Spectral Photon-counting CT: Initial Experience with Dual-Contrast Agent K-Edge Colonography

[DOI:\hrefhttps://dx.doi.org/10.1148/radiol.201616089010.1148/radiol.2016160890] [PubMed:\hrefhttps://www.ncbi.nlm.nih.gov/pubmed/2791870927918709]International audiencePurpose To investigate the feasibility of using spectral photon-counting computed tomography (CT) to differentiate between gadolinium-based and nonionic iodine-based contrast material in a colon phantom by using the characteristic k edge of gadolinium. Materials and Methods A custom-made colon phantom was filled with nonionic iodine-based contrast material, and a gadolinium-filled capsule representing a contrast material-enhanced polyp was positioned on the colon wall. The colon phantom was scanned with a preclinical spectral photon-counting CT system to obtain spectral and conventional data. By fully using the multibin spectral information, material decomposition was performed to generate iodine and gadolinium maps. Quantitative measurements were performed within the lumen and polyp to quantitatively determine the absolute content of iodine and gadolinium. Results In a conventional CT section, absorption values of both contrast agents were similar at approximately 110 HU. Contrast material maps clearly differentiated the distributions, with gadolinium solely in the polyp and iodine in the lumen of the colon. Quantitative measurements of contrast material concentrations in the colon and polyp matched well with those of actual prepared mixtures. Conclusion Dual-contrast spectral photon-counting CT colonography with iodine-filled lumen and gadolinium-tagged polyps may enable ready differentiation between polyps and tagged fecal material. © RSNA, 2016

Net-zero CO2 Germany: a retrospect from the year 2050

Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (similar to 645 Mt CO2), reducing (similar to 50 Mt CO2) and removing (similar to 60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector-specific solutions for industry, transport, and agriculture, as well as natural-sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net-zero CO2 system for Germany by 2050.Plain Language Summary Here a net-zero-2050 Germany is envisioned by combining analysis from an energy-system model with insights into approaches that allow for a higher carbon circularity in the German system, and first results from assessments of national carbon dioxide removal potentials. A back-casting perspective is applied on how net-zero Germany could look like in 2050. We are looking back from 2050, and analyzing how Germany for the first time reached a balance between its sources of CO2 to the atmosphere and the anthropogenic sinks created. This would consider full decarbonization in the entire energy sector and being entirely emission-free by 2050 within three priorities identified as being the most useful strategies for achieving net-zero: (a) Avoiding- (b) Reducing- (c) Removing emissions. This work is a collaboration of interdisciplinary scientists with the Net-Zero-2050 cluster of the Helmholtz Climate Initiative HI-CAM.Industrial Ecolog