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5. Third-Generation Cardiovascular Phantom The Next Generation of Preclinical Research in Diagnostic Imaging

Author

McDermott, M.C., Sartoretti, T., Mihl, C., Pietsch, H., Alkadhi, H., Wildberger, J.E., McDermott, M.C., Sartoretti, T., Mihl, C., Pietsch, H., Alkadhi, H., and Wildberger, J.E.

Abstract

ObjectiveDifferent types of preclinical research tools used in the field of diagnostic imaging such as dynamic flow circulation phantoms have built the foundation for optimization and advancement of clinical procedures including new imaging techniques. The objective was to introduce a third-generation phantom, building on the limitations of earlier versions and unlocking new opportunities for preclinical investigation.Material and MethodsA third-generation phantom was designed and constructed comprising physiological vascular models from head to toe, including a 4-chamber heart with embedded heart valves and a controllable electromechanical pump. The models include modular segments, allowing for interchangeability between healthy and diseased vessels. Clinical sanity checks were performed using the phantom in combination with a dual-head power injector on a third-generation dual-source computed tomography scanner. Contrast media was injected at 1.5 g I/s, and the phantom was configured with a cardiac output of 5.3 L/min. Measurements of mean transit times between key vascular landmarks and peak enhancement values in Hounsfield units (HUs) were measured to compare with expected in vivo results estimated from literature.ResultsGood agreement was obtained between literature reference values from physiology and measured results. Contrast arrival between antecubital vein and right ventricle was measured to be 13.1 +/- 0.3 seconds. Transit time from right ventricle to left ventricle was 12.0 +/- 0.2 seconds, from left internal carotid artery to left internal jugular vein 7.7 +/- 0.4 seconds, and 2.9 +/- 0.2 seconds from aortic arch to aortic bifurcation. The peak enhancement measured in the regions of interest was between 336 HU and 557 HU.ConclusionsThe third-generation phantom demonstrated the capability of simulating physiologic in vivo conditions with accurate contrast media transport timing, good repeatability, and expected enhancement profiles. As a nearly complete

Published
2022

7. Self-organization and nonlinear dynamics with spatially coherent structures

Author

Spatschek, K. H., Heiermann, P., Laedke, E. W., Naulin, V., Pietsch, H., Araki, H., editor, Ehlers, J., editor, Hepp, K., editor, Jaffe, R. L., editor, Kippenhahn, R., editor, Ruelle, D., editor, Weidenmüller, H. A., editor, Wess, J., editor, Zittartz, J., editor, Beiglböck, W., editor, Remoissenet, M., editor, and Peyrand, M., editor

Published
1991
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28. Low-osmolar monomeric versus iso-osmolar dimeric contrast media: an intra-individual comparison in CT angiography using an animal model

Author

Behrendt, F.F., Pietsch, H., Jost, G., Keil, S., Mottaghy, F.M., Gunther, R.W., Mahnken, A.H., MUMC+: DA BV Medische staf (6), RS: NUTRIM - R1 - Metabolic Syndrome, Beeldvorming, and RS: CARIM School for Cardiovascular Diseases

Subjects
arteries, IODINE CONCENTRATION, ENHANCEMENT, CT angiography, vascular, SAFETY, MDCT, COMPUTED-TOMOGRAPHY, IODIXANOL-320, IOMEPROL-400, AGENTS, contrast agents-intravenous
Abstract

INTRODUCTION: The aim of this study was to compare intra-individual contrast enhancement in multidetector-row computed tomography using the low-osmolar monomeric iopromide 300 and the iso-osmolar dimeric iodixanol 320. METHODS: Repeated computed tomography scanning of the chest of five pigs was performed under standardised conditions using iopromide 300 (300 mg I/mL) and iodixanol 320 (320 mg I/mL) with an identical iodine delivery rate of 1.5 g I/sec and a total iodine dose of 300 mg/kg body weight. Time-enhancement curves were computed, and pulmonary and aortic peak enhancement, time-to-peak and plateau time above 300 Hounsfield units (HU) were analysed. RESULTS: Intra-individual comparison revealed no statistically significant differences in contrast enhancement between the iopromide 300 and iodixanol 320 in the pulmonary artery and the aorta (620 vs 552 HU; P = 0.13). There was no significant difference between the two CM in the plateau time at the pulmonary artery and the aorta (P = 0.75 and P = 0.24, respectively). Aortic peak time was significantly earlier with iopromide 300 than with iodixanol 320 (P = 0.004). CONCLUSIONS: Low-osmolar monomeric and iso-osmolar dimeric CM provide a similar and suitable vascular contrast enhancement.

Published
2011

36. Reciprocal Space Mapping by spot profile analyzing low energy electron diffraction

Author

Meyer zu Heringdorf, Frank, Pietsch, H., and Horn-von Hoegen, Michael

Subjects
Physik (inkl. Astronomie)
Abstract

We present an experimental approach for the recording of two-dimensional reciprocal space maps using spot profile analyzing low energy electron diffraction (SPA-LEED). A specialized alignment procedure eliminates the shifting of LEED patterns on the screen which is commonly observed upon variation of the electron energy. After the alignment, a set of one-dimensional sections through the diffraction pattern is recorded at different energies. A freely available software tool is used to assemble the sections into a reciprocal space map. The necessary modifications of the Burr-Brown computer interface of the two Leybold and Omicron type SPA-LEED instruments are discussed and step-by-step instructions are given to adapt the SPA 4.1d software to the changed hardware. Au induced faceting of 4° vicinal Si(001) is used as an example to demonstrate the technique.

Published
2005

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