Search

Your search keyword '"Daerr, Heiner"' showing total 29 results
Start Over Author "Daerr, Heiner"
29 results on '"Daerr, Heiner"'

1. Hybrid spectral CT system with clinical rapid kVp-switching x-ray tube and dual-layer detector for improved iodine quantification

Author

Sandvold, Olivia F., primary, Proksa, Roland, additional, Daerr, Heiner, additional, Perkins, Amy E., additional, Brown, Kevin M., additional, Shapira, Nadav, additional, Köhler, Thomas, additional, Stayman, Joseph W., additional, Gang, Grace J., additional, Manjeshwar, Ravindra M., additional, and Noël, Peter B., additional

Published
2024
Full Text
View/download PDF

2. A novel vacuum ultra violet lamp for metastable rare gas experiments

Author

Daerr, Heiner, Kohler, Markus, Sahling, Peter, Tippenhauer, Sandra, Arabi-Hashemi, Ariyan, Becker, Christoph, Sengstock, Klaus, and Kalinowski, Martin B.

Subjects
Physics - Atomic Physics
Abstract

We report on a new design of a vacuum ultra violet (VUV) lamp for direct optical excitation of high laying atomic states e.g. for excitation of metastable rare gas atoms. The lamp can be directly mounted to ultra high vacuum vessels (p <= 10^(-10) mbar). It is driven by a 2.45 GHz microwave source. For optimum operation it requires powers of approximately 20 W. The VUV light is transmitted through a magnesium fluoride window, which is known to have a decreasing transmittance for VUV photons with time. In our special setup, after a run-time of the VUV lamp of 550 h the detected signal continuously decreased to 25 % of its initial value. This corresponds to a lifetime increase of two orders of magnitude compared to previous setups or commercial lamps.

Published
2011
Full Text
View/download PDF

3. Experimental feasibility of spectral photon-counting computed tomography with two contrast agents for the detection of endoleaks following endovascular aortic repair

Author

Dangelmaier, Julia, Bar-Ness, Daniel, Daerr, Heiner, Muenzel, Daniela, Si-Mohamed, Salim, Ehn, Sebastian, Fingerle, Alexander A., Kimm, Melanie A., Kopp, Felix K., Boussel, Loic, Roessl, Ewald, Pfeiffer, Franz, Rummeny, Ernst J., Proksa, Roland, Douek, Philippe, and Noël, Peter B.

Published
2018
Full Text
View/download PDF

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

Author

Muenzel, Daniela, primary, Bar-Ness, Daniel, additional, Roessl, Ewald, additional, Blevis, Ira, additional, Bartels, Matthias, additional, Fingerle, Alexander A., additional, Ruschke, Stefan, additional, Coulon, Philippe, additional, Daerr, Heiner, additional, Kopp, Felix K., additional, Brendel, Bernhard, additional, Thran, Axel, additional, Rokni, Michal, additional, Herzen, Julia, additional, Boussel, Loic, additional, Pfeiffer, Franz, additional, Proksa, Roland, additional, Rummeny, Ernst J., additional, Douek, Philippe, additional, and Noël, Peter B., additional

Published
2017
Full Text
View/download PDF

16. Gold Nanocrystal Labeling Allows Low-Density Lipoprotein Imaging from the Subcellular to Macroscopic Level

Author

Allijn, Iris E., Leong, Wei, Tang, Jun, Gianella, Anita, Mieszawska, Aneta J., Fay, Francois, Ma, Ge, Russell, Stewart, Callo, Catherine B., Gordon, Ronald E., Korkmaz, Emine, Post, Jan Andries, Zhao, Yiming, Gerritsen, Hans C., Thran, Axel, Proksa, Roland, Daerr, Heiner, Storm, Gert, Fuster, Valentin, Fisher, Edward A., Fayad, Zahi A., Mulder, Willem J. M., and Cormode, David P.

Abstract

Low-density lipoprotein (LDL) plays a critical role in cholesterol transport and is closely linked to the progression of several diseases. This motivates the development of methods to study LDL behavior from the microscopic to whole-body level. We have developed an approach to efficiently load LDL with a range of diagnostically active nanocrystals or hydrophobic agents. We performed focused experiments on LDL labeled with gold nanocrystals (Au-LDL). The labeling procedure had minimal effect on LDL size, morphology, or composition. Biological function was found to be maintained from both in vitroand in vivoexperiments. Tumor-bearing mice were injected intravenously with LDL, DiR-LDL, Au-LDL, or a gold-loaded nanoemulsion. LDL accumulation in the tumors was detected with whole-body imaging methods, such as computed tomography (CT), spectral CT, and fluorescence imaging. Cellular localization was studied with transmission electron microscopy and fluorescence techniques. This LDL labeling procedure should permit the study of lipoprotein biointeractions in unprecedented detail.

Published
2024
Full Text
View/download PDF

22. Gold Nanocrystal Labeling Allows Low-Density Lipoprotein Imaging from the Subcellular to Macroscopic Level

Author

Allijn, Iris E., primary, Leong, Wei, additional, Tang, Jun, additional, Gianella, Anita, additional, Mieszawska, Aneta J., additional, Fay, Francois, additional, Ma, Ge, additional, Russell, Stewart, additional, Callo, Catherine B., additional, Gordon, Ronald E., additional, Korkmaz, Emine, additional, Post, Jan Andries, additional, Zhao, Yiming, additional, Gerritsen, Hans C., additional, Thran, Axel, additional, Proksa, Roland, additional, Daerr, Heiner, additional, Storm, Gert, additional, Fuster, Valentin, additional, Fisher, Edward A., additional, Fayad, Zahi A., additional, Mulder, Willem J. M., additional, and Cormode, David P., additional

Published
2013
Full Text
View/download PDF

29. Hybrid spectral CT system with clinical rapid kVp-switching x-ray tube and dual-layer detector for improved iodine quantification.

Author

Sandvold OF, Proksa R, Daerr H, Perkins AE, Brown KM, Shapira N, Koehler T, Stayman JW, Gang GJ, Manjeshwar RM, and Noël PB

Abstract

Spectral computed tomography (CT) is a powerful diagnostic tool offering quantitative material decomposition results that enhance clinical imaging by providing physiologic and functional insights. Iodine, a widely used contrast agent, improves visualization in various clinical contexts. However, accurately detecting low-concentration iodine presents challenges in spectral CT systems, particularly crucial for conditions like pancreatic cancer assessment. In this study, we present preliminary results from our hybrid spectral CT instrumentation which includes clinical-grade hardware (rapid kVp-switching x-ray tube, dual-layer detector). This combination expands spectral datasets from two to four channels, wherein we hypothesize improved quantification accuracy for low-dose and low-iodine concentration cases. We modulate the system duty cycle to evaluate its impact on quantification noise and bias. We evaluate iodine quantification performance by comparing two hybrid weighting strategies alongside rapid kVp-switching. This evaluation is performed with a polyamide phantom containing seven iodine inserts ranging from 0.5 to 20 mg/mL. In comparison to alternative methodologies, the maximum separation configuration, incorporating data from both the 80 kVp, low photon energy detector layer and the 140 kVp, high photon energy detector layer produces spectral images containing low quantitative noise and bias. This study presents initial evaluations on a hybrid spectral CT system, leveraging clinical hardware to demonstrate the potential for enhanced precision and sensitivity in spectral imaging. This research holds promise for advancing spectral CT imaging performance across diverse clinical scenarios.

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results