TY - JOUR A1 - Winter, Patrick A1 - Kampf, Thomas A1 - Helluy, Xavier A1 - Gutjahr, Fabian T. A1 - Meyer, Cord B. A1 - Rommel, Eberhard A1 - Bauer, Wolfgang R. A1 - Jakob, Peter M. A1 - Herold, Volker T1 - Fast retrospectively triggered local pulse-wave velocity measurements in mice with CMR-microscopy using a radial trajectory JF - Journal of Cardiovascular Magnetic Resonance N2 - Background The aortic pulse-wave velocity (PWV) is an important indicator of cardiovascular risk. In recent studies MRI methods have been developed to measure this parameter noninvasively in mice. Present techniques require additional hardware for cardiac and respiratory gating. In this work a robust self-gated measurement of the local PWV in mice without the need of triggering probes is proposed. Methods The local PWV of 6-months-old wild-type C57BL/6J mice (n=6) was measured in the abdominal aorta with a retrospectively triggered radial Phase Contrast (PC) MR sequence using the flow-area (QA) method. A navigator signal was extracted from the CMR data of highly asymmetric radial projections with short repetition time (TR=3 ms) and post-processed with high-pass and low-pass filters for retrospective cardiac and respiratory gating. The self-gating signal was used for a reconstruction of high-resolution Cine frames of the aortic motion. To assess the local PWV the volume flow Q and the cross-sectional area A of the aorta were determined. The results were compared with the values measured with a triggered Cartesian and an undersampled triggered radial PC-Cine sequence. Results In all examined animals a self-gating signal could be extracted and used for retrospective breath-gating and PC-Cine reconstruction. With the non-triggered measurement PWV values of 2.3±0.2 m/s were determined. These values are in agreement with those measured with the triggered Cartesian (2.4±0.2 m/s) and the triggered radial (2.3±0.2 m/s) measurement. Due to the strong robustness of the radial trajectory against undersampling an acceleration of more than two relative to the prospectively triggered Cartesian sampling could be achieved with the retrospective method. Conclusion With the radial flow-encoding sequence the extraction of a self-gating signal is feasible. The retrospective method enables a robust and fast measurement of the local PWV without the need of additional trigger hardware. KW - pulse-wave velocity KW - mouse KW - self-gating KW - phase-contrast CMR KW - non-triggered KW - retrospective KW - radial KW - aorta Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96602 UR - http://jcmr-online.com/content/15/1/88 ER - TY - JOUR A1 - Munz, Eberhard A1 - Jakob, Peter M. A1 - Borisjuk, Ljudmilla T1 - The potential of nuclear magnetic resonance to track lipids in planta JF - Biochimie N2 - Nuclear Magnetic Resonance (NMR) provides a highly flexible platform for non invasive analysis and imaging biological samples, since the manipulation of nuclear spin allows the tailoring of experiments to maximize the informativeness of the data. MRI is capable of visualizing a holistic picture of the lipid storage in living plant/seed. This review has sought to explain how the technology can be used to acquire functional and physiological data from plant samples, and how to exploit it to characterize lipid deposition in vivo. At the same time, we have referred to the current limitations of NMR technology as applied to plants, and in particular of the difficulty of transferring methodologies optimized for animal/medical subjects to plant ones. A forward look into likely developments in the field is included, anticipating its key future role in the study of living plant. KW - coconut cocos-nucifera KW - H-1-NMR spectroscopy KW - NMR-spectroscopy KW - camelina-sativa KW - high-throughput KW - oil storage KW - seeds KW - accumulation KW - field KW - metabolism KW - NMR KW - Lipid KW - MRI KW - CSI KW - Plants KW - Seeds Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186828 VL - 130 ER - TY - JOUR A1 - Kaireit, Till F. A1 - Sorrentino, Sajoscha A. A1 - Renne, Julius A1 - Schoenfeld, Christian A1 - Voskrebenzev, Andreas A1 - Gutberlet, Marcel A1 - Schulz, Angela A1 - Jakob, Peter M. A1 - Hansen, Gesine A1 - Wacker, Frank A1 - Welte, Tobias A1 - Tümmler, Burkhard A1 - Vogel-Claussen, Jens T1 - Functional lung MRI for regional monitoring of patients with cystic fibrosis JF - PLoS ONE N2 - Purpose To test quantitative functional lung MRI techniques in young adults with cystic fibrosis (CF) compared to healthy volunteers and to monitor immediate treatment effects of a single inhalation of hypertonic saline in comparison to clinical routine pulmonary function tests. Materials and methods Sixteen clinically stable CF patients and 12 healthy volunteers prospectively underwent two functional lung MRI scans and pulmonary function tests before and 2h after a single treatment of inhaled hypertonic saline or without any treatment. MRI-derived oxygen enhanced T1 relaxation measurements, fractional ventilation, first-pass perfusion parameters and a morpho-functional CF-MRI score were acquired. Results Compared to healthy controls functional lung MRI detected and quantified significantly increased ventilation heterogeneity in CF patients. Regional functional lung MRI measures of ventilation and perfusion as well as the CF-MRI score and pulmonary function tests could not detect a significant treatment effect two hours after a single treatment with hypertonic saline in young adults with CF (p>0.05). Conclusion This study shows the feasibility of functional lung MRI as a non-invasive, radiation-free tool for monitoring patients with CF. KW - Physics KW - Magnetic resonance imaging KW - Functional magnetic resonance imaging KW - Cystic fibrosis KW - Oxygen KW - Pulmonary imaging KW - Hypertonic KW - Pulmonary function KW - Quantum chronodynamics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172457 VL - 12 IS - 12 ER - TY - JOUR A1 - Straßer, Marion A1 - Schrauth, Joachim H. X. A1 - Dembski, Sofia A1 - Haddad, Daniel A1 - Ahrens, Bernd A1 - Schweizer, Stefan A1 - Christ, Bastian A1 - Cubukova, Alevtina A1 - Metzger, Marco A1 - Walles, Heike A1 - Jakob, Peter M. A1 - Sextl, Gerhard T1 - Calcium fluoride based multifunctional nanoparticles for multimodal imaging JF - Beilstein Journal of Nanotechnology N2 - New multifunctional nanoparticles (NPs) that can be used as contrast agents (CA) in different imaging techniques, such as photoluminescence (PL) microscopy and magnetic resonance imaging (MRI), open new possibilities for medical imaging, e.g., in the fields of diagnostics or tissue characterization in regenerative medicine. The focus of this study is on the synthesis and characterization of CaF\(_{2}\):(Tb\(^{3+}\),Gd\(^{3+}\)) NPs. Fabricated in a wet-chemical procedure, the spherical NPs with a diameter of 5–10 nm show a crystalline structure. Simultaneous doping of the NPs with different lanthanide ions, leading to paramagnetism and fluorescence, makes them suitable for MR and PL imaging. Owing to the Gd\(^{3+}\) ions on the surface, the NPs reduce the MR T\(_{1}\) relaxation time constant as a function of their concentration. Thus, the NPs can be used as a MRI CA with a mean relaxivity of about r = 0.471 mL·mg\(^{−1}\)·s\(^{−1}\). Repeated MRI examinations of four different batches prove the reproducibility of the NP synthesis and determine the long-term stability of the CAs. No cytotoxicity of NP concentrations between 0.5 and 1 mg·mL\(^{−1}\) was observed after exposure to human dermal fibroblasts over 24 h. Overall this study shows, that the CaF\(_{2}\):(Tb\(^{3+}\),Gd\(^{3+}\)) NPs are suitable for medical imaging. KW - calcium fluoride nanoparticles KW - magnetic resonance imaging (MRI) KW - multifunctional nanoparticles KW - multimodal imaging KW - photoluminescence Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170657 VL - 8 ER -