NMR in Biomedicine

Cover image for Vol. 28 Issue 9

Early View (Online Version of Record published before inclusion in an issue)

Impact Factor: 3.044

ISI Journal Citation Reports © Ranking: 2014: 9/44 (Spectroscopy); 24/125 (Radiology Nuclear Medicine & Medical Imaging); 27/73 (Biophysics)

Online ISSN: 1099-1492

Associated Title(s): Contrast Media & Molecular Imaging

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  1. 1 - 34
  1. Research articles

    1. Reproducibility and effect of tissue composition on cerebellar γ-aminobutyric acid (GABA) MRS in an elderly population

      Zaiyang Long, Jonathan P. Dyke, Ruoyun Ma, Chaorui C. Huang, Elan D. Louis and Ulrike Dydak

      Article first published online: 28 AUG 2015 | DOI: 10.1002/nbm.3381

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      We showed the feasibility and reproducibility of cerebellar γ-aminobutyric acid (GABA)-edited MRS at 3.0 T in an elderly population (65–86 years). GABA-edited spectra yielded robust and stable GABA+ measurements with averaged intra-individual coefficients of variation for relaxation- and cerebrospinal fluid-corrected GABA+ between 4.0% and 13.4%, and inter-individual coefficients of variation between 12.6% and 24.2%, depending on different LCModel basis sets using two sets of published values for chemical shifts and J couplings.

    2. Effect of J coupling on 1.3-ppm lipid methylene signal acquired with localised proton MRS at 3 T

      Dylan Y. Breitkreutz, B. Gino Fallone and Atiyah Yahya

      Article first published online: 28 AUG 2015 | DOI: 10.1002/nbm.3387

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      The effect of J coupling on the quantification of lipid methylene protons (1.3 ppm) and on their T2 measures with MRS sequences was investigated. In phantoms, the consequences of J coupling are more significant for shorter chain fatty acids, where the percentage of coupled 1.3-ppm protons is larger. In tibial bone marrow in vivo, it was found that J-coupling evolution resulted in underestimations of 1.3-ppm lipid methylene levels and their T2 measures by about 20% and 9%, respectively.

    3. Streaking artifact reduction for quantitative susceptibility mapping of sources with large dynamic range

      Hongjiang Wei, Russell Dibb, Yan Zhou, Yawen Sun, Jianrong Xu, Nian Wang and Chunlei Liu

      Article first published online: 27 AUG 2015 | DOI: 10.1002/nbm.3383

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      The estimation of susceptibility maps with a wide range of values is still problematic. For example, in cases such as large veins, contrast agent uptake and intracranial hemorrhages, extreme susceptibility values in focal areas cause severe streaking artifacts. This work introduces a new two-level reconstruction approach (streaking artifact reduction for quantitative susceptibility mapping, STAR-QSM) to reduce these artifacts, whilst preserving subtle susceptibility contrast. Brain imaging in patients with cerebral hematoma and multiple sclerosis illustrated that this method reduces the streaking artifacts caused by large susceptibility sources, whilst maintaining sharp anatomical details.

    4. Ultrashort-TE stimulated echo acquisition mode (STEAM) improves the quantification of lipids and fatty acid chain unsaturation in the human liver at 7 T

      Martin Gajdošík, Grzegorz L. Chadzynski, Gilbert Hangel, Vladimír Mlynárik, Marek Chmelík, Ladislav Valkovič, Wolfgang Bogner, Rolf Pohmann, Klaus Scheffler, Siegfried Trattnig and Martin Krššák

      Article first published online: 27 AUG 2015 | DOI: 10.1002/nbm.3382

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      A modified stimulated echo acquisition mode (STEAM) sequence resulted in a minimum TE of 6 ms and effective cancellation of water sidebands. Offline subtraction of the water resonance enabled the detection of the olefinic lipid signal for calculation of the unsaturation index (UI) in liver tissue at 7 T. A comparison of the hepatocellular content of lipids (HCL) at 7 T with that at 3 T, and test–retest measurements of HCL and UI at 7 T, were in good agreement. There was a negative correlation found between UI and HCL.

    5. 1 H MRS: a potential biomarker of in utero placental function

      Gillian Macnaught, Calum Gray, Jane Walker, Mary Simpson, Jane Norman, Scott Semple and Fiona Denison

      Article first published online: 27 AUG 2015 | DOI: 10.1002/nbm.3370

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      We acquired in utero 1H MR spectra of the placenta of nine small for gestational age (SGA) pregnancies and nine gestation-matched healthy control pregnancies. Placental choline, lipids and the combined contribution of placental glutamine and glutamate (Glx) were quantified as amplitude ratios to that of intrinsic H2O. We found a significant difference in Glx between the two groups, whereas choline and lipids were preserved. 1H MRS warrants further investigation in the assessment of in utero placental function.

    6. Hemisphere, gender and age-related effects on iron deposition in deep gray matter revealed by quantitative susceptibility mapping

      Nan-Jie Gong, Chun-Sing Wong, Edward S. Hui, Chun-Chung Chan and Lam-Ming Leung

      Article first published online: 27 AUG 2015 | DOI: 10.1002/nbm.3366

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      Significant leftward asymmetries in iron measurements were observed in the substantia nigra and caudate nucleus. Gender differences were observed in the thalamus and red nucleus, where men have higher iron measurements than women. The highest rate of iron deposition with aging was observed in the putamen (Pu).

    7. Distribution of temperature changes and neurovascular coupling in rat brain following 3,4-methylenedioxymethamphetamine (MDMA, “ecstasy”) exposure

      Daniel Coman, Basavaraju G. Sanganahalli, Lihong Jiang, Fahmeed Hyder and Kevin L. Behar

      Article first published online: 19 AUG 2015 | DOI: 10.1002/nbm.3375

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      Spatial distributions of MDMA-induced temperature changes and dynamics in rat brain using an exogenous temperature-sensitive probe (TmDOTMA4−) were obtained with Biosensor Imaging of Redundant Deviation in Shifts (BIRDS). Temperature, neuronal activity, and blood flow were measured simultaneously in the cortex and subcortex to investigate possible mechanisms of MDMA-induced warming across regions. MDMA-induced warming correlated with increases in neuronal activity and blood flow in the cortex, whereas no relationship was seen in the thalamus, indicating that MDMA affected neurovascular coupling differently in these regions.

    8. Multi-chromatic magnetic resonance imaging using frequency lock-in suppression

      Yu-Wen Chen and Dennis W. Hwang

      Article first published online: 18 AUG 2015 | DOI: 10.1002/nbm.3361

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      The aim of this study was to show, conceptually, the possibility of obtaining frequency information using a frequency lock-in RF field with a selective narrow bandwidth. In addition to using the evolution of an image over time to differentiate among frequency variations, in the new approach the frequency of the lock-in RF field could be changed directly to enhance the contrast and discriminate among regions in a mouse brain.

    9. Single-voxel 1H spectroscopy in the human hippocampus at 3 T using the LASER sequence: characterization of neurochemical profile and reproducibility

      Najib Allaïli, Romain Valabrègue, Edward J. Auerbach, Vincent Guillemot, Lydia Yahia-Cherif, Eric Bardinet, Maritza Jabourian, Philippe Fossati, Stéphane Lehéricy and Małgorzata Marjańska

      Article first published online: 18 AUG 2015 | DOI: 10.1002/nbm.3364

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      High-quality spectra, which allowed reliable quantification of 10 metabolites, were measured in a 2.4 mL voxel placed in the left hippocampus in 10 healthy subjects. The reproducibility in metabolite concentrations improved with increased number of averages. The reproducibility achieved in this study shows that a change of less than 10% in concentration can be confidently detected for five major metabolites in a group of 20 subjects.

  2. Special issue research articles

    1. Dipole antennas for ultrahigh-field body imaging: a comparison with loop coils

      A. J. E. Raaijmakers, P. R. Luijten and C. A. T. van den Berg

      Article first published online: 17 AUG 2015 | DOI: 10.1002/nbm.3356

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      This article provides electromagnetic insight into the operating principles of dipole antennas by numerical simulations. It focuses on a comparison study of dipole antennas and loop coils at the frequencies of 128, 298 and 400 MHz. When the optimal element is chosen for each depth, loop coils have higher B1+ efficiency for shallow depths, whereas dipole antennas have higher B1+ efficiency for large depths. Loop coils demonstrate a better B1+/√SARmax ratio, but not in an array setup with overlapping elements.

  3. Research articles

    1. Quantitative pulsed CEST-MRI using Ω-plots

      Jan-Eric Meissner, Steffen Goerke, Eugenia Rerich, Karel D. Klika, Alexander Radbruch, Mark E. Ladd, Peter Bachert and Moritz Zaiss

      Article first published online: 17 AUG 2015 | DOI: 10.1002/nbm.3362

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      We propose a new analytical description of pulsed saturation transfer experiments feasible with clinical MR scanners. Analytical integration of the continuous wave eigenvalue as a function of the RF pulse shape leads to two form factors, which are determined by the pulse shape. Using the AREX signal then allows extension of the Ω-plot method, and thus enables the simultaneous determination of exchange rate kBA and relative concentration fB for pulsed CEST experiments. The theory is proven by simulations and in vitro experiments.

    2. Optimization of white matter fiber tractography with diffusional kurtosis imaging

      G. Russell Glenn, Joseph A. Helpern, Ali Tabesh and Jens H. Jensen

      Article first published online: 14 AUG 2015 | DOI: 10.1002/nbm.3374

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      DKI is a promising method for performing white matter (WM) fiber tractography with the ability to directly resolve crossing fibers. DKI tractography is optimized to improve visualization of specific WM fiber bundles and to increase the ability to detect multiple fiber bundle orientations, while minimizing negative effects that can occur with too strong radial weighting. DKI tractography is demonstrated with different acquisition settings, and an efficient image processing algorithm is proposed to decrease image processing times.

    3. Characterization of the ultrashort-TE (UTE) MR collagen signal

      Adrienne G. Siu, Andrew Ramadeen, Xudong Hu, Lily Morikawa, Li Zhang, Justin Y. C. Lau, Garry Liu, Mihaela Pop, Kim A. Connelly, Paul Dorian and Graham A. Wright

      Article first published online: 13 AUG 2015 | DOI: 10.1002/nbm.3372

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      The ultrashort-TE (UTE) MR properties of collagen, including its T2* and chemical shift, were assessed in collagen solutions. Such properties represent a unique MR signature of collagen, specific to the protons in the collagen molecule. Investigation of the collagen MR properties could potentially aid in the imaging of myocardial fibrosis, without the need for gadolinium-based contrast agents.

    4. In vivo mouse myocardial 31P MRS using three-dimensional image-selected in vivo spectroscopy (3D ISIS): technical considerations and biochemical validations

      Adrianus J. Bakermans, Desiree Abdurrachim, Bastiaan J. van Nierop, Anneke Koeman, Inge van der Kroon, Antonius Baartscheer, Cees A. Schumacher, Gustav J. Strijkers, Sander M. Houten, Coert J. Zuurbier, Klaas Nicolay and Jeanine J. Prompers

      Article first published online: 13 AUG 2015 | DOI: 10.1002/nbm.3371

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      Respiratory-gated, cardiac-triggered, three-dimensional image-selected in vivo spectroscopy (3D ISIS) was used for 31P MRS of the in vivo mouse heart. Localization performance was assessed with 31P MRS experiments in the anterior myocardial wall, liver, skeletal muscle and blood. Results were validated against ex vivo biochemical assays. Measurements of hemodynamics and blood gases confirmed that the experimental protocol did not affect cardiovascular physiology. The approach described here allows for the non-invasive assessment of in vivo mouse myocardial energy homeostasis with 31P MRS under physiological conditions.

    5. Time-efficient interleaved human 23Na and 1H data acquisition at 7 T

      Paul W. de Bruin, Peter Koken, Maarten J. Versluis, Sebastian A. Aussenhofer, Ingrid Meulenbelt, Peter Börnert and Andrew G. Webb

      Article first published online: 13 AUG 2015 | DOI: 10.1002/nbm.3368

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      A flexible framework for the interleaving of clinical scanning protocols is introduced with the aim of increasing the efficiency of sodium/proton MR data acquisition. To prove this concept, proton Dixon, proton multi-echo, fluid-suppressed sodium and non-suppressed sodium scans were acquired in an interleaved fashion, with a time saving of a factor of two.

  4. Special issue research articles

    1. Concurrent recording of RF pulses and gradient fields – comprehensive field monitoring for MRI

      David O. Brunner, Benjamin E. Dietrich, Mustafa Çavuşoğlu, Bertram J. Wilm, Thomas Schmid, Simon Gross, Christoph Barmet and Klaas P. Pruessmann

      Article first published online: 13 AUG 2015 | DOI: 10.1002/nbm.3359

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      By using NMR field probes in conjunction with broadband RF receivers, a stand-alone monitoring unit measuring RF pulses and gradient waveforms concurrently and with common timing was built. The unit can capture the field dynamics of multi-channel RF transmission systems without the need for dedicated RF pickups, and delivers a comprehensive sequence depiction as it is executed by the scanner. These abilities are exemplified by monitoring typically challenging applications such bSSFP, UTE and spatially selective parallel transmission pulses at 7 T.

  5. Review articles

    1. Sodium MRI of glioma in animal models at ultrahigh magnetic fields

      Victor D. Schepkin

      Article first published online: 15 JUL 2015 | DOI: 10.1002/nbm.3347

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      Sodium MRI has the potential to reveal tumor chemotherapy resistance both prior to treatment and non-invasively. Application of sodium MRI may lead to individualized cancer treatment strategies, avoiding unsuccessful interventions. It can also serve as a marker for multidrug resistance and as a valuable tool for cancer drug development.

  6. Special issue review articles

    1. Diffusion imaging of the vertebral bone marrow

      Olaf Dietrich, Tobias Geith, Maximilian F. Reiser and Andrea Baur-Melnyk

      Article first published online: 26 JUN 2015 | DOI: 10.1002/nbm.3333

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      Diffusion-weighted MRI (DWI) of the vertebral bone marrow is a clinically important tool for the characterization of bone-marrow pathologies and, in particular, for the differentiation of benign and malignant vertebral compression fractures. DWI of the vertebral bone marrow is, however, complicated by some unique MR and tissue properties of vertebral bone marrow. This review summarizes data from numerous studies in which diffusion measurements of normal vertebral bone marrow and of different vertebral bone-marrow lesions were performed.

    2. Sodium NMR/MRI for anisotropic systems

      U. Eliav and G. Navon

      Article first published online: 24 JUN 2015 | DOI: 10.1002/nbm.3331

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      Many biological tissues contain structures such as fibers and membranes that impose anisotropic translational and rotational motions on the sodium ions. Translational motion can be studied by diffusion measurements. Anisotropic rotational motion, resulting in non-degenerate ±1/2–±3/2 transitions, is best studied using multiple-quantum 23Na NMR and MRI (see the spectrum for the optic nerve). The current review covers various NMR techniques applied to 23Na in anisotropic compartments of cartilage, tendon, intervertebral discs, red blood cells, nervous system and muscles.

  7. Special issue research articles

    1. Quantitative sodium MRI of the human brain at 9.4 T provides assessment of tissue sodium concentration and cell volume fraction during normal aging

      Keith Thulborn, Elaine Lui, Jonathan Guntin, Saad Jamil, Ziqi Sun, Theodore C. Claiborne and Ian C. Atkinson

      Article first published online: 9 JUN 2015 | DOI: 10.1002/nbm.3312

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      Quantitative sodium MRI at 9.4 T performed on human brains shows that the tissue sodium concentration (TSC) and cell volume fraction remain constant during cognitively normal ageing, confirming a result previously available only from neuropathology. The figure shows TSC of the brain as a function of adult age. Representative images of TSC (top) and tissue cell volume fraction (bottom) are shown across the age scale for representative young and old individuals. Images were acquired at 9.4 T.

  8. Review articles

    1. You have full text access to this OnlineOpen article
      Parallel transmission for ultrahigh-field imaging

      Francesco Padormo, Arian Beqiri, Joseph V. Hajnal and Shaihan J. Malik

      Article first published online: 19 MAY 2015 | DOI: 10.1002/nbm.3313

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      Ultrahigh-field MRI provides a powerful new investigational device for in vivo imaging, but is hindered by non-uniform and variable radiofrequency fields. Parallel transmission (PTx) promises to address these issues by providing more control over the fields. In this article, we review methods for exploiting the new degrees of freedom provided by PTx to improve image quality and to reduce the specific absorption rate (SAR).

  9. Special issue review articles

    1. The technological future of 7 T MRI hardware

      A. G. Webb and P. F. Van de Moortele

      Article first published online: 14 MAY 2015 | DOI: 10.1002/nbm.3315

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      In this article we present some projections for future hardware developments on human 7 T MRI scanners. Areas covered include magnet design, magnetic field gradients, RF coils, dynamic shimming, SAR estimation, and patient monitoring.

  10. Special issue research articles

    1. A simple approach to evaluate the kinetic rate constant for ATP synthesis in resting human skeletal muscle at 7 T

      Jimin Ren, A. Dean Sherry and Craig R. Malloy

      Article first published online: 6 MAY 2015 | DOI: 10.1002/nbm.3310

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      Extracting the ATP synthesis rate constant (kPi[RIGHTWARDS ARROW]γATP) from 31P inversion transfer measurements is generally complicated by the tangle of multiple spin relaxation and exchange parameters in the magnetization equations describing the exchange system. This problem can be avoided by using a simple alternative approach based on the Bloch–McConnell equation for inorganic phosphate Pi, which allows the evaluation of kPi[RIGHTWARDS ARROW]γATP by a linear plot of Pi magnetization rate (m˙Pi) against the magnetization difference between Pi and γ-ATP (mPi − mγATP) .

    2. You have full text access to this OnlineOpen article
      Assessment of blood flow velocity and pulsatility in cerebral perforating arteries with 7-T quantitative flow MRI

      W. H. Bouvy, L. J. Geurts, H. J. Kuijf, P. R. Luijten, L. J. Kappelle, G. J. Biessels and J. J. M. Zwanenburg

      Article first published online: 27 APR 2015 | DOI: 10.1002/nbm.3306

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      A two-dimensional, single-slice, quantitative flow (Qflow) sequence on a 7-T system yielded the first non-invasive in vivo measurements of blood flow velocity and pulsatility in cerebral perforating arteries in the basal ganglia (BG) and semioval centre (CSO), with the middle cerebral artery as reference. The precision of the velocity measurements in individual vessels and the pulsatility index per anatomical region was determined using Bland–Altman analysis. This sequence allows the study of the haemodynamics of cerebral perforating arteries and their association with, for example, vascular lesions.

    3. Enhancing the quantification of tissue sodium content by MRI: time-efficient sodium B1 mapping at clinical field strengths

      Jonathan Lommen, Simon Konstandin, Philipp Krämer and Lothar R. Schad

      Article first published online: 21 APR 2015 | DOI: 10.1002/nbm.3292

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      B1 mapping methods for tissue sodium content (TSC) quantification are evaluated. On this basis, a new protocol using the phase-sensitive (PS) method is developed, which allows for simultaneous B1 mapping and spin density-weighted imaging. The accuracy of TSC measurements is increased without the need for additional measurement time, which allows for a better incorporation of quantitative sodium imaging into clinics.

    4. Safety testing and operational procedures for self-developed radiofrequency coils

      Jens Hoffmann, Anke Henning, Ioannis A. Giapitzakis, Klaus Scheffler, G. Shajan, Rolf Pohmann and Nikolai I. Avdievich

      Article first published online: 6 APR 2015 | DOI: 10.1002/nbm.3290

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      Herein, a comprehensive guideline on electrical and mechanical safety tests, specific absorption rate (SAR) simulation, risk analysis and operational procedures for self-developed RF coils is described that helps to recognize and eliminate safety concerns during RF coil design and operation. Although the procedure is generally applicable to all field strengths, specific requirements with regard to SAR simulation and verification, as well as electrical safety and performance, at ultrahigh-field are considered.

  11. Special issue review articles

    1. Sodium MRI of multiple sclerosis

      Maria Petracca, Lazar Fleysher, Niels Oesingmann and Matilde Inglese

      Article first published online: 6 APR 2015 | DOI: 10.1002/nbm.3289

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      Sodium MRI is a topic of increasing interest in multiple sclerosis (MS) research as it allows the metabolic characterization of brain tissue in vivo, aiding in the exploration of pathogenetic mechanisms and possibly offering insights into disease progression and the monitoring of treatment outcomes. We present an up-to-date review of sodium MRI application in MS, organized into four main sections: biological and pathogenetic role of sodium; brief overview of sodium imaging techniques; results of sodium MRI application in clinical studies; and future perspectives.

    2. Evaluation of cartilage repair and osteoarthritis with sodium MRI

      Štefan Zbýň, Vladimír Mlynárik, Vladimir Juras, Pavol Szomolanyi and Siegfried Trattnig

      Article first published online: 23 MAR 2015 | DOI: 10.1002/nbm.3280

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      Sodium MRI is technologically a challenging yet sensitive method for the detection of even small changes in cartilage glycosaminoglycan content, which play a key role in homeostasis. Clinical applications of sodium imaging published over the past decade demonstrate its potential for the non-invasive evaluation of cartilage pathologies. In this review, we present basic information on cartilage composition and sodium imaging methodology, as well as an overview of clinical studies evaluating different cartilage repair techniques and osteoarthritis by sodium imaging.

    3. Recent applications of UHF-MRI in the study of human brain function and structure: a review

      Wietske van der Zwaag, Andreas Schäfer, José P. Marques, Robert Turner and Robert Trampel

      Article first published online: 12 MAR 2015 | DOI: 10.1002/nbm.3275

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      MRI at ultra-high field strength of 7 T and greater has made tremendous progress over the last decade and a half. This review discusses the rapidly expanding literature on UHF applications of BOLD fMRI and structural imaging in the brain, including relaxation-time-weighted imaging, phase imaging, and QSM; angiography and diffusion- and MT-weighted imaging.

    4. Clinical applications at ultrahigh field (7  T). Where does it make the difference?

      Siegfried Trattnig, Wolfgang Bogner, Stephan Gruber, Pavol Szomolanyi, Vladimir Juras, Simon Robinson, Štefan Zbýň and Stefan Haneder

      Article first published online: 12 MAR 2015 | DOI: 10.1002/nbm.3272

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      Although it will probably take some years before full whole-body investigations can be performed routinely with high quality at 7 T, many morphological applications, as well as metabolic and functional MRI applications, in neuroimaging, musculoskeletal and breast imaging have already been shown to be superior compared with the benchmark 3 T, which will further enhance the move to 7 T. The rapid increase in operating 7-T systems indicates the growing interest in ultrahigh-field MRI because of the improved clinical results with regard to morphological detail, as well as functional and metabolic imaging capabilities.

    5. Quantitative sodium MRI of kidney

      Frank G. Zöllner, Simon Konstandin, Jonathan Lommen, Johannes Budjan, Stefan O. Schoenberg, Lothar R. Schad and Stefan Haneder

      Article first published online: 27 FEB 2015 | DOI: 10.1002/nbm.3274

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      The human kidneys maintain the homeostasis of the body's fluid and electrolyte balance by filtration of the plasma and excretion of the end products, herein the regulation of extracellular sodium (23Na). Renal 23Na MRI can provide new insights into the physiological function and viability of tissues via the quantification of the tissue sodium concentration. Initial pre-clinical and clinical studies have already outlined the potential of this technique. Future studies must be extended to larger patient groups to demonstrate its diagnostic power. In conclusion, 23Na MRI is seen as a powerful technique with the option to establish a non-invasive renal biomarker for tissue viability, but is still a long way from real clinical implementation.

    6. W(h)ither human cardiac and body magnetic resonance at ultrahigh fields? technical advances, practical considerations, applications, and clinical opportunities

      Thoralf Niendorf, Katharina Paul, Celal Oezerdem, Andreas Graessl, Sabrina Klix, Till Huelnhagen, Fabian Hezel, Jan Rieger, Helmar Waiczies, Jens Frahm, Armin M. Nagel, Eva Oberacker and Lukas Winter

      Article first published online: 23 FEB 2015 | DOI: 10.1002/nbm.3268

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      This work documents and reviews advances and progress in cardiac and body MR technology at ultrahigh fields and its application in forefront research and in early clinical applications. The achievements of ultrahigh field cardiac and body MR are shown to be a powerful motivator and enabler, since the extra speed, signal and imaging capabilities may be invested to overcome the fundamental constraints that continue to hamper traditional cardiac and body MR applications at lower magnetic field strengths.

    7. Sodium MRI in human heart: a review

      Paul A. Bottomley

      Article first published online: 12 FEB 2015 | DOI: 10.1002/nbm.3265

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      The properties, methods and clinical potential of sodium MRI in human heart are reviewed. The myocardial sodium concentration is about 40 µmol/g wet weight, and its signal-to-noise ratio is about one-6000th of conventional proton MRI. Sodium's short multi-component relaxation behavior necessitates fast, ultra-short-echo MRI sequences, especially for quantification. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved, but increased sodium, primarily attributable to sodium influx, is demonstrated in human myocardial infarction. The added value of cardiac 23Na MRI versus existing methods remains key.

  12. Special issue research articles

    1. Cortical phase changes measured using 7-T MRI in subjects with subjective cognitive impairment, and their association with cognitive function

      Sanneke van Rooden, Mathijs Buijs, Marjolein E. van Vliet, Maarten J. Versluis, Andrew G. Webb, Ania M. Oleksik, Lotte van de Wiel, Huub A. M. Middelkoop, Gerard Jan Blauw, Annelies W. E. Weverling-Rynsburger, Jeroen D. C. Goos, Wiesje M. van der Flier, Ted Koene, Philip Scheltens, Frederik Barkhof, Ondine van de Rest, P. Eline Slagboom, Mark A. van Buchem and Jeroen van der Grond

      Article first published online: 19 DEC 2014 | DOI: 10.1002/nbm.3248

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      In subjects with subjective cognitive impairment (SCI), Alzheimer's disease-like changes may occur in the brain. We investigated whether cortical phase shifts at 7 T in SCI can be detected, implicating the deposition of amyloid-beta (Aβ) plaques and associated iron, and which cognitive domains are associated with cortical phase shifts in SCI. In SCI, an increased cortical phase shift at high field is associated with a poorer memory performance, although no increased phase shift could be determined in subjects with SCI compared with controls.

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