Journal articles: 'Sodium (23Na) Magnetic Resonance Imaging (MRI)'

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Giovannetti, Giulio, Alessandra Flori, Nicola Martini, Roberto Francischello, Giovanni Donato Aquaro, Alessandro Pingitore, and Francesca Frijia. "Sodium Radiofrequency Coils for Magnetic Resonance: From Design to Applications." Electronics 10, no. 15 (July 26, 2021): 1788. http://dx.doi.org/10.3390/electronics10151788.

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Sodium (23Na) is the most abundant cation present in the human body and is involved in a large number of vital body functions. In the last few years, the interest in Sodium Magnetic Resonance Imaging (23Na MRI) has considerably increased for its relevance in physiological and physiopathological aspects. Indeed, sodium MRI offers the possibility to extend the anatomical imaging information by providing additional and complementary information on physiology and cellular metabolism with the heteronuclear Magnetic Resonance Spectroscopy (MRS). Constraints are the rapidly decaying of sodium signal, the sensitivity lack due to the low sodium concentration versus 1H-MRI induce scan times not clinically acceptable and it also constitutes a challenge for sodium MRI. With the available magnetic fields for clinical MRI scanners (1.5 T, 3 T, 7 T), and the hardware capabilities such as strong gradient strengths with high slew rates and new dedicated radiofrequency (RF) sodium coils, it is possible to reach reasonable measurement times (~10–15 min) with a resolution of a few millimeters, where it has already been applied in vivo in many human organs such as the brain, cartilage, kidneys, heart, as well as in muscle and the breast. In this work, we review the different geometries and setup of sodium coils described in the available literature for different in vivo applications in human organs with clinical MR scanners, by providing details of the design, modeling and construction of the coils.

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Kamp, Benedikt, Miriam Frenken, Lena Klein-Schmeink, Armin M. Nagel, Lena M. Wilms, Karl Ludger Radke, Styliani Tsiami, et al. "Evaluation of Sodium Relaxation Times and Concentrations in the Achilles Tendon Using MRI." International Journal of Molecular Sciences 23, no. 18 (September 17, 2022): 10890. http://dx.doi.org/10.3390/ijms231810890.

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Sodium magnetic resonance imaging (MRI) can be used to evaluate the change in the proteoglycan content in Achilles tendons (ATs) of patients with different AT pathologies by measuring the 23Na signal-to-noise ratio (SNR). As 23Na SNR alone is difficult to compare between different studies, because of the high influence of hardware configurations and sequence settings on the SNR, we further set out to measure the apparent tissue sodium content (aTSC) in the AT as a better comparable parameter. Ten healthy controls and one patient with tendinopathy in the AT were examined using a clinical 3 Tesla (T) MRI scanner in conjunction with a dual tuned 1H/23Na surface coil to measure 23Na SNR and aTSC in their ATs. 23Na T1 and T2* of the AT were also measured for three controls to correct for different relaxation behavior. The results were as follows: 23Na SNR = 11.7 ± 2.2, aTSC = 82.2 ± 13.9 mM, 23Na T1 = 20.4 ± 2.4 ms, 23Na T2s* = 1.4 ± 0.4 ms, and 23Na T2l* = 13.9 ± 0.8 ms for the whole AT of healthy controls with significant regional differences. These are the first reported aTSCs and 23Na relaxation times for the AT using sodium MRI and may serve for future comparability in different studies regarding examinations of diseased ATs with sodium MRI.

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Sadykhov, E. G., Yu A. Pirogov, N. V. Anisimov, M. V. Gulyaev, G. E. Pavlovskaya, T. Meersmann, V. N. Belyaev, and D. V. Fomina. "Magnetic Resonance Imaging on Sodium Nuclei: Potential Medical Applications of 23Na MRI." Applied Magnetic Resonance 49, no. 9 (July 27, 2018): 925–57. http://dx.doi.org/10.1007/s00723-018-1045-7.

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Atthe, Bharath K., Andriy M. Babsky, Paige N. Hopewell, Carrie L. Phillips, Bruce A. Molitoris, and Navin Bansal. "Early monitoring of acute tubular necrosis in the rat kidney by 23Na-MRI." American Journal of Physiology-Renal Physiology 297, no. 5 (November 2009): F1288—F1298. http://dx.doi.org/10.1152/ajprenal.00388.2009.

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Reabsorption of water and other molecules is dependent on the corticomedullary sodium concentration gradient in the kidney. During the early course of acute tubular necrosis (ATN), this gradient is altered. Therefore, 23Na magnetic resonance imaging (MRI) was used to study the alterations in renal sodium distribution in the rat kidney during ischemia and reperfusion (IR) injury, which induces ATN. In-magnet ischemia was induced for 0 (control), 10, 20, 30 or 50 min in Wistar rats. 23Na images were collected every 10 min during baseline, ischemia, and 60-min reperfusion periods. T1 and T2 relaxation times were measured by both 23Na-MRI and -MRS on a separate cohort of animals during ischemia and reperfusion for correction of relaxation-related tissue sodium concentration (TSC). A marked decrease was observed in the medulla and cortex 23Na-MRI signal intensity (SI) during the early evolution of ATN caused by IR injury, with the sodium reabsorption function of the kidney being irreversibly damaged after 50 min of ischemia. Sodium relaxation time characteristics were similar in the medulla and cortex of normal kidney, but significantly decreased with IR. The changes in relaxation times in both compartments were identical; thus the medulla-to-cortex sodium SI ratio represents the TSC ratio of both compartments. The extent of IR damage observed with histological examination correlated with the 23Na-MRI data. 23Na-MRI has great potential for noninvasive, clinical diagnosis of evolving ATN in the setup of acute renal failure and in differentiating ATN from other causes of renal failure where tubular function is maintained.

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Moosmann, Julia, Okan Toka, Peter Linz, Anke Dahlmann, Armin M. Nagel, Mario Schiffer, Michael Uder, Robert Cesnjevar, Sven Dittrich, and Christoph Kopp. "Tolvaptan treatment in an adult Fontan patient with protein-losing enteropathy: a serial 23Na-MRI investigation." Therapeutic Advances in Chronic Disease 12 (January 2021): 204062232110040. http://dx.doi.org/10.1177/20406223211004005.

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Background: Protein-losing enteropathy (PLE) is a severe complication of the univentricular Fontan circulation and associated with disturbances in salt and water homeostasis. Fontan patients with PLE have a poor prognosis, with increased morbidity and mortality. Due to limited therapeutic strategies, patients are often treated only symptomatically. Methods: We report our first experience of Tolvaptan (TLV) treatment in a Fontan patient with PLE, severe volume retention and hyponatraemia, refractory to conventional diuretic therapy. In addition to clinical parameters, we monitored drug effects including tissue sodium and volume status via serial 23Na-magnetic resonance imaging (23Na-MRI) and bioimpedance spectroscopy compared with age-matched controls. Results: 23Na-MRI identified elevated tissue sodium, which decreased under TLV treatment, as well as volume status, while serum sodium increased and the patient’s symptoms improved. During long-term treatment, we were able to differentiate between sodium and volume status in our patient, suggesting that TLV uncoupled body sodium from water. Conclusion: TLV in addition to loop diuretics improved clinical symptoms of PLE and lowered tissue sodium overload. Long-term effects should be further evaluated in Fontan patients.

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Perelman, Adi, Naftali Lazarovitch, Jan Vanderborght, and Andreas Pohlmeier. "Quantitative imaging of sodium concentrations in soil-root systems using magnetic resonance imaging (MRI)." Plant and Soil 454, no. 1-2 (July 25, 2020): 171–85. http://dx.doi.org/10.1007/s11104-020-04628-8.

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Abstract Aims Demonstrating the potential of MRI as a 3D, non-invasive and continuous measurement technique to map Na+ concentration distributions in soil and around roots. Methods Dissolved NaCl in soil and soil-plant systems was mapped by 3D 23Na-MRI. The lower limit of detectability in saturated and unsaturated porous media was evaluated, followed by evaporation experiments to test the quantification. Finally, Na+ enrichment around tomato roots, irrigated with saline solution under low/high transpiration rates (LT, HT), was imaged in parallel to the root system,. Results A spin echo pulse sequence allowed the quantitative mapping of the volume concentration of NaCl in sandy porous medium. Evaporation experiments showed slight enrichment in the top surface layer, plus uniform temporal enrichment in the deeper layers. In the tomato experiments, enrichment was more distinct under HT than under LT. Concentration-distance correlation curves revealed thin enrichment zones ranging a few mm around the roots. Conclusions MRI can map Na+ non-invasively in 3D at relevant concentrations for root activity. Visualizing water content, roots and Na+ on the same scale is possible, despite limitations of different scanning times and resolution. This opens a route for further quantitative investigations of salt enrichment processes in soil and soil-plant systems.

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Eisele, Philipp, Simon Konstandin, Martin Griebe, Kristina Szabo, Marc E. Wolf, Angelika Alonso, Anne Ebert, et al. "Heterogeneity of acute multiple sclerosis lesions on sodium (23Na) MRI." Multiple Sclerosis Journal 22, no. 8 (October 9, 2015): 1040–47. http://dx.doi.org/10.1177/1352458515609430.

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Background: Advanced magnetic resonance imaging (MRI) techniques provide a window into pathological processes in multiple sclerosis (MS). Nevertheless, to date only few studies have performed sodium MRI in MS. Objectives: We analysed total sodium concentration (TSC) in hyperacute, acute and chronic lesions in MS with 23Na MRI. Methods: 23Na MRI and 1H MRI were performed in 65 MS patients and 10 healthy controls (HC). Mean TSC was quantified in all MS lesions with a diameter of >5 mm and in the normal appearing white and grey matter (NAWM, NAGM). Results: TSC in the NAWM and the NAGM of MS patients was significantly higher compared to HC (WM: 37.51 ± 2.65 mM versus 35.17 ± 3.40 mM; GM: 43.64 ± 2.75 mM versus 40.09 ± 4.64 mM). Acute and chronic MS lesions showed elevated TSC levels of different extent (contrast-enhancing lesions (49.07 ± 6.99 mM), T1 hypointense lesions (45.06 ± 6.26 mM) and remaining T1 isointense lesions (39.88 ± 5.54 mM)). However, non-enhancing hyperacute lesions with a reduced apparent diffusion coefficient showed a TSC comparable to the NAWM (37.22 ± 4.62 mM). Conclusions: TSC is not only a sensitive marker of the severity of chronic tissue abnormalities in MS but is also highly sensitive to opening of the blood–brain barrier and vasogenic tissue oedema in contrast-enhancing lesions.

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Ronga, Mario, Gloria Angeretti, Sergio Ferraro, Giovanni De Falco, Eugenio Genovese, and Paolo Cherubino. "Imaging of articular cartilage: current concepts." Joints 02, no. 03 (July 2014): 137–40. http://dx.doi.org/10.11138/jts/2014.2.3.137.

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Magnetic resonance imaging (MRI) is the gold standard method for non-invasive assessment of joint cartilage, providing information on the structure, morphology and molecular composition of this tissue. There are certain minimum requirements for a MRI study of cartilage tissue: machines with a high magnetic field (> 1.5 Tesla); the use of surface coils; and the use of T2-weighted, proton density-weighted fast-spin echo (T2 FSE-DP) and 3D fat-suppressed T1-weighted gradient echo (3D-FS T1W GRE) sequences. For better contrast between the different joint structures, MR arthography is a method that can highlight minimal fibrillation or fractures of the articular surface and allow evaluation of the integrity of the native cartilagerepair tissue interface. To assess the biochemical composition of cartilage and cartilage repair tissue, various techniques have been proposed for studying proteoglycans [dGEMRIC, T1rho mapping, sodium (23Na) imaging MRI, etc.], collagen, and water distribution [T2 mapping, “magnetisation transfer contrast”, diffusion-weighted imaging (DWI), and so on]. Several MRI classifications have been proposed for evaluating the processes of joint degeneration (WORMS, BLOKS, ICRS) and post-surgical maturation of repair tissue (MOCART, 3D MOCART). In the future, isotropic 3D sequences set to improve image quality and facilitate the diagnosis of disorders of articular structures adjacent to cartilage.

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Guiheneuf, Thierry M., Stephen J. Gibbs, and Laurance D. Hall. "Measurement of the inter-diffusion of sodium ions during pork brining by one-dimensional 23Na Magnetic Resonance Imaging (MRI)." Journal of Food Engineering 31, no. 4 (March 1997): 457–71. http://dx.doi.org/10.1016/s0260-8774(96)00085-4.

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Eleff, Scott M., Mitchell D. Schnall, Laszlo Ligetti, Mary Osbakken, Harihara Subramanian, Britton Chance, and John S. Leigh. "Concurrent measurements of cerebral blood flow, sodium, lactate, and high-energy phosphate metabolism using19F,23Na,1H, and31P nuclear magnetic resonance spectroscopy." Magnetic Resonance in Medicine 7, no. 4 (August 1988): 412–24. http://dx.doi.org/10.1002/mrm.1910070404.

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Puder, Lia, Sophie Roth, Philipp Krabusch, Susanna Wiegand, Robert Opitz, Martin Bald, Christa Flück, et al. "Cardiac Phenotype and Tissue Sodium Content in Adolescents With Defects in the Melanocortin System." Journal of Clinical Endocrinology & Metabolism 106, no. 9 (May 24, 2021): 2606–16. http://dx.doi.org/10.1210/clinem/dgab368.

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Abstract Context Pro-opiomelanocortin (POMC) and the melanocortin-4 receptor (MC4R) play a pivotal role in the leptin–melanocortin pathway. Mutations in these genes lead to monogenic types of obesity due to severe hyperphagia. In addition to dietary-induced obesity, a cardiac phenotype without hypertrophy has been identified in MC4R knockout mice. Objective We aimed to characterize cardiac morphology and function as well as tissue Na+ content in humans with mutations in POMC and MC4R genes. Methods A cohort of 42 patients (5 patients with bi-allelic POMC mutations, 6 heterozygous MC4R mutation carriers, 19 obese controls without known monogenic cause, and 12 normal weight controls) underwent cardiac magnetic resonance (CMR) imaging and 23Na-MRI. Results Monogenic obese patients with POMC or MC4R mutation respectively had a significantly lower left ventricular mass/body surface area (BSA) than nonmonogenic obese patients. Left ventricular end-diastolic volume/BSA was significantly lower in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. Subcutaneous fat and skin Na+ content was significantly higher in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. In these compartments, the water content was significantly higher in patients with POMC and MC4R mutation than in control groups. Conclusion Patients with POMC or MC4R mutations carriers had a lack of transition to hypertrophy, significantly lower cardiac muscle mass/BSA, and stored more Na+ within the subcutaneous fat tissue than nonmonogenic obese patients. The results point towards the role of the melanocortin pathway for cardiac function and tissue Na+ storage and the importance of including cardiologic assessments into the diagnostic work-up of these patients.

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Wolff, S. D., J. Eng, B. A. Berkowitz, S. James, and R. S. Balaban. "Sodium-23 nuclear magnetic resonance imaging of the rabbit kidney in vivo." American Journal of Physiology-Renal Physiology 258, no. 4 (April 1, 1990): F1125—F1131. http://dx.doi.org/10.1152/ajprenal.1990.258.4.f1125.

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The mechanism by which the mammalian kidney generates a concentration gradient of sodium from cortex to papilla is still not entirely understood. Studies of how the kidney as an organ generates this gradient have been hampered by the lack of a noninvasive method for monitoring the intrarenal sodium distribution. Herein, we demonstrate the value of sodium-23 nuclear magnetic resonance (23Na-NMR) imaging to nondestructively assess the intrarenal sodium distribution. 23Na-NMR images were obtained from a surgically exposed kidney preparation that showed the two-dimensional distribution of sodium in the rabbit kidney. In the antidiuretic kidney this gradient resulted in papillary sodium concentrations that were approximately threefold higher than cortical values. Serial 23Na-NMR images obtained during saline infusion demonstrated the kinetics by which the sodium gradient increases with diuresis. The half-time for 23Na washout of the medulla of the kidney was approximately 6 min with this protocol. In addition, a three-dimensional data set of the sodium distribution of the kidney was obtained with voxel dimensions of 1.5 mm3 by use of a three-dimensional 23Na-NMR imaging technique. Without surgical exposure, 23Na-NMR images of the rabbit kidney were collected under completely noninvasive conditions by use of a surface coil. The 23Na-NMR signal from the kidney was easily detected; however, to obtain images of comparable signal-to-noise ratio to the surgically exposed kidney, spatial and temporal resolution were significantly reduced.

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Nielsen, Per Mose, Christian Østergaard Mariager, Daniel Guldager Kring Rasmussen, Marie Mølmer, Federica Genovese, Morten Asser Karsdal, Christoffer Laustsen, and Rikke Nørregaard. "Noninvasive Assessment of Fibrosis Following Ischemia/Reperfusion Injury in Rodents Utilizing Na Magnetic Resonance Imaging." Pharmaceutics 12, no. 8 (August 14, 2020): 775. http://dx.doi.org/10.3390/pharmaceutics12080775.

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Fibrosis is often heterogeneously distributed, and classical biopsies do not reflect this. Noninvasive methods for renal fibrosis have been developed to follow chronic kidney diseases (CKD) and to monitor anti-fibrotic therapy. In this study, we combined two approaches to assess fibrosis regression following renal ischemia-reperfusion injury (IRI): magnetic resonance imaging (MRI) and noninvasive extracellular matrix (ECM) biomarkers. MRI was used to evaluate fibrosis in bilateral IRI in rats after reperfusion at 7, 14, and 21 days. This was performed with 1HT1 and T2* mapping, dynamic contrast-enhanced (DCE)-MRI, and chemical shift imaging (CSI)-23Na. The degradation of laminin gamma-1 chain (LG1M) and type III collagen (C3M) was measured in urine and plasma. Fibrosis was analyzed in tissue using fibronectin (FN) and alpha-smooth muscle actin (α-SMA) using quantitative polymerase chain reaction qPCR and western blotting. We found increased fibrosis 7 days after reperfusion, which dropped to sham levels after 21 days. Single kidney glomerular filtration rate (skGFR), perfusion (DCE-MRI), and total 23Na kidney content correlated positively with fibrotic markers FN and α-SMA as well as noninvasive LG1M and C3M. We showed that novel MRI protocols and ECM markers could track fibrogenic development. This could give rise to a multi-parametric practice to diagnose and assess fibrosis whilst treating kidney disease without using invasive methods.

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Yu, Zidan, Guillaume Madelin, Daniel K. Sodickson, and Martijn A. Cloos. "Simultaneous proton magnetic resonance fingerprinting and sodium MRI." Magnetic Resonance in Medicine 83, no. 6 (November 20, 2019): 2232–42. http://dx.doi.org/10.1002/mrm.28073.

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Christa, Martin, Andreas M. Weng, Bettina Geier, Caroline Wörmann, Anne Scheffler, Leane Lehmann, Johannes Oberberger, et al. "Increased myocardial sodium signal intensity in Conn’s syndrome detected by 23Na magnetic resonance imaging." European Heart Journal - Cardiovascular Imaging 20, no. 3 (October 10, 2018): 263–70. http://dx.doi.org/10.1093/ehjci/jey134.

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Meyer, Melissa M., Alexander Schmidt, Justus Benrath, Simon Konstandin, Lothar R. Pilz, Michael G. Harrington, Johannes Budjan, et al. "Cerebral sodium (23Na) magnetic resonance imaging in patients with migraine — a case-control study." European Radiology 29, no. 12 (July 1, 2019): 7055–62. http://dx.doi.org/10.1007/s00330-019-06299-1.

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Allen, K. L., A. L. Busza, S. R. Williams, and S. R. Williams. "Early changes in cerebral sodium distribution following ischaemia monitored by 23Na magnetic resonance imaging." Magnetic Resonance Imaging 12, no. 6 (January 1994): 895–900. http://dx.doi.org/10.1016/0730-725x(94)92030-3.

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Burge, Alissa, Hollis Potter, and Erin Argentieri. "Magnetic Resonance Imaging of Articular Cartilage within the Knee." Journal of Knee Surgery 31, no. 02 (January 18, 2018): 155–65. http://dx.doi.org/10.1055/s-0037-1620233.

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AbstractMagnetic resonance imaging (MRI) provides an effective and noninvasive means by which to evaluate articular cartilage within the knee. Existing techniques can be utilized to detect and monitor longitudinal changes in cartilage status due to injury or progression of degenerative disease. Quantitative MRI (qMRI) techniques can provide a metric by which to evaluate the efficacy of cartilage repair techniques and offer insight into the composition of cartilage and cartilage repair tissue. In this review, we provide background on MR signal generation and decay, the utility of morphologic MRI assessment, and qMRI techniques for the biochemical assessment of cartilage (dGEMRIC, T2, T2*, T1ρ, sodium, gagCEST). Finally, the description and utility of these qMRI techniques for the evaluation of cartilage repair are discussed.

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Hernandez, Daniel. "Design of a Coplanar Interlayer Gapped Microstrips Arrangement for Multi-Nuclei (1H, 19F, 31P, and 23Na) Applications in 7T MRI." Applied Sciences 11, no. 3 (January 21, 2021): 957. http://dx.doi.org/10.3390/app11030957.

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Seven Tesla Magnetic Resonance (MR) systems can obtain high quality anatomical images using protons (1H) and can be used for multinuclear imaging and MR spectroscopy. These imaging modes can also obtain images and metabolic information using other nuclei, such as 19F, 31P, and 23Na. Here, we present an RF coil unit using a microstrip capable of resonating at four frequencies: 300 (1H), 280 (19F), 121 (31P), and 78 (23Na) MHz. The RF unit consists of a single feeding port and four lines that resonate and run a current at their respective frequency. We used the gapped microstrip concept to isolate each conducting line and interleaved the dielectric materials used for each line, thereby reducing the coupling between them. We also analyzed this design using electromagnetic (EM) simulations, and found that the quad tuned arrangement produced low coupling between adjacent current lines and achieved a uniform |B1| field in the z-y plane.

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Solomakha, G., N. Egorova, R. Balafendiev, C. Simovski, and S. Glybovski. "Wideband Coil Based on Microstrip Line for Multiheteronuclear Magnetic Resonance Spectroscopy." Journal of Physics: Conference Series 2015, no. 1 (November 1, 2021): 012146. http://dx.doi.org/10.1088/1742-6596/2015/1/012146.

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Abstract Magnetic Resonance Spectroscopy of X-nucleus is a method for mapping metabolite quantity in-vivo in the desired region of the human body. However, this method has a lot of difficulties. Since natural abundance of X-nucleus is much lower than for hydrogen, to improve SNR of the spectrum we need to work in higher static magnetic fields. But, even at such high fields, X-nuclei imaging still a very difficult process. One of the problems are RF-coils, which are required for transmission and reception of signals. Traditionally, for human body X-nuclei MRS multi-tuned loop coils are used. However, such coils suffer from additional losses in the circuits required for double-frequency tuning and high complexity. In this work, we propose an alternative approach, based on a recently introduced leaky-wave antenna for MRI, that allows creating wideband excitation which provides wideband transmit and receive. This wideband frequency range covering 13C, 23Na and 31P Larmor resonant frequencies.

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Matwiyoff, Nicholas A. "NMR imaging and spectroscopy of tissue at high resolution: problems and prospects." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 110–11. http://dx.doi.org/10.1017/s0424820100142190.

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When the nuclei of atoms like hydrogen (1H), carbon (13C), phosphorus (31P), and sodium (23Na) are subjected to a static magnetic field, they can be induced to emit electromagnetic radiation. This phenomenon, called nuclear magnetic resonance (NMR), was first demonstrated experimentally by the research groups of Bloch and Purcell in 1946. Because the spectrum of the radiation emitted depends on the type of nucleus and its chemical environment, NMR spectroscopy was rapidly exploited by chemists and has become a major tool for the investigation of molecular structure and the analysis of complex mixtures. More recently the NMR response of living systems subjected to known gradients of a static magnetic field has been exploited in medicine to construct images of the concentration and environment of hydrogen (protons) in the water and fat of soft tissues in the body.

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Wetterling, Friedrich, Lindsay Gallagher, Jim Mullin, William M. Holmes, Chris McCabe, I. Mhairi Macrae, and Andrew J. Fagan. "Sodium-23 Magnetic Resonance Imaging Has Potential for Improving Penumbra Detection but Not for Estimating Stroke Onset Time." Journal of Cerebral Blood Flow & Metabolism 35, no. 1 (October 22, 2014): 103–10. http://dx.doi.org/10.1038/jcbfm.2014.174.

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Tissue sodium concentration increases in irreversibly damaged (core) tissue following ischemic stroke and can potentially help to differentiate the core from the adjacent hypoperfused but viable penumbra. To test this, multinuclear hydrogen-1/sodium-23 magnetic resonance imaging (MRI) was used to measure the changing sodium signal and hydrogen-apparent diffusion coefficient (ADC) in the ischemic core and penumbra after rat middle cerebral artery occlusion (MCAO). Penumbra and core were defined from perfusion imaging and histologically defined irreversibly damaged tissue. The sodium signal in the core increased linearly with time, whereas the ADC rapidly decreased by >30% within 20 minutes of stroke onset, with very little change thereafter (0.5–6 hours after MCAO). Previous reports suggest that the time point at which tissue sodium signal starts to rise above normal (onset of elevated tissue sodium, OETS) represents stroke onset time (SOT). However, extrapolating core data back in time resulted in a delay of 72±24 minutes in OETS compared with actual SOT. At the OETS in the core, penumbra sodium signal was significantly decreased (88±6%, P=0.0008), whereas penumbra ADC was not significantly different (92±18%, P=0.2) from contralateral tissue. In conclusion, reduced sodium-MRI signal may serve as a viability marker for penumbra detection and can complement hydrogen ADC and perfusion MRI in the time-independent assessment of tissue fate in acute stroke patients.

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Potter, Kimberlee, Bruce J. Balcom, T. Adrian Carpenter, and Laurance D. Hall. "The gelation of sodium alginate with calcium ions studied by magnetic resonance imaging (MRI)." Carbohydrate Research 257, no. 1 (April 1994): 117–26. http://dx.doi.org/10.1016/0008-6215(94)84112-8.

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Juif, L., P. Calame, C. Chausset, S. Koch, C. Briot, M. De Billy, and L. Vuitton. "P306 Efficacy and tolerance of sodium picosulfate preparation in bowel Magnetic Resonance Imaging in Crohn’s disease." Journal of Crohn's and Colitis 16, Supplement_1 (January 1, 2022): i333—i334. http://dx.doi.org/10.1093/ecco-jcc/jjab232.433.

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Abstract Background Polyethylene glycol (PEG) is one of the most commonly used bowel preparation for magnetic resonance imaging (MRI) in Crohn’s Disease (CD). Sodium picosulfate (Pico) is a low volume bowel preparation known for its efficacy and higher tolerability for colonoscopy. No study has to date evaluated tolerance and efficacy of Pico preparations for MRI in CD. Aim: To assess for the first time the efficacy and tolerance of Pico preparation compared to PEG preparation for bowel MRI in CD. Methods The study took place in a French university hospital. To assess the efficacy of low volume preparations compared to PEG, we selected consecutive bowel MRI from January to June, 2017 prepared with PEG formulas, and consecutive MRI from January, 2020 to June, 2020 prepared with low-volume Pico formula.The sample size was calculated to assess the non-inferiority of Pico preparation vs PEG. The efficacy endpoint was the quality of bowel distention on a, 5 points scale and by visual analog scale (VAS) by two independent readers. To study Pico preparation tolerability, we performed a prospective survey in CD patients undergoing MRI from October, 2020 to August, 2021. Patients completed a self-administered validated questionnaire on tolerability and a VAS. Results In the efficacy study,84 MRIs were analysed (42 in each PEG and Pico group). There was no significant difference between PEG and Pico preparation regarding jejunum and ileum distention on the, 5 points quality scale. Moreover, we did not find significant difference between PEG and Pico regarding overall quality in the VAS (8.1 ±, 1.4 in PEG group, vs, 8.7 ±, 1.2 in Pico group, by reader, 1 (p=, 0.125);, 6.35 ±, 1 in PEG group, 6.5 ±, 1 in Pico group by reader, 2 (p=0.298)) with a moderate but significant correlation rate between the two readers (r=, 0.45; p<0.001). There was no significant difference regarding ileal diameter between the two preparations with a moderate correlation rate between the two readers (r=0.41; p<0.01). In the prospective study, 38 patients participated in the survey. The bowel preparation intake was completefor, 94.7% of the patients. The mean tolerance was, 6.84/10. Overall, 81.6% of patients were willing to take the same preparation again. Conclusion The study assessed Pico preparation non-inferiority to PEG preparation for small bowel MRI and confirmed low volume bowel preparations good tolerability profile. This suggests that low-volume preparations could be more widely implemented in clinical practice for small bowel imaging in chronic inflammatory bowel disease and thus improve follow-up acceptance.

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Henderson, Luke A., Paul M. Macey, Chris A. Richard, Matthew L. Runquist, and Ronald M. Harper. "Functional magnetic resonance imaging during hypotension in the developing animal." Journal of Applied Physiology 97, no. 6 (December 2004): 2248–57. http://dx.doi.org/10.1152/japplphysiol.00297.2004.

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Hypotension in adult animals recruits brain sites extending from cerebellar cortex to the midbrain and forebrain, suggesting a range of motor and endocrine reactions to maintain perfusion. We hypothesized that comparable neural actions during development rely more extensively on localized medullary processes. We used functional MRI to assess neural responses during sodium nitroprusside challenges in 14 isoflurane-anesthetized kittens, aged 14–25 days, and seven adult cats. Baseline arterial pressure increased with age in kittens, and basal heart rates were higher. The magnitude of depressor responses increased with age, while baroreceptor reflex sensitivity initially increased over those of adults. In contrast to a decline in adult cats, functional MRI signal intensity increased significantly in dorsal and ventrolateral medullary regions and the midline raphe in the kittens during the hypotensive challenges. In addition, significant signal intensity differences emerged in cerebellar cortex and deep nuclei, dorsolateral pons, midbrain tectum, hippocampus, thalamus, and insular cortex. The altered neural responses in medullary baroreceptor reflex sites may have resulted from disinhibitory or facilitatory influences from cerebellar and more rostral structures as a result of inadequately developed myelination or other neural processes. A comparable immaturity of blood pressure control mechanisms in humans would have significant clinical implications.

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Oei, Edwin, Marius Wick, Anja Müller-Lutz, Christoph Schleich, and Falk Miese. "Cartilage Imaging: Techniques and Developments." Seminars in Musculoskeletal Radiology 22, no. 02 (April 2018): 245–60. http://dx.doi.org/10.1055/s-0038-1639471.

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AbstractCartilage degeneration is one of the most common chronic age-related joint disorders leading to pain and reduced joint motion. The increasing prevalence of osteoarthritis requires accurate cartilage imaging, both clinically and in research. Detailed cartilage imaging is also necessary for traumatic cartilage lesions and for pre- and postoperative assessment of cartilage repair procedures. Although still widely used, conventional radiography bears significant limitations because it assesses cartilage indirectly by joint space width. Magnetic resonance imaging (MRI) enables direct visualization of cartilage damage along with other concomitantly affected joint tissues. Several semiquantitative grading systems and volumetric analysis methods exist to assess cartilage damage and cartilage repair on MRI. Quantification of hyaline and fibrocartilage biochemical composition is possible with novel MRI methods such as T2- and T1ρ-mapping, delayed gadolinium-enhanced MRI of cartilage, glycosaminoglycan chemical exchange saturation transfer, and sodium imaging, along with quantitative computed tomography arthrography. These techniques provide promising quantitative imaging biomarkers that can detect early cartilage changes before morphological alterations occur.

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Baki, Abdulkader, Amani Remmo, Norbert Löwa, Frank Wiekhorst, and Regina Bleul. "Albumin-Coated Single-Core Iron Oxide Nanoparticles for Enhanced Molecular Magnetic Imaging (MRI/MPI)." International Journal of Molecular Sciences 22, no. 12 (June 9, 2021): 6235. http://dx.doi.org/10.3390/ijms22126235.

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Colloidal stability of magnetic iron oxide nanoparticles (MNP) in physiological environments is crucial for their (bio)medical application. MNP are potential contrast agents for different imaging modalities such as magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). Applied as a hybrid method (MRI/MPI), these are valuable tools for molecular imaging. Continuously synthesized and in-situ stabilized single-core MNP were further modified by albumin coating. Synthesizing and coating of MNP were carried out in aqueous media without using any organic solvent in a simple procedure. The additional steric stabilization with the biocompatible protein, namely bovine serum albumin (BSA), led to potential contrast agents suitable for multimodal (MRI/MPI) imaging. The colloidal stability of BSA-coated MNP was investigated in different sodium chloride concentrations (50 to 150 mM) in short- and long-term incubation (from two hours to one week) using physiochemical characterization techniques such as transmission electron microscopy (TEM) for core size and differential centrifugal sedimentation (DCS) for hydrodynamic size. Magnetic characterization such as magnetic particle spectroscopy (MPS) and nuclear magnetic resonance (NMR) measurements confirmed the successful surface modification as well as exceptional colloidal stability of the relatively large single-core MNP. For comparison, two commercially available MNP systems were investigated, MNP-clusters, the former liver contrast agent (Resovist), and single-core MNP (SHP-30) manufactured by thermal decomposition. The tailored core size, colloidal stability in a physiological environment, and magnetic performance of our MNP indicate their ability to be used as molecular magnetic contrast agents for MPI and MRI.

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Nowak, Kristen L., Linda Fried, Anna Jovanovich, Joachim Ix, Kristine Yaffe, Zhiying You, and Michel Chonchol. "Dietary Sodium/Potassium Intake Does Not Affect Cognitive Function or Brain Imaging Indices." American Journal of Nephrology 47, no. 1 (2018): 57–65. http://dx.doi.org/10.1159/000486580.

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Background: Dietary sodium may influence cognitive function through its effects on cerebrovascular function and cerebral blood flow. Methods: The aim of this study was to evaluate the association of dietary sodium intake with cognitive decline in community-dwelling older adults. We also evaluated the associations of dietary potassium and sodium:potassium intake with cognitive decline, and associations of these nutrients with micro- and macro-structural brain magnetic resonance imaging (MRI) indices. In all, 1,194 participants in the Health Aging and Body Composition study with measurements of dietary sodium intake (food frequency questionnaire [FFQ]) and change in the modified Mini Mental State Exam (3MS) were included. Results: The age of participants was 74 ± 3 years with a mean dietary sodium intake of 2,677 ± 1,060 mg/day. During follow-up (6.9 ± 0.1 years), 340 (28%) had a clinically significant decline in 3MS score (≥1.5 SD of mean decline). After adjustment, dietary sodium intake was not associated with odds of cognitive decline (OR 0.96, 95% CI 0.50–1.84 per doubling of sodium). Similarly, potassium was not associated with cognitive decline; however, higher sodium:potassium intake was associated with increased odds of cognitive decline (OR 2.02 [95% CI 1.01–4.03] per unit increase). Neither sodium or potassium alone nor sodium:potassium were associated with micro- or macro-structural brain MRI indices. These results are limited by the use of FFQ. Conclusions: In community-dwelling older adults, higher sodium:potassium, but not sodium or potassium intake alone, was associated with decline in cognitive function, with no associations observed with micro- and macro-structural brain MRI indices. These findings do not support reduction dietary sodium/increased potassium intake to prevent cognitive decline with aging.

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Heye, Anna K., Michael J. Thrippleton, Francesca M. Chappell, Maria del C. Valdés Hernández, Paul A. Armitage, Stephen D. Makin, Susana Muñoz Maniega, et al. "Blood pressure and sodium: Association with MRI markers in cerebral small vessel disease." Journal of Cerebral Blood Flow & Metabolism 36, no. 1 (April 22, 2015): 264–74. http://dx.doi.org/10.1038/jcbfm.2015.64.

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Dietary salt intake and hypertension are associated with increased risk of cardiovascular disease including stroke. We aimed to explore the influence of these factors, together with plasma sodium concentration, in cerebral small vessel disease (SVD). In all, 264 patients with nondisabling cortical or lacunar stroke were recruited. Patients were questioned about their salt intake and plasma sodium concentration was measured; brain tissue volume and white-matter hyperintensity (WMH) load were measured using structural magnetic resonance imaging (MRI) while diffusion tensor MRI and dynamic contrast-enhanced MRI were acquired to assess underlying tissue integrity. An index of added salt intake ( P = 0.021), pulse pressure ( P = 0.036), and diagnosis of hypertension ( P = 0.0093) were positively associated with increased WMH, while plasma sodium concentration was associated with brain volume ( P = 0.019) but not with WMH volume. These results are consistent with previous findings that raised blood pressure is associated with WMH burden and raise the possibility of an independent role for dietary salt in the development of cerebral SVD.

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Pinter, Jule, Charles Chazot, Stefano Stuard, Ulrich Moissl, and Bernard Canaud. "Sodium, volume and pressure control in haemodialysis patients for improved cardiovascular outcomes." Nephrology Dialysis Transplantation 35, Supplement_2 (March 1, 2020): ii23—ii30. http://dx.doi.org/10.1093/ndt/gfaa017.

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Abstract Chronic volume overload is pervasive in patients on chronic haemodialysis and substantially increases the risk of cardiovascular death. The rediscovery of the three-compartment model in sodium metabolism revolutionizes our understanding of sodium (patho-)physiology and is an effect modifier that still needs to be understood in the context of hypertension and end-stage kidney disease. Assessment of fluid overload in haemodialysis patients is central yet difficult to achieve, because traditional clinical signs of volume overload lack sensitivity and specificity. The highest all-cause mortality risk may be found in haemodialysis patients presenting with high fluid overload but low blood pressure before haemodialysis treatment. The second highest risk may be found in patients with both high blood pressure and fluid overload, while high blood pressure but normal fluid overload may only relate to moderate risk. Optimization of fluid overload in haemodialysis patients should be guided by combining the traditional clinical evaluation with objective measurements such as bioimpedance spectroscopy in assessing the risk of fluid overload. To overcome the tide of extracellular fluid, the concept of time-averaged fluid overload during the interdialytic period has been established and requires possible readjustment of a negative target post-dialysis weight. 23Na-magnetic resonance imaging studies will help to quantitate sodium accumulation and keep prescribed haemodialytic sodium mass balance on the radar. Cluster-randomization trials (e.g. on sodium removal) are underway to improve our therapeutic approach to cardioprotective haemodialysis management.

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Haberkorn, Uwe, and Annette Altmann. "Imaging Techniques for Gene Therapy: SPECT, PET, and MRI." Journal of Pharmacy Practice 14, no. 5 (October 2001): 383–96. http://dx.doi.org/10.1106/eqat-deqg-6hr6-11h3.

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Gene therapy by the transfer and expression of suicide genes is performed using genes coding for nonmammalian enzymes that transform nontoxic prodrugs into toxic metabolites. Employing radiolabeled specific substrates and scintigraphic procedures to determine the functional activity of the recombinant enzyme in vivo, a therapeutic window of maximal gene expression and consecutive drug administration may be defined. If the gene therapy approach is based on the transduction of receptor genes, the recombinant gene expression in tumor cells can be monitored with radiolabeled ligands. Transfer of transporter genes as the sodium iodide transporter may also lead to the visualization of transduction via accumulation of iodide or pertechnetate. Furthermore, imaging based on transchelation of oxotechnetate to a polypeptide motif from a biocompatible complex with a higher dissociation constant than that of a diglycilcysteine complex or tyrosinase gene transfer for metal ion scavenging have been described. In addition, therapy effects may be assessed by the evaluation of the morphological changes of the tumor using magnetic resonance imaging or, more effectively, by the measurement of changes in metabolism with positron emission tomography employing tracers of tumor metabolism and proliferation. Finally, enzyme or receptor genes may serve as noninvasive reporter genes, if applied in the context of bicistronic vectors leading to coexpression of the therapeutic gene and the noninvasive reporter gene.

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Wolff, S. D., C. Eng, and R. S. Balaban. "NMR studies of renal phosphate metabolites in vivo: effects of hydration and dehydration." American Journal of Physiology-Renal Physiology 255, no. 4 (October 1, 1988): F581—F589. http://dx.doi.org/10.1152/ajprenal.1988.255.4.f581.

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The present study characterizes the 31P-nuclear magnetic resonance (NMR) spectrum of rabbit kidneys in vivo and evaluates the effect of hydration on phosphorous metabolites including the organic solute glycerophosphorylcholine (GPC). Cortical phosphorylethanolamine is the predominant component of the phosphomonoester region of the 31P spectrum. The contribution of blood to the spectrum is mainly from 2,3 diphosphoglycerate, which comprises approximately 30% of the inorganic phosphate region. Acute infusion of 0.9% saline decreases the sodium content of the inner medulla by greater than 50% in 15 min as shown by 23Na imaging. Despite this medullary Na dilution, no change in renal GPC content was observed for greater than 1 h even with the addition of furosemide (2.5 mg/kg) or furosemide and antidiuretic hormone (0.125 U/kg). However, 20 h of chronic hydration with 0.45% saline did result in a 30% decrease in renal GPC content when compared with dehydrated animals. These findings are consistent with GPC not playing a role in the short-term regulation of the medullary intracellular milieu in response to acute reductions in medullary Na content.

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COX, BRIAN. "CHEMISTRY: HOW DOES IT SHAPE UP?" COSMOS 04, no. 01 (May 2008): 55–69. http://dx.doi.org/10.1142/s0219607708000299.

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There is more to organic chemistry than the covalent bond. The design and synthesis of molecules, because of their particular architecture, are able to bind strongly target ions or molecules by utilizing lots of individually relatively weak non-covalent interactions has led to many novel and important applications. Examples include the transport of ions across biological membranes, the generation of unusual ionic species, such as sodium anions, the recovery of pure metals from mineral ores, and contrasting agents for magnetic resonance imaging (MRI).

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Gomez, Sabas I., Lizette Warner, John A. Haas, Rodney J. Bolterman, Stephen C. Textor, Lilach O. Lerman, and Juan Carlos Romero. "Increased hypoxia and reduced renal tubular response to furosemide detected by BOLD magnetic resonance imaging in swine renovascular hypertension." American Journal of Physiology-Renal Physiology 297, no. 4 (October 2009): F981—F986. http://dx.doi.org/10.1152/ajprenal.90757.2008.

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Oxygen consumption beyond the proximal tubule is mainly determined by active solute reabsorption, especially in the thick ascending limb of the Loop of Henle. Furosemide-induced suppression of oxygen consumption (FSOC) involves inhibition of sodium transport in this segment, which is normally accompanied by a marked decrease in the intrarenal deoxyhemoglobin detectable by blood oxygen level-dependent (BOLD)-magnetic resonance imaging (MRI). This study tested the hypothesis that the magnitude of BOLD-MRI signal change after furosemide is related to impaired renal function in renovascular hypertension. In 16 pigs with unilateral renal artery stenosis, renal hemodynamics, function, and tubular function (FSOC and fluid concentration capacity) were evaluated in both kidneys using MR and multidetector computerized tomography (MDCT) imaging. Animals with adequate FSOC (23.6 ± 2.2%, P > 0.05 vs. baseline) exhibited a mean arterial pressure (MAP) of 113 ± 7 mmHg, and relatively preserved glomerular filtration rate (GFR) of 60 ± 4.5 ml/min, comparable to their contralateral kidney (66 ± 4 ml/min, P > 0.05). In contrast, animals with low FSOC (3.1 ± 2.1%, P = NS vs. baseline) had MAP of 124 ± 9 mmHg and GFR (22 ± 6 ml/min) significantly lower than the contralateral kidneys (66 ± 4 ml/min, P < 0.05). The group with preserved GFR and FSOC showed an increase in intratubular fluid concentration as assessed by MDCT that was greater than that observed in the low GFR group, suggesting better preservation of tubular function in the former group. These results suggest that changes in BOLD-MRI after furosemide can differentiate between underperfused kidneys with preserved tubular function and those with tubular dysfunction. This approach may allow more detailed physiologic evaluation of poststenotic kidneys in renovascular hypertension than previously possible.

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Yamashita, Chikara, Hiroshi Shigeto, Norihisa Maeda, Takako Torii, Yasumasa Ohyagi, and Jun-ichi Kira. "A Case of Central Pontine Myelinolysis Caused by Hypophosphatemia Secondary to Refeeding Syndrome." Case Reports in Neurology 7, no. 3 (October 1, 2015): 196–203. http://dx.doi.org/10.1159/000440711.

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Central pontine myelinolysis (CPM), which was originally considered to be the result of rapid correction of chronic hyponatremia, is not necessarily accompanied by hyponatremia or drastic changes in serum sodium level. Here, we report a case of an anorexic 55-year-old male with a history of pharyngo-laryngo-esophagogastrectomy, initially hospitalized with status epilepticus. Although his consciousness gradually recovered as we were controlling his convulsion, it deteriorated again with new onset of anisocoria, and magnetic resonance imaging (MRI) at this point revealed CPM. Rapid change of serum sodium or osmolarity, which is often associated with CPM, had not been apparent throughout his hospitalization. Instead, a review of the serum biochemistry test results showed that serum phosphate had drastically declined the day before the MRI first detected CPM. In this case, we suspect that hypophosphatemia induced by refeeding syndrome greatly contributed to the occurrence of CPM.

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Schreiner, Markus M., Vladimir Mlynarik, Štefan Zbýň, Pavol Szomolanyi, Sebastian Apprich, Reinhard Windhager, and Siegfried Trattnig. "New Technology in Imaging Cartilage of the Ankle." CARTILAGE 8, no. 1 (June 22, 2016): 31–41. http://dx.doi.org/10.1177/1947603516632848.

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The incidence of osteochondral lesions, as well as osteoarthritis of the ankle joint following osteochondritis dissecans and trauma, has been reappraised in recent years. Consequently, an increasing number of surgical interventions using different cartilage repair techniques is performed in the ankle joint, which has resulted in a growing demand for repetitive and objective assessment of cartilage tissue and its repair. While morphological imaging does enable monitoring of macroscopic changes with increasing precision, it fails to provide information about the ultrastructural composition of cartilage. The significance of molecular changes in cartilage matrix composition, however, is increasingly recognized, as it is assumed that macroscopic cartilage degeneration is preceded by a loss in glycosaminoglycans and a disorganization of the collagen network. Recent advances in biochemical magnetic resonance imaging (MRI) have yielded sequences sensitive to these changes, thus providing invaluable insight into both early cartilage degeneration and maturation of repair tissue, on a molecular level. The aim of this review was to provide a comprehensive overview of these techniques, including water and collagen-sensitive T2/T2* mapping, as well as glycosaminoglycan-sensitive sequences such as delayed gadolinium-enhanced MRI of cartilage dGEMRIC, and sodium imaging, and describe their applications for the ankle joint.

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Getman, Svetlana I., Konstantin V. Romanov, and Aleksej Yu Butov. "POSSIBILITIES OF MAGNETIC RESONANCE IMAGING FORDIAGNOSTIC ETIOLOGIC FACTORS IN THE OCCURRENCE OF ARRHYTHMIASOF THE MILITARYS." Marine Medicine 5, no. 3 (September 11, 2019): 17–23. http://dx.doi.org/10.22328/2413-5747-2019-5-3-17-23.

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Surveyed 652 patients with persistent violations of rhythm who applied to the cardiologist of the center of VMA during the 2 years. Of 652 patients was highlighted that some patients (543), in which the rhythm disturbance with daily monitoring Holter ECG were significant, that is, the number of ventricular and supraventricular extrasystoles exceeded the acceptable rate. These patients were divided into 3 groups to assess the frequency of ventricular and supraventricular arrhythmias: Group 1: patients with a primary rhythm disturbance according to the type of ventricular arrhythmia — 96 people (80 men and 16 women). Their average age was 68 years (18–89). Group 2: patients with a primary rhythm disturbance according to the type of supraventricular extrasystole — 343 (271 male and 72 female). Their average age was 67 years (17–83). Group 3: patients with complex arrhythmias (supraventricular and ventricular premature beats) — 106 patients (94 male and 12 female). Their average age was 65 years (18–87). Compulsory medical examination for the patient included a complete medical examination with the filling of a formalized medical history; laboratory studies (clinical blood analysis, biochemical blood — potassium, sodium, magnesium, chlorine, glucose, lipid spectrum, creatinine, total protein, coagulation profile, thyroid hormones T3, T4, TTG); instrumental examinations (ECG, daily monitoring of Holter ECG, radiography of the chest, echocardiography). Identified possible etiologic factors in the occurrence of arrhythmias in patients. The main etiological factors of arrhythmia were: ischemic heart disease (IHD), arterial hypertension (AH), heart failure II–IV FC, the presence of sclerodermatineae acquired heart disease, cardiomyopathy, diabetes mellitus type II, thyroid disease (hyperthyroidism and hypothyroidism), cancer, history of pulmonary embolism (PE), acute violations of cerebral circulation (cerebral vascular accident), coronary artery bypass graft (CABG), family history of coronary heart disease, overweight, menopause. The main provoking factors according to the survey patients were: alcohol abuse and Smoking, daily repeated use of strong tea and coffee, psycho-emotional and physical stress, infectious diseases.48 surveyed (8,84%) did not identify any apparent cause arrhythmias. This group of patients underwent heart MRI for the purpose of clarifying the nature of the arrhythmias. In 32 patients performing MRI of the heart has allowed to establish probable cause rhythm disturbances, draws attention to the high frequency of detection of MR-signs of myocarditis (1⁄3 of the surveyed).

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Darwish, M. IM, R. K. Rowe, J. RC van der Maarel, L. Pel, H. Huinink, and P. LJ Zitha. "Contaminant containment using polymer gel barriers." Canadian Geotechnical Journal 41, no. 1 (February 1, 2004): 106–17. http://dx.doi.org/10.1139/t03-072.

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Polymer gels are well known in the oil industry, but their potential for use as barriers to contaminant transport has not previously received significant study. As a first step, this paper examines the potential for a polyelectrolyte gel to serve as a barrier to the migration of sodium chloride. Two series of tests are reported. These involve the use of hydrogen pulsed field gradient nuclear magnetic resonance (HPFGNMR) to measure the self-diffusion on a microscopic scale and the use of magnetic resonance imaging (MRI) to monitor Na+ and H+ migration in the polymer gel with time. It is shown that the gel, which has a hydraulic conductivity of 2 × 1012 m/s, has a diffusion coefficient similar to that of compacted clay and greater sorption of Na+ than is typical for compacted clay.Key words: diffusion, contaminant, osmosis, gels, barriers.

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Pruijm, Menno, Lucie Hofmann, Bruno Vogt, Marie-Eve Muller, Maciej Piskunowicz, Matthias Stuber, and Michel Burnier. "Renal Tissue Oxygenation in Essential Hypertension and Chronic Kidney Disease." International Journal of Hypertension 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/696598.

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Animal studies suggest that renal tissue hypoxia plays an important role in the development of renal damage in hypertension and renal diseases, yet human data were scarce due to the lack of noninvasive methods. Over the last decade, blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), detecting deoxyhemoglobin in hypoxic renal tissue, has become a powerful tool to assess kidney oxygenation noninvasively in humans. This paper provides an overview of BOLD-MRI studies performed in patients suffering from essential hypertension or chronic kidney disease (CKD). In line with animal studies, acute changes in cortical and medullary oxygenation have been observed after the administration of medication (furosemide, blockers of the renin-angiotensin system) or alterations in sodium intake in these patient groups, underlining the important role of renal sodium handling in kidney oxygenation. In contrast, no BOLD-MRI studies have convincingly demonstrated that renal oxygenation is chronically reduced in essential hypertension or in CKD or chronically altered after long-term medication intake. More studies are required to clarify this discrepancy and to further unravel the role of renal oxygenation in the development and progression of essential hypertension and CKD in humans.

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He, Siping, Ke Jin, Xicheng Deng, Zhengzhen Zhou, Robert C. McKinstry, and Yong Wang. "Imaging features of neonatal systemic juvenile xanthogranuloma: a case report and review of the literature." Journal of International Medical Research 48, no. 9 (September 2020): 030006052095641. http://dx.doi.org/10.1177/0300060520956416.

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Juvenile xanthogranuloma (JXG) is the most common non-Langerhans cell histiocytic disorder in children. This report describes the case of a 28-day-old boy that presented with multiple subcutaneous nodular lesions on the trunk and extremities, and multiple red nodular lesions on the scrotum. Magnetic resonance imaging (MRI) of the brain showed a well-demarcated extra-axial dura-based mass that appeared isointense or slightly hyperintense on T1-weighted images, hypointense on T2-weighted images and had intense enhancement on gadolinium-enhanced T1-weighted images. Computed tomography (CT) or MRI scans of the chest and abdomen revealed multiple scattered nodular or patchy lesions of varying sizes in the lungs, liver and left kidney. Histological analysis of a subcutaneous mass suggested JXG. The patient was diagnosed with neonatal systemic JXG with involvement of the central nervous system, lungs, liver, kidneys, subcutaneous soft tissue and skin. CT and MRI after 3 months of treatment with methylprednisolone sodium succinate demonstrated that the lesions were obviously diminished. This report discusses the imaging findings in this current case of multi-organ JXG and reviews the imaging literature on this condition to improve awareness of the lesions in order to help radiologists establish an accurate differential diagnosis when confronted with similar cases.

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Sun, Zhenxing, Dan Yuan, Yaxing Sun, Zhanquan Zhang, James Wang, Yi Guo, Guoqin Wang, et al. "Fluorescein Sodium Use during Spinal Ependymoma Resection." Translational Neuroscience and Clinics 3, no. 3 (September 2017): 123–34. http://dx.doi.org/10.18679/cn11-6030_r.2017.021.

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Spinal ependymomas (SEs) are common adult intramedullary tumors; however, determining the absolute boundary between the tumor and the tumor residual may be difficult. We assessed outcomes following the use of fluorescein sodium (FS) during surgical removal of SEs. We performed a retrospective analysis of 112 patients with SEs who were treated at Beijing Tsinghua Changgung Hospital between December 2014 and December 2016. Each patient received intravenous FS (3–4 mg/kg) to determine the SE boundaries during surgery. Tumor removal efficiencies and tumor residuals were assessed using magnetic resonance imaging (MRI) at 10 days and 3 months after surgical recovery; McCormick's spinal function classification was also performed at the 3-month follow-up. The complete tumor removal rate was 92% (103/112). Ninety-four patients underwent tumor removal under fluorescent light, which provided distinctive tumor fluorescence. Tumor removal under white light was performed in 18 patients; fluorescent images were invisible or indistinctive in these 18 patients. At the 3-month follow-up, sensory function (85.8% (91/106)) and movement (84.3% (86/102)) were improved in patients with pre-surgical dysfunction; urination and defecation functions were improved in 66.7% (16/24). The McCormick spinal cord functional classifications, at the 3-month follow-up, showed significant differences in the percentages of patients with disease classified to each grade (I–IV), compared with preoperative classifications (each, P < 0.05). There was no MRI evidence of tumor relapse or residuals at the 3-month follow-up. FS use during the surgical treatment of SE enables complete tumor removal and detection of tumor residuals.

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Dyrberg, Eva, Emil L. Larsen, Helle W. Hendel, and Henrik S. Thomsen. "Diagnostic bone imaging in patients with prostate cancer: patient experience and acceptance of NaF-PET/CT, choline-PET/CT, whole-body MRI, and bone SPECT/CT." Acta Radiologica 59, no. 9 (January 9, 2018): 1119–25. http://dx.doi.org/10.1177/0284185117751280.

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Background Patient acceptance is an important factor when implementing imaging methods in clinical practice in line with availability, diagnostic accuracy, and cost-effectiveness. Purpose To investigate patient experience and acceptance regarding18F-sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT), 11 C-choline-PET/CT, whole-body magnetic resonance imaging (WB-MRI), and 99mTc-hydroxymethane diphosphonate (HDP) single photon emission/computed tomography (SPECT/CT). Material and Methods One hundred and forty-nine patients with prostate cancer filled in a questionnaire regarding their experience of the imaging procedures they had been undergoing as part of a diagnostic accuracy study. Each patient had been undergoing a NaF-PET/CT, a WB-MRI, and either a SPECT/CT (group A) or a choline-PET/CT (group B). Results All four imaging methods received overall experience ratings at the favorable end of a 5-point Likert scale with the two PET/CT scans receiving marginally better average ratings (2.0) compared to SPECT/CT (2.2) and WB-MRI (2.3). The arm positioning above the head was the most uncomfortable part of the three nuclear medicine scans, whereas the acoustic noise was the most unpleasant part of the WB-MRI. The experience of staff instruction was relatively strongly correlated to the overall scanning experience of all four imaging modalities. Overall, the patients were willing to repeat the four imaging methods and NaF-PET/CT was the method most preferred in both groups. Conclusion Four imaging procedures were evaluated from the perspective of a selected group of prostate cancer patients. NaF-PET/CT, choline-PET/CT, WB-MRI, and bone SPECT/CT are well accepted imaging methods, and most patients prefer NaF-PET/CT.

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Li, Xin, Zhenhai Xue, Jinfeng Xia, Guohong Zhou, Danyu Jiang, Mengting Dai, Wenhui Wang, et al. "Gd/Y Hydroxide Nanosheets as Highly Efficient T1/T2 MRI Contrast Agents." Nanomaterials 11, no. 1 (December 24, 2020): 17. http://dx.doi.org/10.3390/nano11010017.

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To develop highly efficient T1/T2 magnetic resonance imaging (MRI) contrast agents (CAs), Gd/Y hydroxide nanosheets were synthesized by a simple exfoliation method from layer compounds using sodium polyacrylate (PAA) as a dispersant and stabilizer. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) results revealed the excellent performance of monolayer nanosheets with thicknesses of up to 1.5 nm. The MRI results of the T1 and T2 relaxation times showed that all of the Gd/Y hydroxide nanosheets have high longitudinal and transverse relaxivities (r1 and r2). In particular, the 10% Gd-LRH nanosheets exhibited excellent MRI performance (r1 = 103 mM−1 s−1, r2 = 372 mM−1 s−1), which is rarely reported. Based on the relationship between the structure of 10% Gd-LRH nanosheets and their MRI performances, and the highly efficient MRI of spaced Gd atoms in the nanosheets, a special model to explain the outstanding MRI performance of the 10% Gd-LRH nanosheets is suggested. The cytotoxicity assessment of the 10% Gd-LRH nanosheets, evaluated by CCK-8 assays on HeLa cells, indicated no significant cytotoxicity. This study presents a significant advancement in 2D nanomaterial MRI CA research, with Gd-doped nanosheets positioned as highly efficient T1/T2 MRI CA candidates.

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Lansdown, Drew A., Kevin Wang, Eric Cotter, Annabelle Davey, and Brian J. Cole. "Relationship Between Quantitative MRI Biomarkers and Patient-Reported Outcome Measures After Cartilage Repair Surgery: A Systematic Review." Orthopaedic Journal of Sports Medicine 6, no. 4 (April 1, 2018): 232596711876544. http://dx.doi.org/10.1177/2325967118765448.

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Background: Treatment of articular cartilage injuries remains a clinical challenge, and the optimal tools to monitor and predict clinical outcomes are unclear. Quantitative magnetic resonance imaging (qMRI) allows for a noninvasive biochemical evaluation of cartilage and may offer advantages in monitoring outcomes after cartilage repair surgery. Hypothesis: qMRI sequences will correlate with early pain and functional measures. Study Design: Systematic review; Level of evidence, 3. Methods: A PubMed search was performed with the following search terms: knee AND (cartilage repair OR cartilage restoration OR cartilage surgery) AND (delayed gadolinium-enhanced MRI OR t1-rho OR T2 mapping OR dgemric OR sodium imaging OR quantitative imaging). Studies were included if correlation data were included on quantitative imaging results and patient outcome scores. Results: Fourteen articles were included in the analysis. Eight studies showed a significant relationship between quantitative cartilage imaging and patient outcome scores, while 6 showed no relationship. T2 mapping was examined in 11 studies, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) in 4 studies, sodium imaging in 2 studies, glycosaminoglycan chemical exchange saturation transfer (gagCEST) in 1 study, and diffusion-weighted imaging in 1 study. Five studies on T2 mapping showed a correlation between T2 relaxation times and clinical outcome scores. Two dGEMRIC studies found a correlation between T1 relaxation times and clinical outcome scores. Conclusion: Multiple studies on T2 mapping, dGEMRIC, and diffusion-weighted imaging showed significant correlations with patient-reported outcome measures after cartilage repair surgery, although other studies showed no significant relationship. qMRI sequences may offer a noninvasive method to monitor cartilage repair tissue in a clinically meaningful way, but further refinements in imaging protocols and clinical interpretation are necessary to improve utility.

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Tiedje, V., M. Schlamann, D. Führer, and LC Moeller. "Diabetes insipidus as a rare cause of acute cognitive impairment in multiple sclerosis." Multiple Sclerosis Journal 19, no. 12 (October 2013): 1676–78. http://dx.doi.org/10.1177/1352458513506952.

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Multiple sclerosis (MS) is a complex neurodegenerative disease presenting with a diversity of clinical symptoms including palsy and cognitive impairment. We present a 59-year-old woman with a history of secondary progressive MS since 1987, who was referred to our department because of recent onset of confusion and polydipsia. Initial lab tests showed mildly elevated serum sodium levels and low urine osmolality. Under water deprivation, diuresis and low urine osmolality persisted and serum sodium levels rose above 150 mmol/l. Oral desmopressin resulted in normalisation of serum sodium as well as urine osmolarity, confirming a diagnosis of central diabetes insipidus. As drug-induced diabetes could be excluded, pituitary magnetic resonance imaging (MRI) was performed. A demyelinating lesion was detected in the hypothalamus. The patient was started on oral desmopressin treatment (0.2 mg/day). Fluid intake and serum sodium levels have since remained normal. In summary, we report the rare case of a patient presenting with diabetes insipidus due to progressive MS. Diabetes insipidus should be considered in MS patients who develop new onset of polydipsia.

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De Riu, Giacomo, Mirella Stimolo, Silvio Mario Meloni, Damiano Soma, Milena Pisano, Salvatore Sembronio, and Antonio Tullio. "Arthrocentesis and Temporomandibular Joint Disorders: Clinical and Radiological Results of a Prospective Study." International Journal of Dentistry 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/790648.

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Purpose. We evaluated the efficacy of arthrocentesis in the treatment of temporomandibular joint (TMJ) disorders.Material and Methods. In this prospective clinical case series, 30 consecutive patients with TMJ disorders underwent arthrocentesis using saline and sodium hyaluronate injections. Outcome measures were TMJ pain, maximum mouth opening (MMO), joint noises, and anatomical changes in the TMJ architecture. Patients were evaluated using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) at the beginning of treatment and 60 days after the last arthrocentesis. Pretreatment and posttreatment clinical parameters were compared using paired and unpairedt-tests, and McNemar’s test was used to evaluate CBCT and MRI changes ().Results. At 1-year follow-up examinations, visual analogue scale scores indicated that pain was reduced significantly and mean postoperative MMO was increased significantly. CBCT findings showed no significant change, and MRI showed only slight reductions in inflammatory signs.Conclusions. Within the limitations of this study, we can conclude that arthrocentesis is a simple, minimally invasive procedure with a relatively low risk of complications and significant clinical benefits in patients with TMJ disorders. This trial is registered withNCT01903512.

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Carranza-León, D. A., A. Oeser, A. Marton, P. Wang, J. C. Gore, J. Titze, C. M. Stein, C. P. Chung, and M. J. Ormseth. "Tissue sodium content in patients with systemic lupus erythematosus: association with disease activity and markers of inflammation." Lupus 29, no. 5 (February 18, 2020): 455–62. http://dx.doi.org/10.1177/0961203320908934.

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Objectives Sodium (Na+) is stored in the skin and muscle and plays an important role in immune regulation. In animal models, increased tissue Na+ is associated with activation of the immune system, and high salt intake exacerbates autoimmune disease and worsens hypertension. However, there is no information about tissue Na+ and human autoimmune disease. We hypothesized that muscle and skin Na+ content is (a) higher in patients with systemic lupus erythematosus (SLE) than in control subjects, and (b) associated with blood pressure, disease activity, and inflammation markers (interleukin (IL)-6, IL-10 and IL-17 A) in SLE. Methods Lower-leg skin and muscle Na+ content was measured in 23 patients with SLE and in 28 control subjects using 23Na+ magnetic resonance imaging. Demographic and clinical information was collected from interviews and chart review, and blood pressure was measured. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Plasma inflammation markers were measured by multiplex immunoassay. Results Muscle Na+ content was higher in patients with SLE (18.8 (16.7–18.3) mmol/L) than in control subjects (15.8 (14.7–18.3) mmol/L; p < 0.001). Skin Na+ content was also higher in SLE patients than in controls, but this difference was not statistically significant. Among patients with SLE, muscle Na+ was associated with SLEDAI and higher concentrations of IL-10 after adjusting for age, race, and sex. Skin Na+ was significantly associated with systolic blood pressure, but this was attenuated after covariate adjustment. Conclusion Patients with SLE had higher muscle Na+ content than control subjects. In patients with SLE, higher muscle Na+ content was associated with higher disease activity and IL-10 concentrations.

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Sheveleva, E. M., L. G. Zaslavskii, A. G. Kovelenov, and E. A. Skorniakova. "Central pontine myelinolysis and extrapontine myelinolysis: literature review and case report." Scientific Notes of the Pavlov University 27, no. 2 (September 25, 2020): 72–78. http://dx.doi.org/10.24884/1607-4181-2020-27-2-72-78.

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Central pontine myelinolysis (CPM) is a concentrated, symmetric, non-inflammatory demyelination within the central basis pontis. In 10 % of patients with СРМ, demyelination also occurs in extrapontine regions: the mid brain, thalamus, basal nuclei, and cerebellum. Demyelination occurs in regions of compact interdigitation of white and gray matter as a result of cellular edema, which is caused by fluctuating osmotic forces, results in compression of fiber tracts. The most frequent cause of abrupt change in osmotic pressure is the rapid sodium correction of prolonged hyponatremia. In case that we report, there is a combination of central pontine and extrapontine myelinolysis, which occurs in 71-year-old woman owing to rapid sodium correction of prolonged hyponatremia which by turn developed due to salt-free diet, improper antihypertensive therapy and overheating. The diagnosis was confirmed by magnetic resonance imaging (MRI). The treatment led to significant decrease of neurological deficit.

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Dyrberg, Eva, Helle W. Hendel, Gina Al-Farra, Lone Balding, Vibeke B. Løgager, Claus Madsen, and Henrik S. Thomsen. "A prospective study comparing whole-body skeletal X-ray survey with 18F-FDG-PET/CT, 18F-NaF-PET/CT and whole-body MRI in the detection of bone lesions in multiple myeloma patients." Acta Radiologica Open 6, no. 10 (October 2017): 205846011773880. http://dx.doi.org/10.1177/2058460117738809.

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Background For decades, the most widely used imaging technique for myeloma bone lesions has been a whole-body skeletal X-ray survey (WBXR), but newer promising imaging techniques are evolving. Purpose To compare WBXR with the advanced imaging techniques 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), 18F-sodium fluoride (NaF) PET/CT and whole-body magnetic resonance imaging (WB-MRI) in the detection of myeloma bone lesions. Material and Methods Fourteen patients with newly diagnosed multiple myeloma were prospectively enrolled. In addition to WBXR, all patients underwent FDG-PET/CT, NaF-PET/CT, and WB-MRI. Experienced specialists performed blinded readings based on predefined anatomical regions and diagnostic criteria. Results In a region-based analysis, a two-sided ANOVA test showed that the extent of detected skeletal disease depends on the scanning technique ( P < 0.0001). Tukey’s multiple comparison test revealed that WB-MRI on average detects significantly more affected regions than WBXR ( P < 0.005), FDG-PET/CT ( P < 0.0001), and NaF-PET/CT ( P < 0.05). In a patient-based analysis, a Cochran’s Q test showed that there are no significant differences in the proportion of patients with bone disease detected by the different scanning techniques ( P = 0.23). Determination of intrareader variability resulted in Kappa coefficients corresponding to moderate (FDG-PET/CT) and substantial agreement (WB-MRI, WBXR, NaF-PET/CT). Conclusion WB-MRI detects on average significantly more body regions indicative of myeloma bone disease compared to WBXR, FDG-PET/CT, and NaF-PET/CT. The lack of significance in the patient-based analysis is most likely due to the small number of study participants.

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Florea, Alexandru, M. Eline Kooi, Werner Mess, Leon J. Schurgers, Jan Bucerius, and Felix M. Mottaghy. "Effects of Combined Vitamin K2 and Vitamin D3 Supplementation on Na[18F]F PET/MRI in Patients with Carotid Artery Disease: The INTRICATE Rationale and Trial Design." Nutrients 13, no. 3 (March 19, 2021): 994. http://dx.doi.org/10.3390/nu13030994.

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INTRICATE is a prospective double-blind placebo-controlled feasibility study, assessing the influence of combined vitamin K2 and vitamin D3 supplementation on micro-calcification in carotid artery disease as imaged by hybrid Sodium [18F]Fluoride (Na[18F]F) positron emission tomography (PET)/ magnetic resonance imaging (MRI). Arterial calcification is an actively regulated process and results from the imbalance between calcification promoting and inhibiting factors. Considering the recent advancements in medical imaging, ultrasound (US), PET/MRI, and computed tomography (CT) can be used for the selection and stratification of patients with atherosclerosis. Fifty-two subjects with asymptomatic carotid artery disease on at least one side of the neck will be included in the study. At baseline, an Na[18F]F PET/MRI and CT examination will be performed. Afterwards, subjects will be randomized (1:1) to a vitamin K (400 µg MK-7/day) and vitamin D3 (80 µg/day) or to placebo. At the 3-month follow-up, subjects will undergo a second Na[18F]F PET/MRI and CT scan. The primary endpoint is the change in Na[18F]F PET/MRI (baseline vs. after 3 months) in the treatment group as compared to the placebo arm. Secondary endpoints are changes in plaque composition and in blood-biomarkers. The INTRICATE trial bears the potential to open novel avenues for future large scale randomized controlled trials to intervene in the plaque development and micro-calcification progression.

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Journal articles on the topic 'Sodium (23Na) Magnetic Resonance Imaging (MRI)'

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