Development of Gestational Age-Based Fetal Brain and Intracranial Volume Reference Norms Using Deep Learning.

BACKGROUND AND PURPOSE: Fetal brain MR imaging interpretations are subjective and require subspecialty expertise. We aimed to develop a deep learning algorithm for automatically measuring intracranial and brain volumes of fetal brain MRIs across gestational ages. MATERIALS AND METHODS: This retrospective study included 246 patients with singleton pregnancies at 19-38 weeks gestation. A 3D U-Net was trained to segment the intracranial contents of 2D fetal brain MRIs in the axial, coronal, and sagittal planes. An additional 3D U-Net was trained to segment the brain from the output of the first model. Models were tested on MRIs of 10 patients (28 planes) via Dice coefficients and volume comparison with manual reference segmentations. Trained U-Nets were applied to 200 additional MRIs to develop normative reference intracranial and brain volumes across gestational ages and then to 9 pathologic fetal brains. RESULTS: Fetal intracranial and brain compartments were automatically segmented in a mean of 6.8 (SD, 1.2) seconds with median Dices score of 0.95 and 0.90, respectively (interquartile ranges, 0.91-0.96/0.89-0.91) on the test set. Correlation with manual volume measurements was high (Pearson r = 0.996, P < .001). Normative samples of intracranial and brain volumes across gestational ages were developed. Eight of 9 pathologic fetal intracranial volumes were automatically predicted to be >2 SDs from this age-specific reference mean. There were no effects of fetal sex, maternal diabetes, or maternal age on intracranial or brain volumes across gestational ages. CONCLUSIONS: Deep learning techniques can quickly and accurately quantify intracranial and brain volumes on clinical fetal brain MRIs and identify abnormal volumes on the basis of a normative reference standard.

AEgIS at ELENA: outlook for physics with a pulsed cold antihydrogen beam.

The efficient production of cold antihydrogen atoms in particle traps at CERN's Antiproton Decelerator has opened up the possibility of performing direct measurements of the Earth's gravitational acceleration on purely antimatter bodies. The goal of the AEgIS collaboration is to measure the value of g for antimatter using a pulsed source of cold antihydrogen and a Moiré deflectometer/Talbot-Lau interferometer. The same antihydrogen beam is also very well suited to measuring precisely the ground-state hyperfine splitting of the anti-atom. The antihydrogen formation mechanism chosen by AEgIS is resonant charge exchange between cold antiprotons and Rydberg positronium. A series of technical developments regarding positrons and positronium (Ps formation in a dedicated room-temperature target, spectroscopy of the n=1-3 and n=3-15 transitions in Ps, Ps formation in a target at 10 K inside the 1 T magnetic field of the experiment) as well as antiprotons (high-efficiency trapping of [Formula: see text], radial compression to sub-millimetre radii of mixed [Formula: see text] plasmas in 1 T field, high-efficiency transfer of [Formula: see text] to the antihydrogen production trap using an in-flight launch and recapture procedure) were successfully implemented. Two further critical steps that are germane mainly to charge exchange formation of antihydrogen-cooling of antiprotons and formation of a beam of antihydrogen-are being addressed in parallel. The coming of ELENA will allow, in the very near future, the number of trappable antiprotons to be increased by more than a factor of 50. For the antihydrogen production scheme chosen by AEgIS, this will be reflected in a corresponding increase of produced antihydrogen atoms, leading to a significant reduction of measurement times and providing a path towards high-precision measurements.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'.

A moiré deflectometer for antimatter.

The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational interaction is of high interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics--the moiré deflectometer--for a measurement of the acceleration of slow antiprotons. The setup consists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleration of neutral antimatter.

Increasing springtime ozone mixing ratios in the free troposphere over western North America.

In the lowermost layer of the atmosphere-the troposphere-ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA's compliance with its ozone air quality standard.

Early EUS of the bile duct before endoscopic sphincterotomy for acute biliary pancreatitis.

BACKGROUND: Endoscopic sphincterotomy can benefit patients with suspected biliary pancreatitis, although there are procedure-related complications. EUS can be used to select patients for endoscopic sphincterotomy. The results of this strategy were assessed. METHODS: Information on patients referred for EUS were recorded in a database. One hundred twenty-three patients with suspected biliary pancreatitis (57 men, 66 women; median age 55 years) were included and followed. All underwent EUS followed by endoscopic sphincterotomy during the same procedure if choledocholithiasis was identified. Outcomes were studied in relation to the initial severity of biliary pancreatitis (Ranson and Balthazar scores), presence of stones, and time span between onset of biliary pancreatitis and EUS plus endoscopic sphincterotomy. RESULTS: Thirty-five patients (28%) had a Ranson score greater than 3 on admission and 38 (31%) were Balthazar D-E. The median time from admission to EUS was 3 days. EUS imaging of the bile duct was complete in all but 3 patients. Thirty-three patients (27%) had choledocholithiasis on EUS and underwent endoscopic sphincterotomy. Stones were more frequent in patients with jaundice (p < 0.005) and when EUS was performed less than 3 days after admission (p < 0.05). One hundred patients (81%) recovered without complication. Two patients (1.6%) died, 1 had recurrent BP develop, 6 (5%) had further biliary symptoms, and 16 (13%) had complications of pancreatitis develop (9 pseudocysts). There were 3 mild endoscopic sphincterotomy-related complications (complication rate 6.5%). CONCLUSIONS: In this series in which endoscopic sphincterotomy was performed selectively depending on the endosonographic presence or absence of ductal stones early in the course of the pancreatitis, and not according to its predicted severity, mortality and complications of endoscopic sphincterotomy were low and unrelated to the predicted severity of biliary pancreatitis or the presence of choledocholithiasis. Controlled trials are needed to confirm the superiority of this strategy compared with ERCP alone for the management of biliary pancreatitis.

[Fascioliasis of the common bile duct: endoscopic ultrasonographic diagnosis and endoscopic sphincterotomy]. / Distomatose de la voie biliaire principale: diagnostic écho- endoscopique et traitement par sphinctérotomie endoscopique.

Two cases of biliary fasciolasis are reported. The patients presented with biliary pain and/or acute pancreatitis. Pre-operative ultrasound endoscopy showed main bile duct dilation and linear elongated echogenic structures in the common bile duct lumen. Endoscopic retrograde cholangiography and endoscopic sphincterotomy were performed. Parasites were endoscopically removed resulting in disappearance of symptoms and biological abnormalities. Serological tests and pathological examination confirmed the presence of Fasciola hepatica. During follow-up, stool examination failed to show any Fasciola hepatica eggs, and in one case, serology became negative. This report emphasizes the value of ultrasound endoscopy in the diagnosis of unsuspected biliary fasciolasis. This report also confirms the therapeutic role of endoscopic sphincterotomy in patients with obstructive biliary fasciolasis.

[Hepatic function and significance of the increase in serum concentrations of IgA in alcoholic cirrhosis]. / Fonction hépatique et signification de l'augmentation de la concentration sérique des IgA au cours de la cirrhose alcoolique.

Elevated serum gammaglobulin concentrations are frequently observed in patients with liver cirrhosis. Predominant elevation of the IgA is generally considered as suggestive of an alcoholic aetiology. The aim of this study was to define the factors that determine the serum concentration of IgA in alcoholic cirrhosis. Twenty-seven patients with alcoholic cirrhosis were studied. Serum concentrations of IgG, IgA and IgM were measured by immunonephelometry. Hepatocellular function was assessed by the Child-Turcotte score, the prothrombin time and the intrinsic clearance of indocyanine green. The importance of intra-hepatic shunts was estimated according to the intact hepatocyte theory, and the degree of hepatic necrosis by serum levels of transaminases. It was noted that: 1) the IgA concentration correlated significantly with the Child-Turcotte score and with the decrease of the prothrombin time, intrinsic clearance and the functional fraction of hepatic blood flow; 2) there was no such correlation between the serum concentration of IgA and the total hepatic blood flow or transaminase levels; 3) there was no correlation between serum concentration of IgG or IgM and the factors studied. These results suggest that in alcoholic cirrhosis, increase in serum IgA, reflects the degree of impairment of hepatic function and intrahepatic shunting.