Rosa Brancaccio

Skeletal evidence of tuberculosis in a modern identified human skeletal collection (Certosa cemetery, Bologna, Italy)

The diagnosis of tuberculosis (TB) in osteoarcheological series relies on the identification of osseous lesions caused by the disease. The study of identified skeletal collections provides the opportunity to investigate the distribution of skeletal lesions in relation to this disease. The aim of this study was to examine the skeletal evidence for TB in late adolescent and adult individuals from the identified human collection of the Certosa cemetery of Bologna (Italy, 19th-20th c.). The sample group consists of 244 individuals (138 males, 106 females) ranging from 17 to 88 years of age. The sample was divided into three groups on the basis of the recorded cause of death: TB (N = 64), pulmonary non-TB (N = 29), and other diseases (N = 151). Skeletal lesions reported to be related to TB were analyzed. The vertebral lesions were classified into three types: enlarged foramina (EnF, vascular foramina with diameter of 3-5 mm), erosions (ER), and other foramina (OtF, cavities of various shapes > 3 mm). A CT scan analysis was also performed on vertebral bodies. Some lesions were seldom present in our sample (e.g., tuberculous arthritis). OtF (23.7%) and subperiosteal new bone formation on ribs (54.2%) are significantly more frequent in the TB group with respect to the other groups. The CT scan analysis showed that the vertebrae of individuals who have died of TB may have internal cavities in the absence of external lesions. These traits represent useful elements in the paleopathological diagnosis of TB.

X-Ray Computed Tomography Applied to Objects of Cultural Heritage: Porting and Testing the Filtered Back-Projection Reconstruction Algorithm on Low Power Systems-on-Chip

The embedded and high-performance computing (HPC) sectors, that in the past were completely separated, are now somehow converging under the pressure of two driving forces: the release of less power consuming server processors and the increased performance of the new low power Systems-on-Chip (SoCs) developed to meet the requirements of the demanding mobile market. This convergence allows the porting to low power embedded architectures of applications that were originally confined to traditional HPC systems. In this paper, we present our experience of porting the Filtered Back-projection Algorithm to a low power, low cost system-on-chip, the NVIDIA Tegra K1, which is based on a quad core ARM CPU and on a NVIDIA Kepler GPU. This Filtered Back-projection Algorithm is heavily used in 3D Tomography reconstruction software. The porting has been done exploiting various programming languages (i.e. OpenMP, CUDA) and multiple versions of the application have been developed to exploit both the SoC CPU and GPU. The performances have been measured in terms of 2D slices (of a 3D volume) reconstructed per time unit and per energy unit. The results obtained with all the developed versions are reported and compared with those obtained on a typical x86 HPC node accelerated with a recent NVIDIA GPU. The best performances are achieved combining the OpenMP version and the CUDA version of the algorithm. In particular, we discovered that only three Jetson TK1 boards, equipped with Giga Ethernet interconnections, allow to reconstruct as many images per time unit as a traditional server, using one order of magnitude less energy. The results of this work can be applied for instance to the construction of an energy-efficient computing system of a portable tomographic apparatus.

Study of an appropriate reconstruction algorithm for an innovative electron beam imaging system for dosimetry in 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. 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.

Dynamic Angiothermography (DATG)

Dynamic Angiothermography (DATG) is a noninvasive technique for the diagnosis of breast cancer . The instrument consists of a thin plate with liquid crystals that changes color due to a change in temperature, consequently offering an image of breast vasculature . DATG is based on the angiogenesis theory on tumor initiation, development, and growth. A tumor needs new vessels. Therefore, by studying the changes in the pattern of vascular blood supply, it is also possible to diagnose neoplasms very early. In particular, it is shown that every human being has his or her own vascular pattern which, in the absence of disease, does not vary throughout the life time. By repeating DATG periodically, an efficient control of the onset of disease is possible, even in its early stages. This is not new but still little-known technique which is a component of the overall diagnostic techniques for the study and prevention of breast cancer that serves to offer a complete clinical picture of the patient. The great advantages of DATG are: it does not use radiation; it is not invasive or painful; it is low-cost and can be repeated periodically and successfully with no drawbacks. The angiothermographic examination thus makes it possible to visualize the breast vascularity pattern without using contrast medium. On the other hand, while highlighting changes in mammary vascularization, DATG is not able to indicate the size or depth of the tumor; even if recent researches (based on the approximated solution of the inverse Fourier heat equation) show the possibility to evaluate the depth of the tumor. This paper, after the introduction in Sect. 1, starts with a description of historical context in Sect. 2, and outlines the instrumentation in Sect. 3. Section 4 describes the technique, while a comparison with other diagnostic techniques is provided in Sect. 5. To close, Sect. 6 offers a practical guide on the use of this method.

Dosimetry of High Intensity Electron Beams Produced by Dedicated Accelerators in Intra-Operative Radiation Therapy (IORT)

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.

A mobile computed tomography system for on-site cultural heritage analysis

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.

Image quality and dose assessment in inner ear computed tomography imaging with a flat panel-based system.

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-&mgr;m spatial resolution (5% of modulation transfer function) with a voxel size of 88 &mgr;m, 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.

Innovative anatomical representation through the use of x-ray tomography and holographic display emulator

The “L. Cattaneo” Anatomy Museum wax anatomical models in Bologna, works of great historical, artistic and scientific value, have been used since the beginning of the 18th century for medical sciences students practical demonstrations. For this work, which aims to use innovative diagnostic investigation techniques for advancement either in education and scientific communication through a new “remote” method for the museum fruition, we used anatomical preparations and both normal human anatomical and pathological one wax models, from the dawn of the nineteenth according to the new Morgagni’s theories. We acquired a lot of high resolution photographs as many as tomographic images than processed using innovative representation techniques through new generation hardware equipment and an original software especially developed for full three-dimensional display. The several high-resolution photographs acquired around the object, combined with the results of the X-ray computed tomography (CT) investigation, show the 3D reconstruction of the object with their internal parts reassembled and, at the same time, reveal hidden structures and materials used, all in a non-invasive way. The CT analysis was performed using a specifically designed system, developed for application on Cultural Heritage at the Physics and Astronomy Department of Bologna University. The results of this work are shown through a virtual 3D projection using a device able to emulate a holographic representation

3D tomographic reconstruction on HPC cluster of the Kongo Rikishi (Japanese wooden statue of the XIII century)

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.

High resolution X-ray analysis of a proximal human femur with synchrotron radiation and an innovative linear detector

Synchrotron based digital radiography and micro tomography devices are powerful, non-destructive, high-resolution 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.