In vitro study to simulate the intracardiac magnetohydrodynamic effect.

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:Quantitative susceptibility mapping can be performed through the minimization of a function consisting of data fidelity and regularization terms. For data consistency, a Gaussian-phase noise distribution is often assumed, which breaks down when the signal-to-noise ratio is low. A previously proposed alternative...

journal_title：Magnetic resonance in medicine

authors： Milovic C,Bilgic B,Zhao B,Acosta-Cabronero J,Tejos C

更新日期：2018-08-01 00:00:00

abstract：:High-resolution turbo spin echo (TSE) images have demonstrated important details of carotid artery morphology; however, it is evident that pulsatile blood and wall motion related to the cardiac cycle are still significant sources of image degradation. Although ECG gating can reduce artifacts due to cardiac-induced pul...

journal_title：Magnetic resonance in medicine

authors： Mendes J,Parker DL,Hulet J,Treiman GS,Kim SE

更新日期：2011-11-01 00:00:00

abstract：:Precise relaxation time (RT) measurements have been made, with a standard deviation of 3% for T1 and T2 in white matter in normal volunteers. This sets an upper limit to the instrumental random errors (imprecision). Achieving this precision requires careful adjustment and use of the imager. The wide variation in RTs s...

journal_title：Magnetic resonance in medicine

authors： Miller DH,Johnson G,Tofts PS,MacManus D,McDonald WI

更新日期：1989-09-01 00:00:00

abstract：PURPOSE:We aimed to develop a novel free-breathing cardiac diffusion tensor MRI (DT-MRI) approach, M2-MT-MOCO, capable of whole left ventricular coverage that leverages second-order motion compensation (M2) diffusion encoding and multitasking (MT) framework to efficiently correct for respiratory motion (MOCO). METHODS...

journal_title：Magnetic resonance in medicine

authors： Nguyen CT,Christodoulou AG,Coll-Font J,Ma S,Xie Y,Reese TG,Mekkaoui C,Lewis GD,Bi X,Sosnovik DE,Li D

更新日期：2020-11-30 00:00:00

abstract：:For sodium imaging of the human brain, Gibbs' ringing can degrade image appearance and confound image analysis; k-space filtering is generally required. In this work, the signal to noise ratio (SNR) advantage of sampling density weighted apodization (SDWA) over uniform k-space sampling with postacquisition filtering a...

journal_title：Magnetic resonance in medicine

authors： Stobbe R,Beaulieu C

更新日期：2008-10-01 00:00:00

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

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

更新日期：2005-10-01 00:00:00

abstract：:A simple iterative algorithm, termed deconvolution-interpolation gridding (DING), is presented to address the problem of reconstructing images from arbitrarily-sampled k-space. The new algorithm solves a sparse system of linear equations that is equivalent to a deconvolution of the k-space with a small window. The dec...

journal_title：Magnetic resonance in medicine

authors： Gabr RE,Aksit P,Bottomley PA,Youssef AB,Kadah YM

更新日期：2006-12-01 00:00:00

abstract：:Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice prof...

journal_title：Magnetic resonance in medicine

authors： Keilholz-George SD,Knight-Scott J,Berr SS

更新日期：2001-07-01 00:00:00

abstract：:A multimodal MR study including relaxometry, diffusion tensor imaging (DTI), and MR spectroscopy was performed on patients with classical phenylketonuria (PKU) and matched controls, to improve our understanding of white matter (WM) lesions. Relaxometry yields information on myelin loss or malformation and may substant...

journal_title：Magnetic resonance in medicine

authors： Vermathen P,Robert-Tissot L,Pietz J,Lutz T,Boesch C,Kreis R

更新日期：2007-12-01 00:00:00

abstract：:Continuous arterial spin labeling (CASL) was used to obtain an index of cerebral blood flow (ICBF) in the normal mouse brain and in an orthotopic mouse model of human U87 high-grade glioma at 8.5 T. Under the assumption of a constant tissue:blood partition coefficient for water in different tissues, the mean ICBF (n =...

journal_title：Magnetic resonance in medicine

authors： Sun Y,Schmidt NO,Schmidt K,Doshi S,Rubin JB,Mulkern RV,Carroll R,Ziu M,Erkmen K,Poussaint TY,Black P,Albert M,Burstein D,Kieran MW

更新日期：2004-05-01 00:00:00

abstract：:With the advent of breath-hold MR cardiac imaging techniques, the minimization of TR and TE for oblique planes has become a critical issue. The slew rates and maximum currents of gradient amplifiers limit the minimum possible TR and TE by adding dead-periods to the pulse sequences. We propose a method of designing gra...

journal_title：Magnetic resonance in medicine

authors： Atalar E,McVeigh ER

更新日期：1994-12-01 00:00:00

abstract：:Consideration of spatially variable noise fields is becoming increasingly necessary in MRI given recent innovations in artifact identification and statistically driven image processing. Fast imaging methods enable study of difficult anatomical targets and improve image quality but also increase the spatial variability...

journal_title：Magnetic resonance in medicine

authors： Landman BA,Bazin PL,Smith SA,Prince JL

更新日期：2009-08-01 00:00:00

abstract：PURPOSE:To test octafluorocyclobutane (OFCB) as an inhalation contrast agent for fluorine-19 MRI of the lung, and to compare the image quality of OFCB scans with perfluoropropane (PFP) scans THEORY AND METHODS: After normalizing for the number of signal averages, a theoretical comparison between the OFCB signal-to-nois...

journal_title：Magnetic resonance in medicine

authors： Shepelytskyi Y,Li T,Grynko V,Newman C,Hane FT,Albert MS

更新日期：2021-02-01 00:00:00

abstract：:The course of pulmonary edema formation after an intratracheal (i.t.) instillation of ovalbumin was followed noninvasively by magnetic resonance imaging (MRI) in actively sensitized Brown Norway (BN) rats. Changes in edema volume assessed by MRI mimicked the results from the analysis of the number and activation of in...

journal_title：Magnetic resonance in medicine

authors： Beckmann N,Tigani B,Ekatodramis D,Borer R,Mazzoni L,Fozard JR

更新日期：2001-01-01 00:00:00

abstract：:A robust postprocessing method to detect regions of magnetic field change is presented. High resolution gradient echo data is acquired to create a complex baseline image. From this image, two low resolution images are obtained by applying a low pass filter on the magnitude image and the complex image, respectively. Su...

journal_title：Magnetic resonance in medicine

authors： Lai S,Reichenbach JR,Haacke EM

更新日期：1996-11-01 00:00:00

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：PURPOSE:Magnetically labeled cells and tissue iron deposits provide qualitative means to detect and monitor cardiovascular and cerebrovascular diseases with magnetic resonance imaging. However, to quantitatively examine the extent of pathological micromorphological changes, detailed knowledge about microstructural para...

journal_title：Magnetic resonance in medicine

authors： Kurz FT,Kampf T,Heiland S,Bendszus M,Schlemmer HP,Ziener CH

更新日期：2014-05-01 00:00:00

abstract：:Motion-sensitive phase contrast magnetic resonance imaging and magnetic resonance elastography are applied for the measurement of volumetric strain and tissue compressibility in human brain. Volumetric strain calculated by the divergence operator using a biphasic effective-medium model is related to dilatation and com...

journal_title：Magnetic resonance in medicine

authors： Hirsch S,Klatt D,Freimann F,Scheel M,Braun J,Sack I

更新日期：2013-09-01 00:00:00

abstract：:Hyperpolarized gases ((129)Xe and (3)He) are being used increasingly in both MRI and NMR spectroscopy studies. However, it has been shown that carrier agents are required to preserve the long relaxation times of gases in biological fluids. Optimized gas transport can be achieved through controlled T(1) and T(2) measur...

journal_title：Magnetic resonance in medicine

authors： Oregioni A,Parizel N,de Sousa PL,Grucker D

更新日期：2003-06-01 00:00:00

abstract：:Magnetization transfer experiments using an off-resonance irradiation technique were performed on bovine serum albumin solutions by varying the irradiation frequency and the concentration. A transition of the magnetization transfer spectrum from Lorentzian to Gaussian line shape was observed around the critical concen...

journal_title：Magnetic resonance in medicine

authors： Iino M

更新日期：1994-10-01 00:00:00

abstract：:Experiments have been performed to demonstrate and quantify cross-relaxation between water and methylene resonances in a simple model system. Inversion recovery experiments on aqueous solutions of polyethylene glycol produce a transient nuclear Overhauser effect that alters the recovery of the methylene resonance. The...

journal_title：Magnetic resonance in medicine

authors： Gore JC,Brown MS,Armitage IM

更新日期：1989-03-01 00:00:00

abstract：:The advent of event-related functional magnetic resonance imaging (fMRI) has resulted in many exciting studies that have exploited its unique capability. However, the utility of event-related fMRI is still limited by several technical difficulties. One significant limitation in event-related fMRI is the low signal-to-...

journal_title：Magnetic resonance in medicine

authors： LaConte SM,Ngan SC,Hu X

更新日期：2000-11-01 00:00:00

abstract：PURPOSE:Acquisition of high-resolution imaging data using multiple excitations without the sensitivity to fluctuations of the transverse magnetization phase, which is a major problem of multi-shot MRI. THEORY AND METHODS:The concept of superresolution MRI based on microscopic tagging is analyzed using an analogy with ...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Tian R,Engel M,Pruessmann KP

更新日期：2018-12-01 00:00:00

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

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

abstract：PURPOSE:Correlation imaging is a previously developed high-speed MRI framework that converts parallel imaging reconstruction into the estimate of correlation functions. The presented work aims to demonstrate this framework can provide a speed gain over parallel imaging by estimating k-space variant correlation function...

journal_title：Magnetic resonance in medicine

authors： Li Y,Edalati M,Du X,Wang H,Cao JJ

更新日期：2018-03-01 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: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：PURPOSE:Diffusion-weighted imaging (DWI) and 18 F-fluorodeoxyglucose-positron emission tomography (18 F-FDG-PET) independently correlate with malignancy in breast cancer, but the relationship between their structural and metabolic metrics is not completely understood. This study spatially correlates diffusion, perfusio...

journal_title：Magnetic resonance in medicine

authors： Ostenson J,Pujara AC,Mikheev A,Moy L,Kim SG,Melsaether AN,Jhaveri K,Adams S,Faul D,Glielmi C,Geppert C,Feiweier T,Jackson K,Cho GY,Boada FE,Sigmund EE

更新日期：2017-09-01 00:00:00

abstract：:Fractional anisotropy (FA) and relative anisotropy (RA) are the two most commonly used scalar measures of anisotropy in diffusion tensor (DT) MRI. While a few published studies have shown that FA has superior noise immunity relative to RA, no theoretical basis has been proposed to explain this behavior. In the current...

journal_title：Magnetic resonance in medicine

authors： Hasan KM,Alexander AL,Narayana PA

更新日期：2004-02-01 00:00:00