Detection superiority of 7 T MRI protocol in patients with epilepsy and suspected focal cortical dysplasia

In 11 adult patients with suspicion of Focal cortical dysplasia (FCD) on 1.5 T (n = 1) or 3 T (n = 10) magnetic resonance imaging (MRI), 7 T MRI was performed. Visibility, extent, morphological features and delineation were independently rated and subsequently discussed by three observers. Additionally, head-to-head comparisons with corresponding 3 T images were made in the eight patients with a previous 3 T MRI and sustained suspicion of FCD. Comparison with histopathology was done in the five patients that underwent surgery. All lesions, seen at 1.5 and 3 T, were also recognized on 7 T. At 7 T FLAIR highlighted the FCD-like lesions best, whereas T2 and T2* were deemed better suited to review structure and extent of the lesion. Image quality with the used 7 T MRI setup was higher than the quality with the used 3 T MRI setup. In 2 out of 11 patients diagnosis changed, in one after re-evaluation of the images, and in the other based on histopathology. With the used 7 T MRI setup, FCD-like lesions can be detected with more confidence and detail as compared to lower field strength. However, concordance between radiologic diagnosis and final diagnosis seems to be lower than expected

On graviton non-Gaussianities during inflation

We consider the most general three point function for gravitational waves produced during a period of exactly de Sitter expansion. The de Sitter isometries constrain the possible shapes to only three: two preserving parity and one violating parity. These isometries imply that these correlation functions should be conformal invariant. One of the shapes is produced by the ordinary gravity action. The other shape is produced by a higher derivative correction and could be as large as the gravity contribution. The parity violating shape does not contribute to the bispectrum [1106.3228, 1108.0175], even though it is present in the wavefunction. We also introduce a spinor helicity formalism to describe de Sitter gravitational waves with circular polarization. These results also apply to correlation functions in Anti-de Sitter space. They also describe the general form of stress tensor correlation functions, in momentum space, in a three dimensional conformal field theory. Here all three shapes can arise, including the parity violating one.Comment: 51 pages, v2: Corrected statement about parity violation in the gravitational wave bispectrum. Some other changes and references adde

Spinning Conformal Blocks

For conformal field theories in arbitrary dimensions, we introduce a method to derive the conformal blocks corresponding to the exchange of a traceless symmetric tensor appearing in four point functions of operators with spin. Using the embedding space formalism, we show that one can express all such conformal blocks in terms of simple differential operators acting on the basic scalar conformal blocks. This method gives all conformal blocks for conformal field theories in three dimensions. We demonstrate how this formalism can be applied in a few simple examples.Comment: 29 page

NSL 2023 monitoring report. State of affairs of National Air Quality Cooperative Programme (NSL)

In het Nationaal Samenwerkingsprogramma Luchtkwaliteit (NSL(Nationaal Samenwerkingsprogramma Luchtkwaliteit)) werken verschillende Nederlandse overheden sinds 2009 samen om de luchtkwaliteit te verbeteren. De monitor van het NSL is onder meer bedoeld om te kijken of Nederland de Europese grenswaarden voor luchtkwaliteit haalt. Als dat niet zo is, zijn extra maatregelen nodig om die grenswaarden toch zo snel mogelijk te halen. Het RIVM volgt daarom elk jaar de concentraties stikstofdioxiden en fijnstof in de lucht en rapporteert daarover. Voor beide stoffen wordt gekeken naar de bijdrage van wegverkeer. Voor fijnstof kijken we ook naar de bijdrage van veehouderijen. In 2022 voldeed Nederland voor wegverkeer bijna aan de Europese grenswaarden voor stikstofdioxide. Op één punt was er een overschrijding: direct naast de tunnelmond van de Maastunnel in Rotterdam. Ook voor fijnstof voldeed Nederland bijna aan de grenswaarden voor wegverkeer. Alleen een klein stuk weg van 200 meter bij Velsen lag boven de grenswaarde. Op enkele woonlocaties in gebieden met intensieve veehouderij werden de grenswaarden van fijnstof in 2022 nog steeds overschreden. Dat waren er net iets minder dan in 2021. De concentraties stikstofdioxiden en fijnstof waren in 2022 iets hoger dan tijdens de ‘coronajaren’ 2020 en 2021. Nadat de coronamaatregelen waren opgeheven, was er meer verkeer en economische activiteit. Dit zorgde voor meer uitstoot. De concentraties waren daardoor hoger, maar wel minder hoog dan vóór de coronajaren. Het aantal overschrijdingen van de Europese norm voor deze stoffen was daardoor bijna hetzelfde als in eerdere jaren. Het ziet ernaar uit dat de luchtkwaliteit de komende jaren verder verbetert. Verkeer, industrie en veehouderijen zullen naar verwachting minder stikstofdioxide en fijnstof uitstoten. Dat komt bijvoorbeeld doordat elk jaar oudere auto’s worden vervangen door nieuwe en schonere auto’s, die minder of zelfs geen stikstofoxiden uitstoten. Op dit moment wordt in de Europese Unie onderhandeld over de herziening van de Europese richtlijn luchtkwaliteit. Dit zal tot nieuwe grenswaarden leiden. Hoe hoog de grenswaarden zullen zijn en wanneer deze wetgeving zal ingaan, is nog niet bekend. Op 1 januari 2024 gaat de Omgevingswet van start. De monitoring van de luchtkwaliteit is daar een onderdeel van, en gaat op dezelfde manier door als in het NSL.Dutch public authorities have been working together to improve air quality through the National Air Quality Cooperation Programme (NSL) since 2009. The purpose of the NSL monitor is, among other things, to check whether the Netherlands complies with European limit values for air quality. If it does not, it needs to introduce additional measures to ensure it complies with these limit values as soon as possible. Each year, RIVM monitors the nitrogen dioxide and particulate matter concentrations in the air and reports on this. For both of these substances, RIVM looks at the contributions from road traffic. For particulate matter, it also looks at the contributions from livestock farming. In 2022, the Netherlands almost complied with the European nitrogen dioxide limit values for road traffic. It failed to do so at a single location, directly next to the entrance to the Maastunnel in Rotterdam. The Netherlands almost complied with the European particulate matter limit values for road traffic as well. The limit values were only exceeded along a small, 200-metre stretch of road near Velsen. At several residential locations in areas with intensive livestock farming, particulate matter concentrations exceeded the limit values in 2022. This was the case for slightly fewer locations than in 2021. The concentrations of nitrogen dioxide and particulate matter were slightly higher in 2022 than during the ‘coronavirus years’ 2020 and 2021. After the coronavirus measures were lifted, traffic and economic activity went up. This resulted in higher emissions. The concentrations were therefore higher, but less high than before the coronavirus pandemic. As a result, the number of locations where the European limit values were exceeded was almost the same as in previous years. Air quality is expected to improve further in the coming years as traffic, industry and livestock farming are expected to emit less nitrogen dioxide and particulate matter. One reason for this is that older cars are replaced every year with newer cars, which emit less or even zero nitrogen oxides. The European Union is currently negotiating the revision of the European Air Quality Directive. This will lead to new limit values. It is not yet known how high the limit values will be and when this legislation will come into effect. The Environment and Planning Act will enter into force on 1 January 2024. Monitoring air quality is a component of this Act as well. This will be done in the same way as for the NSL

NSL monitoring report for 2022. State of affairs of the National Air Quality Cooperation Programme

In het Nationaal Samenwerkingsprogramma Luchtkwaliteit ( NSL (Nationaal Samenwerkingsprogramma Luchtkwaliteit)) werken de overheden sinds 2009 samen om de luchtkwaliteit te verbeteren. De monitor van het NSL is onder andere bedoeld om te kijken of Nederland de Europese grenswaarden voor luchtkwaliteit haalt. En als dat niet zo is, of extra maatregelen nodig zijn om ze toch zo snel mogelijk te halen. Het RIVM rapporteert elk jaar over stikstofdioxiden en fijnstof in de lucht. Uit de rapportage 2022 blijkt dat de luchtkwaliteit in 2021 bijna hetzelfde is als in 2020. Ook in 2021 voldoet Nederland voor wegverkeer aan de Europese grenswaarden voor stikstofdioxide. Voor fijnstof is dat ook het geval langs de wegen in Nederland, met uitzondering van een klein stuk weg van 200 meter bij Velsen. Op enkele woonlocaties in gebieden met intensieve veehouderijen zijn de grenswaarden van fijnstof in 2021 nog steeds overschreden; iets meer dan in 2020. De lage concentraties voor stikstofdioxide en fijnstof in 2020 en 2021 komen onder andere door de maatregelen die zijn genomen tegen de verspreiding van het coronavirus. Er was daardoor binnen en buiten Nederland minder verkeer en economische activiteit, en dus minder uitstoot. Dit effect is waarschijnlijk tijdelijk. In 2021 zijn de concentraties wel iets hoger dan in 2020, waardoor er iets meer overschrijdingen berekend zijn. Dit komt mogelijk doordat er in 2021 meer verkeer en meer economische activiteit waren dan in 2020. Het is niet duidelijk of het effect helemaal verdwijnt als de coronamaatregelen worden opgeheven. De verwachting is wel dat de luchtkwaliteit de komende jaren verder verbetert. Dat komt doordat verkeer, industrie en veehouderijen naar verwachting minder stikstofdioxide en fijnstof zullen uitstoten. Zo worden bijvoorbeeld elk jaar oudere auto’s vervangen door nieuwere die minder stikstofoxiden uitstoten. In 2030 worden de Europese grenswaarden die nu voor stikstofdioxiden en fijnstof gelden naar verwachting niet meer overschreden. Tegen die tijd zijn er, naar verwachting, nog meer maatregelen genomen voor een nog betere luchtkwaliteit en voor het klimaat. Een ander beeld ontstaat als wordt gerekend met de nieuwe, strengere advieswaarden van de WHO (World Health Organization) uit 2021. Dan zijn veel inwoners in 2021 blootgesteld geweest aan concentraties boven de advieswaarden. Deze waarden zijn nu niet in Nederlandse wetgeving opgenomen.Since 2009, all tiers of government have been working together to improve air quality through the National Air Quality Cooperation Programme (Nationaal Samenwerkingsprogramma Luchtkwaliteit, NSL). The NSL monitoring report is intended, among other things, to ensure that the Netherlands meets the European limit values for air quality and, in case these are not met, whether additional measures are needed to meet them as quickly as possible. Each year, RIVM reports on nitrogen dioxides and particulate matter in the air. The 2022 report shows that the air quality in 2021 was almost the same as in 2020. In 2021, the Netherlands once again met the European limit values for nitrogen dioxide emitted by road traffic. This was also the case for particulate matter along the roads, with the exception of a small 200-metre stretch of road near Velsen. At some residential locations in areas with intensive livestock farming, the limit values for particulate matter were still exceeded in 2021. This occurred slightly more often than in 2020. The low concentrations of nitrogen dioxide and particulate matter in 2020 and 2021 were partly due to the measures taken to prevent the spread of the coronavirus. As a result, there was less traffic and less economic activity both inside and outside the Netherlands, leading to fewer emissions. This effect is likely to be temporary. In 2021, the concentrations were slightly higher than in 2020, to the extent that slightly more exceedances were calculated. This may be because there was more traffic and more economic activity in 2021 than in 2020. It is not clear whether the effect will disappear completely once the coronavirus measures are lifted. Air quality is expected to improve further in the coming years because traffic, industry and livestock farming are expected to emit less nitrogen dioxide and particulate matter. For example, older cars are replaced by newer ones that emit fewer nitrogen oxides every year. In 2030, the European limit values that now apply for nitrogen dioxide and particulate matter are no longer expected to be exceeded. By then, it is expected that even more measures will have been taken to improve air quality and mitigate climate change. A different picture arises if you take into account the new, stricter air quality guidelines of the WHO from 2021. In that scenario, many residents were exposed to concentrations above the recommended levels in 2021. These guidelines are currently not included in Dutch legislation

Morphological MRI criteria improve the detection of lymph node metastases in head and neck squamous cell carcinoma: multivariate logistic regression analysis of MRI features of cervical lymph nodes

The aim was to evaluate whether morphological criteria in addition to the size criterion results in better diagnostic performance of MRI for the detection of cervical lymph node metastases in patients with head and neck squamous cell carcinoma (HNSCC). Two radiologists evaluated 44 consecutive patients in which lymph node characteristics were assessed with histopathological correlation as gold standard. Assessed criteria were the short axial diameter and morphological criteria such as border irregularity and homogeneity of signal intensity on T2-weighted and contrast-enhanced T1-weighted images. Multivariate logistic regression analysis was performed: diagnostic odds ratios (DOR) with 95% confidence intervals (95% CI) and areas under the curve (AUCs) of receiver-operating characteristic (ROC) curves were determined. Border irregularity and heterogeneity of signal intensity on T-2-weighted images showed significantly increased DORs. AUCs increased from 0.67 (95% CI: 0.61-0.73) using size only to 0.81 (95% CI: 0.75-0.87) using all four criteria for observer 1 and from 0.68 (95% CI: 0.62-0.74) to 0.96 (95% CI: 0.94-0.98) for observer 2 (p < 0.001). This study demonstrated that the morphological criteria border irregularity and heterogeneity of signal intensity on T2-weighted images in addition to size significantly improved the detection of cervical lymph nodes metastases