of a cone-beam CT system for industrial applications. The full simulation of the X-ray tube, object, and area detector was considered. The model was validated through comparison with experimental measurements of different test objects. There is good agreement between the simulated and measured projections. To validate the model we reduced the beam aperture of the X-ray tube, using a source–collimator, to decrease the scattered radiation from the CT system structure and from the walls of the X-ray shielding room. The degradation of the image contrast using larger beam apertures is also shown. Thereafter, the CT model was used to calculate the spatial distribution and the magnitude of the scattered radiation from different objects. It has been assessed that the scatter-to-primary ratio (SPR) is below 5% for small aluminum objects (approx. 5 cm path length), and in the case of large aluminum objects (approx. 20 cm path length) it can reach up to a factor of 3 in the region corresponding to the maximum path length. Therefore, the scatter from the object significantly affects quantitative accuracy. The model was also used to evaluate the degradation of the image contrast due to the detector box. r 2007 Elsevier B.V. All rights reserved.

An accurate knowledge of the X-ray source spectrum is required in order to optimize X-ray Computed Tomography systems. A simulation model based on the Monte Carlo code GEANT4 was developed to determine the X-ray spectrum generated by a 450 kV tube. The X-ray spectra were measured using a Cadmium Telluride stack detector. The measured spectra were corrected for spurious detector effects and detector efficiency. The X-ray spectra simulated by GEANT4 were validated by comparison with X-ray spectra measured at 350, 400 and 450 kV. We observed a good agreement between the simulated and the measured X-ray spectra. In addition, we simulated and measured attenuation curves using aluminium and copper filtration. The comparison of the attenuation curves shows an excellent agreement.

Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70–100 kVp and 1–4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4′′ and 6′′) and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10–15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1–1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market.

The result of Computed Tomography (CT) investigation consists in a 3D volume of the object able to show its inner parts, revealing hidden structures and materials used in a completely non-invasive way. Its application, in Cultural Heritage field, is an important resource to enhance the knowledge of execution the construction technique and the state of conservation. This work was triggered by a need of diagnostic investigation before the restoration of anatomical wax model of the 18th century made by Anna Morandi Manzolini, kept at the Palazzo Poggi Museum in Bologna, but the peculiarity of the application and its results has yielded new purposes to the diagnostic investigation related to scientific communication and museum fruition. CT analysis was carried out using an experimental CT system specifically designed for the analysis of Cultural Heritage materials, developed by the X-ray imaging research group at the Physics and Astronomy Department of the University of Bologna. The results of the investigation were shown then at the Anatomical Wax Museum "Luigi Cattaneo" in Bologna, during the "Festival of Medical Science. Long Life", from 7 to 10 May 2015, through a 3D virtual projection.

Rapid prototyping, automatic image processing (computer-aided design (CAD)) and computer-aided manufacturing techniques are opening new and interesting prospects for medical devices and tissue engineering, especially for hard tissues such as bone. The development of a bone high-resolution scaffold prototype using these techniques is described. The results testify to the fidelity existing between microtomographic reconstruction and CAD. Furthermore, stereolithographic manufacturing of this scaffold, which possesses a high degree of similarity to the starting model as monitored by morphological evaluations (mean diameter 569 +/- 147 microm), represents a promising result for regenerative medicine applications.

Digital imaging has proven to be a valid technique to determine the spatial distribution of radioisotopes in nuclear applications. In the present work, an intensified EBCCD camera with 80 mm photocathode and a fiber optics plate covered by a thin Gadolinium oxysulfide layer was used as a detector to obtain a digital map of the activity distribution for a variety of beta sources. The distribution map was elaborated and displayed in a 1024 × 1024 pixel format by using digital imaging techniques. The decay constant of various radioisotopes was calculated in different regions of interest of the image, with a deviation of 5–9% (depending on the signal intensity) from theoretical values, even in single pixel areas. The EBCCD camera has shown strong detection capabilities even for single beta particle interaction and the response of the system has found to be very fast, allowing us to achieve a real time distribution map of radioisotopes. In fact, it is possible to load in RAM and display on a monitor a single distribution image map in about 1 s. Better distribution uniformity was obtained by integrating a sequence of 16, 32 or 64 images. By analysing a single beta interaction (i.e. a point spread function (PSF) on the image) the modulation transfer function (MTF) of the system has been calculated leading to a global resolution of about 80 m at 10% MTF.

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 Gd2O2S: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.

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 μm, 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.

Diagnostics based on X-ray computed tomography (CT) are becoming increasingly important, not only in the medical field but in industry and cultural heritage. CT devices typical for medical applications, however, can seldom be used on art objects because both they are not easily transportable and they often present high X-ray absorption. It is therefore necessary to make use of portable instrumentation and/or to develop tomographic systems optimized to the characteristics of the objects under examination. This work describes the computed tomography of a first century A.D. Roman bronze statue of Cupid (96.AB.53) in the collection of the J. Paul Getty Museum, within the collaborative framework between the Getty Conservation Institute and the Department of Physics and Astronomy (DIFA) of the University of Bologna (Italy). The tomography performed at the Getty facilities employed a 450 kV X-ray tube and a detection system developed at DIFA. The study highlighted the casting and construction techniques used by Roman foundry workers and provided information on the status of conservation of the statue. A 3D virtual reconstruction allowed the user to define different cross-sections enabling the study of the internal features.

The famous castrato singer Carlo Broschi, better known as Farinelli (1705-1782), was exhumed by our research group in July 2006 to study his skeletal remains and reconstruct his osteobiography. He was castrated before puberty to preserve his high voice into adulthood. The osteological study has revealed several skeletal features probably related to the effects of castration (Hyperostosis frontalis interna, long limb bones, persistence of epiphyseal lines, osteoporosis) (Belcastro et al., 2011). Here we present the study of the teeth and maxilla-mandibular region using classic and tomographic morphological methods. Considering the subject's age and the period during which he lived, his oral health conditions were good. On the basis of the very pronounced anomalous vestibular buccal wear, a overbite visualized by 3D reconstruction, was hypothesized. This facial disharmony is of particular interest when considering Farinelli's extraordinary singing qualities and stage presence. (C) 2014 Elsevier Inc. All rights reserved.

The diagnostic investigations are an important resource in the studies on Cultural Heritage to enhance the knowledge on execution techniques, materials and conservation status of a work of art. In this field, due to the great historical and artistic value of the objects, preservation is the main concern; for this reason, new technological equipment has been designed and developed in the Physics Departments of the Universities of Ferrara and Bologna to enhance the non-invasive approach to the study of pictorial artworks and other objects of cultural interest. Infrared (IR) reflectography, X-ray radiography and computed tomography (CT), applied to works of art, are joined by the same goal: to get hidden information on execution techniques and inner structure pursuing the non-invasiveness of the methods, although using different setup and physical principles. In this work transportable imaging systems to investigate large objects in museums and galleries are presented. In particular, 2D scanning devices for IR reflectography and X-ray radiography, CT systems and some applications to the Cultural Heritage are described.

Cadmium zinc telluride (Cd0.8Zn0.2Te) is nowadays one of the most promising room temperature semiconductors for X- and γ-ray detection. Indeed, its physical characteristics make this detector very suitable for operating under high-intensity fluxes, such as those produced by linear accelerators. For this reason, CdZnTe has been chosen for the set-up of a tomographic facility based on a 12-MeV linear accelerator. This system is a first generation tomograph; it has already been used for preliminary phantoms image acquisition, showing rather good imaging capabilities. The polychromaticity of the source may induce severe beam-hardening artifacts in the final tomographic images. Extensive experimental studies have been carried out to optimize correction algorithms able to reduce such artifacts. A set of images of relevant samples have been acquired in order to evaluate the relationship between the absorption coefficients and the resulting CT numbers.

Among non-destructive evaluations and methodologies—the important set of analyses which preserve the integrity of the tested object—neutron imaging techniques, and neutron computerized tomography in particular, represent powerful tools. Although they have been considered more an amusement for scientists rather than an effective tool for engineers until few years ago, it can be stated that they can now provide valuable quantitative results in many circumstances of interest, being the only available choice in some specific cases. This wider interest and the attempt to give neutron imaging a certain prominence reflect themselves in the birth of an international group of people involved in the field of neutron research; the so-called ENRWG (European Neutron Radiography Working Group). Connected to a general interest and a diffuse curiosity in the fascinating interactive world of INTERNET there is also the possibility, since last year, to get information about neutron radiography state of the art and current projects from a free-access WWW site. As a consequence of these fervent activities, a new deal in studies of advanced materials, sources, detectors and algorithms is now growing to promote and to develop the capabilities of neutron imaging techniques after a long period during which the interest in neutron physics and in their applications was limited to selected specialists involved in the nuclear-energy production. The results of this effort will not be limited to improved technological processes, but will include an improved knowledge in relevant fields of nuclear and material science.

This work presents a particular application in which cadmium-zinc telluride (CdZnTe) detectors are used in photoconductive mode in a high-energy computerized tomography system for industrial applications. A first-generation tomography facility has been set up at the University of Bologna, based on a 12-MeV pulsed linear accelerator X-ray source and a single 10/spl times/10/spl times/2 mm/sup 3/ CdZnTe detector. The obtained results show that CdZnTe detectors exhibit better timing performances than CdTe detectors, and are thus more suitable for tomographic applications. Special-purpose signal conditioning electronics have been developed in order to compensate slow and fast signal fluctuations induced by temperature variations and Linac instabilities, In such a way, the dynamic range of the detector has been improved up to more than 3 orders of magnitude. A set of images was acquired in order to evaluate the overall performances of the tomographic facility. >

In recent years, a variety of special-purpose software has been developed to simulate gamma-ray semiconductor detector and associated electronics performances. Unfortunately, these software systems often lack flexibility and cannot be applied outside rather limited ranges. General radiation transport Monte Carlo codes such as ITS and EGS4 can achieve high levels of physical accuracy, but the simulated pulse;height spectra are completely noise free, and therefore differ significantly from experimental results. In this work, the ITS output files have been modified, so as to add to Monte Carlo simulated spectra the subsequent degradation effects inherent in the detection process. Ballistic deficit losses, electronic noise, charge trapping and detrapping are taken into account: the corresponding simulation algorithms are independently combined into the final spectra. As the charge collection efficiency depends upon the position of gamma-ray interactions within the bulk, the detector has been virtually sliced into a large number of sections so as to statistically evaluate the spectrum distortion on a local spectra basis. Although the algorithms developed were applied to gamma-ray spectra obtained from CdTe detectors only, the generality of the method makes it suitable for any semiconductor detector.

During the course of 2009, in the framework of a project supported by the National Institute of Nuclear Physics, a number of tests were carried out at the Department of Physics of the University of Bologna in order to achieve a good quality CT scan of the internal human ear. The work was carried out in collaboration with the local “S. Orsola” Hospital in Bologna and a company (CEFLA) already involved in the production and commercialization of a CT scanner dedicated to dentistry. A laboratory scanner with a simple concept detector (CCD camera-lens-mirror-scintillator) was used to see to what extent it was possible to enhance the quality of a conventional CT scanner when examining the internal human ear. To test the system, some conventional measurements were made, such as the spatial resolution calculation with the MTF and dynamic range evaluation. Different scintillators were compared to select the most suitable for the purpose. With 0.5 mm thick structured cesium iodide and a field of view of 120×120 mm 2 , a spatial resolution of 6.5l p/mm at 5% MTF was obtained. The CT of a pair of human head phantoms was performed at an energy of 120 kVp. The first phantom was a rough representation of the human head shape, with soft tissue made of coarse slabs of Lucite. Some inserts, like small aluminum cylinders and cubes, with 1 mm diameter drilled holes, were used to simulate the channels that one finds inside the human inner ear. The second phantom is a plastic PVC fused head with a real human cranium inside. The bones in the cranium are well conserved and the inner ear features, such as the cochlea and semicircular channels, are clearly detectable. After a number of CT tests we obtained good results as far as structural representation and channel detection are concerned. Some images of the 3D rendering of the CT volume are shown below. The doctors of the local hospital who followed our experimentation expressed their satisfaction. The CT was compared to a virtual endoscopy and judged particularly useful for clinical pre-surgery diagnostics. The experimentation proceeds with a faster scanner now under development in our laboratories. We believe this work could be of a certain interest for the medical imaging world.

The successful use of Computed Tomography (CT) as an efficient and powerful non-destructive tool for the study of archaeological artefacts has been reported by several authors (Rossi et al. 1999a, b; Rossi and Casali 2001; Applbaum and Applbaum 2005). The 3D reconstruction of the objects enables the archaeologists to carry out archaeological analyses; information about manufacturing and assembly techniques, as well as information useful for dating artefacts or determining the appropriate maintenance and restoration procedures can be obtained with this technique (Casali 2006). Most of the studies of archaeological artefacts reported in the literature are carried out using medical CT (Mazansky 1993; Anderson 1995; Allen 2007), whereas investigations performed with industrial CT systems are rather limited. The present study illustrates the results obtained with a high resolution CT system for industrial applications developed in our laboratories. The advantage of our system as compared to medical CT is the higher penetration capability that allows the investigation of high density objects. The system provides isotropic spatial resolution and fast data acquisition due to the cone-beam geometry employed. In this study, we have focused on demonstrating the potential of this procedure for extracting and analysing an item from a cluster. To this aim, we have investigated a ceramic vase with a diameter of 20 cm, filled with ancient coins.

Computed Tomography is a non-destructive technique for which the object volume is reconstructed from a large series of radiographs acquired at different angles. Information can be retrieved as 2D cross section images allowing the inspection and the classification of the object; moreover, by processing tomographic data, a 3D numerical model of the full-volume sample can be obtained for virtual reality applications or digital archives storage. Computed Tomography is well known, specially in the medical field. However, it is a complex technique as soon as one wants to use it in a different way than in medicine (that means different scale, different energy range, different material composition and so on). The Kongo Rikishi is a Japanese wooden statue (over 200 cm of height) of the XIII century. The restoration has been carried out by the Conservation and Restoration Center La Venaria Reale, Turin, Italy. An high resolution Computed Tomography has been realized by the X-Ray Imaging Group of the Physics Department of Bologna University, Italy. To investigate the whole statue volume, up to 36 shootings are needed and for each of them 720 radiographs are acquired. To obtain the final volume (120 GB) 20 days of calculation are needed with a standard PC. In this work we will show the Proof of Concept that we have done using the Microsoft HPC cluster in Redmond. The Microsoft HPC environment has proved to be dramatically powerful and easy to use letting us reach important results quickly. Simply running many copies of the same software on different chunks of data using 20 cores has lead to an impressive speedup: up to a speed factor of 28. The same code, running on a new generation cluster of 32 cores, completed the elaborations with a speed rate factor of 75. These extraordinary results permit to reconstruct the volume in 6 hours instead of 20 days, making possible the real-time investigation of cultural objects.

Physical methods of diagnosis are more and more frequently applied in the field of Cultural Heritage either for scientific investigations or for restoration and conservation purposes. X-ray Computed Tomography (CT) is one of the most powerful non-destructive testing techniques for the full-volume inspection of an object, as it is able to give morphological and physical information on the inner structure of the investigated sample. The great variety of size and composition that characterizes archaeological findings and art objects requires the development of tomographic systems specifically designed for Cultural Heritage analysis. In the last few years our research group has developed several acquisition systems for Digital Radiography and X-ray CT. We are able to perform high resolution micro-tomography of small objects (voxel size of few microns) as well as CT of large objects (up to 2 m of size). In this paper we will mainly focus the attention on the results of the investigation recently performed on two Japanese wooden statues with our CT system for large works of art. The CT analysis was carried out on site at the Conservation and Restoration Center “La Venaria Reale”, where the statues have been restored before their exposition at the Oriental Art Museum in Turin.

In recent years there has been a growing demand from museums for computed tomography (CT) diagnostic measurements to be performed on famous artworks (sculptures and paintings) inside the museum itself in order to assess whether are they in good condition or need a restoration procedure. The problem of radioprotection becomes critical when the energy used in CT is high, as typically occurs in the case of CT measurements on sculptures, where linacs are used to produce the high-energy X-rays necessary to penetrate marble or metal. In this study we used Monte Carlo simulations in order to evaluate dose distribution inside a museum where a high-energy CT system is used for diagnostic measurements on a sculpture.

The technique of High Dose Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately following the removal of a cancerous mass, where the same incision is used to direct the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a volume target whose extension and depths will be determined directly during the operation. Since the possibility of devising a treatment plan using a TPS (Treatment Planning System) is not available, it is necessary to know the physical and geometric characteristics of the beam. Defining the physical characteristics of the beam entails both measuring the delivered dose and defining (monitoring) procedures. In any case a much higher dose will be released than occurs with conventional external accelerators. The ionization chamber recommended by the standard protocols for radiotherapy cannot be used because of the ion recombination inside the gas. In this work we propose the use of a calorimetric phantom, the Dosiort, to measure the beam properties. We describe the main characteristics and some preliminary results of the Dosiort System, which is proposed within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics). The set-up is a solid phantom of density approaching 1 g/cc with sensitive layers of scintillating fibres at fixed a position in a calorimetric configuration for the containment of electrons of energy 4-12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (quality, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: Percentage Depth Dose; Beam profiles; Isodose curves; Values of dose for MU.

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. Novac7 and Liac are new linear accelerators expressly conceived to perform in the operating room. These accelerators supply electron beams with high dose rate. Because of this peculiar characteristic, classical dosimetric techniques are not able to give at once a real-time response and an extensive measure of the absorbed dose. In past years the authors realized a prototype for IORT dosimetry able to give the real time bi-dimensional image of dose distribution on a single layer. In the framework of a research project funded by the INFN (Italian National Institute of Nuclear Physics), a collaboration between the Physics Department of Bologna, Italy, the Physics Department of Cosenza and the Medicine Department of Catanzaro, Italy, has studied a new system composed of six layers. Each layer includes two orthogonal bundles of scintillating optical fibres. The fibres are optically coupled with four arrays of photodiodes as read-out system. This new system will be able to characterize completely the electron beam in energy, intensity and spatial distribution. In real time it will be able to measure the 3D dose distribution, providing a full check of quality assurance for IORT. The various phases of design, development and characterization of the instrument will be illustrated, as well as some experimental tests performed with the prototype. We verified that the system is able to give a real time response, which is linear versus dose and not affected by the high dose rate. The conclusions confirm the capability of the instrument to overcome problems encountered with classic dosimetry, showing that the obtained results strongly encourage the continuation of this research.

CCD cameras are widely used for different applications. Recently they are employed for imaging in industrial X-ray digital radiography or computed tomography inspections. Scientific grade CCD sensors are usually characterized for what concern defects (bad pixels), resolution capability, spectral sensitivity, dark current, pixel full well capacity and so on. In former times CCDs were mostly used in astronomy and dark current was one of the most important parameters to evaluate in this kind of applications because of the long exposure time needed to obtain a good image. Thus, most manufacturers still refer to noise of a CCD as the background (or dark current) noise. This might be in some cases misleading. When one wants to compute the effective dynamic range on the full scale of greylevels, in order to match with the correct number of bit required to quantize the information, and, most of all, to evaluate if the dynamics is adequate, a different analysis of noise is required. It is possible to find an experimental method to measure noise and to derive the effective intrinsic dynamic range of a CCD. A case study, carried out on a commercial CCD camera used in a prototype industrial CT system, is reported in this work and the experimental results are discussed.

Computed tomography (CT) is a very useful non-destructive testing technique in the industrial field, since it permits the detection of small inner defects in a reliable and accurate way. In order to get very good performance, in terms of image contrast and spatial resolution, the configuration of the tomography system has to be optimized carefully. Monte Carlo simulations can be very helpful for choosing different conditions and selecting the best configurations of a CT system. In this paper, we present a preliminary optimization of an industrial CT apparatus, obtained by means of Monte Carlo simulations. The system is composed of an X-ray tube, filtering and collimation devices, and a detector made of a scintillator coupled to a CCD camera. We focus our attention on large aluminum objects, such as motor heads, and investigate the contribution of the scattered radiation. Some options have been simulated, for reducing the scattering photons, thus improving the overall image quality.

Methods of diagnosis based on digital radiography (DR) and computed tomography (CT), are more and more frequently used in the cultural heritage field. The application of these techniques can help restoration and conservation planners to understand historical construction techniques and to reveal poor restoration work and forgeries. As the size of objects of cultural interest varies greatly, from small fragments (for which high spatial resolution is needed) to large works of art (for which large detectors are necessary), it would not be appropriate to describe any one particular measuring device in detail. In this chapter, we will therefore provide an overview on Digital Radiography (DR) and Computed Tomography (CT) systems, underlining their range of applications. The chapter focuses mainly on X-ray radiation (with different kinds of sources) although neutron DR and CT are also mentioned, as neutron imaging should be considered complementary to X-ray imaging. Some DR and CT images, most of which were taken by researchers at the Department of Physics of the University of Bologna, are shown. This overview adopts a tutorial approach, as it is aimed at those with no specific knowledge of digital imaging. Three appendices have also been included (concerning Fourier transforms, modulation transfer function and DR and CT acquisition systems) for those readers who wish to acquire further skills in the field of digital imaging.

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 major stumbling block to the large-scale application of this radiotherapy 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, Novac7, a new linear accelerator expressly conceived to perform in the operating room, has been developed. It can deliver electron beams of different energies with a high dose rate (up to 20 Gy/min). 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 the University of Bologna, Italy, two original systems have been developed to study and visualise the Novac7 electron beam in real time. The first system is composed by an electron-light converter, a cooled CCD camera and a computer with dedicated software. The second dosimeter is based on a grid of scintillating optical fibres coupled with photodiodes. The achieved results prove that the first system is able to obtain two dimensional measurements of dose distributions in real time and it is a good system for quality controls. The second system has the same capabilities of the first one, but moreover it has the possibility to monitor the delivered beam impulse by impulse. The conclusions confirm the capability of both instruments to overcome problems encountered with classic dosimetry, showing that the results obtained strongly encourage the continuation of this research.

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 mum 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 cmtimes13 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 mum 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

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.

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 room. This accelerator supplies electron beams with high dose rate. Because these peculiar characteristics, classical dosimetric techniques are not able to give at once a real-time response and an extensive measure of the absorbed dose. The new system is composed by a grid of scintillating optical fibres coupled with two arrays of photodiodes. The instrument samples the delivered beam at 100 Hz. The dedicated software collects the two projection-signals and reconstructs the bi-dimensional image. Moreover it provides a series of dosimetric parameters. We studied an appropriate reconstruction algorithm searching the best compromise between the computational complexity and an high precision. An accelerator having energies ranging from 3 to 12 MeV has been used for the tests. The system is able to give a real time response (within 30 seconds), the resolution is of 1 millimeter. The response is linear versus dose and the measures are not affected by the high dose rate. The conclusions confirm the capability of the instrument to overcome problems encountered with classic dosimetry, showing that the results obtained strongly encourage the continuation of this research

Computed Tomography (CT) is becoming a very useful non-destructive testing technique, in the industrial field, since it permits the detection of small inner defects in a reliable and accurate way. In order to get very good performance, in terms of image contrast and spatial resolution, the configuration of the tomography system has to be optimized carefully. Monte Carlo simulations can be a very helpful method, for choosing different conditions and selecting the best configuration of a CT system. In this paper we present a preliminary optimization of an industrial CT apparatus, obtained by means of Monte Carlo simulations. The system is composed of an X-ray tube, filtering and collimation devices, and a detector made of a scintillator coupled to a CCD camera. We focus our attention on large aluminum objects and investigate the contribution of the scattered radiation. Some options have been simulated, for reducing the scattering photons, thus improving the overall image quality.

The size distribution of the diamonds in a kimberlitic rock is a negative exponential function—i.e., the frequency of large diamonds diminishes exponentially with increasing size. The number of microdiamonds in narrow fine sizes allows predicting the probability of discovering coarser valuable diamonds. For deposit evaluation, the microdiamonds are recovered in the solid residue of the leaching of some hundreds kilograms of rock samples. Computed tomography (CT) systems—based on nano- and micro-focus X-ray sources and high-resolution detectors—capable of scanning drill-hole cores have been indicated as a possible practicable alternative to leaching for microdiamond studies. A simple model is developed that allows valuating the size of the microdiamond detectable with a given X-ray tube spot size and detector Modulation Transfer Function (MTF). Basically, the model describes the diamond as a nodule of known attenuation, projects it on the detector plane with a given magnification, resamples the magnified nodule according to the detector pixel array, calculates the frequency content of the nodule on the detector plane by FFT, composes the frequency content with the overall MTF of the system and by FFT −1 recalculates the object. By comparing the reconstructed object with the original one, the lost in attenuation and the blurring due to the radiography system can be evaluated. Preliminary experimental tests with synchrotron radiation were carried out to characterize the X-ray attenuation properties of the kimberlite and evaluate the resolution in relation to the mineral texture. Both commercial X-ray micro-CT systems and a number of different systems assembled in our laboratories combining different components were tested and compared with a phantom core.

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.

This paper illustrates the effectiveness of a new multi-slice CT system to study the trabecular bone tissue. The system is capable of acquiring 3D images of 5600/spl times/5600/spl times/52 voxels on specimens up to 130 mm with a spatial resolution of 22.5 micrometers. This new detector is coupled to a CCD intensified camera (EBCCD) and was patented by the University of Bologna. The CT acquisitions were performed with an experimental setup at Elettra facilities at beamline SYRMEP. The reconstructed images were sections containing the femoral head, femoral neck and trochantere. The used spatial resolution allows to visualize also thin trabeculae, which typically lie in a range below 100 microns. The morphometric trabecular characterization parameters as BV/TV, Tb.Th, Tb.Sp, Tb.N were calculated over three regions of interest. The local variations in trabecular and cortical structure of the examined bone are clearly visible at a level not obtainable with medical CT scanners. The quality of the reconstructed cross sections images confirm that this investigation technique is an advanced tool for high resolution three-dimensional imaging of bone structure.