Rapid radiofrequency field mapping in vivo using single-shot STEAM MRI.

abstract：:Quantitative estimation of T1 is a challenging but important task inherent to many clinical applications. The most commonly used paradigm for estimating T1 in vivo involves performing a sequence of spoiled gradient-recalled echo acquisitions at different flip angles, followed by fitting of an exponential model to the ...

journal_title：Magnetic resonance in medicine

authors： Trzasko JD,Mostardi PM,Riederer SJ,Manduca A

更新日期：2013-06-01 00:00:00

abstract：:A study was made of the in vivo detectability of a pH-sensitive, imidazolidine spin probe, and the efficacy of low-frequency electron spin resonance (ESR)-based techniques for pH measurement in vitro and in vivo in rats. The techniques used were longitudinally-detected ESR (LODESR) and field-cycled dynamic nuclear pol...

journal_title：Magnetic resonance in medicine

authors： Foster MA,Grigor'ev IA,Lurie DJ,Khramtsov VV,McCallum S,Panagiotelis I,Hutchison JM,Koptioug A,Nicholson I

更新日期：2003-03-01 00:00:00

abstract：PURPOSE:MRI-guided thermal ablations require reliable monitoring methods to ensure complete destruction of the diseased tissue while avoiding damage to the surrounding healthy tissue. Based on the fact that thermal ablations result in substantial changes in biomechanical properties, interventional MR elastography (MRE)...

journal_title：Magnetic resonance in medicine

authors： Corbin N,Vappou J,Breton E,Boehler Q,Barbé L,Renaud P,de Mathelin M

更新日期：2016-03-01 00:00:00

abstract：PURPOSE:In contrast to conventional linear gradients, gradient coil arrays with arbitrary spatial dependency might experience strong mutual coupling. Although conventional gradient power amplifiers with feedback loop might compensate the effect of coupling, required voltages for the compensation are generally unknown a...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Atalar E

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:To measure the apparent diffusion coefficients (ADC) of five main metabolites in the human brain at 3T with PRESS and STEAM, avoiding measurement biases because of cross-terms. Cross-terms arise from interactions between slice-selection and spoiler gradients in the localized spectroscopy sequence and the diffus...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Auerbach EJ,Marjańska M

更新日期：2018-06-01 00:00:00

abstract：:An intermolecular double-quantum coherence (iDQC) imaging technique was used to study auditory activation in the human brain at 1.5T with a dual temporal lobe surface phased array coil and a quadrature head coil. Preliminary results demonstrate that it is feasible to obtain auditory activation maps using iDQC imaging ...

journal_title：Magnetic resonance in medicine

authors： Zhong J,Kwok E,Chen Z

更新日期：2001-03-01 00:00:00

abstract：PURPOSE:The purpose of the present study was to apply noninvasive methods for monitoring regeneration and mechanical properties of tissue-engineered cartilage in vivo at different growth stages using MR elastography (MRE). METHODS:Three types of scaffolds, including silk, collagen, and gelatin seeded by human mesenchy...

journal_title：Magnetic resonance in medicine

authors： Khalilzad-Sharghi V,Han Z,Xu H,Othman SF

更新日期：2016-03-01 00:00:00

abstract：PURPOSE:Imaging gradients result in the generation of concomitant fields, or Maxwell fields, which are of increasing importance at higher gradient amplitudes. These time-varying fields cause additional phase accumulation, which must be compensated for to avoid image artifacts. In the case of gradient systems employing ...

journal_title：Magnetic resonance in medicine

authors： Weavers PT,Tao S,Trzasko JD,Frigo LM,Shu Y,Frick MA,Lee SK,Foo TK,Bernstein MA

更新日期：2018-03-01 00:00:00

abstract：:Chemical shift imaging benefits from signal-to-noise ratio (SNR) and chemical shift dispersion increases at stronger main field such as 7 Tesla, but the associated shorter radiofrequency (RF) wavelengths encountered require B1+ mitigation over both the spatial field of view (FOV) and a specified spectral bandwidth. Th...

journal_title：Magnetic resonance in medicine

authors： Setsompop K,Alagappan V,Gagoski BA,Potthast A,Hebrank F,Fontius U,Schmitt F,Wald LL,Adalsteinsson E

更新日期：2009-02-01 00:00:00

abstract：PURPOSE:To directly compare in vivo versus postmortem second-order motion-compensated spin-echo diffusion tensor imaging of the porcine heart. METHODS:Second-order motion-compensated spin-echo cardiac diffusion tensor imaging was performed during systolic contraction in vivo and repeated upon cardiac arrest by bariumc...

journal_title：Magnetic resonance in medicine

authors： Stoeck CT,von Deuster C,Fleischmann T,Lipiski M,Cesarovic N,Kozerke S

更新日期：2018-04-01 00:00:00

abstract：:Since background signal from NMR probes can overwhelm the signal from a sample, the NMR analysis of plastics or machinable ceramics is a prerequisite to their use in probe implementations. The contributions from a variety of materials to proton, fluorine, and carbon NMR spectra are presented. ...

journal_title：Magnetic resonance in medicine

authors： Babcock EE,Vaughan JT,Lesan B,Nunnally RL

更新日期：1990-03-01 00:00:00

abstract：:As a high-speed imaging technique based on stimulated echoes single-shot STEAM MRI is insensitive to chemical shift artifacts and magnetic susceptibility differences. The achievable signal-to-noise ratio (SNR) is limited by the fact that high flip angles of the read-out excitation pulses cause a steep decay of the sti...

journal_title：Magnetic resonance in medicine

authors： Finsterbusch J,Frahm J

更新日期：2002-03-01 00:00:00

abstract：:Temperature estimation in proton resonance frequency (PRF) shift MR thermometry requires a reference, or pretreatment, phase image that is subtracted from image phase during thermal treatment to yield a phase difference image proportional to temperature change. Referenceless thermometry methods derive a reference phas...

journal_title：Magnetic resonance in medicine

authors： Grissom WA,Lustig M,Holbrook AB,Rieke V,Pauly JM,Butts-Pauly K

更新日期：2010-10-01 00:00:00

abstract：:Steady-state free precession (SSFP) methods have gained widespread recognition for their ability to provide fast scans at high signal-to-noise ratio. This paper demonstrates that such methods are also capable of reflecting functional information, particularly blood oxygenation state. It is well known that SSFP signals...

journal_title：Magnetic resonance in medicine

authors： Dharmakumar R,Hong J,Brittain JH,Plewes DB,Wright GA

更新日期：2005-03-01 00:00:00

abstract：:Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses hig...

journal_title：Magnetic resonance in medicine

authors： Rosen BR,Belliveau JW,Aronen HJ,Kennedy D,Buchbinder BR,Fischman A,Gruber M,Glas J,Weisskoff RM,Cohen MS

更新日期：1991-12-01 00:00:00

abstract：PURPOSE:To investigate the relative gain in sensitivity of five histology coils designed in-house to accommodate tissue sections of various sizes and compare with commercial mouse head coils. METHODS:The coil set was tailored to house tissue sections ranging from 5 to1000 µm encased in either glass slides or coverslip...

journal_title：Magnetic resonance in medicine

authors： Hoang DM,Voura EB,Zhang C,Fakri-Bouchet L,Wadghiri YZ

更新日期：2014-05-01 00:00:00

abstract：:If magnetic resonance spectroscopy (MRS) is to become a useful tool in clinical medicine, it will be necessary to find reliable methods for analyzing and classifying MRS data. Automated methods are desirable because they can remove user bias and can deal with large amounts of data, allowing the use of all the availabl...

journal_title：Magnetic resonance in medicine

authors： Tate AR,Watson D,Eglen S,Arvanitis TN,Thomas EL,Bell JD

更新日期：1996-06-01 00:00:00

abstract：:Two-dimensional T2-selective proton imaging of human head has been performed at 10 MHz employing Carr-Purcell-Gill-Meiboom pulse trains with echo separation of 6 and 12 msec. Using the information of 36 spin echoes and applying a recovery time of 2 sec the magnetization decay has been traced. The multi-exponential T2 ...

journal_title：Magnetic resonance in medicine

authors： Gersonde K,Felsberg L,Tolxdorff T,Ratzel D,Ströbel B

更新日期：1984-12-01 00:00:00

abstract：:A modified inversion-recovery sequence is introduced which performs subtraction angiography by varying time-of-flight effects of blood flowing into an imaged slab. The selective 180 degrees excitation inverts different regions between measurements to isolate arterial and/or venous blood. On normal human subjects, high...

journal_title：Magnetic resonance in medicine

authors： Nishimura DG,Macovski A,Pauly JM,Conolly SM

更新日期：1987-02-01 00:00:00

abstract：PURPOSE:Establishing a high-resolution non-ECG-gated first-pass perfusion (FPP) cardiac MRI technique may improve accessibility and diagnostic capability of FPP imaging. We propose a non-ECG-gated FPP imaging technique using continuous magnetization-driven golden-angle radial acquisition. The main purpose of this preli...

journal_title：Magnetic resonance in medicine

authors： Sharif B,Dharmakumar R,Arsanjani R,Thomson L,Bairey Merz CN,Berman DS,Li D

更新日期：2014-12-01 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:We describe a 2 × 6 channel sodium/proton array for knee MRI at 3T. Multielement coil arrays are desirable because of well-known signal-to-noise ratio advantages over volume and single-element coils. However, low tissue-coil coupling that is characteristic of coils operating at low frequency can make the potent...

journal_title：Magnetic resonance in medicine

authors： Brown R,Lakshmanan K,Madelin G,Alon L,Chang G,Sodickson DK,Regatte RR,Wiggins GC

更新日期：2016-10-01 00:00:00

abstract：PURPOSE:A new method, called Transmit and Receive Patterns from Low-Tip-angle gradient-Echo Images (TRIPLET), is described which simultaneously maps the B1+ and B1- fields of a transmit/receive radiofrequency coil array. The input data are low-tip-angle gradient-echo images, which can be acquired in a relatively short ...

journal_title：Magnetic resonance in medicine

authors： Sbrizzi A,Raaijmakers AJ,Hoogduin H,Lagendijk JJ,Luijten PR,van den Berg CA

更新日期：2014-07-01 00:00:00

abstract：:In a research environment, a magnetic resonance imaging system's manufacturer-supplied protection against excessive rf power deposition in the sample is often compromised. This paper presents a widely applicable scheme, based on a commonly available fuse, that simply and effectively limits the average rf power into a ...

journal_title：Magnetic resonance in medicine

authors： Hedges LK

更新日期：1989-02-01 00:00:00

abstract：:A lactate editing sequence based on the use of spin-locking pulses with surface coils is described. The sequence retains more than 90% of the available lactate magnetization and suppresses at least 95% of the lipid signal in a single scan and ca. 99.5% after a simple two step cycle. The technique allows simultaneous o...

journal_title：Magnetic resonance in medicine

authors： Bourgeois D,Kozlowski P

更新日期：1993-03-01 00:00:00

abstract：:AFI (actual flip angle imaging) represents an interesting approach to map the B(1) transmit fields by measuring the spatial variations of the effective flip angle. However, the accuracy of the technique relies on the adequate spoiling of transverse magnetization. In the present work configuration theory was employed t...

journal_title：Magnetic resonance in medicine

authors： Nehrke K

更新日期：2009-01-01 00:00:00

abstract：:Phase-sensitive inversion-recovery (PSIR) imaging may provide enhanced T(1) contrast. However, clinical implementation of PSIR imaging is hindered because image reconstruction with this method often lacks robustness and requires manual intervention, particularly for data acquired in multiple slices and with phased-arr...

journal_title：Magnetic resonance in medicine

authors： Ma J

更新日期：2005-04-01 00:00:00

abstract：:Passive MR tracking of catheters and guidewires is usually done by dynamically imaging a single thick slab, subtracting a baseline image, and combining the result with a previously acquired MR angiogram. In the in vitro and in vivo experiments reported here, it is demonstrated that this approach may be greatly simplif...

journal_title：Magnetic resonance in medicine

authors： Bakker CJ,Bos C,Weinmann HJ

更新日期：2001-01-01 00:00:00

abstract：:How stem cells promote myocardial repair in myocardial infarction (MI) is not well understood. The purpose of this study was to noninvasively monitor and quantify mesenchymal stem cells (MSC) from bone marrow to MI sites using magnetic resonance imaging (MRI). MSC were dual-labeled with an enhanced green fluorescent p...

journal_title：Magnetic resonance in medicine

authors： Yang Y,Schumacher A,Yang Y,Liu J,Shi X,Hill WD,Hu TC

更新日期：2011-05-01 00:00:00

abstract：:To quantify the extraction fraction, E, for gadopentetate across tumor capillaries, R3230 adenocarcinomas were implanted in the mammary fat pads of seven rats. The value of E was determined by using a two-compartment tissue model in which the endothelial transfer coefficient, K(PS) (ml x min(-1) x cc(-1) of tissue), w...

journal_title：Magnetic resonance in medicine

authors： Daldrup HE,Shames DM,Husseini W,Wendland MF,Okuhata Y,Brasch RC

更新日期：1998-10-01 00:00:00