95 results on '"Sonia Waiczies"'
Search Results
2. Arterial Spin Labeling and T2* Mapping Detect Early Changes in Hypertrophic Cardiomyopathy
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Oumaima Laghzali, MSc, Shahriar Shalikar, MSc, Siqin Liu, MSc, Joao dos Santos Periquito, PhD, Andreas Pohlmann, PhD, Frank Kober, PhD, Lucie Carrier, PhD, Thoralf Niendorf, Sonia Waiczies, PhD, and Min-Chi Ku, PhD
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Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Published
- 2024
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3. Simulating rigid head motion artifacts on brain magnitude MRI data-Outcome on image quality and segmentation of the cerebral cortex.
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Hampus Olsson, Jason Michael Millward, Ludger Starke, Thomas Gladytz, Tobias Klein, Jana Fehr, Wei-Chang Lai, Christoph Lippert, Thoralf Niendorf, and Sonia Waiczies
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Medicine ,Science - Abstract
Magnetic Resonance Imaging (MRI) datasets from epidemiological studies often show a lower prevalence of motion artifacts than what is encountered in clinical practice. These artifacts can be unevenly distributed between subject groups and studies which introduces a bias that needs addressing when augmenting data for machine learning purposes. Since unreconstructed multi-channel k-space data is typically not available for population-based MRI datasets, motion simulations must be performed using signal magnitude data. There is thus a need to systematically evaluate how realistic such magnitude-based simulations are. We performed magnitude-based motion simulations on a dataset (MR-ART) from 148 subjects in which real motion-corrupted reference data was also available. The similarity of real and simulated motion was assessed by using image quality metrics (IQMs) including Coefficient of Joint Variation (CJV), Signal-to-Noise-Ratio (SNR), and Contrast-to-Noise-Ratio (CNR). An additional comparison was made by investigating the decrease in the Dice-Sørensen Coefficient (DSC) of automated segmentations with increasing motion severity. Segmentation of the cerebral cortex was performed with 6 freely available tools: FreeSurfer, BrainSuite, ANTs, SAMSEG, FastSurfer, and SynthSeg+. To better mimic the real subject motion, the original motion simulation within an existing data augmentation framework (TorchIO), was modified. This allowed a non-random motion paradigm and phase encoding direction. The mean difference in CJV/SNR/CNR between the real motion-corrupted images and our modified simulations (0.004±0.054/-0.7±1.8/-0.09±0.55) was lower than that of the original simulations (0.015±0.061/0.2±2.0/-0.29±0.62). Further, the mean difference in the DSC between the real motion-corrupted images was lower for our modified simulations (0.03±0.06) compared to the original simulations (-0.15±0.09). SynthSeg+ showed the highest robustness towards all forms of motion, real and simulated. In conclusion, reasonably realistic synthetic motion artifacts can be induced on a large-scale when only magnitude MR images are available to obtain unbiased data sets for the training of machine learning based models.
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- 2024
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4. Transient enlargement of brain ventricles during relapsing-remitting multiple sclerosis and experimental autoimmune encephalomyelitis
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Jason M. Millward, Paula Ramos Delgado, Alina Smorodchenko, Laura Boehmert, Joao Periquito, Henning M. Reimann, Christian Prinz, Antje Els, Michael Scheel, Judith Bellmann-Strobl, Helmar Waiczies, Jens Wuerfel, Carmen Infante-Duarte, Claudia Chien, Joseph Kuchling, Andreas Pohlmann, Frauke Zipp, Friedemann Paul, Thoralf Niendorf, and Sonia Waiczies
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Autoimmunity ,Inflammation ,Medicine - Abstract
The brain ventricles are part of the fluid compartments bridging the CNS with the periphery. Using MRI, we previously observed a pronounced increase in ventricle volume (VV) in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). Here, we examined VV changes in EAE and MS patients in longitudinal studies with frequent serial MRI scans. EAE mice underwent serial MRI for up to 2 months, with gadolinium contrast as a proxy of inflammation, confirmed by histopathology. We performed a time-series analysis of clinical and MRI data from a prior clinical trial in which RRMS patients underwent monthly MRI scans over 1 year. VV increased dramatically during preonset EAE, resolving upon clinical remission. VV changes coincided with blood-brain barrier disruption and inflammation. VV was normal at the termination of the experiment, when mice were still symptomatic. The majority of relapsing-remitting MS (RRMS) patients showed dynamic VV fluctuations. Patients with contracting VV had lower disease severity and a shorter duration. These changes demonstrate that VV does not necessarily expand irreversibly in MS but, over short time scales, can expand and contract. Frequent monitoring of VV in patients will be essential to disentangle the disease-related processes driving short-term VV oscillations from persistent expansion resulting from atrophy.
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- 2020
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5. MR Elastography-Based Assessment of Matrix Remodeling at Lesion Sites Associated With Clinical Severity in a Model of Multiple Sclerosis
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Shuangqing Wang, Jason M. Millward, Laura Hanke-Vela, Bimala Malla, Kjara Pilch, Ana Gil-Infante, Sonia Waiczies, Susanne Mueller, Philipp Boehm-Sturm, Jing Guo, Ingolf Sack, and Carmen Infante-Duarte
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magnetic resonance elastography ,experimental autoimmune encephalomyelitis ,extracellular matrix ,fibronectin ,gadolinium-based contrast agent ,multiple sclerosis ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Magnetic resonance imaging (MRI) with gadolinium based contrast agents (GBCA) is routinely used in the clinic to visualize lesions in multiple sclerosis (MS). Although GBCA reveal endothelial permeability, they fail to expose other aspects of lesion formation such as the magnitude of inflammation or tissue changes occurring at sites of blood-brain barrier (BBB) disruption. Moreover, evidence pointing to potential side effects of GBCA has been increasing. Thus, there is an urgent need to develop GBCA-independent imaging tools to monitor pathology in MS. Using MR-elastography (MRE), we previously demonstrated in both MS and the animal model experimental autoimmune encephalomyelitis (EAE) that inflammation was associated with a reduction of brain stiffness. Now, using the relapsing-remitting EAE model, we show that the cerebellum—a region with predominant inflammation in this model—is especially prone to loss of stiffness. We also demonstrate that, contrary to GBCA-MRI, reduction of brain stiffness correlates with clinical disability and is associated with enhanced expression of the extracellular matrix protein fibronectin (FN). Further, we show that FN is largely expressed by activated astrocytes at acute lesions, and reflects the magnitude of tissue remodeling at sites of BBB breakdown. Therefore, MRE could emerge as a safe tool suitable to monitor disease activity in MS.
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- 2020
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6. Labeling of cell therapies: How can we get it right?
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Sonia Waiczies, Thoralf Niendorf, and Giovanna Lombardi
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cell labeling ,cell tracking ,clinical application ,electron microscopy ,excess nanoparticles ,internalization ,intracellular ,membrane-bound ,mri ,nk cells ,phagocytes ,nanolabel ,nanoparticles ,patient studies ,t cells ,Immunologic diseases. Allergy ,RC581-607 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Labeling cells for non-invasive tracking in vivo using magnetic resonance imaging (MRI) is an emerging hot topic garnering ever increasing attention, yet it is fraught with numerous methodological challenges, which merit careful attention. Several of the current procedures used to label cells for tracking by MRI take advantage of the intrinsic phagocytic nature of cells to engulf nanoparticles, though cells with low intrinsic phagocytic capacity are also commonly studied. Before we take the next steps towards administering such cells in vivo, it is essential to understand how the nanolabel is recognized, internalized, trafficked and distributed within the specific host cell. This is even more critical when contemplating labeling of cells that may ultimately be applied in vivo to patients in a therapeutic context.
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- 2017
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7. Modulation of dendritic cell immunobiology via inhibition of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase.
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Tina Leuenberger, Caspar F Pfueller, Felix Luessi, Ivo Bendix, Magdalena Paterka, Timour Prozorovski, Denise Treue, Sarah Luenstedt, Josephine Herz, Volker Siffrin, Carmen Infante-Duarte, Frauke Zipp, and Sonia Waiczies
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Medicine ,Science - Abstract
The maturation status of dendritic cells determines whether interacting T cells are activated or if they become tolerant. Previously we could induce T cell tolerance by applying a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor (HMGCRI) atorvastatin, which also modulates MHC class II expression and has therapeutic potential in autoimmune disease. Here, we aimed at elucidating the impact of this therapeutic strategy on T cell differentiation as a consequence of alterations in dendritic cell function. We investigated the effect of HMGCRI during differentiation of peripheral human monocytes and murine bone marrow precursors to immature DC in vitro and assessed their phenotype. To examine the stimulatory and tolerogenic capacity of these modulated immature dendritic cells, we measured proliferation and suppressive function of CD4+ T cells after stimulation with the modulated immature dendritic cells. We found that an HMGCRI, atorvastatin, prevents dendrite formation during the generation of immature dendritic cells. The modulated immature dendritic cells had a diminished capacity to take up and present antigen as well as to induce an immune response. Of note, the consequence was an increased capacity to differentiate naïve T cells towards a suppressor phenotype that is less sensitive to proinflammatory stimuli and can effectively inhibit the proliferation of T effector cells in vitro. Thus, manipulation of antigen-presenting cells by HMGCRI contributes to an attenuated immune response as shown by promotion of T cells with suppressive capacities.
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- 2014
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8. Enlargement of cerebral ventricles as an early indicator of encephalomyelitis.
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Stefano Lepore, Helmar Waiczies, Jan Hentschel, Yiyi Ji, Julia Skodowski, Andreas Pohlmann, Jason M Millward, Friedemann Paul, Jens Wuerfel, Thoralf Niendorf, and Sonia Waiczies
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Medicine ,Science - Abstract
Inflammatory disorders of the central nervous system such as multiple sclerosis and acute disseminated encephalomyelitis involve an invasion of immune cells that ultimately leads to white matter demyelination, neurodegeneration and development of neurological symptoms. A clinical diagnosis is often made when neurodegenerative processes are already ongoing. In an attempt to seek early indicators of disease, we studied the temporal and spatial distribution of brain modifications in experimental autoimmune encephalomyelitis (EAE). In a thorough magnetic resonance imaging study performed with EAE mice, we observed significant enlargement of the ventricles prior to disease clinical manifestation and an increase in free water content within the cerebrospinal fluid as demonstrated by changes in T2 relaxation times. The increase in ventricle size was seen in the lateral, third and fourth ventricles. In some EAE mice the ventricle size started returning to normal values during disease remission. In parallel to this macroscopic phenomenon, we studied the temporal evolution of microscopic lesions commonly observed in the cerebellum also starting prior to disease onset. Our data suggest that changes in ventricle size during the early stages of brain inflammation could be an early indicator of the events preceding neurological disease and warrant further exploration in preclinical and clinical studies.
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- 2013
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9. High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury.
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Andreas Pohlmann, Jan Hentschel, Mandy Fechner, Uwe Hoff, Gordana Bubalo, Karen Arakelyan, Kathleen Cantow, Erdmann Seeliger, Bert Flemming, Helmar Waiczies, Sonia Waiczies, Wolf-Hagen Schunck, Duska Dragun, and Thoralf Niendorf
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Medicine ,Science - Abstract
Ischemia/reperfusion (I/R) injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI). There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive in vivo parametric magnetic resonance imaging (MRI) may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T2* and T2, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T2*/T2 mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of in vivo changes in all kidney regions during ischemia and early reperfusion. Significant changes in T2* and T2 were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.
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- 2013
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10. Functional and morphological cardiac magnetic resonance imaging of mice using a cryogenic quadrature radiofrequency coil.
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Babette Wagenhaus, Andreas Pohlmann, Matthias Alexander Dieringer, Antje Els, Helmar Waiczies, Sonia Waiczies, Jeanette Schulz-Menger, and Thoralf Niendorf
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Medicine ,Science - Abstract
Cardiac morphology and function assessment by magnetic resonance imaging is of increasing interest for a variety of mouse models in pre-clinical cardiac research, such as myocardial infarction models or myocardial injury/remodeling in genetically or pharmacologically induced hypertension. Signal-to-noise ratio (SNR) constraints, however, limit image quality and blood myocardium delineation, which crucially depend on high spatial resolution. Significant gains in SNR with a cryogenically cooled RF probe have been shown for mouse brain MRI, yet the potential of applying cryogenic RF coils for cardiac MR (CMR) in mice is, as of yet, untapped. This study examines the feasibility and potential benefits of CMR in mice employing a 400 MHz cryogenic RF surface coil, compared with a conventional mouse heart coil array operating at room temperature. The cryogenic RF coil affords SNR gains of 3.0 to 5.0 versus the conventional approach and hence enables an enhanced spatial resolution. This markedly improved image quality--by better deliniation of myocardial borders and enhanced depiction of papillary muscles and trabeculae--and facilitated a more accurate cardiac chamber quantification, due to reduced intraobserver variability. In summary the use of a cryogenically cooled RF probe represents a valuable means of enhancing the capabilities of CMR of mice.
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- 2012
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11. Identification of cellular infiltrates during early stages of brain inflammation with magnetic resonance microscopy.
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Helmar Waiczies, Jason M Millward, Stefano Lepore, Carmen Infante-Duarte, Andreas Pohlmann, Thoralf Niendorf, and Sonia Waiczies
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Medicine ,Science - Abstract
A comprehensive view of brain inflammation during the pathogenesis of autoimmune encephalomyelitis can be achieved with the aid of high resolution non-invasive imaging techniques such as microscopic magnetic resonance imaging (μMRI). In this study we demonstrate the benefits of cryogenically-cooled RF coils to produce μMRI in vivo, with sufficient detail to reveal brain pathology in the experimental autoimmune encephalomyelitis (EAE) model. We could visualize inflammatory infiltrates in detail within various regions of the brain, already at an early phase of EAE. Importantly, this pathology could be seen clearly even without the use of contrast agents, and showed excellent correspondence with conventional histology. The cryogenically-cooled coil enabled the acquisition of high resolution images within short scan times: an important practical consideration in conducting animal experiments. The detail of the cellular infiltrates visualized by in vivo μMRI allows the opportunity to follow neuroinflammatory processes even during the early stages of disease progression. Thus μMRI will not only complement conventional histological examination but will also enable longitudinal studies on the kinetics and dynamics of immune cell infiltration.
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- 2012
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12. High spatial resolution and temporally resolved T2* mapping of normal human myocardium at 7.0 Tesla: an ultrahigh field magnetic resonance feasibility study.
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Fabian Hezel, Christof Thalhammer, Sonia Waiczies, Jeanette Schulz-Menger, and Thoralf Niendorf
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Medicine ,Science - Abstract
Myocardial tissue characterization using T(2)(*) relaxation mapping techniques is an emerging application of (pre)clinical cardiovascular magnetic resonance imaging. The increase in microscopic susceptibility at higher magnetic field strengths renders myocardial T(2)(*) mapping at ultrahigh magnetic fields conceptually appealing. This work demonstrates the feasibility of myocardial T(2)(*) imaging at 7.0 T and examines the applicability of temporally-resolved and high spatial resolution myocardial T(2)(*) mapping. In phantom experiments single cardiac phase and dynamic (CINE) gradient echo imaging techniques provided similar T(2)(*) maps. In vivo studies showed that the peak-to-peak B(0) difference following volume selective shimming was reduced to approximately 80 Hz for the four chamber view and mid-ventricular short axis view of the heart and to 65 Hz for the left ventricle. No severe susceptibility artifacts were detected in the septum and in the lateral wall for T(2)(*) weighting ranging from TE = 2.04 ms to TE = 10.2 ms. For TE >7 ms, a susceptibility weighting induced signal void was observed within the anterior and inferior myocardial segments. The longest T(2)(*) values were found for anterior (T(2)(*) = 14.0 ms), anteroseptal (T(2)(*) = 17.2 ms) and inferoseptal (T(2)(*) = 16.5 ms) myocardial segments. Shorter T(2)(*) values were observed for inferior (T(2)(*) = 10.6 ms) and inferolateral (T(2)(*) = 11.4 ms) segments. A significant difference (p = 0.002) in T(2)(*) values was observed between end-diastole and end-systole with T(2)(*) changes of up to approximately 27% over the cardiac cycle which were pronounced in the septum. To conclude, these results underscore the challenges of myocardial T(2)(*) mapping at 7.0 T but demonstrate that these issues can be offset by using tailored shimming techniques and dedicated acquisition schemes.
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- 2012
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13. Perfluorocarbon particle size influences magnetic resonance signal and immunological properties of dendritic cells.
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Helmar Waiczies, Stefano Lepore, Nicole Janitzek, Ulrike Hagen, Frank Seifert, Bernd Ittermann, Bettina Purfürst, Antonio Pezzutto, Friedemann Paul, Thoralf Niendorf, and Sonia Waiczies
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Medicine ,Science - Abstract
The development of cellular tracking by fluorine ((19)F) magnetic resonance imaging (MRI) has introduced a number of advantages for following immune cell therapies in vivo. These include improved signal selectivity and a possibility to correlate cells labeled with fluorine-rich particles with conventional anatomic proton ((1)H) imaging. While the optimization of the cellular labeling method is clearly important, the impact of labeling on cellular dynamics should be kept in mind. We show by (19)F MR spectroscopy (MRS) that the efficiency in labeling cells of the murine immune system (dendritic cells) by perfluoro-15-crown-5-ether (PFCE) particles increases with increasing particle size (560>365>245>130 nm). Dendritic cells (DC) are professional antigen presenting cells and with respect to impact of PFCE particles on DC function, we observed that markers of maturation for these cells (CD80, CD86) were also significantly elevated following labeling with larger PFCE particles (560 nm). When labeled with these larger particles that also gave an optimal signal in MRS, DC presented whole antigen more robustly to CD8+ T cells than control cells. Our data suggest that increasing particle size is one important feature for optimizing cell labeling by PFCE particles, but may also present possible pitfalls such as alteration of the immunological status of these cells. Therefore depending on the clinical scenario in which the (19)F-labeled cellular vaccines will be applied (cancer, autoimmune disease, transplantation), it will be interesting to monitor the fate of these cells in vivo in the relevant preclinical mouse models.
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- 2011
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14. Oral high-dose atorvastatin treatment in relapsing-remitting multiple sclerosis.
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Friedemann Paul, Sonia Waiczies, Jens Wuerfel, Judith Bellmann-Strobl, Jan Dörr, Helmar Waiczies, Mareile Haertle, Klaus D Wernecke, Hans-Dieter Volk, Orhan Aktas, and Frauke Zipp
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Medicine ,Science - Abstract
BACKGROUND:Recent data from animal models of multiple sclerosis (MS) and from a pilot study indicated a possible beneficial impact of statins on MS. METHODOLOGY/PRINCIPAL FINDINGS:Safety, tolerability and effects on disease activity of atorvastatin given alone or in combination with interferon-beta (IFN-beta) were assessed in a phase II open-label baseline-to-treatment trial in relapsing-remitting MS (RRMS). Patients with at least one gadolinium-enhancing lesion (CEL) at screening by magnetic resonance imaging (MRI) were eligible for the study. After a baseline period of 3 monthly MRI scans (months -2 to 0), patients followed a 9-month treatment period on 80 mg atorvastatin daily. The number of CEL in treatment months 6 to 9 compared to baseline served as the primary endpoint. Other MRI-based parameters as well as changes in clinical scores and immune responses served as secondary endpoints. Of 80 RRMS patients screened, 41 were included, among them 16 with IFN-beta comedication. The high dose of 80 mg atorvastatin was well tolerated in the majority of patients, regardless of IFN-beta comedication. Atorvastatin treatment led to a substantial reduction in the number and volume of CEL in two-sided multivariate analysis (p = 0.003 and p = 0.008). A trend towards a significant decrease in number and volume of CEL was also detected in patients with IFN-beta comedication (p = 0.060 and p = 0.062), in contrast to patients without IFN-beta comedication (p = 0.170 and p = 0.140). Immunological investigations showed no suppression in T cell response but a significant increase in IL-10 production. CONCLUSIONS/SIGNIFICANCE:Our data suggest that high-dose atorvastatin treatment in RRMS is safe and well tolerated. Moreover, MRI analysis indicates a possible beneficial effect of atorvastatin, alone or in combination with IFN-beta, on the development of new CEL. Thus, our findings provide a rationale for phase II/III trials, including combination of atorvastatin with already approved immunomodulatory therapy regimens. TRIAL REGISTRATION:ClinicalTrials.gov NCT00616187.
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- 2008
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15. Quantifying model uncertainty for semantic segmentation of Fluorine-19 MRI using stochastic gradient MCMC.
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Masoumeh Javanbakhat, Ludger Starke, Sonia Waiczies, and Christoph Lippert
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- 2024
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16. Ku et al_supplemental_methods from ERK1 as a Therapeutic Target for Dendritic Cell Vaccination against High-Grade Gliomas
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Sonia Waiczies, Thoralf Niendorf, Wolfgang Uckert, Helmut Kettenmann, Susanne A. Wolf, Gilles Pagès, Conrad Martin, Martin Günther, Tim Prozorovski, Helmar Waiczies, Andreas Pohlmann, Ivo Bendix, Inan Edes, and Min-Chi Ku
- Abstract
Supplemental Methods
- Published
- 2023
17. First in vivo fluorine-19 magnetic resonance imaging of the multiple sclerosis drug siponimod
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Ludger Starke, Jason M. Millward, Christian Prinz, Fatima Sherazi, Helmar Waiczies, Christoph Lippert, Marc Nazaré, Friedemann Paul, Thoralf Niendorf, and Sonia Waiczies
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Cardiovascular and Metabolic Diseases ,Medicine (miscellaneous) ,Technology Platforms ,Function and Dysfunction of the Nervous System ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) - Abstract
Theranostic imaging methods could greatly enhance our understanding of the distribution of CNS-acting drugs in individual patients. Fluorine-19 magnetic resonance imaging ((19)F MRI) offers the opportunity to localize and quantify fluorinated drugs non-invasively, without modifications and without the application of ionizing or other harmful radiation. Here we investigated siponimod, a sphingosine 1-phosphate (S(1)P) receptor antagonist indicated for secondary progressive multiple sclerosis (SPMS), to determine the feasibility of in vivo (19)F MR imaging of a disease modifying drug. METHODS: The (19)F MR properties of siponimod were characterized using spectroscopic techniques. Four MRI methods were investigated to determine which was the most sensitive for (19)F MR imaging of siponimod under biological conditions. We subsequently administered siponimod orally to 6 mice and acquired (19)F MR spectra and images in vivo directly after administration, and in ex vivo tissues. RESULTS: The (19)F transverse relaxation time of siponimod was 381 ms when dissolved in dimethyl sulfoxide, and substantially reduced to 5 ms when combined with serum, and to 20 ms in ex vivo liver tissue. Ultrashort echo time (UTE) imaging was determined to be the most sensitive MRI technique for imaging siponimod in a biological context and was used to map the drug in vivo in the stomach and liver. Ex vivo images in the liver and brain showed an inhomogeneous distribution of siponimod in both organs. In the brain, siponimod accumulated predominantly in the cerebrum but not the cerebellum. No secondary (19)F signals were detected from metabolites. From a translational perspective, we found that acquisitions done on a 3.0 T clinical MR scanner were 2.75 times more sensitive than acquisitions performed on a preclinical 9.4 T MR setup when taking changes in brain size across species into consideration and using equivalent relative spatial resolution. CONCLUSION: Siponimod can be imaged non-invasively using (19)F UTE MRI in the form administered to MS patients, without modification. This study lays the groundwork for more extensive preclinical and clinical investigations. With the necessary technical development, (19)F MRI has the potential to become a powerful theranostic tool for studying the time-course and distribution of CNS-acting drugs within the brain, especially during pathology.
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- 2023
18. B 1 inhomogeneity correction of RARE MRI at low SNR: Quantitative in vivo 19 F MRI of mouse neuroinflammation with a cryogenically‐cooled transceive surface radiofrequency probe
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Helmar Waiczies, Mariya Aravina, Thoralf Niendorf, Andreas Pohlmann, Paula Ramos Delgado, Alonso Vázquez, Ludger Starke, Andre Kuehne, Jason M. Millward, and Sonia Waiczies
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Physics ,Rapid acquisition ,Nuclear magnetic resonance ,Correction method ,In vivo ,Monte Carlo method ,Radiology, Nuclear Medicine and imaging ,Signal intensity ,Signal ,Imaging phantom ,Ex vivo - Abstract
PURPOSE Low SNR in fluorine-19 (19 F) MRI benefits from cryogenically-cooled transceive surface RF probes (CRPs), but strong B1 inhomogeneities hinder quantification. Rapid acquisition with refocused echoes (RARE) is an SNR-efficient method for MRI of neuroinflammation with perfluorinated compounds but lacks an analytical signal intensity equation to retrospectively correct B1 inhomogeneity. Here, a workflow was proposed and validated to correct and quantify 19 F-MR signals from the inflamed mouse brain using a 19 F-CRP. METHODS In vivo 19 F-MR images were acquired in a neuroinflammation mouse model with a quadrature 19 F-CRP using an imaging setup including 3D-printed components to acquire co-localized anatomical and 19 F images. Model-based corrections were validated on a uniform 19 F phantom and in the neuroinflammatory model. Corrected 19 F-MR images were benchmarked against reference images and overlaid on in vivo 1 H-MR images. Computed concentration uncertainty maps using Monte Carlo simulations served as a measure of performance of the B1 corrections. RESULTS Our study reports on the first quantitative in vivo 19 F-MR images of an inflamed mouse brain using a 19 F-CRP, including in vivo T1 calculations for 19 F-nanoparticles during pathology and B1 corrections for 19 F-signal quantification. Model-based corrections markedly improved 19 F-signal quantification from errors > 50% to < 10% in a uniform phantom (p < 0.001). Concentration uncertainty maps ex vivo and in vivo yielded uncertainties that were generally < 25%. Monte Carlo simulations prescribed SNR ≥ 10.1 to reduce uncertainties < 10%, and SNR ≥ 4.25 to achieve uncertainties < 25%. CONCLUSION Our model-based correction method facilitated 19 F signal quantification in the inflamed mouse brain when using the SNR-boosting 19 F-CRP technology, paving the way for future low-SNR 19 F-MRI applications in vivo.
- Published
- 2021
19. Monitoring kidney size to interpret <scp>MRI</scp> ‐based assessment of renal oxygenation in acute pathophysiological scenarios
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Kathleen Cantow, Thomas Gladytz, Jason M. Millward, Sonia Waiczies, Thoralf Niendorf, and Erdmann Seeliger
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Physiology - Abstract
Tissue hypoxia is an early key feature of acute kidney injury. Assessment of renal oxygenation using magnetic resonance imaging (MRI) markers TKS was determined from TUpon aortic occlusion KS decreased; this correlated with a decrease in TMonitoring KS allows physiological interpretation of acute renal oxygenation changes obtained by T
- Published
- 2022
20. Advanced Radio Frequency Applicators for Thermal Magnetic Resonance Theranostics of Brain Tumors
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Nandita Saha, Andre Kuehne, Jason M. Millward, Thomas Wilhelm Eigentler, Ludger Starke, Sonia Waiczies, and Thoralf Niendorf
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Cancer Research ,theranostics ,hyperthermia ,brain tumor ,MRI ,ThermalMR ,RF applicator ,Oncology ,Cardiovascular and Metabolic Diseases ,Technology Platforms - Abstract
Thermal Magnetic Resonance (ThermalMR) is a theranostic concept that combines diagnostic magnetic resonance imaging (MRI) with targeted thermal therapy in the hyperthermia (HT) range using a radiofrequency (RF) applicator in an integrated system. ThermalMR adds a therapeutic dimension to a diagnostic MRI device. Focused, targeted RF heating of deep-seated brain tumors, accurate non-invasive temperature monitoring and high-resolution MRI are specific requirements of ThermalMR that can be addressed with novel concepts in RF applicator design. This work examines hybrid RF applicator arrays combining loop and self-grounded bow-tie (SGBT) dipole antennas for ThermalMR of brain tumors, at magnetic field strengths of 7.0 T, 9.4 T and 10.5 T. These high-density RF arrays improve the feasible transmission channel count, and provide additional degrees of freedom for RF shimming not afforded by using dipole antennas only, for superior thermal therapy and MRI diagnostics. These improvements are especially relevant for ThermalMR theranostics of deep-seated brain tumors because of the small surface area of the head. ThermalMR RF applicators with the hybrid loop+SGBT dipole design outperformed applicators using dipole-only and loop-only designs, with superior MRI performance and targeted RF heating. Array variants with a horse-shoe configuration covering an arc (270°) around the head avoiding the eyes performed better than designs with 360° coverage, with a 1.3 °C higher temperature rise inside the tumor while sparing healthy tissue. Our EMF and temperature simulations performed on a virtual patient with a clinically realistic intracranial tumor provide a technical foundation for implementation of advanced RF applicators tailored for ThermalMR theranostics of brain tumors.
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- 2023
21. B 1 inhomogeneity correction of RARE MRI with transceive surface radiofrequency probes
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Paula Ramos Delgado, Jason M. Millward, Thoralf Niendorf, Sonia Waiczies, Andreas Pohlmann, Andre Kuehne, and João S. Periquito
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Correction method ,Materials science ,RF probe ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Resonator ,0302 clinical medicine ,Rapid acquisition ,Rf technology ,Radiology, Nuclear Medicine and imaging ,Signal intensity ,030217 neurology & neurosurgery ,Excitation ,Biomedical engineering ,Radiofrequency coil - Abstract
PURPOSE: The use of surface radiofrequency (RF) coils is common practice to boost sensitivity in (pre)clinical MRI. The number of transceive surface RF coils is rapidly growing due to the surge in cryogenically cooled RF technology and ultrahigh‐field MRI. Consequently, there is an increasing need for effective correction of the excitation field (B(1)(+)) inhomogeneity inherent in these coils. Retrospective B(1) correction permits quantitative MRI, but this usually requires a pulse sequence‐specific analytical signal intensity (SI) equation. Such an equation is not available for fast spin‐echo (Rapid Acquisition with Relaxation Enhancement, RARE) MRI. Here we present, test, and validate retrospective B(1) correction methods for RARE. METHODS: We implemented the commonly used sensitivity correction and developed an empirical model‐based method and a hybrid combination of both. Tests and validations were performed with a cryogenically cooled RF probe and a single‐loop RF coil. Accuracy of SI quantification and T(1) contrast were evaluated after correction. RESULTS: The three described correction methods achieved dramatic improvements in B(1) homogeneity and significantly improved SI quantification and T(1) contrast, with mean SI errors reduced from >40% to >10% following correction in all cases. Upon correction, images of phantoms and mouse heads demonstrated homogeneity comparable to that of images acquired with a volume resonator. This was quantified by SI profile, SI ratio (error 80% in vivo and ex vivo compared to PIU > 87% with the reference RF coil). CONCLUSIONS: This work demonstrates the efficacy of three B(1) correction methods tailored for transceive surface RF probes and RARE MRI. The corrected images are suitable for quantification and show comparable results between the three methods, opening the way for T(1) measurements and X‐nuclei quantification using surface transceiver RF coils. This approach is applicable to other MR techniques for which no analytical SI exists.
- Published
- 2020
22. B
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Paula Ramos, Delgado, Andre, Kuehne, Mariya, Aravina, Jason M, Millward, Alonso, Vázquez, Ludger, Starke, Helmar, Waiczies, Andreas, Pohlmann, Thoralf, Niendorf, and Sonia, Waiczies
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Mice ,Phantoms, Imaging ,Radio Waves ,Neuroinflammatory Diseases ,Animals ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
Low SNR in fluorine-19 (In vivoOur study reports on the first quantitative in vivoOur model-based correction method facilitated
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- 2021
23. Reliable kidney size determination by magnetic resonance imaging in pathophysiological settings
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Thomas, Gladytz, Jason M, Millward, Kathleen, Cantow, Luis, Hummel, Kaixuan, Zhao, Bert, Flemming, Joāo S, Periquito, Andreas, Pohlmann, Sonia, Waiczies, Erdmann, Seeliger, and Thoralf, Niendorf
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Animals ,Vascular Diseases ,Kidney ,Magnetic Resonance Imaging ,Rats - Abstract
Kidney diseases constitute a major health challenge, which requires noninvasive imaging to complement conventional approaches to diagnosis and monitoring. Several renal pathologies are associated with changes in kidney size, offering an opportunity for magnetic resonance imaging (MRI) biomarkers of disease. This work uses dynamic MRI and an automated bean-shaped model (ABSM) for longitudinal quantification of pathophysiologically relevant changes in kidney size.A geometry-based ABSM was developed for kidney size measurements in rats using parametric MRI (TThe ABSM yielded renal size measurements with accuracy and precision equivalent to the manual segmentation, with70-fold time savings. The automated method could detect a ~7% reduction (aortic occlusion) and a ~5%, a ~2% and a ~6% increase in kidney size (venous occlusion, pelvis and intratubular pressure increase and injection of X-ray contrast medium, respectively). These measurements were not affected by reduced image quality following administration of ferumoxytol.Dynamic MRI in conjunction with renal segmentation using an ABSM supports longitudinal quantification of changes in kidney size in pathophysiologically relevant experimental setups mimicking realistic clinical scenarios. This can potentially be instrumental for developing MRI-based diagnostic tools for various kidney disorders and for gaining new insight into mechanisms of renal pathophysiology.
- Published
- 2021
24. Fluorine-19 MRI at 21.1 T: enhanced spin–lattice relaxation of perfluoro-15-crown-5-ether and sensitivity as demonstrated in ex vivo murine neuroinflammation
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Paula Ramos Delgado, Sonia Waiczies, João S. Periquito, Ludger Starke, Thoralf Niendorf, Christian Prinz, Andreas Pohlmann, Jens T. Rosenberg, Jason M. Millward, Helmar Waiczies, and Andre Kuehne
- Subjects
Encephalomyelitis, Autoimmune, Experimental ,Radio Waves ,Biophysics ,chemistry.chemical_element ,Contrast Media ,Signal-To-Noise Ratio ,Sensitivity and Specificity ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Nuclear magnetic resonance ,In vivo ,Crown Ethers ,medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Neuroinflammation ,Inflammation ,Experimental autoimmune encephalomyelitis ,Radiological and Ultrasound Technology ,Chemistry ,Fluorine-19 magnetic resonance imaging ,Spin–lattice relaxation ,Brain ,Reproducibility of Results ,Fluorine ,Perfluoro-15-crown-5-ether ,medicine.disease ,Signal-to-noise ratio (imaging) ,Magnetic fields ,Calibration ,Nanoparticles ,Female ,Spin Labels ,Lymph Nodes ,Ex vivo ,Spleen ,Research Article - Abstract
Objective Fluorine MR would benefit greatly from enhancements in signal-to-noise ratio (SNR). This study examines the sensitivity gain of 19F MR that can be practically achieved when moving from 9.4 to 21.1 T. Materials and methods We studied perfluoro-15-crown-5-ether (PFCE) at both field strengths (B0), as a pure compound, in the form of nanoparticles (NP) as employed to study inflammation in vivo, as well as in inflamed tissue. Brains, lymph nodes (LNs) and spleens were obtained from mice with experimental autoimmune encephalomyelitis (EAE) that had been administered PFCE NPs. All samples were measured at both B0 with 2D-RARE and 2D-FLASH using 19F volume radiofrequency resonators together. T1 and T2 of PFCE were measured at both B0 strengths. Results Compared to 9.4 T, an SNR gain of > 3 was observed for pure PFCE and > 2 for PFCE NPs at 21.1 T using 2D-FLASH. A dependency of 19F T1 and T2 relaxation on B0 was demonstrated. High spatially resolved 19F MRI of EAE brains and LNs at 21.1 T revealed signals not seen at 9.4 T. Discussion Enhanced SNR and T1 shortening indicate the potential benefit of in vivo 19F MR at higher B0 to study inflammatory processes with greater detail. Electronic supplementary material The online version of this article (10.1007/s10334-018-0710-z) contains supplementary material, which is available to authorized users.
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- 2018
25. Simultaneous T
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Carl J J, Herrmann, Antje, Els, Laura, Boehmert, Joao, Periquito, Thomas Wilhelm, Eigentler, Jason M, Millward, Sonia, Waiczies, Joseph, Kuchling, Friedemann, Paul, and Thoralf, Niendorf
- Subjects
Multiple Sclerosis ,Phantoms, Imaging ,Reference Values ,Brain ,Humans ,Magnetic Resonance Imaging - Abstract
The characteristic MRI features of multiple sclerosis (MS) lesions make it conceptually appealing to pursue parametric mapping techniques that support simultaneous generation of quantitative maps of 2 or more MR contrast mechanisms. We present a modular rapid acquisition with relaxation enhancement (RARE)-EPI hybrid that facilitates simultaneous TIn 2in1-RARE-EPI the first echoes in the echo train are acquired with a RARE module, later echoes are acquired with an EPI module. To define the fraction of echoes covered by the RARE and EPI module, an error analysis of TThere was a good agreement between TThis work demonstrates the feasibility of radially (under)sampled 2in1-RARE-EPI for simultaneous T
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- 2021
26. Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
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Carl Herrmann, Helmar Waiczies, Karin Markenroth Bloch, Anna Pankowska, Joseph Kuchling, Antje Els, Sonia Waiczies, Carsten Finke, Claudia Chien, Thoralf Niendorf, and Friedemann Paul
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medicine.medical_specialty ,Multiple Sclerosis ,General Chemical Engineering ,Neuroimaging ,Grey matter ,General Biochemistry, Genetics and Molecular Biology ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Image Processing, Computer-Assisted ,Humans ,Susac Syndrome ,Cerebral Cortex ,Neuromyelitis optica ,General Immunology and Microbiology ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Multiple sclerosis ,Magnetic resonance imaging ,McDonald criteria ,medicine.disease ,Magnetic Resonance Imaging ,White Matter ,medicine.anatomical_structure ,Radiology ,Differential diagnosis ,business ,030217 neurology & neurosurgery ,Software - Abstract
The overall goal of this article is to demonstrate a state-of-the-art ultrahigh field (UHF) magnetic resonance (MR) protocol of the brain at 7.0 Tesla in multiple sclerosis (MS) patients. MS is a chronic inflammatory, demyelinating, neurodegenerative disease that is characterized by white and gray matter lesions. Detection of spatially and temporally disseminated T2-hyperintense lesions by the use of MRI at 1.5 T and 3 T represents a crucial diagnostic tool in clinical practice to establish accurate diagnosis of MS based on the current version of the 2017 McDonald criteria. However, the differentiation of MS lesions from brain white matter lesions of other origins can sometimes be challenging due to their resembling morphology at lower magnetic field strengths (typically 3 T). Ultrahigh field MR (UHF-MR) benefits from increased signal-to-noise ratio and enhanced spatial resolution, both key to superior imaging for more accurate and definitive diagnoses of subtle lesions. Hence, MRI at 7.0 T has shown encouraging results to overcome the challenges of MS differential diagnosis by providing MS-specific neuroimaging markers (e.g., central vein sign, hypointense rim structures and differentiation of MS grey matter lesions). These markers and others can be identified by other MR contrasts other than T1 and T2 (T2*, phase, diffusion) and substantially improve the differentiation of MS lesions from those occurring in other neuroinflammatory conditions such as neuromyelitis optica and Susac syndrome. In this article, we describe our current technical approach to study cerebral white and grey matter lesions in MS patients at 7.0 T using different MR acquisition methods. The up-to-date protocol includes the preparation of the MR setup including the radio-frequency coils customized for UHF-MR, standardized screening, safety and interview procedures with MS patients, patient positioning in the MR scanner and acquisition of dedicated brain scans tailored for examining MS.
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- 2021
27. Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
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Thoralf Niendorf, Friedemann Paul, Carsten Finke, Claudia Chien, Carl Herrmann, Helmar Waiczies, Anna Pankowska, Karin Markenroth Bloch, Joseph Kuchling, Antje Els, and Sonia Waiczies
- Subjects
General Immunology and Microbiology ,General Chemical Engineering ,General Neuroscience ,General Biochemistry, Genetics and Molecular Biology - Published
- 2021
28. Data Preparation Protocol for Low Signal-to-Noise Ratio Fluorine-19 MRI
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Ludger Starke, Thoralf Niendorf, and Sonia Waiczies
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Protocol (science) ,Background subtraction ,Computer science ,SIGNAL (programming language) ,Signal-To-Noise Ratio ,computer.software_genre ,Image Enhancement ,Kidney ,Rats ,Fluorine-19 Magnetic Resonance Imaging ,Mice ,Signal-to-noise ratio ,Renal imaging ,Image Processing, Computer-Assisted ,Biomarker (medicine) ,Animals ,Data mining ,computer ,Biomarkers ,Software ,Monitoring, Physiologic ,Research Article - Abstract
Fluorine-19 MRI shows great promise for a wide range of applications including renal imaging, yet the typically low signal-to-noise ratios and sparse signal distribution necessitate a thorough data preparation.This chapter describes a general data preparation workflow for fluorine MRI experiments. The main processing steps are: (1) estimation of noise level, (2) correction of noise-induced bias and (3) background subtraction. The protocol is supplemented by an example script and toolbox available online.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This analysis protocol chapter is complemented by two separate chapters describing the basic concept and experimental procedure.
- Published
- 2021
29. Preparation of Ex Vivo Rodent Phantoms for Developing, Testing, and Training MR Imaging of the Kidney and Other Organs
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Paula Ramos Delgado, João S. Periquito, Sonia Waiczies, Jason M. Millward, Thoralf Niendorf, and Christian Prinz
- Subjects
Kidney ,Imaging phantom ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Mice ,0302 clinical medicine ,In vivo ,Teaching tool ,Image Processing, Computer-Assisted ,Medicine ,media_common.cataloged_instance ,Animals ,European union ,media_common ,Monitoring, Physiologic ,business.industry ,Phantoms, Imaging ,Brain ,Mr imaging ,Magnetic Resonance Imaging ,Rats ,medicine.anatomical_structure ,business ,030217 neurology & neurosurgery ,Ex vivo ,Target organ ,Biomarkers ,Software ,Biomedical engineering ,Research Article - Abstract
Here we describe a simple and inexpensive protocol for preparing ex vivo rodent phantoms for use in MR imaging studies. The experimental animals are perfused and fixed with formaldehyde, and then wrapped with gauze and sealed with liquid latex. This yields a phantom that preserves all organs in situ, and which avoids the need to keep fixed animals and organs in containers that have dimensions very different from living animals. This is especially important for loading in MR detectors, and specifically the RF coils, they are usually used with. The phantom can be safely stored and conveniently reused, and can provide MR scientists with a realistic phantom with which to establish protocols in preparation for preclinical in vivo studies—for renal, brain, and body imaging. The phantom also serves as an ideal teaching tool, for trainees learning how to perform preclinical MRI investigations of the kidney and other target organs, while avoiding the need for handling living animals, and reducing the total number of animals required.This protocol chapter is part of the PARENCHIMA initiative “MRI Biomarkers for CKD” (CA16103), a community-driven Action of the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers.
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- 2021
30. Recommendations for Preclinical Renal MRI: A Comprehensive Open-Access Protocol Collection to Improve Training, Reproducibility, and Comparability of Studies
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Martin Meier, Andrea Fekete, João S. Periquito, Stefanie J. Hectors, Thoralf Niendorf, Neil P. Jerome, Christoffer Laustsen, Iris Friedli, Andreas Pohlmann, Suraj D. Serai, Jason M. Millward, Sonia Waiczies, Erdmann Seeliger, Susan J. Back, Min-Chi Ku, Steven Sourbron, and Dario Livio Longo
- Subjects
medicine.medical_specialty ,Standardization ,Mri studies ,Kidney ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Resource (project management) ,medicine ,media_common.cataloged_instance ,Humans ,Medical physics ,Cost action ,European union ,media_common ,Protocol (science) ,business.industry ,Comparability ,Acute kidney injury ,Reproducibility of Results ,medicine.disease ,Magnetic Resonance Imaging ,Practice Guidelines as Topic ,Disease Progression ,Kidney Diseases ,business ,030217 neurology & neurosurgery ,Biomarkers ,Research Article - Abstract
Renal MRI holds incredible promise for making a quantum leap in improving diagnosis and care of patients with a multitude of diseases, by moving beyond the limitations and restrictions of current routine clinical practice. Clinical and preclinical renal MRI is advancing with ever increasing rapidity, and yet, aside from a few examples of renal MRI in routine use, it is still not good enough. Several roadblocks are still delaying the pace of progress, particularly inefficient education of renal MR researchers, and lack of harmonization of approaches that limits the sharing of results among multiple research groups.Here we aim to address these limitations for preclinical renal MRI (predominantly in small animals), by providing a comprehensive collection of more than 40 publications that will serve as a foundational resource for preclinical renal MRI studies. This includes chapters describing the fundamental principles underlying a variety of renal MRI methods, step-by-step protocols for executing renal MRI studies, and detailed guides for data analysis. This collection will serve as a crucial part of a roadmap toward conducting renal MRI studies in a robust and reproducible way, that will promote the standardization and sharing of data.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers.
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- 2021
31. Contribution of preclinical MRI to responsible animal research: living up to the 3R principle
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Armand Mensen, Pasquina Marzola, Henning M Reimann, Marlène Wiart, Cristina Barca, Catarina Tristão-Pereira, Angèle Viola, Cornelius Faber, Sonia Waiczies, Alice Busato, Lydia Wachsmuth, Bruno Pradier, Ileana O. Jelescu, Uwe Himmelreich, Jason M. Millward, University Hospital Münster - Universitaetsklinikum Muenster [Germany] (UKM), University of Bern, European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ecole Polytechnique Fédérale de Lausanne (EPFL), Center for Biomedical Imaging [Lausanne] (CIBM), Università degli studi di Verona = University of Verona (UNIVR), Max Delbrück Center for Molecular Medicine [Berlin] (MDC), Helmholtz-Gemeinschaft = Helmholtz Association, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Westfälische Wilhelms-Universität Münster (WWU), and University of Verona (UNIVR)
- Subjects
Animal Experimentation ,3R principle ,[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging ,Biophysics ,MEDLINE ,Health informatics ,animal welfare ,03 medical and health sciences ,0302 clinical medicine ,pet ,Medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,Science & Technology ,model ,Radiological and Ultrasound Technology ,Animal Welfare (journal) ,business.industry ,Radiology, Nuclear Medicine & Medical Imaging ,Magnetic Resonance Imaging ,3. Good health ,MODEL ,Disease Models, Animal ,PET ,preclinical MRI ,Cardiovascular and Metabolic Diseases ,Solid State Physics ,Biomedical Engineering and Bioengineering ,Imaging / Radiology ,Health Informatics ,Computer Appl. in Life Sciences ,Commentary ,Engineering ethics ,Technology Platforms ,business ,Life Sciences & Biomedicine ,030217 neurology & neurosurgery - Abstract
ispartof: MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE vol:34 issue:4 pages:469-474 ispartof: location:Germany status: published
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- 2021
32. Functional Imaging Using Fluorine (19F) MR Methods: Basic Concepts
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Jens T. Rosenberg, Jason M. Millward, Paula Ramos Delgado, Helmar Waiczies, Sonia Waiczies, Andreas Pohlmann, Thoralf Niendorf, Christian Prinz, Ludger Starke, Marc Nazaré, Pohlmann, A., and Niendorf, T.
- Subjects
Computer science ,Renal function ,Kidney ,Machine learning ,computer.software_genre ,030218 nuclear medicine & medical imaging ,Fluorine-19 Magnetic Resonance Imaging ,03 medical and health sciences ,0302 clinical medicine ,In vivo ,Image Processing, Computer-Assisted ,medicine ,Animals ,Humans ,Cost action ,Monitoring, Physiologic ,030304 developmental biology ,0303 health sciences ,business.industry ,Fluorine ,Functional imaging ,medicine.anatomical_structure ,Tissue oxygenation ,Cardiovascular and Metabolic Diseases ,Biomarker (medicine) ,Artificial intelligence ,Technology Platforms ,business ,computer ,Biomarkers ,Software ,Research Article - Abstract
Kidney-associated pathologies would greatly benefit from noninvasive and robust methods that can objectively quantify changes in renal function. In the past years there has been a growing incentive to develop new applications for fluorine (19F) MRI in biomedical research to study functional changes during disease states. 19F MRI represents an instrumental tool for the quantification of exogenous 19F substances in vivo. One of the major benefits of 19F MRI is that fluorine in its organic form is absent in eukaryotic cells. Therefore, the introduction of exogenous 19F signals in vivo will yield background-free images, thus providing highly selective detection with absolute specificity in vivo. Here we introduce the concept of 19F MRI, describe existing challenges, especially those pertaining to signal sensitivity, and give an overview of preclinical applications to illustrate the utility and applicability of this technique for measuring renal function in animal models.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.
- Published
- 2021
33. Fluorine (19F) MRI for Assessing Inflammatory Cells in the Kidney: Experimental Protocol
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Paula Ramos Delgado, Min-Chi Ku, Andreas Pohlmann, Philipp Boehm-Sturm, Sonia Waiczies, Thoralf Niendorf, Ralph Kettritz, and Adrian Schreiber
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0301 basic medicine ,Kidney ,business.industry ,Inflammation ,030204 cardiovascular system & hematology ,medicine.disease ,Pathogenesis ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,In vivo ,Immunology ,medicine ,media_common.cataloged_instance ,Kidney disorder ,medicine.symptom ,European union ,business ,media_common ,Kidney disease ,Anti-neutrophil cytoplasmic antibody - Abstract
Inflammation is one underlying contributing factor in the pathology of acute and chronic kidney disorders. Phagocytes such as monocytes, neutrophils and dendritic cells are considered to play a deleterious role in the progression of kidney disease but may also contribute to organ homeostasis. The kidney is a target of life-threatening autoimmune disorders such as the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). Neutrophils and monocytes express ANCA antigens and play an important role in the pathogenesis of AAV. Noninvasive in vivo methods that can quantify the distribution of inflammatory cells in the kidney as well as other organs in vivo would be vital to identify the causality and significance of inflammation during disease progression. Here we describe an noninvasive technique to study renal inflammation in rodents in vivo using fluorine (19F) MRI. In this protocol we chose a murine ANCA-AAV model of renal inflammation and made use of nanoparticles prepared from perfluoro-5-crown-15-ether (PFCE) for renal 19F MRI.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by two separate chapters describing the basic concept and data analysis.
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- 2021
34. Imagine physiology without imaging
- Author
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Bert Flemming, Sonia Waiczies, Erdmann Seeliger, Thoralf Niendorf, Kathleen Cantow, and Luis Hummel
- Subjects
medicine.medical_specialty ,Physiology ,business.industry ,medicine ,MEDLINE ,Intensive care medicine ,business - Published
- 2020
35. B
- Author
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Paula Ramos, Delgado, Andre, Kuehne, João S, Periquito, Jason M, Millward, Andreas, Pohlmann, Sonia, Waiczies, and Thoralf, Niendorf
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Mice ,Phantoms, Imaging ,Radio Waves ,Animals ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
The use of surface radiofrequency (RF) coils is common practice to boost sensitivity in (pre)clinical MRI. The number of transceive surface RF coils is rapidly growing due to the surge in cryogenically cooled RF technology and ultrahigh-field MRI. Consequently, there is an increasing need for effective correction of the excitation field (We implemented the commonly used sensitivity correction and developed an empirical model-based method and a hybrid combination of both. Tests and validations were performed with a cryogenically cooled RF probe and a single-loop RF coil. Accuracy of SI quantification and TThe three described correction methods achieved dramatic improvements in BThis work demonstrates the efficacy of three B
- Published
- 2020
36. Cardiorenal sodium MRI in small rodents using a quadrature birdcage volume resonator at 9.4 T
- Author
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Thoralf Niendorf, Erdmann Seeliger, Andreas Pohlmann, Ludger Starke, Laura Boehmert, Celal Oezerdem, Andre Kuehne, Min-Chi Ku, Sonia Waiczies, and Helmar Waiczies
- Subjects
Materials science ,Radio Waves ,Renal cortex ,Heart Ventricles ,Transducers ,Biophysics ,Signal-To-Noise Ratio ,Kidney ,030218 nuclear medicine & medical imaging ,Translational Research, Biomedical ,03 medical and health sciences ,Resonator ,0302 clinical medicine ,Nuclear magnetic resonance ,medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Image resolution ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,Phantoms, Imaging ,Myocardium ,Magnetic resonance imaging ,Heart ,Equipment Design ,Magnetic Resonance Imaging ,Quadrature (astronomy) ,Rats ,medicine.anatomical_structure ,Ventricle ,Calibration ,Sodium MRI ,Sodium Isotopes ,Preclinical imaging - Abstract
Design, implementation, evaluation and application of a quadrature birdcage radiofrequency (RF) resonator tailored for renal and cardiac sodium (23Na) magnetic resonance imaging (MRI) in rats at 9.4 T. A low pass birdcage resonator (16 rungs, din = 62 mm) was developed. The transmission field (B1+) was examined with EMF simulations. The scattering parameter (S-parameter) and the quality factor (Q-factor) were measured. For experimental validation B1+-field maps were acquired with the double-angle method. In vivo sodium imaging of the heart (spatial resolution: (1 × 1 × 5) mm3) and kidney (spatial resolution: (1 × 1 × 10) mm3) was performed with a FLASH technique. The RF resonator exhibits RF characteristics, transmission field homogeneity and penetration that afford 23Na MR in vivo imaging of the kidney and heart at 9.4 T. For the renal cortex and medulla a SNRs of 8 and 13 were obtained and a SNRs of 14 and 15 were observed for the left and right ventricle. These initial results obtained in vivo in rats using the quadrature birdcage volume RF resonator for 23Na MRI permit dedicated studies on experimental models of cardiac and renal diseases, which would contribute to translational research of the cardiorenal syndrome.
- Published
- 2019
37. Probing renal blood volume with magnetic resonance imaging
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Erdmann Seeliger, Andreas Pohlmann, Bert Flemming, Kathleen Cantow, Sonia Waiczies, and Thoralf Niendorf
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Physiology ,Blood volume ,030204 cardiovascular system & hematology ,urologic and male genital diseases ,Kidney ,03 medical and health sciences ,0302 clinical medicine ,Oxygen Consumption ,Internal medicine ,medicine ,Animals ,Humans ,Blood Volume ,medicine.diagnostic_test ,business.industry ,Acute kidney injury ,Hemodynamics ,Magnetic resonance imaging ,Oxygenation ,medicine.disease ,Magnetic Resonance Imaging ,Ferrosoferric Oxide ,Ferumoxytol ,Oxygen ,030104 developmental biology ,medicine.anatomical_structure ,Cardiology ,Kidney Diseases ,business ,Perfusion ,Kidney disease - Abstract
Damage to the kidney substantially reduces life expectancy. Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. In vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) is sensitive to changes in the effective transversal relaxation time (T2 *) in vivo, and is non-invasive and indicative of renal tissue oxygenation. However, the renal T2 * to tissue pO2 relationship is not governed exclusively by renal blood oxygenation, but is affected by physiological confounders with alterations in renal blood volume fraction (BVf) being of particular relevance. To decipher this interference probing renal BVf is essential for the pursuit of renal MR oximetry. Superparamagnetic iron oxide nanoparticle (USPIO) preparations can be used as MRI visible blood pool markers for detailing alterations in BVf. This review promotes the opportunities of MRI-based assessment of renal BVf. Following an outline on the specifics of renal oxygenation and perfusion, changes in renal BVf upon interventions and their potential impact on renal T2 * are discussed. We also describe the basic principles of renal BVf assessment using ferumoxytol-enhanced MRI in the equilibrium concentration regimen. We demonstrate that ferumoxytol does not alter control of renal haemodynamics and oxygenation. Preclinical applications of ferumoxytol enhanced renal MRI as well as considerations for its clinical implementation for examining renal BVf changes are provided alongside practical considerations. Finally, we explore the future directions of MRI-based assessment of renal BVf.
- Published
- 2019
38. Diffusion-weighted Renal MRI at 9.4 Tesla Using RARE to Improve Anatomical Integrity
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Joāo dos Santos Periquito, Katharina Paul, Till Huelnhagen, Min-Chi Ku, Yiyi Ji, Kathleen Cantow, Thomas Gladytz, Dirk Grosenick, Bert Flemming, Erdmann Seeliger, Sonia Waiczies, Thoralf Niendorf, and Andreas Pohlmann
- Subjects
Cardiovascular and Metabolic Diseases ,Preclinical research ,lcsh:R ,lcsh:Medicine ,lcsh:Q ,Technology Platforms ,lcsh:Science ,Kidney ,Biomedical engineering ,Article - Abstract
Diffusion-weighted magnetic resonance imaging (DWI) is a non-invasive imaging technique sensitive to tissue water movement. By enabling a discrimination between tissue properties without the need of contrast agent administration, DWI is invaluable for probing tissue microstructure in kidney diseases. DWI studies commonly make use of single-shot Echo-Planar Imaging (ss-EPI) techniques that are prone to suffering from geometric distortion. The goal of the present study was to develop a robust DWI technique tailored for preclinical magnetic resonance imaging (MRI) studies that is free of distortion and sensitive to detect microstructural changes. Since fast spin-echo imaging techniques are less susceptible to B0 inhomogeneity related image distortions, we introduced a diffusion sensitization to a split-echo Rapid Acquisition with Relaxation Enhancement (RARE) technique for high field preclinical DWI at 9.4 T. Validation studies in standard liquids provided diffusion coefficients consistent with reported values from the literature. Split-echo RARE outperformed conventional ss-EPI, with ss-EPI showing a 3.5-times larger border displacement (2.60 vs. 0.75) and a 60% higher intra-subject variability (cortex = 74%, outer medulla = 62% and inner medulla = 44%). The anatomical integrity provided by the split-echo RARE DWI technique is an essential component of parametric imaging on the way towards robust renal tissue characterization, especially during kidney disease.
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- 2019
39. Special issue on fluorine-19 magnetic resonance: technical solutions, research promises and frontier applications
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Philipp Boehm-Sturm, Thoralf Niendorf, Sonia Waiczies, Mangala Srinivas, and Ulrich Flögel
- Subjects
Engineering ,Biomedical Research ,Radiological and Ultrasound Technology ,business.industry ,Biophysics ,Contrast Media ,Capsules ,Fluorine ,Image Enhancement ,Engineering physics ,Health informatics ,Fluorine-19 Magnetic Resonance Imaging ,Translational Research, Biomedical ,Frontier ,Magnetic Fields ,Humans ,Radiology, Nuclear Medicine and imaging ,business ,Nanomedicine Radboud Institute for Molecular Life Sciences [Radboudumc 19] - Abstract
Contains fulltext : 206945.pdf (Publisher’s version ) (Closed access)
- Published
- 2019
40. Transient enlargement of brain ventricles in the course of neuroinflammatory disease
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Christian Prinz, Sonia Waiczies, and Jason Millward
- Published
- 2018
41. Toward
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Christian, Prinz, Paula Ramos, Delgado, Thomas Wilhelm, Eigentler, Ludger, Starke, Thoralf, Niendorf, and Sonia, Waiczies
- Subjects
Isoflurane ,Toluidines ,Phantoms, Imaging ,Temperature ,Hydroxybutyrates ,Fluorine ,Hyperthermia, Induced ,Thermometry ,Fluorine-19 Magnetic Resonance Imaging ,Flupenthixol ,Mice, Inbred C57BL ,Mice ,Pharmaceutical Preparations ,Crotonates ,Crown Ethers ,Nitriles ,Image Processing, Computer-Assisted ,Animals ,Fiber Optic Technology ,Nanoparticles ,Female ,Spin Labels - Abstract
This study examines the influence of the environmental factor temperature on theStudies on PFCE, isoflurane, teriflunomide, and flupentixol showed a relationship between temperature and their physicochemical characteristics, namely, chemical shift, TThe impact of temperature on the
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- 2018
42. Assessment of Blood Brain Barrier Leakage with Gadolinium-Enhanced MRI
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Min-Chi, Ku, Sonia, Waiczies, Thoralf, Niendorf, and Andreas, Pohlmann
- Subjects
Capillary Permeability ,Mice ,Blood-Brain Barrier ,Image Processing, Computer-Assisted ,Animals ,Brain ,Contrast Media ,Gadolinium ,Magnetic Resonance Imaging - Abstract
The integrity of the blood-brain barrier (BBB) can be noninvasively monitored by magnetic resonance imaging (MRI). Conventional MR contrast agents (CAs) containing gadolinium are used in association with MRI in routine clinical practice to detect and quantify BBB leakage. Under normal circumstances CAs do not cross the intact BBB. However due to their small size they extravasate from the blood into the brain tissue even when the BBB is partially compromised. Here we describe an MR method based on T
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- 2018
43. Assessment of Blood Brain Barrier Leakage with Gadolinium-Enhanced MRI
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Min-Chi Ku, Sonia Waiczies, Andreas Pohlmann, and Thoralf Niendorf
- Subjects
0301 basic medicine ,medicine.diagnostic_test ,business.industry ,Gadolinium ,chemistry.chemical_element ,Magnetic resonance imaging ,Mr contrast ,Brain tissue ,Blood–brain barrier ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,chemistry ,In vivo ,cardiovascular system ,medicine ,business ,Bbb permeability ,030217 neurology & neurosurgery ,Neuroinflammation ,Biomedical engineering - Abstract
The integrity of the blood-brain barrier (BBB) can be noninvasively monitored by magnetic resonance imaging (MRI). Conventional MR contrast agents (CAs) containing gadolinium are used in association with MRI in routine clinical practice to detect and quantify BBB leakage. Under normal circumstances CAs do not cross the intact BBB. However due to their small size they extravasate from the blood into the brain tissue even when the BBB is partially compromised. Here we describe an MR method based on T1-weighted images taken prior to and after CA injection. This MR method is useful for investigating BBB permeability in in vivo mouse models and can be easily applied in a number of experimental disease conditions including neuroinflammation disorders, or to assess (un)wanted drug effects.
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- 2018
44. Experimental MRI Monitoring of Renal Blood Volume Fraction Variations En Route to Renal Magnetic Resonance Oximetry
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Thoralf Niendorf, Thomas Gladytz, Bert Flemming, Andreas Pohlmann, Till Huelnhagen, Laura Boehmert, Sonia Waiczies, Erdmann Seeliger, Dirk Grosenick, Joāo dos Santos Periquito, and Kathleen Cantow
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medicine.medical_specialty ,kidney ,urologic and male genital diseases ,Internal medicine ,ultrasmall superparamagnetic iron oxide (USPIO) ,Occlusion ,medicine ,oxygenation ,blood volume fraction ,magnetic resonance imaging ,blood oxygenation level dependent (BOLD) ,Radiology, Nuclear Medicine and imaging ,Kidney ,medicine.diagnostic_test ,business.industry ,Acute kidney injury ,Magnetic resonance imaging ,Oxygenation ,Hypoxia (medical) ,medicine.disease ,Ferumoxytol ,medicine.anatomical_structure ,Cardiovascular and Metabolic Diseases ,Cardiology ,Renal vein ,medicine.symptom ,Technology Platforms ,business ,Research Article - Abstract
Diagnosis of early-stage acute kidney injury (AKI) will benefit from a timely identification of local tissue hypoxia. Renal tissue hypoxia is an early feature in AKI pathophysiology, and renal oxygenation is increasingly being assessed through T(2)*-weighted magnetic resonance imaging (MRI). However, changes in renal blood volume fraction (BVf) confound renal T(2)*. The aim of this study was to assess the feasibility of intravascular contrast-enhanced MRI for monitoring renal BVf during physiological interventions that are concomitant with variations in BVf and to explore the possibility of correcting renal T(2)* for BVf variations. A dose-dependent study of the contrast agent ferumoxytol was performed in rats. BVf was monitored throughout short-term occlusion of the renal vein, which is known to markedly change renal blood partial pressure of O(2) and BVf. BVf calculated from MRI measurements was used to estimate oxygen saturation of hemoglobin (SO(2)). BVf and SO(2) were benchmarked against cortical data derived from near-infrared spectroscopy. As estimated from magnetic resonance parametric maps of T(2) and T(2)*, BVf was shown to increase, whereas SO(2) was shown to decline during venous occlusion (VO). This observation could be quantitatively reproduced in test-retest scenarios. Changes in BVf and SO(2) were in good agreement with data obtained from near-infrared spectroscopy. Our findings provide motivation to advance multiparametric MRI for studying AKIs, with the ultimate goal of translating MRI-based renal BVf mapping into clinical practice en route noninvasive renal magnetic resonance oximetry as a method of assessing AKI and progression to chronic damage.
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- 2017
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45. Eight-channel transceiver RF coil array tailored for 1 H/19 F MR of the human knee and fluorinated drugs at 7.0 T
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Jan Rieger, Yiyi Ji, Sonia Waiczies, Daniela Hofmann, Pavla Neumanova, Thoralf Niendorf, Ralf Mekle, Helmar Waiczies, and Lukas Winter
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Materials science ,medicine.diagnostic_test ,Magnetic resonance imaging ,Signal ,Flufenamic acid ,Nuclear magnetic resonance ,In vivo ,medicine ,Proton imaging ,Molecular Medicine ,Radiology, Nuclear Medicine and imaging ,Transceiver ,Sensitivity (electronics) ,Spectroscopy ,Radiofrequency coil ,medicine.drug - Abstract
The purpose of this study was to evaluate the feasibility of an eight-channel dual-tuned transceiver surface RF coil array for combined (1) H/(19) F MR of the human knee at 7.0 T following application of (19) F-containing drugs. The (1) H/(19) F RF coil array includes a posterior module with two (1) H loop elements and two anterior modules, each consisting of one (1) H and two (19) F elements. The decoupling of neighbor elements is achieved by a shared capacitor. Electromagnetic field simulations were performed to afford uniform transmission fields and to be in accordance with RF safety guidelines. Localized (19) F MRS was conducted with 47 and 101 mmol/L of flufenamic acid (FA) - a (19) F-containing non-steroidal anti-inflammatory drug - to determine T1 and T2 and to study the (19) F signal-to-dose relationship. The suitability of the proposed approach for (1) H/(19) F MR was examined in healthy subjects. Reflection coefficients of each channel were less than -17 dB and coupling between channels was less than -11 dB. QL /QU was less than 0.5 for all elements. MRS results demonstrated signal stability with 1% variation. T1 and T2 relaxation times changed with concentration of FA: T1 /T2 = 673/31 ms at 101 mmol/L and T1 /T2 = 616/26 ms at 47 mmol/L. A uniform signal and contrast across the patella could be observed in proton imaging. The sensitivity of the RF coil enabled localization of FA ointment administrated to the knee with an in-plane spatial resolution of (1.5 × 1.5) mm(2) achieved in a total scan time of approximately three minutes, which is well suited for translational human studies. This study shows the feasibility of combined (1) H/(19) F MRI of the knee at 7.0 T and proposes T1 and T2 mapping methods for quantifying fluorinated drugs in vivo. Further technological developments are necessary to promote real-time bioavailability studies and quantification of (19) F-containing medicinal compounds in vivo.
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- 2015
46. Labeling of cell therapies: How can we get it right?
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Thoralf Niendorf, Sonia Waiczies, and Giovanna Lombardi
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0301 basic medicine ,patient studies ,lcsh:Immunologic diseases. Allergy ,Computer science ,Membrane bound ,Immunology ,Cell ,Context (language use) ,lcsh:RC254-282 ,Cell labeling ,03 medical and health sciences ,0302 clinical medicine ,In vivo ,medicine ,Immunology and Allergy ,Point of View ,nk cells ,mri ,t cells ,electron microscopy ,excess nanoparticles ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,intracellular ,internalization ,clinical application ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,cell tracking ,membrane-bound ,nanolabel ,030220 oncology & carcinogenesis ,phagocytes ,nanoparticles ,Cell tracking ,lcsh:RC581-607 ,Neuroscience ,cell labeling - Abstract
Labeling cells for non-invasive tracking in vivo using magnetic resonance imaging (MRI) is an emerging hot topic garnering ever increasing attention, yet it is fraught with numerous methodological challenges, which merit careful attention. Several of the current procedures used to label cells for tracking by MRI take advantage of the intrinsic phagocytic nature of cells to engulf nanoparticles, though cells with low intrinsic phagocytic capacity are also commonly studied. Before we take the next steps towards administering such cells in vivo, it is essential to understand how the nanolabel is recognized, internalized, trafficked and distributed within the specific host cell. This is even more critical when contemplating labeling of cells that may ultimately be applied in vivo to patients in a therapeutic context.
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- 2017
47. Enhanced Fluorine-19 MRI Sensitivity using a Cryogenic Radiofrequency Probe: Technical Developments and Ex Vivo Demonstration in a Mouse Model of Neuroinflammation
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Didier Wecker, Paula Ramos Delgado, Ludger Starke, Philipp Boehm-Sturm, Christian Prinz, Thoralf Niendorf, Ralph Wissmann, Jason M. Millward, Helmar Waiczies, Till Huelnhagen, Stefan Koch, Sonia Waiczies, Andreas Pohlmann, and Daniel Marek
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Pathology ,medicine.medical_specialty ,Materials science ,Encephalomyelitis, Autoimmune, Experimental ,Encephalomyelitis ,lcsh:Medicine ,600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit ,RF probe ,Article ,030218 nuclear medicine & medical imaging ,Fluorine-19 Magnetic Resonance Imaging ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Nuclear magnetic resonance ,Magnetic resonance imaging ,In vivo ,medicine ,Image Processing, Computer-Assisted ,Animals ,lcsh:Science ,Neuroinflammation ,Multidisciplinary ,medicine.diagnostic_test ,lcsh:R ,Experimental autoimmune encephalomyelitis ,Brain ,medicine.disease ,Image Enhancement ,Experimental models of disease ,Disease Models, Animal ,Cardiovascular and Metabolic Diseases ,Nanoparticles ,lcsh:Q ,Technology Platforms ,030217 neurology & neurosurgery ,Ex vivo ,Radiofrequency coil - Abstract
Neuroinflammation can be monitored using fluorine-19 (19F)-containing nanoparticles and 19F MRI. Previously we studied neuroinflammation in experimental autoimmune encephalomyelitis (EAE) using room temperature (RT) 19F radiofrequency (RF) coils and low spatial resolution 19F MRI to overcome constraints in signal-to-noise ratio (SNR). This yielded an approximate localization of inflammatory lesions. Here we used a new 19F transceive cryogenic quadrature RF probe ( 19 F-CRP) that provides the SNR necessary to acquire superior spatially-resolved 19F MRI. First we characterized the signal-transmission profile of the 19 F-CRP. The 19 F-CRP was then benchmarked against a RT 19F/1H RF coil. For SNR comparison we used reference compounds including 19F-nanoparticles and ex vivo brains from EAE mice administered with 19F-nanoparticles. The transmit/receive profile of the 19 F-CRP diminished with increasing distance from the surface. This was counterbalanced by a substantial SNR gain compared to the RT coil. Intraparenchymal inflammation in the ex vivo EAE brains was more sharply defined when using 150 μm isotropic resolution with the 19 F-CRP, and reflected the known distribution of EAE histopathology. At this spatial resolution, most 19F signals were undetectable using the RT coil. The 19 F-CRP is a valuable tool that will allow us to study neuroinflammation with greater detail in future in vivo studies.
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- 2017
48. Application of Europium-Doped Very Small Iron Oxide Nanoparticles to Visualize Neuroinflammation with MRI and Fluorescence Microscopy
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Eyk Schellenberger, Matthias Taupitz, Yuske Kobayashi, Susanne Wagner, Angela Ariza de Schellenberger, Jason M. Millward, Laura Hanke-Vela, Sonia Waiczies, Carmen Infante-Duarte, and Dominique Berndt
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Encephalomyelitis, Autoimmune, Experimental ,Central nervous system ,Contrast Media ,Ferric Compounds ,Cell Line ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Europium ,In vivo ,medicine ,Choroid Plexus Epithelium ,Animals ,Neuroinflammation ,Inflammation ,Plexus ,Chemistry ,General Neuroscience ,Experimental autoimmune encephalomyelitis ,Brain ,Endothelial Cells ,VSOP ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,medicine.anatomical_structure ,Microscopy, Fluorescence ,Nanoparticles ,Choroid plexus ,Female ,030217 neurology & neurosurgery - Abstract
Our recent studies demonstrated that electrostatically stabilized very small superparamagnetic iron oxide particles (VSOPs) are promising MRI probes for detecting various pathological aspects of autoimmunity in the central nervous system (CNS). However, investigation of the precise tissue and cellular distribution of VSOP has been technically limited due to the need to use iron detection methods for VSOP visualization. Therefore, we assessed here the utility of europium (Eu)-doped VSOP as an MRI tool for in vivo investigations in the animal model experimental autoimmune encephalomyelitis (EAE), and as a tool to investigate histopathological processes in the CNS using fluorescence microscopy. We demonstrated that Eu-VSOP display the same properties as VSOP in terms of revealing inflammation-mediated changes by binding to brain endothelium in vitro, and in terms of visualizing brain lesions in EAE in vivo. MRI examinations with Eu-VSOP confirm that at peak disease particles accumulated inside the choroid plexus, and in cerebellar and meningeal lesions. Importantly, Eu-VSOP-based MRI showed for the first time in a longitudinal setup that particles were absent from the choroid plexus in mice during remission of EAE, but accumulated again during subsequent relapse. Within the choroid plexus, Eu-VSOP were associated both with monocytes/macrophages present in the plexus stroma, and associated with epithelial cells. Using Eu-VSOP, we demonstrated for the first time the involvement of the choroid plexus in relapses. Thus, Eu-VSOP have the potential to reveal various aspects of choroid plexus involvement in neuroinflammation, including monocyte recruitment from the blood and alterations of the choroid plexus epithelium.
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- 2017
49. Cerebral blood volume estimation by ferumoxytol-enhanced steady-state MRI at 9.4 T reveals microvascular impact of α1 -adrenergic receptor antibodies
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Min-Chi Ku, Helmar Waiczies, Petra Hempel, Bernd Lemke, Irina Palatnik, Henning M Reimann, Christina Eichhorn, Peter Karczewski, Marion Bimmler, Babette Dieringer, Natali Wisbrun, Andreas Pohlmann, Stefanie Kox, Sonia Waiczies, and Thoralf Niendorf
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Pathology ,medicine.medical_specialty ,business.industry ,Cerebrum ,Hippocampus ,Hippocampal formation ,medicine.disease ,Ferumoxytol ,Cerebral circulation ,medicine.anatomical_structure ,Neuroimaging ,medicine ,Molecular Medicine ,Dementia ,Radiology, Nuclear Medicine and imaging ,business ,Spectroscopy ,Blood vessel - Abstract
Cerebrovascular abnormality is frequently accompanied by cognitive dysfunctions, such as dementia. Antibodies against the α1-adrenoceptor (α1-AR) can be found in patients with Alzheimer’s disease with cerebrovascular disease, and have been shown to affect the larger vessels of the brain in rodents. However, the impact of α1-AR antibodies on the cerebral vasculature remains unclear. In the present study, we established a neuroimaging method to measure the relative cerebral blood volume (rCBV) in small rodents with the ultimate goal to detect changes in blood vessel density and/or vessel size induced by α1-AR antibodies. For this purpose, mapping of R2* and R2 was performed using MRI at 9.4T, before and after the injection of intravascular iron oxide particles (ferumoxytol). The change in the transverse relaxation rates (ΔR2*, ΔR2) showed a significant rCBV decrease in the cerebrum, cortex and hippocampus of rats (except hippocampal ΔR2), which was more pronounced for ΔR2* than for ΔR2. Immunohistological analyses confirmed that the α1-AR antibody induced blood vessel deficiencies. Our findings support the hypothesis that α1-AR antibodies lead to cerebral vessel damage throughout the brain, which can be monitored by MRI-derived rCBV, a non-invasive neuroimaging method. This demonstrates the value of rCBV estimation by ferumoxytolenhanced MRI at 9.4T, and further underlines the significance of this antibody in brain diseases involving vasculature impairments, such as dementia. Copyright © 2014 John Wiley & Sons, Ltd. Additional supporting information may be found in the online version of this article at the publisher’s web site.
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- 2014
50. Ophthalmic Magnetic Resonance Imaging at 7 T Using a 6-Channel Transceiver Radiofrequency Coil Array in Healthy Subjects and Patients With Intraocular Masses
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Soenke Langner, Karen Falke, Maximilian Muhle, Jan Rieger, Lukas Winter, Oliver Stachs, Celal Oezerdem, Fabian Hezel, P.-C. Krueger, Davide Santoro, Sonia Waiczies, Thoralf Niendorf, Darius Lysiak, Michael Schwerter, Stefan Hadlich, Norbert Hosten, Andreas Graessl, and Rudolf F. Guthoff
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Adult ,Male ,Materials science ,Signal-To-Noise Ratio ,Eye ,Imaging phantom ,Young Adult ,Imaging, Three-Dimensional ,Reference Values ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Image resolution ,Aged ,medicine.diagnostic_test ,Phantoms, Imaging ,Eye Neoplasms ,RF power amplifier ,Specific absorption rate ,Magnetic resonance imaging ,Equipment Design ,General Medicine ,Middle Aged ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Feasibility Studies ,Female ,Human eye ,Transceiver ,Biomedical engineering ,Radiofrequency coil - Abstract
OBJECTIVES: This study was designed to examine the feasibility of ophthalmic magnetic resonance imaging (MRI) at 7.0 T using a local 6-channel transmit/receive radiofrequency (RF) coil array in healthy volunteers and patients with intraocular masses. MATERIALS AND METHODS: A novel 6-element transceiver RF coil array that makes uses of loop elements and that is customized for eye imaging at 7.0 T is proposed. Considerations influencing the RF coil design and the characteristics of the proposed RF coil array are presented. Numerical electromagnetic field simulations were conducted to enhance the RF coil characteristics. Specific absorption rate simulations and a thorough assessment of RF power deposition were performed to meet the safety requirements. Phantom experiments were carried out to validate the electromagnetic field simulations and to assess the real performance of the proposed transceiver array. Certified approval for clinical studies was provided by a local notified body before the in vivo studies. The suitability of the RF coil to image the human eye, optical nerve, and orbit was examined in an in vivo feasibility study including (a) 3-dimensional (3D) gradient echo (GRE) imaging, (b) inversion recovery 3D GRE imaging, and (c) 2D T2-weighted fast spin-echo imaging. For this purpose, healthy adult volunteers (n = 17; mean age, 34 +- 11 years) and patients with intraocular masses (uveal melanoma, n = 5; mean age, 57 +- 6 years) were investigated. RESULTS: All subjects tolerated all examinations well with no relevant adverse events. The 6-channel coil array supports high-resolution 3D GRE imaging with a spatial resolution as good as 0.2 × 0.2 × 1.0 mm, which facilitates the depiction of anatomical details of the eye. Rather, uniform signal intensity across the eye was found. A mean signal-to-noise ratio of approximately 35 was found for the lens, whereas the vitreous humor showed a signal-to-noise ratio of approximately 30. The lens-vitreous humor contrast-to-noise ratio was 8, which allows good differentiation between the lens and the vitreous compartment. Inversion recovery prepared 3D GRE imaging using a spatial resolution of 0.4 × 0.4 × 1.0 mm was found to be feasible. T2-weighted 2D fast spin-echo imaging with the proposed RF coil afforded a spatial resolution of 0.25 × 0.25 × 0.7 mm. CONCLUSIONS: This work provides valuable information on the feasibility of ophthalmic MRI at 7.0 T using a dedicated 6-channel transceiver coil array that supports the acquisition of high-contrast, high-spatial resolution images in healthy volunteers and patients with intraocular masses. The results underscore the challenges of ocular imaging at 7.0 T and demonstrate that these issues can be offset by using tailored RF coil hardware. The benefits of such improvements would be in positive alignment with explorations that are designed to examine the potential of MRI for the assessment of spatial arrangements of the eye segments and their masses with the ultimate goal to provide imaging means for guiding treatment decisions in ophthalmological diseases.
- Published
- 2014
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