NMR relaxometric investigation on human methemoglobin and fluoromethemoglobin. An improved quantitative in vitro assay of human methemoglobin.


:Longitudinal water proton relaxation rates of methemoglobin solutions show a strong dependence on temperature and pH. The increase of the relaxation rates with temperature is associated with shortened exchange lifetime of the coordinated water molecule. An accurate measurement of the relaxation rate of methemoglobin solutions thus requires careful control of the experimental temperature. This observation prompted the authors to look for an improved version of the relaxometric in vitro determination of methemoglobin. The method is based on transforming methemoglobin into the corresponding fluoromethemoglobin derivative, which shows both a higher relaxivity and a negligible dependence on temperature. The proposed method has been found to be in good agreement with data from spectrophotometric assays.


Magn Reson Med


Aime S,Fasano M,Paoletti S,Arnelli A,Ascenzi P




Has Abstract


1995-06-01 00:00:00












  • Per-subject characterization of bolus width in pulsed arterial spin labeling using bolus turbo sampling.

    abstract::Quantification of cerebral blood flow using QUIPSSII pulsed arterial spin labeling requires that the QUIPSS saturation delay TI1 is shorter than the natural temporal bolus width. Yet the duration of the bolus of tagged spins entering the region of interest varies during vasoactive stimuli such as gaseous challenges or...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Villien M,Chipon E,Troprès I,Bouvier J,Cantin S,Chechin D,Le Bas JF,Krainik A,Warnking JM

    更新日期:2013-06-01 00:00:00

  • Self-supervised learning of physics-guided reconstruction neural networks without fully sampled reference data.

    abstract:PURPOSE:To develop a strategy for training a physics-guided MRI reconstruction neural network without a database of fully sampled data sets. METHODS:Self-supervised learning via data undersampling (SSDU) for physics-guided deep learning reconstruction partitions available measurements into two disjoint sets, one of wh...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Yaman B,Hosseini SAH,Moeller S,Ellermann J,Uğurbil K,Akçakaya M

    更新日期:2020-12-01 00:00:00

  • Simultaneous assessment of cardiac metabolism and perfusion using copolarized [1-13 C]pyruvate and 13 C-urea.

    abstract:PURPOSE:To demonstrate the feasibility of imaging a bolus of co-polarized [1-13 C]pyruvate and 13 C-urea to simultaneously assess both metabolism and perfusion in the rodent heart. METHODS:Copolarized [1-13 C]pyruvate and 13 C-urea was imaged using a multi-echo, flow-sensitized spiral pulse sequence. Healthy rats were...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Lau AZ,Miller JJ,Robson MD,Tyler DJ

    更新日期:2017-01-01 00:00:00

  • Simultaneous image acquisition from the head (or body) coil and a surface coil.

    abstract::Any number of coils can in principle be used simultaneously and independently in magnetic resonance imaging if the mutual inductances are sufficiently small. Surface coils and head or body coils have equal sensitivity at some crossover depth of the order of 6 to 10 cm. Using a 7.5-cm-diameter surface coil that was int...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Hyde JS,Froncisz W,Jesmanowicz A,Kneeland JB

    更新日期:1988-02-01 00:00:00

  • Self-navigated 4D cartesian imaging of periodic motion in the body trunk using partial k-space compressed sensing.

    abstract:PURPOSE:To enable fast and flexible high-resolution four-dimensional (4D) MRI of periodic thoracic/abdominal motion for motion visualization or motion-corrected imaging. METHODS:We proposed a Cartesian three-dimensional k-space sampling scheme that acquires a random combination of k-space lines in the ky/kz plane. A p...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Küstner T,Würslin C,Schwartz M,Martirosian P,Gatidis S,Brendle C,Seith F,Schick F,Schwenzer NF,Yang B,Schmidt H

    更新日期:2017-08-01 00:00:00

  • Investigation of human cervical and upper thoracic spinal cord motion: implications for imaging spinal cord structure and function.

    abstract::Spinal cord (SC) motion is thought to be the dominant source of error in current diffusion and spinal functional MRI (fMRI) methods. However, until now, such motion has not been well characterized in three dimensions. While previous studies have predominantly examined motion in the superior/inferior (S/I) direction, t...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Figley CR,Stroman PW

    更新日期:2007-07-01 00:00:00

  • DREAM--a novel approach for robust, ultrafast, multislice B₁ mapping.

    abstract::A novel multislice B₁-mapping method dubbed dual refocusing echo acquisition mode is proposed, able to cover the whole transmit coil volume in only one second, which is more than an order of magnitude faster than established approaches. The dual refocusing echo acquisition mode technique employs a stimulated echo acqu...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Nehrke K,Börnert P

    更新日期:2012-11-01 00:00:00

  • Multifrequency reconstruction for frequency-modulated bSSFP.

    abstract:PURPOSE:Banding artifacts in images acquired by balanced steady-state free precession (bSSFP) remain a challenge in MRI as they considerably reduce image quality, and diagnostic value deteriorates accordingly. As the steady-state tolerates small shifts in frequency, it is possible to acquire frequency-modulated bSSFP. ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Slawig A,Wech T,Ratz V,Tran-Gia J,Neubauer H,Bley T,Köstler H

    更新日期:2017-12-01 00:00:00

  • On the overestimation of early wall thickening at the carotid bulb by black blood MRI, with implications for coronary and vulnerable plaque imaging.

    abstract::Black blood MRI is an attractive tool for monitoring normal and pathological wall thickening; however, limited spatial resolutions can conspire with complex vascular geometries to distort the appearance of the wall in ways hitherto unclear. To elucidate this, a thin-walled cylinder model was developed to predict the c...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Antiga L,Wasserman BA,Steinman DA

    更新日期:2008-11-01 00:00:00

  • SLIP, a lipid suppression technique to improve image contrast in inflow angiography.

    abstract::In rapidly acquired gradient echo images, lipid regions usually appear as areas of high signal intensity. In 2D inflow angiograms processed by the maximum intensity projection algorithm, this high lipid signal may prevent angiographic visualization of some blood vessels. We present a new approach to suppress the lipid...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Doyle M,Matsuda T,Pohost GM

    更新日期:1991-09-01 00:00:00

  • Multi-angle ratiometric approach to measure chemical exchange in amide proton transfer imaging.

    abstract::Amide proton transfer imaging, a specific form of chemical exchange saturation transfer imaging, has previously been applied to studies of acute ischemic acidosis, stroke, and cancer. However, interpreting the resulting contrast is complicated by its dependence on the exchange rate between amides and water, the amide ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Zu Z,Janve VA,Li K,Does MD,Gore JC,Gochberg DF

    更新日期:2012-09-01 00:00:00

  • Input parameter sensitivity analysis and comparison of quantification models for continuous arterial spin labeling.

    abstract::The regional cerebral blood flow (rCBF) values determined using continuous arterial spin labeling (CASL) are subject to several sources of variability, including natural physiologic variations, sensitivity to the input parameters, and the use of different quantification models. To date, a thorough analysis of the impa...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Steger TR,White RA,Jackson EF

    更新日期:2005-04-01 00:00:00

  • The field dependence of NMR imaging. II. Arguments concerning an optimal field strength.

    abstract::Some of the factors involved in the choice of field strength for NMR imaging are examined. The influences of relaxation times and chemical shift upon image quality and signal-to-noise ratio are highlighted, and power deposition is introduced as a significant factor which may limit the flexibility and information avail...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Hoult DI,Chen CN,Sank VJ

    更新日期:1986-10-01 00:00:00

  • Hyperpolarized 13C NMR detects rapid drug-induced changes in cardiac metabolism.

    abstract:PURPOSE:The diseased myocardium lacks metabolic flexibility and responds to stimuli differently compared with healthy hearts. Here, we report the use of hyperpolarized 13C NMR spectroscopy to detect sudden changes in cardiac metabolism in isolated, perfused rat hearts in response to adrenergic stimulation. METHODS:Met...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Khemtong C,Carpenter NR,Lumata LL,Merritt ME,Moreno KX,Kovacs Z,Malloy CR,Sherry AD

    更新日期:2015-08-01 00:00:00

  • MRI-based transfer function determination through the transfer matrix by jointly fitting the incident and scattered B 1 + field.

    abstract:PURPOSE:A purely experimental method for MRI-based transfer function (TF) determination is presented. A TF characterizes the potential for radiofrequency heating of a linear implant by relating the incident tangential electric field to a scattered electric field at its tip. We utilize the previously introduced transfer...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Tokaya JP,Raaijmakers AJE,Luijten PR,Sbrizzi A,van den Berg CAT

    更新日期:2020-03-01 00:00:00

  • Relationships between tissue microstructure and the diffusion tensor in simulated skeletal muscle.

    abstract:PURPOSE:To establish a series of relationships defining how muscle microstructure and diffusion tensor imaging (DTI) are related. METHODS:The relationship among key microstructural features of skeletal muscle (fiber size, fibrosis, edema, and permeability) and the diffusion tensor were systematically simulated over ph...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Berry DB,Regner B,Galinsky V,Ward SR,Frank LR

    更新日期:2018-07-01 00:00:00

  • Single-shot localized echo-planar imaging (STEAM-EPI) at 4.7 tesla.

    abstract::The resolution and homogeneity limitations of echo-planar imaging (EPI) are overcome by zoom imaging of an easily shimmed localized volume. Use of the stimulated echo enables single-shot localization. In vivo 0.5-mm resolution EPI images of selected regions of a cat brain at 4.7 T are presented. ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Turner R,von Kienlin M,Moonen CT,van Zijl PC

    更新日期:1990-05-01 00:00:00

  • Evaluation of motion and realignment for functional magnetic resonance imaging in real time.

    abstract::Functional magnetic resonance imaging in real time is an emerging tool for the assessment of dynamic changes in brain activation. The short response latency (tens of seconds) renders the technique more sensitive to motion artifacts. Motion correction in real time requires computationally efficient algorithms which can...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Mathiak K,Posse S

    更新日期:2001-01-01 00:00:00

  • Iterative reweighted linear least squares for accurate, fast, and robust estimation of diffusion magnetic resonance parameters.

    abstract:PURPOSE:Diffusion-weighted magnetic resonance imaging suffers from physiological noise, such as artifacts caused by motion or system instabilities. Therefore, there is a need for robust diffusion parameter estimation techniques. In the past, several techniques have been proposed, including RESTORE and iRESTORE (Chang e...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Collier Q,Veraart J,Jeurissen B,den Dekker AJ,Sijbers J

    更新日期:2015-06-01 00:00:00

  • Susceptibility mapping in the human brain using threshold-based k-space division.

    abstract::A method for calculating quantitative three-dimensional susceptibility maps from field measurements acquired using gradient echo imaging at high field is presented. This method is based on division of the three-dimensional Fourier transforms of high-pass-filtered field maps by a simple function that is the Fourier tra...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Wharton S,Schäfer A,Bowtell R

    更新日期:2010-05-01 00:00:00

  • Towards elimination of the dark-rim artifact in first-pass myocardial perfusion MRI: removing Gibbs ringing effects using optimized radial imaging.

    abstract:PURPOSE:Subendocardial dark-rim artifacts (DRAs) remain a major concern in first-pass perfusion (FPP) myocardial MRI and may lower the diagnostic accuracy for detection of ischemia. A major source of DRAs is the "Gibbs ringing" effect. We propose an optimized radial acquisition strategy aimed at eliminating ringing-ind...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Sharif B,Dharmakumar R,LaBounty T,Arsanjani R,Shufelt C,Thomson L,Merz CN,Berman DS,Li D

    更新日期:2014-07-01 00:00:00

  • Free-breathing cine MRI.

    abstract::Standard MRI cine exams for the study of cardiac function are segmented over several heartbeats and thus require a breath-hold to minimize breathing motion artifacts, which is a current limitation of this approach. The purpose of this study was to develop a method for the measurement and correction of respiratory moti...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Leung AO,Paterson I,Thompson RB

    更新日期:2008-09-01 00:00:00

  • Concentrations of human cardiac phosphorus metabolites determined by SLOOP 31P NMR spectroscopy.

    abstract::Human cardiac 31P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31P metabolites...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Meininger M,Landschütz W,Beer M,Seyfarth T,Horn M,Pabst T,Haase A,Hahn D,Neubauer S,von Kienlin M

    更新日期:1999-04-01 00:00:00

  • Cationized ferritin as a magnetic resonance imaging probe to detect microstructural changes in a rat model of non-alcoholic steatohepatitis.

    abstract:PURPOSE:The goal of this work was to detect disease-related microstructural changes to the liver using magnetic resonance imaging. Chronic liver disease can cause microstructural changes in the liver that reduce plasma access to the perisinusoidal space--the site of exchange between the blood plasma and the hepatic par...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Beeman SC,Mandarino LJ,Georges JF,Bennett KM

    更新日期:2013-12-01 00:00:00

  • Quantitative proton magnetic resonance spectroscopy of the human cervical spinal cord at 3 Tesla.

    abstract::Cervical spinal cord spectroscopy has the potential to add metabolic information to spinal cord MRI and improve the clinical evaluation and research investigation of spinal cord diseases, such as multiple sclerosis (MS) and intraspinal tumors. However, in vivo proton MR spectroscopy ((1)H-MRS) of the spinal cord is di...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Marliani AF,Clementi V,Albini-Riccioli L,Agati R,Leonardi M

    更新日期:2007-01-01 00:00:00

  • Perfusion-weighted imaging of interictal hypoperfusion in temporal lobe epilepsy using FAIR-HASTE: comparison with H(2)(15)O PET measurements.

    abstract::To detect perfusion abnormalities in areas of high magnetic susceptibility in the brain, an arterial spin-labeling MRI technique utilizing flow-sensitive alternating inversion recovery (FAIR) and half-Fourier single shot turbo spin-echo (HASTE) for spin preparation and image acquisition, respectively, was developed. I...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Liu HL,Kochunov P,Hou J,Pu Y,Mahankali S,Feng CM,Yee SH,Wan YL,Fox PT,Gao JH

    更新日期:2001-03-01 00:00:00

  • Dysprosium-bearing red cells as potential transverse relaxation agents for MRI.

    abstract::The cytosol of intact human red blood cells was loaded with 28.1 +/- 3.4 mM of dysprosium DTPA-BMA using a hypoosmotic technique. When loaded cells were diluted with saline and control cells to give an average dysprosium concentration of 3.3 +/- 0.5 mM, the transverse relaxation rate constants R(*)(2) and R(2) increas...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Johnson KM,Tao JZ,Kennan RP,Gore JC

    更新日期:2001-05-01 00:00:00

  • Murine orthostatic response during prolonged vertical studies: effect on cerebral blood flow measured by arterial spin-labeled MRI.

    abstract::High-field MRI scanners are, in principle, well suited for mouse studies; however, many high-field magnets employ a vertical design that may influence the physiological state of the rodent. The purpose of this study was to investigate the orthostatic response of cerebral blood flow (CBF) in mice during a prolonged MR ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Foley LM,Hitchens TK,Kochanek PM,Melick JA,Jackson EK,Ho C

    更新日期:2005-10-01 00:00:00

  • T1 rho relaxation and its application to MR histology.

    abstract::The application of T1 rho an an alternative contrast parameter in high-field magnetic resonance histology (MRH) has been investigated. Spectroscopic measurements of T1 rho were performed on 5.75% agar and 1.0 mM MnCI2 phantoms at 9.4 T to validate the accuracy of the imaging measurements. Image studies were performed ...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Engelhardt RT,Johnson GA

    更新日期:1996-05-01 00:00:00

  • Electrocardiogram acquisition during MR examinations for patient monitoring and sequence triggering.

    abstract::We have developed a method for measuring the electrocardiogram (ECG) continuously during MR examinations. In contrast to ECG acquisition by wires, our new method is to amplify and convert the ECG into an optical signal directly above the patient's heart. The optical signal is transmitted out of the magnet bore by opti...

    journal_title:Magnetic resonance in medicine

    pub_type: 杂志文章


    authors: Felblinger J,Lehmann C,Boesch C

    更新日期:1994-10-01 00:00:00