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

abstract：:Parallel magnetic resonance imaging in k-space such as generalized auto-calibrating partially parallel acquisition exploits spatial correlation among neighboring signals over multiple coils in calibration to estimate missing signals in reconstruction. It is often challenging to achieve accurate calibration information...

journal_title：Magnetic resonance in medicine

authors： Park S,Park J

更新日期：2012-06-01 00:00:00

abstract：:The idea of using parallel imaging to shorten the acquisition time by the simultaneous use of multiple receive coils can be adapted for the parallel transmission of a spatially-selective multidimensional RF pulse. As in data acquisition, a multidimensional RF pulse follows a certain k-space trajectory. Shortening this...

journal_title：Magnetic resonance in medicine

authors： Katscher U,Börnert P,Leussler C,van den Brink JS

更新日期：2003-01-01 00:00:00

abstract：:An automated retrospective image registration based on mutual information is adapted to a multislice functional magnetic resonance imaging (fMRI) acquisition protocol to provide accurate motion correction. Motion correction is performed by mapping each slice to an anatomic volume data set acquired in the same fMRI ses...

journal_title：Magnetic resonance in medicine

authors： Kim B,Boes JL,Bland PH,Chenevert TL,Meyer CR

更新日期：1999-05-01 00:00:00

abstract：:Detre et al. (Magn. Reson. Med. 23, 37-45 (1992)) and Zhang et al., (Magn. Reson. Med. 25, 362 (1992)) have recently demonstrated a technique for the measurement of regional cerebral blood flow (rCBF) based on the continuous saturation (or inversion) of the arterial blood supply to the brain in rats at 4.7 T. In the w...

journal_title：Magnetic resonance in medicine

authors： Walsh EG,Minematsu K,Leppo J,Moore SC

更新日期：1994-02-01 00:00:00

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

authors： Mathiak K,Posse S

更新日期：2001-01-01 00:00:00

abstract：:Diffusion-weighted imaging suffers from motion artifacts and relatively low signal quality due to the long echo times required to permit the diffusion encoding. We investigated the inclusion of a noncylindrical fourth gradient coil, dedicated entirely to diffusion encoding, into the imaging system. Standard three-axis...

journal_title：Magnetic resonance in medicine

authors： Feldman RE,Scholl TJ,Alford JK,Handler WB,Harris CT,Chronik BA

更新日期：2011-12-01 00:00:00

abstract：:The natural abundance 13C NMR intensity of the glycogen C1 resonance was measured in the surgically exposed liver of rabbits in vivo (n = 17) by integration from 98 to 104 ppm and compared double blindedly to the subsequent biochemical measurement. Coil loading was measured each time from a reference sphere at the coi...

journal_title：Magnetic resonance in medicine

authors： Gruetter R,Magnusson I,Rothman DL,Avison MJ,Shulman RG,Shulman GI

更新日期：1994-06-01 00:00:00

abstract：:To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/...

journal_title：Magnetic resonance in medicine

authors： van der Toorn A,Syková E,Dijkhuizen RM,Vorísek I,Vargová L,Skobisová E,van Lookeren Campagne M,Reese T,Nicolay K

更新日期：1996-07-01 00:00:00

abstract：:Volume-localized proton NMR spectroscopy was used to estimate bone marrow cellularity in the posterior iliac crests of patients undergoing treatment with hematopoietic growth factors for a variety of hematologic and neoplastic disorders. Twelve patients were accrued, six of whom were studied more than once, yielding a...

journal_title：Magnetic resonance in medicine

authors： Ballon D,Jakubowski A,Gabrilove J,Graham MC,Zakowski M,Sheridan C,Koutcher JA

更新日期：1991-05-01 00:00:00

abstract：PURPOSE:To test and implement a motion-robust and respiratory-resolved 3D Radial Flow framework that addresses the need for rapid, high resolution imaging in neonatal patients with congenital heart disease. METHODS:A 4-point velocity encoding and 3D radial trajectory with double-golden angle ordering was combined with...

journal_title：Magnetic resonance in medicine

authors： Schrauben EM,Lim JM,Goolaub DS,Marini D,Seed M,Macgowan CK

更新日期：2020-02-01 00:00:00

abstract：PURPOSE:Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase ...

journal_title：Magnetic resonance in medicine

authors： Cui SX,Epstein FH

更新日期：2018-04-01 00:00:00

abstract：:Velocity-encoded phase contrast imaging is being used increasingly in clinical imaging for quantization of blood flow. In this study, the accuracy and precision of ascending aorta flow measurements were found to depend on several subtle aspects of the scan prescription and image analysis. While the usual scan paramete...

journal_title：Magnetic resonance in medicine

authors： Buonocore MH,Bogren H

更新日期：1992-07-01 00:00:00

abstract：:Radiofrequency (RF) -spoiled gradient echo sequences were developed with the aim to produce images with T(1) weighted contrast within short acquisition time. Over the past two decades, this type of sequence has proven to be a robust technique and represents a reliable workhorse in clinical MRI. This study presents an ...

journal_title：Magnetic resonance in medicine

authors： Leupold J,Hennig J,Scheffler K

更新日期：2008-07-01 00:00:00

abstract：:MR-thermometry allows monitoring of the local temperature evolution during minimally invasive interventional therapies. However, for the particular case of MR-thermometry in the human breast, magnetic field variations induced by the respiratory cycle lead to phase fluctuations requiring a suitable correction strategy ...

journal_title：Magnetic resonance in medicine

authors： Hey S,Maclair G,de Senneville BD,Lepetit-Coiffe M,Berber Y,Köhler MO,Quesson B,Moonen CT,Ries M

更新日期：2009-06-01 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：:Higher field strengths entail less homogeneous RF fields. This may influence quantitative MRI and MRS. A method for rapidly mapping the RF field in the human head with minimal distortion was developed on the basis of a single-shot stimulated echo acquisition mode (STEAM) sequence. The flip angle of the second RF pulse...

journal_title：Magnetic resonance in medicine

authors： Helms G,Finsterbusch J,Weiskopf N,Dechent P

更新日期：2008-09-01 00:00:00

abstract：PURPOSE:Due to host-mediated adverse reaction to metallic debris, there is an increasing need for noninvasive assessment of the soft tissue surrounding large joint arthroplasties. Quantitative T 2 ...

journal_title：Magnetic resonance in medicine

authors： Bhave S,Koff MF,Sivaram Kaushik S,Potter HG,Koch KM

更新日期：2019-08-01 00:00:00

abstract：:The water proton resonance frequency (PRF) is temperature dependent and can thus be used for magnetic resonance (MR) thermometry. Since lipid proton resonance frequencies do not depend on temperature, fat suppression is essential for PRF-based temperature mapping. The efficacy of echo-shifted (TE > TR) gradient-echo i...

journal_title：Magnetic resonance in medicine

authors： de Zwart JA,Vimeux FC,Delalande C,Canioni P,Moonen CT

更新日期：1999-07-01 00:00:00

abstract：:Excitation by conventional B1 pulses in surface coil chemical-shift imaging experiments yields resonance intensities that vary greatly with position. B1-compensated semi-selective pulses overcome much of this problem. These pulses are employed for excitation and refocusing in 1H NMR spectroscopic localization in the i...

journal_title：Magnetic resonance in medicine

authors： Balschi JA,Hetherington HP,Pohost GM

更新日期：1992-05-01 00:00:00

abstract：:Phase-contrast magnetic resonance imaging is subject to numerous sources of error, which decrease clinical confidence in the reported measures. This work outlines how stationary perivascular fat can impart a significant chemical shift induced phase-contrast magnetic resonance imaging measurement error using computatio...

journal_title：Magnetic resonance in medicine

authors： Middione MJ,Ennis DB

更新日期：2013-02-01 00:00:00

abstract：PURPOSE:Coil-by-coil reconstruction methods are followed by coil combination to obtain a single image representing a spin density map. Typical coil combination methods, such as square-root sum-of-squares and adaptive coil combining, yield images that exhibit spatially varying modulation of image intensity. Existing pra...

journal_title：Magnetic resonance in medicine

authors： Gol Gungor D,Potter LC

更新日期：2016-02-01 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：:Magnetic resonance imaging allows numerous k-space sampling schemes such as cartesian, polar, spherical, and other non-rectilinear trajectories. Non-rectilinear MR acquisitions permit fast scan times and can suppress motion artifacts. Still, these sampling schemes may adversely affect the image characteristics due to ...

journal_title：Magnetic resonance in medicine

authors： Lauzon ML,Rutt BK

更新日期：1996-12-01 00:00:00

abstract：:Stejskal and Tanner's ingenious pulsed field gradient design from 1965 has made diffusion NMR and MRI the mainstay of most studies seeking to resolve microstructural information in porous systems in general and biological systems in particular. Methods extending beyond Stejskal and Tanner's design, such as double diff...

journal_title：Magnetic resonance in medicine

authors： Shemesh N,Jespersen SN,Alexander DC,Cohen Y,Drobnjak I,Dyrby TB,Finsterbusch J,Koch MA,Kuder T,Laun F,Lawrenz M,Lundell H,Mitra PP,Nilsson M,Özarslan E,Topgaard D,Westin CF

更新日期：2016-01-01 00:00:00

abstract：PURPOSE:To validate an automatic algorithm for offline T2* measurements, providing robust, vendor-independent T2*, and uncertainty estimates for iron load quantification in the heart and liver using clinically available imaging sequences. METHODS:A T2* region of interest (ROI)-based algorithm was developed for robustn...

journal_title：Magnetic resonance in medicine

authors： Bidhult S,Xanthis CG,Liljekvist LL,Greil G,Nagel E,Aletras AH,Heiberg E,Hedström E

更新日期：2016-04-01 00:00:00

abstract：:The experiments reported herein are the first MRI investigations of the orientational dependence of T(2) relaxation in articular cartilage at microscopic resolution over the 360 degrees angular space. For each of six canine cartilage specimens, 48 independent T(2)-weighted proton images were acquired for 12 different ...

journal_title：Magnetic resonance in medicine

authors： Xia Y,Moody JB,Alhadlaq H

更新日期：2002-09-01 00:00:00

abstract：:At TE values of 136 ms, it has recently been shown that the lactate methyl signal, when obtained with a stimulated-echo (STE) sequence, is modulated at the zero-quantum (ZQ) frequency when TM is varied. Here we describe an additional modulation of the ZQ lactate signal, due to spin-spin coupling, that results in a 10-...

journal_title：Magnetic resonance in medicine

authors： Sotak CH,Alger JR

更新日期：1991-02-01 00:00:00

abstract：:The apparent diffusion coefficient (ADC) in the optic nerve was measured from diffusion-weighted magnetic resonance imaging using an intravoxel incoherent motion (IVIM) sequence. The subjects were seven normal volunteers and eight patients with multiple sclerosis (MS) with a total of four optic nerves with acute neuri...

journal_title：Magnetic resonance in medicine

authors： Iwasawa T,Matoba H,Ogi A,Kurihara H,Saito K,Yoshida T,Matsubara S,Nozaki A

更新日期：1997-09-01 00:00:00

abstract：:The resolution in conventional BOLD FMRI is considerably lower than can be achieved with other MRI methods, and is insufficient for many important applications. One major difficulty in robustly improving spatial resolution is the poor image quality in BOLD FMRI, which suffers from distortions, blurring, and signal dro...

journal_title：Magnetic resonance in medicine

authors： Miller KL,Smith SM,Jezzard P,Pauly JM

更新日期：2006-01-01 00:00:00

abstract：PURPOSE:To develop a 256-channel dense-array electroencephalography (dEEG) sensor net (the Ink-Net) using high-resistance polymer thick film (PTF) technology to improve safety and data quality during simultaneous dEEG/MRI. METHODS:Heating safety was assessed with temperature measurements in an anthropomorphic head pha...

journal_title：Magnetic resonance in medicine

authors： Poulsen C,Wakeman DG,Atefi SR,Luu P,Konyn A,Bonmassar G

更新日期：2017-02-01 00:00:00