TY  - JOUR
A1  - Roelofs, Freek
A1  - Blackburn, Lindy
A1  - Lindahl, Greg
A1  - Doeleman, Sheperd S.
A1  - Johnson, Michael D.
A1  - Arras, Philipp
A1  - Chatterjee, Koushik
A1  - Emami, Razieh
A1  - Fromm, Christian
A1  - Fuentes, Antonio
A1  - Knollmüller, Jakob
A1  - Kosogorov, Nikita
A1  - Müller, Hendrik
A1  - Patel, Nimesh
A1  - Raymond, Alexander
A1  - Tiede, Paul
A1  - Traianou, Efthalia
A1  - Vega, Justin
T1  - The ngEHT analysis challenges
JF  - Galaxies
N2  - The next-generation Event Horizon Telescope (ngEHT) will be a significant enhancement of the Event Horizon Telescope (EHT) array, with ∼10 new antennas and instrumental upgrades of existing antennas. The increased uv-coverage, sensitivity, and frequency coverage allow a wide range of new science opportunities to be explored. The ngEHT Analysis Challenges have been launched to inform the development of the ngEHT array design, science objectives, and analysis pathways. For each challenge, synthetic EHT and ngEHT datasets are generated from theoretical source models and released to the challenge participants, who analyze the datasets using image reconstruction and other methods. The submitted analysis results are evaluated with quantitative metrics. In this work, we report on the first two ngEHT Analysis Challenges. These have focused on static and dynamical models of M87* and Sgr A* and shown that high-quality movies of the extended jet structure of M87* and near-horizon hourly timescale variability of Sgr A* can be reconstructed by the reference ngEHT array in realistic observing conditions using current analysis algorithms. We identify areas where there is still room for improvement of these algorithms and analysis strategies. Other science cases and arrays will be explored in future challenges.
KW  - very long baseline interferometry
KW  - black holes
KW  - active galactic nuclei
KW  - radio astronomy
KW  - imaging
KW  - instrument design
KW  - telescopes
KW  - algorithms
KW  - data analysis
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304976
SN  - 2075-4434
VL  - 11
IS  - 1
ER  - 
TY  - JOUR
A1  - Vogel, P.
A1  - Rückert, M. A.
A1  - Greiner, C.
A1  - Günther, J.
A1  - Reichl, T.
A1  - Kampf, T.
A1  - Bley, T. A.
A1  - Behr, V. C.
A1  - Herz, S.
T1  - iMPI: portable human-sized magnetic particle imaging scanner for real-time endovascular interventions
JF  - Scientific Reports
N2  - Minimally invasive endovascular interventions have become an important tool for the treatment of cardiovascular diseases such as ischemic heart disease, peripheral artery disease, and stroke. X-ray fluoroscopy and digital subtraction angiography are used to precisely guide these procedures, but they are associated with radiation exposure for patients and clinical staff. Magnetic Particle Imaging (MPI) is an emerging imaging technology using time-varying magnetic fields combined with magnetic nanoparticle tracers for fast and highly sensitive imaging. In recent years, basic experiments have shown that MPI has great potential for cardiovascular applications. However, commercially available MPI scanners were too large and expensive and had a small field of view (FOV) designed for rodents, which limited further translational research. The first human-sized MPI scanner designed specifically for brain imaging showed promising results but had limitations in gradient strength, acquisition time and portability. Here, we present a portable interventional MPI (iMPI) system dedicated for real-time endovascular interventions free of ionizing radiation. It uses a novel field generator approach with a very large FOV and an application-oriented open design enabling hybrid approaches with conventional X-ray-based angiography. The feasibility of a real-time iMPI-guided percutaneous transluminal angioplasty (PTA) is shown in a realistic dynamic human-sized leg model.
KW  - biomedical engineering
KW  - electrical and electronic engineering
KW  - imaging
KW  - three-dimensional imaging
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357794
VL  - 13
ER  -