NMR in Biomedicine

Cover image for Vol. 27 Issue 5

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

Impact Factor: 3.446

ISI Journal Citation Reports © Ranking: 2012: 5/43 (Spectroscopy); 20/72 (Biophysics); 20/120 (Radiology Nuclear Medicine & Medical Imaging)

Online ISSN: 1099-1492

Associated Title(s): Contrast Media & Molecular Imaging

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  1. Research articles

    1. Quantitative blood oxygenation level-dependent (BOLD) response of the left ventricular myocardium to hyperoxic respiratory challenge at 1.5 and 3.0 T

      Sebastian Winklhofer, Shila Pazahr, Robert Manka, Hatem Alkadhi, Andreas Boss and Paul Stolzmann

      Article first published online: 16 APR 2014 | DOI: 10.1002/nbm.3119

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      We sought to assess the blood oxygenation level-dependent (BOLD) response of the myocardial transverse relaxation times (ΔT2*) to a hyperoxic respiratory challenge (HRC) during the breathing of medical air, pure oxygen and carbogen, inducing normoxia, hyperoxia and hyperoxic hypercapnia, respectively. The myocardial ∆T2* response to HRC can reliably be imaged and quantified with BOLD MRI at both 1.5 and 3.0 T. During HRC, hyperoxia and hyperoxic hypercapnia induce a significant increase in T2*, with ∆T2* being largest at 3.0 T.

  2. Rapid communications

    1. MR-monitored focused ultrasound using the acoustic-coupling water bath as an intrinsic high-mode dielectric resonator

      A. G. Webb

      Article first published online: 16 APR 2014 | DOI: 10.1002/nbm.3120

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      A new approach to MRI-monitored focused ultrasound is presented. A radiofrequency coil is not required for transmission or reception; rather, the TE012 dielectric resonator mode of the water bath is used for this purpose. A high magnetic field is present at the focal point of the ultrasound transducer, allowing MR-based temperature mapping to be performed.

  3. Research articles

    1. Functional assessment of the mouse heart by MRI with a 1-min acquisition

      Guido Buonincontri, Carmen Methner, Thomas Krieg, T. Adrian Carpenter and Stephen J. Sawiak

      Article first published online: 16 APR 2014 | DOI: 10.1002/nbm.3116

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      A method based on spatiotemporal compressed sensing and parallel imaging was used to accelerate cine imaging of the mouse heart. Using a radial acquisition, examination for systolic function was possible with a 1-min acquisition with preserved accuracy.

  4. Rapid communications

    1. Ventricular B1+ perturbation at 7 T – real effect or measurement artifact?

      Wyger M. Brink, Peter Börnert, Kay Nehrke and Andrew G. Webb

      Article first published online: 14 APR 2014 | DOI: 10.1002/nbm.3112

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      Local B1+ perturbations in the ventricles at 7 T can be in part explained by the high contrast in electrical conductivity between cerebrospinal fluid and white matter, in addition to effects related to the particular B1+ measurement technique used.

  5. Research articles

    1. Texture analysis of T1- and T2-weighted MR images and use of probabilistic neural network to discriminate posterior fossa tumours in children

      Eleni Orphanidou-Vlachou, Nikolaos Vlachos, Nigel P. Davies, Theodoros N. Arvanitis, Richard G. Grundy and Andrew C. Peet

      Article first published online: 13 APR 2014 | DOI: 10.1002/nbm.3099

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      Texture analysis of MR images provides quantitative and reproducible results which can support the diagnostic process. Texture analysis performed on standard T1- and T2-weighted images of childhood posterior fossa tumours (pilocytic astrocytomas, medulloblastomas and ependymomas), combined with probabilistic neural network analysis using readily available software, can provide high diagnostic accuracy. Discriminatory features do not correspond to those used in the clinical interpretation of the images and therefore provide novel tumour information.

    2. Reproducibility of creatine kinase reaction kinetics in human heart: a 31P time-dependent saturation transfer spectroscopy study

      Adil Bashir and Robert Gropler

      Article first published online: 6 APR 2014 | DOI: 10.1002/nbm.3103

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      A 31P MRS approach with one-dimensional image-selected in vivo spectroscopy (ISIS) localization was developed at 3 T to measure forward creatine kinase (CK) reaction kinetics in the human heart. The CK reaction rate constant (kf), measured in 15 healthy subjects, was found to be 0.32 ± 0.05 s–1 and phosphocreatine (PCr) T1 = 7.36 ± 1.79 s. Test–retest reliability was measured in a subset of subjects (n = 7) with intraclass correlation coefficients (ICCs) of 0.90 and 0.79 for kf and T1, respectively, demonstrating good agreement between repeated measurements.

    3. Diffusion-weighted MRI for staging and evaluation of response in diffuse large B-cell lymphoma: a pilot study

      Marilyn J. Siegel, Clint E. Jokerst, Dhana Rajderkar, Charles F. Hildebolt, Sagun Goyal, Farrokh Dehdashti, Nina Wagner Johnston and Barry A. Siegel

      Article first published online: 3 APR 2014 | DOI: 10.1002/nbm.3105

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      Twelve patients with diffuse large B-cell lymphoma were imaged by diffusion-weighted MRI (DW-MRI) and positron emission tomography/computed tomography (PET/CT) prior to therapy, and eight of these after two cycles of chemotherapy. At staging, DW-MRI detected 60 of 62 lesions (97%) and, at interim assessment, apparent diffusion coefficients (ADCs) increased by 85%, accompanied by an 83% decrease in the standardized uptake value. The results show that DW-MRI has the potential to offer both diagnostic and prognostic value that complements PET/CT.

    4. Effects of diffusion on high-resolution quantitative T2 MRI

      Wendy Oakden and Greg J. Stanisz

      Article first published online: 2 APR 2014 | DOI: 10.1002/nbm.3104

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      Diffusion sensitivity, resulting from the large gradients required by high-resolution imaging, distorts the T2 decay curve, decreasing the apparent T2 measured using the quantitative T2 (qT2) sequence and increasing the signal-to-noise ratio required to avoid an underestimation of the myelin water fraction. Refocused readout gradients increase the resolution at which qT2 images can be acquired. We recommend that the diffusion b values arising from both readout and spoiler gradients should be reported to allow improved literature comparison.

    5. MR-detectable metabolic consequences of mitogen-activated protein kinase kinase (MEK) inhibition

      Alessia Lodi, Sarah M. Woods and Sabrina M. Ronen

      Article first published online: 2 APR 2014 | DOI: 10.1002/nbm.3109

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      The goal of this study was to investigate some of the MRS-detectable metabolic consequences of mitogen-activated protein kinase kinase (MEK) inhibition with U0126 in prostate cancer, breast cancer and melanoma cells. MRS-detectable levels of phosphocholine decreased in all cells, as did the expression of choline kinase α. In contrast, the impact of MEK inhibition on glycolysis was cell line dependent: glucose uptake and lactate production decreased in A375 melanoma cells, but increased in PC3 and MCF-7 cells, probably as a result of activation of the phosphoinositide 3-kinase (PI3K) pathway and AMP-activated protein kinase (AMPK).

    6. Signal-to-noise ratio of a mouse brain 13C CryoProbe™ system in comparison with room temperature coils: spectroscopic phantom and in vivo results

      M. Sack, F. Wetterling, A. Sartorius, G. Ende and W. Weber-Fahr

      Article first published online: 1 APR 2014 | DOI: 10.1002/nbm.3110

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      The aim of this work was to evaluate the performance of a prototype 13C CryoProbe™ for mouse brain. The cryogenically cooled resonator achieved approximately four-fold higher signal-to-noise ratio (7SNR) in phantom tests when compared with the best-performing room temperature coil. In addition, we present localized 13C spectra of mouse brain demonstrating the performance in vivo. The cryogenic cooling technique significantly enhances the 13C signal sensitivity at 9.4 T and enables investigations of metabolism within mouse brain.

    7. Fast multidimensional NMR spectroscopy for sparse spectra

      Dany Merhej, Hélène Ratiney, Chaouki Diab, Mohamad Khalil, Michaël Sdika and Rémy Prost

      Article first published online: 24 MAR 2014 | DOI: 10.1002/nbm.3100

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      A method for under-sampling two-dimensional NMR of sparse spectra is presented. It uses a priori knowledge about the nonzero locations in the two-dimensional frequency domain to recover an over-determined linear system from the under-determined system induced when under-sampled acquisitions are performed. This a priori knowledge is obtained from a one-dimensional NMR acquisition. Spectra are then recovered using least squares. The optimized sampling scheme permits deterministic and optimized results. The approach can be easily extended to higher dimensions.

    8. Quantification of rate constants for successive enzymatic reactions with DNP hyperpolarized MR

      Hyla Allouche-Arnon, Yonatan Hovav, Lanette Friesen-Waldner, Jacob Sosna, J. Moshe Gomori, Shimon Vega and Rachel Katz-Brull

      Article first published online: 17 MAR 2014 | DOI: 10.1002/nbm.3102

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      A kinetic model is provided to obtain reaction rate constants in successive enzymatic reactions monitored using NMR spectroscopy and hyperpolarized substrates. The model was applied for the simulation and analysis of the successive oxidation of choline to betaine aldehyde hydrate and, further, to betaine by the enzyme choline oxidase. Reactions were monitored using two hyperpolarized choline molecular probes, [1,1,2,2-D4, 1-13C]choline chloride and [1,1,2,2-D4, 2-13C]choline chloride, in both a clinical scanner and a high-resolution spectrometer.

    9. Requirements for static and dynamic higher order B0 shimming of the human breast at 7 T

      Vincent O. Boer, Mariska P. Luttje, Peter R. Luijten and Dennis W. J. Klomp

      Article first published online: 25 FEB 2014 | DOI: 10.1002/nbm.3096

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      Higher order B0 shimming is investigated for clinical breast MRI at 7 T. Static higher order shimming is shown to be essential for full bilateral lipid suppression. On top of static field distortions, dynamic B0 field variations were observed, with significant higher order spatially varying fields.

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