722 research outputs found

    Arms down cone beam CT hepatic angiography: are we focusing on the wrong target?

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    We read with great interest the recent article by Dr. Gonzalez-Aguirre and colleagues entitled ‘‘Arms Down Cone Beam CT Hepatic Angiography Performance Assessment: Vascular Imaging Quality and Imaging Artefacts’’ [1]. One of the most important advantages of cone beam CT (CBCT) is the possibility to evaluate the lesion’s feeders assisting their identification and catheterization [2]. In this set, the patient’s arms positioning is crucial in order not to impair CBCT imaging. Dr. Gonzalez-Aguirre et al. had elegantly demonstrated that vessels’ visualization is independent from the patient’s arms position, allowing to perform the entire procedure without patient’s movements. This minimizes the risk of contamination and reduces procedural time. However, literature shows that the major pivotal strength of CBCT, either mono-phasic or possibly bi-phasic, is the ability to depict in intra-procedurally ‘‘occult lesions’’, not visible at pre-procedural second-line non-invasive imaging (MRI, MDCT) [3]. This ability is not just for show, but yield to some major clinical implications: the visualization of an occult nodule identifies a subset of population experiencing fast tumour growth, having consequences on the number of adjunctive treatments controlling tumour growth (adjunctive RFA, or TACE procedures) and prioritization for transplantation [4]. Moreover, bi-phasic CBCT, with its unique ability to intra-procedural permit nodule characterization, could help in patients’ reclassification and real-time TACE strategy modification [5]. In this light would be a crucial interest for the audience to know whether the CBCT acquisition with arms down does not alter the diagnostic performance of the modality and ability of lesion’s characterization, especially for those lesion localized peripherally, where the beam hardening artefacts have been shown to be significant. Finally, patient’s positioning is fundamental for CBCT imaging. By acquiring the scan with patient’s arm down, liver volume would not be located within the rotation isocentre. This could be a substantial limitation for lesion located within the left liver lobe, eventually hypertrophied, and for high BMI patients

    Archeorobotics. Applicazioni robotiche aperte e archeologia estrema

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    This paper presents an overview on the development and use of open hardware devices in archaeology and their operation in extreme conditions. State-of-the-art technologies are analysed, based on the working experience of the Arc-Team company, which, in 2006, started up a new branch of research, informally called Archeorobotics. The research was initially focused on open hardware radio-controlled UAVs (Unmanned Aerial Vehicle); over time different devices were developed, like ROV (Remotely Operated underwater Vehicle), USV (Unmanned Surface Vehicle), CNC (Computer Numerical Control) machine and other electronic and mechanical tools

    Circular Bedforms Due to Pit Foraging of Greater Flamingo Phoenicopterus roseus in a Back-barrier Intertidal Habitat

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    The Greater Flamingo Phoenicopterus roseus is known as an ecosystem engineer, rearranging sediment in peculiar bedforms as a consequence of its filter-feeding behaviour. In recent decades, the populations of the Greater Flamingo have notably increased, and now the species is one of the most abundant waterbirds in Mediterranean wetlands. Owing to its range expansion, it inhabits and exploits new and suitable foraging sites detectable by foraging structures left on the sediment. There are few images of the foraging morphologies in the literature, possibly due to their ephemeral nature and difficulty in detecting them. In this manuscript, we present a very detailed UAV (Unmanned Aerial Vehicle) image of an aggregate of pit foraging structures of Greater Flamingo discovered on a back-barrier washover fan in the Marano and Grado Lagoon (Northern Adriatic, Italy)

    Polyethylene Glycol Epirubicin-Loaded Transcatheter Arterial Chemoembolization Procedures Utilizing a Combined Approach with 100 and 200 ÎŒm Microspheres: A Promising Alternative to Current Standards

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    PURPOSE:To report clinical effectiveness, toxicity profile, and prognostic factors of combined 100 ÎŒm ± 25 and 200 ÎŒm ± 50 epirubicin-loaded polyethylene glycol (PEG) microsphere drug-eluting embolic transcatheter arterial chemoembolization protocol in patients with hepatocellular carcinoma. MATERIALS AND METHODS: In this prospective, single-center, single-arm study with 18 months of follow-up, 36 consecutive patients (mean age 69.9 y ± 10.8; 26 men, 10 women; 54 naĂŻve lesions) were treated. Embolization was initiated with 100 ÎŒm ± 25 microspheres, and if stasis (10 heart beats) was not achieved, 200 ÎŒm ± 50 microspheres were administered. Each syringe (2 mL) of PEG microsphere was loaded with 50 mg of epirubicin. Results were evaluated using Modified Response Evaluation Criteria In Solid Tumors with multidetector computed tomography/magnetic resonance imaging at 1, 3-6, 9-12, and 15-18 months. Toxicity profile was assessed by laboratory testing before and after the procedure. Complications were recorded. Postembolization syndrome (PES) was defined as onset of fever/nausea/pain after the procedure. Patient/lesion characteristics and treatment results were correlated with predicted outcome using regression analysis. Child-Pugh score was A in 86.1% of patients (31/36) and B in 13.9% (5/36). RESULTS: In 10 of 21 lesions, < 2 cm in diameter (47.5%) stasis was achieved with 100 ÎŒm ± 25 microspheres only, whereas all other lesions required adjunctive treatment with 200 ÎŒm ± 50 microspheres. Reported adverse events were grade 1 acute liver bile duct injury (3/39 cases, 7.7%) and PES (grade 2; 3/39 cases, 7.7%). Complete response (CR) at 1, 3-6, 9-12, and 15-18 months was 61.1%, 65.5%, 63.63%, and 62.5%. Objective response (CR + partial response) at 1, 3-6, 9-12, and 15-18 months was 83.3%, 65.85%, 63.63%, and 62.5%. No single factor (laboratory testing, etiology, patient status, hepatic status, tumor characteristics, administration protocol) predicted outcomes except for albumin level at baseline for CR (P < .05, odds ratio = 1.09). CONCLUSIONS: The combined microsphere sizing strategy was technically feasible and yielded promising results in terms of effectiveness and toxicity

    Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery, and barrier flooding assessment and interferences with human and natural assets

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    The advantages derived from the use of Uncrewed Aerial Vehicles (UAVs) are well-established: they are cost-effective and easy to use. There are numerous environmental applications, particularly when monitoring contexts characterized by rapid morphological changes and high rates of sediment transport, such as coastal areas. In this paper, three different case studies of survey and monitoring with high resolution and accuracy obtained through the use of UAVs are presented; these concern transgressive coastal sites. Results allow for the definition and quantification of coastal landforms and processes, including: (i) The anatomy of a parabolic dune and the rate of landward migration that could interfere with a tourist settlement; (ii) The mode and timing of morphological recovery and realignment of a barrier island overwashed by storm surge episodes; and (iii) The potential flood risk of a progradational spit that is a nesting site of a species of migratory breeding birds of conservation concern. The results demonstrate and confirm that, through a good coupling of drone-sensed quality data and accurate topographic control, quantitative estimates that are useful in assessing the impacts of natural processes involving both human and natural assets can be obtained

    Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)

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    Coastal vulnerability is evaluated against inundation risk triggered by wave run-up through the evaluation of vulnerability levels (referred to as VLs) introduced by Bosom and Jiménez (2011). VLs are assessed through different wave climate characterizations, referring to regional (offshore wave climate) or local (nearshore wave climate) scales. The study is set along the Bay of Lalzit, a coastal area near Durrës (Albania). The analysis reveals that the results vary due to uncertainties inherent in the run-up estimation, showing that the computational procedure should be developed by taking into account detailed information about the local wave climate. Different approaches in choosing wave characteristics for run-up estimation significantly affect the estimate of shoreline vulnerability. The analysis also shows the feasibility and challenges of applying VL estimates in contexts characterized by limited data availability through targeted field measurements of the coast geomorphology and an overall understanding of the recent coastal dynamics and related controlling factors.</p

    Le lesioni polipoidi della colecisti: problemi diagnostici e terapeutici

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    Le lesioni polipoidi della colecisti costituiscono un’entitĂ  eterogenea di difficile definizione diagnostica preoperatoria. L’indicazione chirurgica Ăš discutibile ma in alcuni casi obbligatoria . In questo studio abbiamo analizzato i dati clinici relativi a 25 pazienti sottoposti consecutivamente a colecistectomia laparoscopica per formazioni polipoidi. CiĂČ al fine di evidenziare la possibile correlazione fra aspetto ecografico e valutazione istopatologica e di definire l’indicazione terapeutica

    “Mura della Bastia” – Onigo di Pederobba (Treviso). Ricerche archeologiche, rilievo 3D laser scanning e anastilosi virtuale in un castello medievale del pedemonte trevigiano

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    The paper presents the results of the ongoing research coordinated by the Chair of Ancient Topography at the University of Padova. The work concerns the medieval site of “Mura della Bastia” in Onigo di Pederobba (Treviso), in the North-Eastern part of Italy. Historical information from written documents and results obtained from the archaeological investigation at the Onigo castle (1994-2007) are discussed. The study provided the historical reconstruction of recent collapses of the Onigo tower and allowed the virtual reconstruction of still-cohesive blocks, which had fallen down in 1989, and which were recovered during the summer of 2007. At this time, five of the ten building blocks have been positioned; the procedure was carried out by comparing the panoply of each agglomerate with the prospect of the tower, which was obtained from the photogrammetric rectification of the historical images (2D). The 3D survey of the tower and of nine blocks was performed with a Leica HDS 2500 laser scanner. The resulting point clouds were aligned with Cyclone software, also using the coordinates of some laser scanning targets, which were measured with the Leica TC 2003 total station in a local reference system. The final 3D model obtained by the co-registration of the scans was textured with the digital images acquired with a Canon EOS 1 ds Mark II camera. Subsequently, three of the five recognized blocks were positioned on the 3D model using Reconstructor software
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