@article{GuggenbergerTorreLudwigetal.2022,
  author    = {Guggenberger, Konstanze Viktoria and Torre, Giulia Dalla and Ludwig, Ute and Vogel, Patrick and Weng, Andreas Max and Vogt, Marius Lothar and Fr{\"o}hlich, Matthias and Schmalzing, Marc and Raithel, Esther and Forman, Christoph and Urbach, Horst and Meckel, Stephan and Bley, Thorsten Alexander},
  title     = {Vasa vasorum of proximal cerebral arteries after dural crossing - potential imaging confounder in diagnosing intracranial vasculitis in elderly subjects on black-blood MRI},
  series = {European Radiology},
  volume    = {32},
  journal   = {European Radiology},
  number    = {2},
  issn      = {1432-1084},
  doi       = {10.1007/s00330-021-08181-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266524},
  pages     = {1276-1284},
  year      = {2022},
  abstract  = {Objectives Vessel wall enhancement (VWE) may be commonly seen on MRI images of asymptomatic subjects. This study aimed to characterize the VWE of the proximal internal carotid (ICA) and vertebral arteries (VA) in a non-vasculitic elderly patient cohort. Methods Cranial MRI scans at 3 Tesla were performed in 43 patients (aged ≥ 50 years) with known malignancy for exclusion of cerebral metastases. For vessel wall imaging (VWI), a high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo sequence (T1 CS-SPACE prototype) was applied post gadolinium with an isotropic resolution of 0.55 mm. Bilateral proximal intradural ICA and VA segments were evaluated for presence, morphology, and longitudinal extension of VWE. Results Concentric VWE of the proximal intradural ICA was found in 13 (30\%) patients, and of the proximal intradural VA in 39 (91\%) patients. Mean longitudinal extension of VWE after dural entry was 13 mm in the VA and 2 mm in the ICA. In 14 of 39 patients (36\%) with proximal intradural VWE, morphology of VWE was suggestive of the mere presence of vasa vasorum. In 25 patients (64 \%), morphology indicated atherosclerotic lesions in addition to vasa vasorum. Conclusions Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in elderly subjects. Concentric VWE in these locations should not be confused with large artery vasculitis. Distal to these segments, VWE may be more likely related to pathologic conditions such as vasculitis.},
  language  = {en}
}
@article{HerzStefanescuLohretal.2022,
  author    = {Herz, Stefan and Stefanescu, Maria R. and Lohr, David and Vogel, Patrick and Kosmala, Aleksander and Terekhov, Maxim and Weng, Andreas M. and Grunz, Jan-Peter and Bley, Thorsten A. and Schreiber, Laura M.},
  title     = {Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission},
  series = {PloS One},
  volume    = {17},
  journal   = {PloS One},
  number    = {6},
  doi       = {10.1371/journal.pone.0270689},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300129},
  year      = {2022},
  abstract  = {Background To investigate the effects of B\(_1\)-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI). Methods Stenosis phantoms with different grades of stenosis (0\%, 20\%, 40\%, 60\%, 80\%, and 100\%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans. Samples were centrally positioned in a thorax phantom of 30 cm diameter filled with a custom-made liquid featuring dielectric properties of muscle tissue. MRI was performed on a 7 T whole-body system. 2D-gradient-echo sequences were acquired with an 8-channel transmit 16-channel receive (8 Tx / 16 Rx) cardiac array prototype coil with and without pTX mode. Measurements were compared to those obtained with identical scan parameters using a commercially available 1 Tx / 16 Rx single transmit coil (sTX). To assess reproducibility, measurements (n = 15) were repeated at different horizontal angles with respect to the B0-field. Results B\(_1\)-shimming and pTX markedly improved flip angle homogeneity across the thorax phantom yielding a distinctly increased signal-to-noise ratio (SNR) averaged over a whole slice relative to non-manipulated RF fields. Images without B\(_1\)-shimming showed shading artifacts due to local B\(_1\)\(^+\)-field inhomogeneities, which hampered stenosis quantification in severe cases. In contrast, B\(_1\)-shimming and pTX provided superior image homogeneity. Compared with a conventional sTX coil higher grade stenoses (60\% and 80\%) were graded significantly (p<0.01) more precise. Mild to moderate grade stenoses did not show significant differences. Overall, SNR was distinctly higher with B\(_1\)-shimming and pTX than with the conventional sTX coil (inside the stenosis phantoms 14\%, outside the phantoms 32\%). Both full and half concentration (10.2 mM and 5.1 mM) of a conventional Gd-DOTA dose for humans were equally suitable for stenosis evaluation in this phantom study. Conclusions B\(_1\)-shimming and pTX at 7 T can distinctly improve image homogeneity and therefore provide considerably more accurate MR image analysis, which is beneficial for imaging of small vessel structures.},
  language  = {en}
}
@article{VogelRueckertFriedrichetal.2022,
  author    = {Vogel, Patrick and R{\"u}ckert, Martin Andreas and Friedrich, Bernhard and Tietze, Rainer and Lyer, Stefan and Kampf, Thomas and Hennig, Thomas and D{\"o}lken, Lars and Alexiou, Christoph and Behr, Volker Christian},
  title     = {Critical Offset Magnetic PArticle SpectroScopy for rapid and highly sensitive medical point-of-care diagnostics},
  series = {Nature Communications},
  volume    = {13},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-022-34941-y},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300893},
  year      = {2022},
  abstract  = {Magnetic nanoparticles (MNPs) have been adapted for many applications, e.g., bioassays for the detection of biomarkers such as antibodies, by controlled engineering of specific surface properties. Specific measurement of such binding states is of high interest but currently limited to highly sensitive techniques such as ELISA or flow cytometry, which are relatively inflexible, difficult to handle, expensive and time-consuming. Here we report a method named COMPASS (Critical-Offset-Magnetic-Particle-SpectroScopy), which is based on a critical offset magnetic field, enabling sensitive detection to minimal changes in mobility of MNP ensembles, e.g., resulting from SARS-CoV-2 antibodies binding to the S antigen on the surface of functionalized MNPs. With a sensitivity of 0.33 fmole/50 µl (≙7 pM) for SARS-CoV-2-S1 antibodies, measured with a low-cost portable COMPASS device, the proposed technique is competitive with respect to sensitivity while providing flexibility, robustness, and a measurement time of seconds per sample. In addition, initial results with blood serum demonstrate high specificity.},
  language  = {en}
}
@article{HorvatVogelKampfetal.2020,
  author    = {Horvat, Sonja and Vogel, Patrick and Kampf, Thomas and Brandl, Andreas and Alshamsan, Aws and Alhadlaq, Hisham A. and Ahamed, Maqusood and Albrecht, Krystyna and Behr, Volker C. and Beilhack, Andreas and Groll, J{\"u}rgen},
  title     = {Crosslinked Coating Improves the Signal-to-Noise Ratio of Iron Oxide Nanoparticles in Magnetic Particle Imaging (MPI)},
  series = {ChemNanoMat},
  volume    = {6},
  journal   = {ChemNanoMat},
  number    = {5},
  doi       = {10.1002/cnma.202000009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214718},
  pages     = {755 -- 758},
  year      = {2020},
  abstract  = {Magnetic particle imaging is an emerging tomographic method used for evaluation of the spatial distribution of iron-oxide nanoparticles. In this work, the effect of the polymer coating on the response of particles was studied. Particles with covalently crosslinked coating showed improved signal and image resolution.},
  language  = {en}
}
@article{VogelMarkertRueckertetal.2019,
  author    = {Vogel, Patrick and Markert, Jonathan and R{\"u}ckert, Martin A. and Herz, Stefan and Keßler, Benedikt and Dremel, Kilian and Althoff, Daniel and Weber, Matthias and Buzug, Thorsten M. and Bley, Thorsten A. and Kullmann, Walter H. and Hanke, Randolf and Zabler, Simon and Behr, Volker C.},
  title     = {Magnetic Particle Imaging meets computed tomography: first simultaneous imaging},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-019-48960-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202501},
  pages     = {12627},
  year      = {2019},
  abstract  = {Magnetic Particle Imaging (MPI) is a promising new tomographic modality for fast as well as three-dimensional visualization of magnetic material. For anatomical or structural information an additional imaging modality such as computed tomography (CT) is required. In this paper, the first hybrid MPI-CT scanner for multimodal imaging providing simultaneous data acquisition is presented.},
  language  = {en}
}