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Functional MR

Shelley HuaLei Zhang, Stephan E Maier, Lawrence P Panych
PURPOSE: Magnetic resonance spectroscopic imaging (MRSI), under low-spatial resolution settings, often suffers signal contamination from neighboring voxels due to ringing artifacts. Spatial localization can be improved by constraining the point-spread-function (PSF). Here the effectiveness of the two-dimensional PSF-Choice technique in providing improved spatial localization for MRSI is demonstrated. THEORY AND METHODS: The PSF-Choice technique constrains the PSF to a desired shape by manipulating the weighting of RF excitation pulse throughout phase-encode steps...
March 3, 2018: Journal of Magnetic Resonance
T Brusa, D Abler, R Tutuian, C Gingert, J T Heverhagen, M Adamina, L E Brügger, P Büchler
BACKGROUND: A large proportion of age-related fecal incontinence is attributed to weakness or degeneration of the muscles composing the anal continence organ. However, the individual role of these muscles and their functional interplay remain poorly understood. METHODS: This study employs a novel technique based on the combination of MR imaging and FLIP measurements (MR-FLIP) to obtain anatomical and mechanical information simultaneously. Unlike previous methods used to assess the mechanics of the continence organ, MR-FLIP allows inter-individual comparisons and statistical analysis of the sphincter morpho-mechanical parameters...
March 15, 2018: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Robin Bülow, Till Ittermann, Marcus Dörr, Axel Poesch, Sönke Langner, Henry Völzke, Norbert Hosten, Marc Dewey, Robin Bülow
OBJECTIVES: Reference ranges of left ventricular (LV) parameters from cardiac magnetic resonance (CMR) were established to investigate the impact of ageing and hypertension as important determinants of cardiac structure and function. METHODS: One thousand five hundred twenty-five contrast-enhanced CMRs were conducted in the Study of Health in Pomerania. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV), stroke volume (LVSV), ejection fraction (LVEF), and myocardial mass (LVMM) were determined using long- and short-axis steady-state free-precession sequences...
March 14, 2018: European Radiology
Toshinari Onishi, Kaoruko Sengoku, Yasuhiro Ichibori, Isamu Mizote, Koichi Maeda, Toru Kuratani, Yoshiki Sawa, Yasushi Sakata
Transcatheter aortic valve implantation (TAVI) is an effective and less invasive treatment for the increasing population of individuals with severe aortic stenosis (AS). Echocardiography is crucial in the assessment of AS patients from pre- to post-procedure. Transthoracic echocardiography (TTE) may be used to assess patient suitability for TAVI, as well as evaluate the severity of AS, the aortic valve complex, aortic valve morphology, mitral regurgitation (MR), and left ventricular function. Transesophageal echocardiography (TEE) is usually used as an intra-procedural monitoring tool to provide feedback during the procedure, to assess prosthetic valve function, and to detect complications rapidly before and after balloon aortic valvuloplasty (BAV) or transcatheter heart valve (THV) deployment...
February 2018: Cardiovascular Diagnosis and Therapy
Antonietta Messina, Ilaria Bitetti, Francesco Precenzano, Diego Iacono, Giovanni Messina, Michele Roccella, Lucia Parisi, Margherita Salerno, Anna Valenzano, Agata Maltese, Monica Salerno, Francesco Sessa, Giuseppe Davide Albano, Rosa Marotta, Ines Villano, Gabriella Marsala, Christian Zammit, Francesco Lavano, Marcellino Monda, Giuseppe Cibelli, Serena Marianna Lavano, Beatrice Gallai, Roberto Toraldo, Vincenzo Monda, Marco Carotenuto
Introduction: Sleep and migraine share a common pathophysiological substrate, although the underlying mechanisms are unknown. The serotonergic and orexinergic systems are both involved in the regulation of sleep/wake cycle, and numerous studies show that both are involved in the migraine etiopathogenesis. These two systems are anatomically and functionally interconnected. Our hypothesis is that in migraine a dysfunction of orexinergic projections on the median raphe (MR) nuclei, interfering with serotonergic regulation, may cause Non-Rapid Eye Movement parasomnias, such as somnambulism...
2018: Frontiers in Neurology
Kiaran P McGee, Robert S Stormont, Scott A Lindsay, Victor Taracila, Dennis Savitskij, Fraser Robb, Robert Witte, Timothy Kaufmann, John Huston Iii, Stephen J Riederer, Eric Borisch, Phillip J Rossman
The growth in the use of magnetic resonance imaging (MRI) data for radiation therapy (RT) treatment planning has been facilitated by scanner hardware and software advances that have enabled RT patients to be imaged in treatment position while providing morphologic and functional assessment of tumor volumes and surrounding normal tissues. Despite these advances, manufacturers have been slow to develop radiofrequency (RF) coils that closely follow the contour of a RT patient undergoing MR imaging. Instead, relatively large form surface coil arrays have been adapted from diagnostic imaging...
March 14, 2018: Physics in Medicine and Biology
Junu Bae, Zijian Zhou, Thomas Theis, Warren S Warren, Qiu Wang
Hyperpolarized magnetic resonance (HP-MR) is a powerful, sensitive, and noninvasive approach to visualize molecular structure, function, and dynamics in vitro and in vivo. Current applications of HP-MR mostly rely on hyperpolarization of target compounds in dedicated hyperpolarizers because biomolecules can typically not be hyperpolarized directly in vivo. The injected hyperpolarized probes often undergo multiple metabolic pathways in living systems, and it remains challenging to localize and identify specific targets with high chemical selectivity...
March 2018: Science Advances
Esra Gucuk Ipek, Siddharth Singh, Esperanza Viloria, Ted Feldman, Paul Grayburn, Elyse Foster, Atif Qasim
BACKGROUND: Although reverse remodeling of the left atrium (LA) has been shown after MitraClip placement in degenerative mitral regurgitation (MR), changes in LA strain and strain rate have not been evaluated in these patients or compared with surgical mitral valve repair. METHODS AND RESULTS: We included 87 subjects (mean age 59.7±12.3 years) with degenerative MR enrolled in the randomized EVEREST II trial (Endovascular Valve Edge-to-Edge Repair Study II). Baseline peak positive LA strain (ε) and strain rates along with longitudinal left ventricular strain (LV ε) were compared with 12-month follow-up measures...
March 2018: Circulation. Cardiovascular Imaging
R Draganova, A Schollbach, F Schleger, J Braendle, S Brucker, H Abele, K O Kagan, D Wallwiener, A Fritsche, H Eswaran, H Preissl
The human fetal auditory system is functional around the 25th week of gestational age when the thalamocortical connections are established. Fetal magnetoencephalography (fMEG) provides evidence for fetal auditory brain responses to pure tones and syllables. Fifty-five pregnant women between 31 and 40 weeks of gestation were included in the study. Fetal MEG was recorded during the presentation of an amplitude modulated tone (AM) with a carrier frequency of 500 Hz to the maternal abdomen modulated by low modulation rates (MRs) - 2/s and 4/s, middle MR - 8/s and high MRs - 27/s, 42/s, 78/s and 91/s...
March 6, 2018: Hearing Research
Rita Sofia Garcia Ribeiro, Ashwini Ketkar-Atre, Ting Yin, Karim Louchami, Tom Struys, Ivo Lambrichts, Abdullah Sener, Willy Jean Malaisse, Marcel De Cuyper, Uwe Himmelreich
Pancreatic islets (PIs) transplantation is an alternative approach for the treatment of severe forms of type 1 diabetes (T1D). To monitor the success of transplantation, it is desirable to follow the location of engrafted PIs non-invasively. In vivo magnetic resonance imaging (MRI) of transplanted PIs is a feasible cell tracking method; however, this requires labeling with a suitable contrast agent prior to transplantation. We have tested the feasibility of cationic magnetoliposomes (MLs), compared to commercial contrast agents (Endorem and Resovist), by labeling insulinoma cells and freshly isolated rat PIs...
March 12, 2018: Journal of Personalized Medicine
Michael Haimerl, Irene Fuhrmann, Stefanie Poelsterl, Claudia Fellner, Marcel D Nickel, Kilian Weigand, Marc H Dahlke, Niklas Verloh, Christian Stroszczynski, Philipp Wiggermann
OBJECTIVES: To determine whether liver function as determined by intravenous administration of13 C-methacetin and continuous real-time breath analysis can be estimated quantitatively from gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) relaxometry. METHODS: Sixty-six patients underwent a13 C-methacetin breath test (13 C-MBT) for evaluation of liver function and Gd-EOB-DTPA-enhanced T1-relaxometry at 3 T. A transverse 3D VIBE sequence with an inline T1 calculation based on variable flip angles was acquired prior to (T1 pre) and 20 min post-Gd-EOB-DTPA (T1 post) administration...
March 12, 2018: European Radiology
Y Valcárcel, A Valdehíta, E Becerra, M López de Alda, A Gil, M Gorga, M Petrovic, D Barceló, J M Navas
Endocrine disruptors (EDs) are natural or man-made chemicals that can affect the health of organisms by interfering with their normal hormonal functions. Many of these substances can cause their effects at very low doses and, considering the key role played by the endocrine system on development, organisms in early phases of growth (foetal, childhood, puberty) are especially sensitive to the action of EDs. In addition, when combined, they can show additive, antagonistic and synergistic activities. Taking all this into account it is essential to determine the presence of this kind of compounds in drinking water...
February 22, 2018: Chemosphere
Sangeeta Taneja, Amarnath Jena, Rajesh Taneja, Aru Singh, Aashim Ahuja
OBJECTIVE: The purpose of this study is to assess whether temporal changes in68 Ga-prostate-specific membrane antigen (PSMA)-HBED-CC uptake and multiparametric MRI parameters derived using PET/MRI can aid in characterization of benign and malignant prostate lesions. MATERIALS AND METHODS: Thirty-five men with 29 malignant and six benign prostate lesions undergoing complete clinical workup including histologic analysis were enrolled for this retrospective study. All had undergone simultaneous whole-body68 Ga-PSMAHBED-CC PET/MRI...
March 12, 2018: AJR. American Journal of Roentgenology
Deepa Sasikumar, Baiju S Dharan, Priyadarshini Arunakumar, Arun Gopalakrishnan, Sivasubramonian Sivasankaran, Kavasseri M Krishnamoorthy
OBJECTIVES: Mitral regurgitation (MR) in the majority of infants with an anomalous left coronary artery from the pulmonary artery (ALCAPA) has been shown to improve without concomitant mitral valve repair. However, the outcome of MR in older children with ALCAPA is unclear. The purpose of this study was to compare the outcome of MR following the ALCAPA repair in infants and older children. METHODS: Forty-six patients (34 were younger than 1 year and 12 were aged 1-12 years) underwent the repair for ALCAPA in our institution from June 2006 to June 2016...
March 8, 2018: Interactive Cardiovascular and Thoracic Surgery
Cen Zhang, John A Detre, Scott E Kasner, Brett Cucchiara
Objective: The objective of this study is to determine whether structural features of the vertebrobasilar arterial system are related to migraine. Background: Alterations in cerebral vascular structure and function have been associated with migraine, possibly mediated by hypoperfusion and/or endothelial dysfunction triggering cortical spreading depression. Vessel tortuosity, in particular, has been associated with both altered hemodynamics and endothelial function...
2018: Frontiers in Neurology
Shota Hodono, Akihiro Shimokawa, Neil J Stewart, Yukiko Yamauchi, Renya Nishimori, Mami Yamane, Hirohiko Imai, Hideaki Fujiwara, Atsuomi Kimura
PURPOSE: High Mobility Group Box1 (HMGB1), which is one of the damage-associated molecular pattern molecules relating to various inflammatory diseases, has gained interest as a therapeutic target because of its involvement in wound healing processes. In the present study, we investigated HMGB1 as a potential therapeutic target in a model of lung fibrosis using a preclinical hyperpolarized129 Xe (HPXe) MRI system. METHODS: Lung injury was induced by intra-peritoneal injection of bleomycin (BLM) in 19 mice...
March 9, 2018: Magnetic Resonance in Medical Sciences: MRMS
P Górka, Z M Kowalski, R Zabielski, P Guilloteau
Promotion of microbial butyrate production in the reticulorumen is a widely used method for enhancing forestomach development in calves. Additional acceleration of gastrointestinal tract (GIT) development, both the forestomach and lower parts of the GIT (e.g., abomasum, intestine, and also pancreas), can be obtained by dietary butyrate supplementation. For this purpose, different sources (e.g., butyrate salts or butyrins), forms (e.g., protected or unprotected), methods (e.g., in liquid feed or solid feed), and periods (e...
March 7, 2018: Journal of Dairy Science
Anna Kurek, Katarzyna Głombik, Jan Detka, Agnieszka Basta-Kaim, Marta Kubera, Władysław Lasoń, Bogusława Budziszewska
Obesity is a disease that often co-occurs with depression, and some evidence indicates that chronic stress in the perinatal period, in association with overactive glucocorticoids, can cause permanent changes that increase the risk of the development of both depression and obesity later in life. However, the mechanism responsible for the overly potent action of glucocorticoids in both depression and obesity is not known. The aim of the present study was to determine the expression of glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs) and the factors that affect GR function (FKBP51, Bag-1 and HSP70) in a prenatal stress animal model of depression, a model of obesity and a model of both depression and obesity...
March 9, 2018: Journal of Neuroendocrinology
Patrick Krumm, Stefanie Mangold, Sergios Gatidis, Konstantin Nikolaou, Felix Nensa, Fabian Bamberg, Christian la Fougère
Combined PET/MRI is a novel imaging method integrating the advances of functional and morphological MR imaging with PET applications that include assessment of myocardial viability, perfusion, metabolism of inflammatory tissue and tumors, as well as amyloid deposition imaging. As such, PET/MRI is a promising tool to detect and characterize ischemic and non-ischemic cardiomyopathies. To date, the greatest benefit may be expected for diagnostic evaluation of systemic diseases and cardiac masses that remain unclear in cardiac MRI, as well as for clinical and scientific studies in the setting of ischemic cardiomyopathies...
March 10, 2018: Japanese Journal of Radiology
R Jansen, A M Wind, M J Cramer, F Nijhoff, P Agostoni, F Z Ramjankhan, W J Suyker, P R Stella, S A J Chamuleau
The purpose of this study was to evaluate mitral regurgitation (MR) severity in patients undergoing transcatheter aortic valve replacement (TAVR) by standardized assessment of two-dimensional (2D) transthoracic echocardiography (TTE) and 1-year echocardiographic and clinical outcomes. Pre- and post-procedural TTE's of patients undergoing TAVR between 2008 and 2014 were analyzed. MR was graded according to current guidelines with a systematic and integrated approach. Longitudinal echocardiographic and clinical results were analyzed...
March 10, 2018: International Journal of Cardiovascular Imaging
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