Maceration determines diagnostic yield of fetal and neonatal whole body post‐mortem ultrasound

OBJECTIVES: To determine factors in non-diagnostic fetal and neonatal post-mortem ultrasound (PMUS) examinations. METHODS: All fetal and neonatal PMUS examinations were included over a 5 year study period (2014 - 2019). Non-diagnostic image quality by body parts (brain, spine, thorax, cardiac, abdomen) were recorded, and correlated with patient variables. Descriptive statistics and logistic regression analyses were performed to identify significant factors for non-diagnostic studies. RESULTS: 265 PMUS examinations were included, with median gestational age of 22 weeks (12 - 42 weeks), post-mortem weight 363g (16 - 4033g) and post-mortem interval of 8 days (0 - 39 days). Diagnostic imaging quality was achieved for 178/265 (67.2%) studies. It was high for abdominal (263/265, 99.2%); thoracic (264/265, 99.6%) and spine (265/265, 100%), but lower for brain (210/265, 79.2%) and cardiac imaging (213/265, 80.4%). Maceration was the best overall predictor for non-diagnostic imaging quality (p<0.0001). Post-mortem fetal weight was positively associated with cardiac (p =0.0133), and negatively associated with brain imaging quality (p =0.0002). Post-mortem interval was not a significant predictor. CONCLUSIONS: Fetal maceration was the best predictor for non-diagnostic PMUS, particularly for brain and heart. Fetuses with marked maceration and suspected cardiac or brain anomalies should be prioritised for post-mortem MRI

Postmortem examination of human fetuses: a comparison of 2-dimensional ultrasound with invasive autopsy

OBJECTIVE: To compare the diagnostic usefulness of postmortem ultrasound with invasive autopsy in fetuses at different gestational ages. METHODS: We performed postmortem 2-dimensional ultrasound on 163 fetuses at 13-42 weeks gestation, blinded to clinical details. Logistic regression analysis was used to investigate the effect on non-diagnostic results of gestational age during postmortem ultrasound, presence of maceration, and cause of death. In 123 cases where invasive autopsy was available, the diagnostic accuracy of ultrasound in detecting major organ abnormalities was evaluated, using invasive autopsy as a gold standard. RESULTS: For the fetal brain, a non-diagnostic result was found in 17 (39.5%) of 43 fetuses with maceration and was significantly more common as compared to fetuses without maceration (24 [20.0%] of 120 fetuses [p=0.013]). For the fetal thorax, a non-diagnostic result was found in 15 (34.1%) of 44 fetuses at <20 weeks of gestation and in 13 (10.9%) of 119 fetuses at ≥20 weeks (p<0.001). For the heart and abdominal organs no association was demonstrated with the tested variables. For fetuses <20 weeks, specificity was 83.3% for brain anomalies, 68.6% for the thorax, and 77.4% for the heart. For fetuses ≥20 weeks, sensitivity and specificity were, respectively, 61.9% and 74.2% for the brain, 29.5% and 87.0% for the thorax, and 57.1% and 76.9% for the heart. Sensitivity was 60.7% and specificity 75.8% for fetal abdominal organs, mainly the kidneys, irrespective of gestational age. CONCLUSION: Although maceration may lead to failure in some cases, postmortem ultrasound reaches diagnostically acceptable levels for brain and abdominal organs, compared with conventional autopsy. It may therefore play a role as a first-line examination before other virtual autopsy techniques are indicated

Search for Quantum Gravity Using Astrophysical Neutrino Flavour with IceCube

Along their long propagation from production to detection, neutrino states undergo quantum interference which converts their types, or flavours. High-energy astrophysical neutrinos, first observed by the IceCube Neutrino Observatory, are known to propagate unperturbed over a billion light years in vacuum. These neutrinos act as the largest quantum interferometer and are sensitive to the smallest effects in vacuum due to new physics. Quantum gravity (QG) aims to describe gravity in a quantum mechanical framework, unifying matter, forces and space-time. QG effects are expected to appear at the ultra-high-energy scale known as the Planck energy, $E_{P}\equiv 1.22\times 10^{19}$~giga-electronvolts (GeV). Such a high-energy universe would have existed only right after the Big Bang and it is inaccessible by human technologies. On the other hand, it is speculated that the effects of QG may exist in our low-energy vacuum, but are suppressed by the Planck energy as $E_{P}^{-1}$ ($\sim 10^{-19}$~GeV$^{-1}$), $E_{P}^{-2}$ ($\sim 10^{-38}$~GeV$^{-2}$), or its higher powers. The coupling of particles to these effects is too small to measure in kinematic observables, but the phase shift of neutrino waves could cause observable flavour conversions. Here, we report the first result of neutrino interferometry~\cite{Aartsen:2017ibm} using astrophysical neutrino flavours to search for new space-time structure. We did not find any evidence of anomalous flavour conversion in IceCube astrophysical neutrino flavour data. We place the most stringent limits of any known technologies, down to $10^{-42}$~GeV$^{-2}$, on the dimension-six operators that parameterize the space-time defects for preferred astrophysical production scenarios. For the first time, we unambiguously reach the signal region of quantum-gravity-motivated physics.Comment: The main text is 7 pages with 3 figures and 1 table. The Appendix includes 5 pages with 3 figure

The IceCube Neutrino Observatory - Contributions to ICRC 2017 Part VI: IceCube-Gen2, the Next Generation Neutrino Observatory

Papers on research & development towards IceCube-Gen2, the next generation neutrino observatory at South Pole, submitted to the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the IceCube-Gen2 Collaboration

Neutrino interferometry for high-precision tests of Lorentz symmetry with IceCube

We acknowledge the support from the following agencies: USA—US National Science Foundation–Office of Polar Programs, US National Science Foundation–Physics Division, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin–Madison, Open Science Grid (OSG), Extreme Science and Engineering Discovery Environment (XSEDE), US Department of Energy–National Energy Research Scientific Computing Center, Particle astrophysics research computing centre at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University and Astroparticle physics computational facility at Marquette University; Belgium—Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany—Bundesministerium für Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Deutsches Elektronen Synchrotron (DESY), and High Performance Computing cluster of the RWTH Aachen; Sweden—Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; Australia—Australian Research Council; Canada—Natural Sciences and Engineering Research Council of Canada, Calcul Québec, Compute Ontario, Canada Foundation for Innovation, WestGrid and Compute Canada; Denmark—Villum Fonden, Danish National Research Foundation (DNRF); New Zealand—Marsden Fund; Japan—Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea—National Research Foundation of Korea (NRF); Switzerland—Swiss National Science Foundation (SNSF); UK—Science and Technology Facilities Council (STFC) and The Royal Society