M. Bettuzzi

An Innovative CCD-Based High-Resolution CT System for Analysis of Trabecular Bone Tissue

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

Real-Time Reconstruction for 3-D CT Applied to Large Objects of Cultural Heritage

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 25thinspace000 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.

Advanced imaging systems for diagnostic investigations applied to Cultural Heritage

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.

A novel approach for an integrated straw tube-microstrip detector

We report on a novel concept of silicon microstrips and straw tubes detector, where integration is accomplished by a straw module with straws not subjected to mechanical tension in a Rohacell/spl reg/ lattice and carbon fiber reinforced plastic shell. Results on mechanical and test beam performances are reported as well.

X-ray computed tomography of an ancient large globe

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.

Real-time system for dosimetry in IORT (intra operative radiation therapy)

Intraoperative radiation therapy (IORT) is a technique based on delivery of a high dose of ionizing radiation to the cancer tissue, after tumor 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 a high precision. An accelerator 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 millimetre. 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

Dental status and 3D reconstruction of the malocclusion of the famous singer Farinelli (1705–1782)

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 subjects 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 Farinellis extraordinary singing qualities and stage presence.

Preliminary results of a new approach for three-dimensional reconstruction of Dynamic AngioThermography (DATG) images based on the inversion of heat equation

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.

The Use of Industrial Computed Tomography in the Study of Archaeological Finds

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.

Study and realization of real-time in-depth dosimetry system for IORT (intra operative radiation therapy)

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.