Parallel MRI reconstruction using variance partitioning regularization.

abstract：:A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV-MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume fo...

journal_title：Magnetic resonance in medicine

authors： Pisani L,Bammer R,Glover G

更新日期：2007-02-01 00:00:00

abstract：PURPOSE:Our clinical understanding of the relationship between 3D bone morphology and knee osteoarthritis, as well as our ability to investigate potential causative factors of osteoarthritis, has been hampered by the time-intensive nature of manually segmenting bone from MR images. Thus, we aim to develop and validate ...

journal_title：Magnetic resonance in medicine

authors： Cheng R,Alexandridi NA,Smith RM,Shen A,Gandler W,McCreedy E,McAuliffe MJ,Sheehan FT

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Magnetic resonance imaging of humans at high magnetic field strengths is strongly influenced by the interference of the radiofrequency (RF) electromagnetic field and the body. To minimize this effect, multiple RF sources could be used. A novel setup (called multimode, coaxial waveguide) is proposed that facilit...

journal_title：Magnetic resonance in medicine

authors： Andreychenko A,Kroeze H,Boer VO,Lagendijk JJ,Luijten PR,van den Berg CA

更新日期：2014-04-01 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：:Magnetic field homogeneity is of major concern for in vivo spectroscopy, and with the increased use of volumetric chemical shift imaging (CSI) techniques, the ability to shim over a large volume of tissue is now one of the primary limiting constraints in performing these studies. In vivo shimming is routinely performe...

journal_title：Magnetic resonance in medicine

authors： Spielman DM,Adalsteinsson E,Lim KO

更新日期：1998-09-01 00:00:00

abstract：:Alternate methods to quantify mitochondrial activity or function have been extensively used for studying insulin resistance and type 2 diabetes mellitus, namely saturation transfer and phosphocreatine (PCr) recovery. As these methods are in fact determining different parameters, this study aimed to compare saturation ...

journal_title：Magnetic resonance in medicine

authors： Schmid AI,Schrauwen-Hinderling VB,Andreas M,Wolzt M,Moser E,Roden M

更新日期：2012-04-01 00:00:00

abstract：:Nitroprusside, a vasodilatory nitric oxide donor, is clinically used during vascular surgery and to lower blood pressure in acute hypertension. This article reports a novel application of blood flow (BF) and blood oxygenation level dependent (BOLD) MRI on an 11.7T scanner to image the rat chorioretinal BF and BOLD cha...

journal_title：Magnetic resonance in medicine

authors： Shih YY,Li G,Muir ER,De La Garza BH,Kiel JW,Duong TQ

更新日期：2012-10-01 00:00:00

abstract：PURPOSE:Multiple nonlinear gradient fields offer many potential benefits for spatial encoding including reduced acquisition time, fewer artefacts and region-specific imaging, although designing a suitable trajectory for such a setup is difficult. This work aims to optimize encoding trajectories for multiple nonlinear g...

journal_title：Magnetic resonance in medicine

authors： Layton KJ,Kroboth S,Jia F,Littin S,Yu H,Zaitsev M

更新日期：2016-07-01 00:00:00

abstract：PURPOSE:In typical MRI protocols, time is spent acquiring a field map to calculate the shim settings for best image quality. We propose a fast template-based field map prediction method that yields near-optimal shims without measuring the field. METHODS:The template-based prediction method uses prior knowledge of the ...

journal_title：Magnetic resonance in medicine

authors： Shi Y,Vannesjo SJ,Miller KL,Clare S

更新日期：2018-07-01 00:00:00

abstract：:The role of relative cerebral blood volume (rCBV) in the early response of blood oxygenation level-dependent (BOLD) signal following sensory stimulation was assessed. Magnetic resonance imaging (MRI) measurements of rCBV and BOLD signal as a function of time (t) were compared with relative cerebral blood flow (rCBF) o...

journal_title：Magnetic resonance in medicine

authors： Marota JJ,Ayata C,Moskowitz MA,Weisskoff RM,Rosen BR,Mandeville JB

更新日期：1999-02-01 00:00:00

abstract：PURPOSE:To establish a cardiac signal from scattering matrix or scattering coefficient measurements made on a 7T 8-channel parallel transmit (pTx) system, and to evaluate its use for cardiac gating. METHODS:Measurements of the scattering matrix and scattering coefficients were acquired using a monitoring pulse sequenc...

journal_title：Magnetic resonance in medicine

authors： Jaeschke SHF,Robson MD,Hess AT

更新日期：2018-08-01 00:00:00

abstract：PURPOSE:Delta relaxation enhanced magnetic resonance (dreMR) imaging requires an auxiliary B0 electromagnet capable of shifting the main magnetic field within a clinical 1.5 Tesla (T) MR system. In this work, the main causes of interaction between an actively shielded, insertable resistive B0 electromagnet and a 1.5T s...

journal_title：Magnetic resonance in medicine

authors： Harris CT,Handler WB,Araya Y,Martínez-Santiesteban F,Alford JK,Dalrymple B,Van Sas F,Chronik BA,Scholl TJ

更新日期：2014-10-01 00:00:00

abstract：PURPOSE:MR fingerprinting (MRF) is a technique for quantitative tissue mapping using pseudorandom measurements. To estimate tissue properties such as T1 , T2 , proton density, and B0 , the rapidly acquired data are compared against a large dictionary of Bloch simulations. This matching process can be a very computation...

journal_title：Magnetic resonance in medicine

authors： Cauley SF,Setsompop K,Ma D,Jiang Y,Ye H,Adalsteinsson E,Griswold MA,Wald LL

更新日期：2015-08-01 00:00:00

abstract：:Quantification of peak velocity is important in the assessment of stenotic flow jets in patients with congenital heart disease. Phase-contrast magnetic resonance underestimates peak velocities. Hence, clinically Doppler ultrasound is used as the reference standard for assessing stenoses. It is possible to accurately m...

journal_title：Magnetic resonance in medicine

authors： Steeden JA,Jones A,Pandya B,Atkinson D,Taylor AM,Muthurangu V

更新日期：2012-06-01 00:00:00

abstract：:A new contrast preparation based on modified driven equilibrium Fourier transfer is introduced and evaluated for generation of T1-weighted images for assessment of the myocardial perfusion with contrast agent first-pass kinetics. The new preparation scheme produces T1 contrast with insensitivity to arrhythmias in pros...

journal_title：Magnetic resonance in medicine

authors： Tsekos NV,Zhang Y,Merkle H,Wilke N,Jerosch-Herold M,Stillman A,Uğurbil K

更新日期：1995-10-01 00:00:00

abstract：PURPOSE:In diffusion MRI, the actual b-value played out on the scanner may deviate from the nominal value due to magnetic field imperfections. A simple image-based correction method for this problem is presented. METHODS:The apparent diffusion constant (ADC) of a water phantom was measured voxel-wise along 64 diffusio...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Kettinger AO,Wilm BJ,Deichmann R,Weiskopf N,Lambert C,Pruessmann KP,Nagy Z

更新日期：2020-06-01 00:00:00

abstract：:Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arteri...

journal_title：Magnetic resonance in medicine

authors： Newbould RD,Skare ST,Jochimsen TH,Alley MT,Moseley ME,Albers GW,Bammer R

更新日期：2007-07-01 00:00:00

abstract：:Intra-plaque hemorrhage (IPH) and lipid core, characteristics of rupture prone carotid plaques, are often visualized in vivo with MRI using T1 weighted gradient and spin echo, respectively. Increasing magnetic field strength may help to identify IPH and lipid core better. As a proof of concept, automatic segmentation ...

journal_title：Magnetic resonance in medicine

authors： te Boekhorst BC,van 't Klooster R,Bovens SM,van de Kolk KW,Cramer MJ,van Oosterhout MF,Doevendans PA,van der Geest RJ,Pasterkamp G,van Echteld CJ

更新日期：2012-06-01 00:00:00

abstract：:A novel method, called relaxo-oximetry, for rapid spatially resolved in vivo measurements of oxygen concentration using time-domain radiofrequency (RF) electron paramagnetic resonance (EPR) is described. Time-domain data from triaryl methyl (TAM)-based single-electron contrast agents were processed by systematic delet...

journal_title：Magnetic resonance in medicine

authors： Subramanian S,Yamada K,Irie A,Murugesan R,Cook JA,Devasahayam N,Van Dam GM,Mitchell JB,Krishna MC

更新日期：2002-05-01 00:00:00

abstract：PURPOSE:To present a time-efficient technique for banding reduction in balanced steady-state free precession (bSSFP) imaging using phase-cycled simultaneous multislice (SMS) acquisition with CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration). THEORY:The proposed technique exploits the ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Shao X,Martin T,Moeller S,Yacoub E,Wang DJ

更新日期：2016-12-01 00:00:00

abstract：:In in vivo phosphorus magnetic resonance spectroscopy (MRS), spectroscopic imaging (SI) can be used as a flexible localization technique, producing spectra from multiple volumes in a single examination. Presented here are phosphorus SI studies of human organs in which a selective-volume SI reconstruction was used rath...

journal_title：Magnetic resonance in medicine

authors： Twieg DB,Meyerhoff DJ,Hubesch B,Roth K,Sappey-Marinier D,Boska MD,Gober JR,Schaefer S,Weiner MW

更新日期：1989-12-01 00:00:00

abstract：PURPOSE:Cross-term spatiotemporal encoding (xSPEN) is a single-shot approach with exceptional immunity to field heterogeneities, the images of which faithfully deliver 2D spatial distributions without requiring a priori information or using postacquisition corrections. xSPEN, however, suffers from signal-to-noise ratio...

journal_title：Magnetic resonance in medicine

authors： Zhang Z,Frydman L

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:Fourier decomposition (FD) is a noninvasive method for assessing ventilation and perfusion-related information in the lungs. However, the technique has a low signal-to-noise ratio (SNR) in the lung parenchyma. We present an approach to increase the SNR in both morphological and functional images. METHODS:The d...

journal_title：Magnetic resonance in medicine

authors： Corteville DM,Kjïrstad Å,Henzler T,Zöllner FG,Schad LR

更新日期：2015-05-01 00:00:00

abstract：:This report describes a noninvasive 1H-NMR method for measuring absolute temperatures (+/- 0.2 degrees C) in biological samples and, in particular, in cell culture perfusion systems, utilizing the linear temperature dependence of the water chemical shift relative to the temperature-independent shift of one of the comp...

journal_title：Magnetic resonance in medicine

authors： Lutz NW,Kuesel AC,Hull WE

更新日期：1993-01-01 00:00:00

abstract：PURPOSE:Cross-relaxation imaging (CRI) is a family of quantitative magnetization transfer techniques that utilize images obtained with off-resonance saturation and longitudinal relaxation rate (R1) maps reconstructed by the variable flip angle (VFA) method. It was demonstrated recently that a significant bias in an app...

journal_title：Magnetic resonance in medicine

authors： Mossahebi P,Yarnykh VL,Samsonov A

更新日期：2014-02-01 00:00:00

abstract：:Magnetic resonance (MR) diffusion imaging is a useful technique with which to increase our understanding of pathologic damage to the central nervous system. To fully quantitate diffusion and anisotropy in the spinal cord, as in other tissues, it is necessary to determine the diffusion tensor. If spinal cord diffusion ...

journal_title：Magnetic resonance in medicine

authors： Clark CA,Werring DJ,Miller DH

更新日期：2000-01-01 00:00:00

abstract：PURPOSE:To improve signal-to-noise ratio (SNR) for high-resolution spectroscopic imaging using a subspace-based technique known as SPectroscopic Imaging by exploiting spatiospectral CorrElation (SPICE). METHODS:The proposed method is based on a union-of-subspaces model of MRSI signals, which exploits the partial separ...

journal_title：Magnetic resonance in medicine

authors： Ma C,Lam F,Ning Q,Johnson CL,Liang ZP

更新日期：2017-02-01 00:00:00

abstract：:Radiofrequency induced pacemaker lead tip heating is one of the main reasons magnetic resonance imaging (MRI) is contraindicated for patients with pacemakers. The objective of this work was to evaluate the dependence of pacemaker lead tip heating during MRI scanning on the electrical conductivity of the medium surroun...

journal_title：Magnetic resonance in medicine

authors： Langman DA,Goldberg IB,Judy J,Paul Finn J,Ennis DB

更新日期：2012-08-01 00:00:00

abstract：:We studied the fluxes of a potassium congener (Rb(+)) in mouse hearts by (87)Rb MRS at 8.4T. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). We initiated Rb(+) efflux by changing the perfusion medium to Rb(+)-free buffer. Spectra were acquire...

journal_title：Magnetic resonance in medicine

authors： Jilkina O,Xiang B,Kuzio B,Rendell J,Kupriyanov VV

更新日期：2005-05-01 00:00:00

abstract：PURPOSE:MR elastography (MRE) of the brain is being explored as a biomarker of neurodegenerative disease such as dementia. However, MRE measures for healthy brain have varied widely. Differing wave delivery methodologies may have influenced this, hence finite element-based simulations were performed to explore this pos...

journal_title：Magnetic resonance in medicine

authors： McGrath DM,Ravikumar N,Beltrachini L,Wilkinson ID,Frangi AF,Taylor ZA

更新日期：2017-07-01 00:00:00