RF heating measurement using MR thermometry and field monitoring: Methodological considerations and first in vivo results.

abstract：PURPOSE:To develop a one-step quantification approach that accounts for joint preprocessing and quantification of whole-range kinetics (early and late-phase washout) of dynamic contrast-enhanced (DCE) MRI of indeterminate adnexal masses. METHODS:Preoperative DCE-MRI of 43 (24 benign, 19 malignant) sonographically inde...

journal_title：Magnetic resonance in medicine

authors： Fathi Kazerooni A,Nabil M,Haghighat Khah H,Parviz S,Gity M,Saligheh Rad H

更新日期：2018-02-01 00:00:00

abstract：:The incoherent displacement of water in living tissues is of considerable interest because of the widespread use of diffusion-weighted MRI, for which image contrast is based on the water apparent diffusion coefficient (ADC). It has been hypothesized that the decrease in water ADC associated with brain injury is primar...

journal_title：Magnetic resonance in medicine

authors： Sehy JV,Ackerman JJ,Neil JJ

更新日期：2002-07-01 00:00:00

abstract：PURPOSE:The aim of this study was to develop a technique for rapid collection of chemical exchange saturation transfer images with the saturation varied to modulate signal loss transfer and enhance contrast. METHODS:Multi-echo Length and Offset VARied Saturation (MeLOVARS) divides the saturation pulse of length Tsat i...

journal_title：Magnetic resonance in medicine

authors： Song X,Xu J,Xia S,Yadav NN,Lal B,Laterra J,Bulte JW,van Zijl PC,McMahon MT

更新日期：2015-02-01 00:00:00

abstract：:The myelin sheath, which is wrapped around the axons in the brain, can be affected by many diseases, resulting in cognitive and physical disability. Other work showed water in the myelin sheath has a T2 approximately 15 ms. The current standard technique to estimate the fraction of myelin water in vivo is to collect m...

journal_title：Magnetic resonance in medicine

authors： Jones CK,Xiang QS,Whittall KP,MacKay AL

更新日期：2004-03-01 00:00:00

abstract：:The ability to directly detect neuronal magnetic fields by MRI would help investigators achieve the "holy grail" of neuroimaging, namely both high spatial and temporal resolution. Both positive and negative findings have been reported in the literature, with no clear consensus as to the feasibility of direct detection...

journal_title：Magnetic resonance in medicine

authors： Parkes LM,de Lange FP,Fries P,Toni I,Norris DG

更新日期：2007-02-01 00:00:00

abstract：:Iron-mediated tissue damage is present in cerebrovascular and neurodegenerative diseases and neurotrauma. Brain microbleeds are often present in these maladies and are assuming increasing clinical importance. Because brain microbleeds present a source of pathologic iron to the brain, the noninvasive quantification of ...

journal_title：Magnetic resonance in medicine

authors： McAuley G,Schrag M,Sipos P,Sun SW,Obenaus A,Neelavalli J,Haacke EM,Holshouser B,Madácsi R,Kirsch W

更新日期：2010-01-01 00:00:00

abstract：:Magnetic resonance imaging has achieved clinical importance and has become the primary tool in the investigation of head, spinal cord, pelvis, cancellous bone, pericardium (with gating), gallbladder, lymph node masses, and very soon, in the evaluation of joints. In many areas, particularly with respiratory and ECG gat...

journal_title：Magnetic resonance in medicine

authors： Margulis AR,Fisher MR

更新日期：1985-08-01 00:00:00

abstract：PURPOSE:Previous work has evaluated the quality of different analytic methods for extracting relaxation times from magnitude imaging data exhibiting Rician noise. However, biexponential analysis of relaxation in tissue, including cartilage, and materials is of increasing interest. We, therefore, analyzed biexponential ...

journal_title：Magnetic resonance in medicine

authors： Bouhrara M,Reiter DA,Celik H,Bonny JM,Lukas V,Fishbein KW,Spencer RG

更新日期：2015-01-01 00:00:00

abstract：PURPOSE:Magnetic resonance imaging (MRI)-based techniques for assessing liver iron concentration (LIC) have been limited by single scanner calibration against biopsy. Here, the calibration of spin-density projection-assisted (SDPA) R2-MRI (FerriScan®) in iron-overloaded β-thalassemia patients treated with the iron chel...

journal_title：Magnetic resonance in medicine

authors： St Pierre TG,El-Beshlawy A,Elalfy M,Al Jefri A,Al Zir K,Daar S,Habr D,Kriemler-Krahn U,Taher A

更新日期：2014-06-01 00:00:00

abstract：:The incorporation of RF coils into the tips of intravascular devices has been shown to enable the localization of catheters and guidewires under MR guidance. Furthermore, such coils can be used for endoluminal imaging. The long cable required to connect the coil with the scanner input inadvertently acts as a dipole an...

journal_title：Magnetic resonance in medicine

authors： Ladd ME,Quick HH

更新日期：2000-04-01 00:00:00

abstract：:An array of 33 prototype polypeptides was examined as putative contrast agents that can be distinguished from each other based on the chemical exchange saturation transfer (CEST) mechanism. These peptides were chosen based on predictions of the chemical exchange rates of exchangeable amide, amine, and hydroxyl protons...

journal_title：Magnetic resonance in medicine

authors： McMahon MT,Gilad AA,DeLiso MA,Berman SM,Bulte JW,van Zijl PC

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:To enable highly accelerated distortion-free MRI near metal by separating on- and off-resonance to exploit the redundancy of slice-phase encoding for the dominant on-resonance component. METHODS:Multispectral MRI techniques resolve off-resonance distortions by a combination of limited excitation bins and addit...

journal_title：Magnetic resonance in medicine

authors： Levine E,Stevens K,Beaulieu C,Hargreaves B

更新日期：2018-03-01 00:00:00

abstract：:Parallel transmission has emerged as an efficient means for implementing multidimensional spatially selective radiofrequency excitation pulses. To date, most theoretical and experimental work on parallel transmission radiofrequency (RF) pulse design is based on the small-tip-angle approximation to the Bloch equation. ...

journal_title：Magnetic resonance in medicine

authors： Zheng H,Zhao T,Qian Y,Ibrahim TS,Boada FE

更新日期：2011-09-01 00:00:00

abstract：:New algorithms for correlation analysis are presented that allow the mapping of brain activity from functional MRI (fMRI) data in real time during the ongoing scan. They combine the computation of the correlation coefficients between measured fMRI time-series data and a reference vector with "detrending", a technique ...

journal_title：Magnetic resonance in medicine

authors： Gembris D,Taylor JG,Schor S,Frings W,Suter D,Posse S

更新日期：2000-02-01 00:00:00

abstract：PURPOSE:To characterize and optimize 19 F MRI for different perfluorocarbons (PFCs) at 3T and quantify the loss of acquisition efficiency as a function of different temperature and cellular conditions. METHODS:The T1 and T2 relaxation times of the commonly used PFCs perfluoropolyether (PFPE), perfluoro-15-crown-5-ethe...

journal_title：Magnetic resonance in medicine

authors： Colotti R,Bastiaansen JAM,Wilson A,Flögel U,Gonzales C,Schwitter J,Stuber M,van Heeswijk RB

更新日期：2017-06-01 00:00:00

abstract：PURPOSE:To develop a framework for respiratory motion-corrected 3D whole-heart water/fat coronary MR angiography (CMRA) at 3T with reduced and predictable scan time. METHODS:A 3D dual-echo acquisition and respiratory motion-corrected reconstruction framework for water/fat CMRA imaging was developed. The acquisition se...

journal_title：Magnetic resonance in medicine

authors： Munoz C,Cruz G,Neji R,Botnar RM,Prieto C

更新日期：2019-08-01 00:00:00

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

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

abstract：PURPOSE:Compare the transmural distribution of forward creatine kinase reaction (kf,CK ) and ATP hydrolysis rate (kr,ATPase ) in the myocardium of normal porcine heart. Rate constants were extracted from partially relaxed spectra by applying the T1nom method, effectively reducing data acquisition time by up to an order...

journal_title：Magnetic resonance in medicine

authors： Jang A,Xiong Q,Zhang P,Zhang J

更新日期：2016-05-01 00:00:00

abstract：:The goal of this work was to develop and evaluate a numerically optimized inversion pulse to be used with a homonuclear editing sequence to measure human cerebral GABA in vivo at 4.1 T in the occipital lobe. The optimized pulse was constructed using pallindromic symmetry with 30 pulses and 29 delays. The optimized pul...

journal_title：Magnetic resonance in medicine

authors： Hetherington HP,Newcomer BR,Pan JW

更新日期：1998-01-01 00:00:00

abstract：:In active catheter tracking, small RF coils are attached to the catheter for localization. For interactive catheter steering at vessel branchings, it is necessary to visualize not only a single point near the catheter tip but also the entire shape and orientation of the catheter's distal end. Therefore, a 35-mm-long t...

journal_title：Magnetic resonance in medicine

authors： Zuehlsdorff S,Umathum R,Volz S,Hallscheidt P,Fink C,Semmler W,Bock M

更新日期：2004-07-01 00:00:00

abstract：:Pattern recognition techniques (factor analysis and neural networks) were used to investigate and classify human brain tumors based on the 1H NMR spectra of chemically extracted biopsies (n = 118). After removing information from lactate (because of variable ischemia times), unsupervised learning suggested that the sp...

journal_title：Magnetic resonance in medicine

authors： Maxwell RJ,Martínez-Pérez I,Cerdán S,Cabañas ME,Arús C,Moreno A,Capdevila A,Ferrer E,Bartomeus F,Aparicio A,Conesa G,Roda JM,Carceller F,Pascual JM,Howells SL,Mazucco R,Griffiths JR

更新日期：1998-06-01 00:00:00

abstract：:Of the various techniques employed to quantify temperature changes by MR, proton resonance frequency (PRF) shift-based phase-difference imaging (PDI) is the most accurate and widely used. However, PDI is associated with various artifacts. Motivated by these limitations, we developed a new method to monitor temperature...

journal_title：Magnetic resonance in medicine

authors： Paliwal V,El-Sharkawy AM,Du X,Yang X,Atalar E

更新日期：2004-10-01 00:00:00

abstract：:The fate of the 13C label arising from [U-13C]succinate in rabbit renal proximal convoluted tubular (PCT) cells, incubated with [U-13C]succinate, was investigated by 13C NMR spectroscopy of the perchloric acid extracts of the cell pellets. The 13C label of [U-13C]succinate was predominantly metabolized into glutamate,...

journal_title：Magnetic resonance in medicine

authors： Jans AW,Willem R

更新日期：1990-04-01 00:00:00

abstract：:Fitting a model to an experimental spectrum is a difficult nonlinear estimation problem. The solution presented here is to start an iterative search procedure sufficiently close to the optimal model parameter set. This is achieved by providing tissue-dependent a priori peak information and by a novel correlation metho...

journal_title：Magnetic resonance in medicine

authors： Burger C,McKinnon G,Buchli R,Boesiger P

更新日期：1991-10-01 00:00:00

abstract：:An approach to efficiently measure three-dimensional velocity vector fields and turbulent kinetic energy of blood flow is presented. Multipoint phase-contrast imaging is used in combination with Bayesian analysis to map both mean and fluctuating velocities over a large dynamic range and for practically relevant signal...

journal_title：Magnetic resonance in medicine

authors： Binter C,Knobloch V,Manka R,Sigfridsson A,Kozerke S

更新日期：2013-05-01 00:00:00

abstract：:The purpose of this study was to evaluate an optimized multislice acquisition technique for oxygen-enhanced MRI of the lung using slice-selective inversion and refocusing pulses in combination with parallel imaging. An inversion recovery HASTE sequence was implemented with respiratory triggering to perform imaging in ...

journal_title：Magnetic resonance in medicine

authors： Dietrich O,Losert C,Attenberger U,Fasol U,Peller M,Nikolaou K,Reiser MF,Schoenberg SO

更新日期：2005-06-01 00:00:00

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

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

更新日期：2018-07-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 00:00:00

abstract：PURPOSE:A systematic study of the short-term and long-term variability of regional alveolar partial pressure of oxygen tension (pA O2 ) measurements using (3) He magnetic resonance imaging was presented. Additionally, the repeatability of the average evaluated pA O2 was compared with that of the standard pulmonary func...

journal_title：Magnetic resonance in medicine

authors： Hamedani H,Kadlecek SJ,Ishii M,Emami K,Kuzma NN,Xin Y,Rossman M,Rizi RR

更新日期：2013-12-01 00:00:00

abstract：:The purpose of this study is (1) to determine the correlation between T(1rho) and T(2) and degenerative grade in intervertebral discs using in vivo 3.0-T MRI, and (2) to determine the association between T(1rho) and T(2) and clinical findings as quantified by the SF-36 Questionnaire and Oswestry Disability Index. Sixt...

journal_title：Magnetic resonance in medicine

authors： Blumenkrantz G,Zuo J,Li X,Kornak J,Link TM,Majumdar S

更新日期：2010-05-01 00:00:00