Synchrotron radiation in radiology: novel X-ray sources

X-rays, the key ingredient of radiology, are still primarily produced with the mechanism discovered by Röntgen over one century ago. A different approach, however, is becoming increasingly important: the use of synchrotron sources based on fast-moving electrons and on their relativistic properties. We discuss the elements of this new strategy, its practical implementation, and some new types of synchrotron sources under development. The present and potential impact on radiology of different classes of synchrotron sources is briefly and realistically analyze

Connecting biodiversity monitoring with soil inventory information - A Swiss case study

Switzerland is one of the first countries in the world to monitor its biological diversity. The Federal Office for the environment (FOEN), triggered by the Rio world summit, initiated 1995 a program for this purpose called Biodiversity Monitoring in Switzerland (BDM). According to the Convention on Biological Diversity various biodiversity targets were defined and the action plan strategy biodiversity Switzerland serves to implement these strategic goals. Unfortunately, up to very recently, soil was not part of these considerations. In the Swiss biodiversity monitoring system a core indicator, species diversity in habitats, is designed to document changes in species diversity of vascular plants and mosses in Switzerland’s major habitats. Together with the current land use and general metadata like elevation, slope, exposition and geology these data are stored in a central database. Since 2001 the totally 1’600 sites based on a regular grid (6 by 4 km) are resampled in a 5 years interval. In the third sampling campaign (2011-2015) the setting was broadened by taking soil samples at all locations possible. At each site 4 replicates 0-20 cm were taken to provide predictions on plot scale variability. All samples were prepared in the laboratory of the Swiss Soil Monitoring Network. Exploratory data analyses for pH, soil organic carbon and nitrogen revealed distinct patterns according to land use as well as to altitude; pH decreases from colline to alpine zones. Furthermore, regional analyses show enormous differences between the northern and southern side of the Alps. Connecting measured soil parameters with the outcome of the BDM survey enables to determine the impact of environmental conditions on species diversity of vascular plants and mosses as well as on soil-plant interactions. Therefore, connecting measured soil inventory data and plant and moss diversity information provide a clear added value to the Biodiversity Monitoring in Switzerland

Bacillus cereus bacteraemia: comparison between haematologic and nonhaematologic patients.

Bacillus cereus bacteraemia can be severe, especially among patients with haematologic malignancy. We retrospectively reviewed first episodes of true B. cereus bacteraemia (more than one positive bottle plus signs of infection) at our institution between 1997 and 2013 with the aim to compare haematologic versus nonhaematologic patients and analyse episodes with complicated outcome. Among 56 episodes of positive-blood cultures for B. cereus, 21 were considered significant. Median age was 54 years (range 23-82 years). Ten patients (48%) had a haematologic malignancy; all were neutropenic at the time of B. cereus bacteraemia. Nonhaematologic patients were either intravenous drug users (n = 3, 14%), polytraumatized (n = 3, 14%) or had multiple chronic comorbidities (n = 5, 24%). Most episodes were hospital acquired (15, 71%). Sources of bacteraemia were intravascular catheter (n = 11, 52%), digestive tract (n = 6, 29%), drug injection (n = 3, 14%) and wound (n = 1, 5%). Adequate antibiotic therapy was provided to 18 patients (86%) during a median of 17 days (range 2-253 days). The intravascular catheter was removed in eight cases (42%). Three haematologic patients had a complicated course with neurologic complications (meningoencephalitis and cerebral abscesses). Complications appeared to be associated with catheter infection (100% of complicated cases vs. 29% of noncomplicated cases). In conclusion, B. cereus bacteraemia can have a complicated course in a subset of patients, mainly those with haematologic malignancy. Catheter infection may be associated with a worse outcome with frequent neurologic complications

Enamel interproximal reduction during treatment with clear aligners: digital planning versus OrthoCAD analysis

Background The aim of the study was to compare the amount of interproximal enamel reduction (IPR) provided on ClinCheck software with the amount of IPR carried out by the orthodontist during treatment with clear aligners. Methods 30 subjects (14 males, 16 females; mean age of 24.53 +/- 13.41 years) randomly recruited from the Invisalign account of the Department of Orthodontics at the University of Rome "Tor Vergata" from November 2018 to October 2019, were collected according to the following inclusion criteria: mild to moderate dento-alveolar discrepancy (1.5-6.5 mm); Class I canine and molar relationship; full permanent dentition (excluding third molars); both arches treated only using Comprehensive Package by Invisalign system; treatment plan including IPR. Pre- (T0) and post-treatment (T1) digital models (.stl files), created from an iTero scan, were collected from all selected patients. The OrthoCAD digital software was used to measure tooth mesiodistal width in upper and lower arches before (T0) and at the end of treatment (T1) before any refinement. The widest mesio-distal diameter was measured for each tooth excluding molars by "Diagnostic" OrthoCAD tool. The total amount of IPR performed during treatment was obtained comparing the sum of mesio-distal widths of all measured teeth at T0 and T1. Significant T1-T0 differences were tested with dependent sample t-test (P < 0.05). Results In the upper arch, IPR was digitally planned on average for 0.62 mm while in the lower arch was on average for 1.92 mm. As for the amount of enamel actually removed after IPR performing, it was on average 0.62 mm in the maxillary arch. In the mandibular arch, the mean of IPR carried out was 1.93 mm. The difference between planned IPR and performed IPR is described: this difference was on average 0.00 mm in the upper arch and 0.01 in the lower arch. Conclusions The amount of enamel removed in vivo corresponded with the amount of IPR planned by the Orthodontist using ClinCheck software

A New Approach for Deep Gray Matter Analysis Using Partial-Volume Estimation.

INTRODUCTION: The existence of partial volume effects in brain MR images makes it challenging to understand physio-pathological alterations underlying signal changes due to pathology across groups of healthy subjects and patients. In this study, we implement a new approach to disentangle gray and white matter alterations in the thalamus and the basal ganglia. The proposed method was applied to a cohort of early multiple sclerosis (MS) patients and healthy subjects to evaluate tissue-specific alterations related to diffuse inflammatory or neurodegenerative processes. METHOD: Forty-three relapsing-remitting MS patients and nineteen healthy controls underwent 3T MRI including: (i) fluid-attenuated inversion recovery, double inversion recovery, magnetization-prepared gradient echo for lesion count, and (ii) T1 relaxometry. We applied a partial volume estimation algorithm to T1 relaxometry maps to gray and white matter local concentrations as well as T1 values characteristic of gray and white matter in the thalamus and the basal ganglia. Statistical tests were performed to compare groups in terms of both global T1 values, tissue characteristic T1 values, and tissue concentrations. RESULTS: Significant increases in global T1 values were observed in the thalamus (p = 0.038) and the putamen (p = 0.026) in RRMS patients compared to HC. In the Thalamus, the T1 increase was associated with a significant increase in gray matter characteristic T1 (p = 0.0016) with no significant effect in white matter. CONCLUSION: The presented methodology provides additional information to standard MR signal averaging approaches that holds promise to identify the presence and nature of diffuse pathology in neuro-inflammatory and neurodegenerative diseases