Differential effect of isoflurane, medetomidine, and urethane on BOLD responses to acute levo-tetrahydropalmatine in the rat.

abstract：:Minimally invasive cardiac surgery requires arresting and emptying of the heart, which compromises visualization of the surgical field. In this feasibility study a novel surgical procedure is demonstrated in which real-time MRI is used to guide the placement of a prosthetic aortic valve in the beating heart via direct...

journal_title：Magnetic resonance in medicine

authors： McVeigh ER,Guttman MA,Lederman RJ,Li M,Kocaturk O,Hunt T,Kozlov S,Horvath KA

更新日期：2006-11-01 00:00:00

abstract：:In vivo MR spectroscopy (MRS) studies have shown reductions in NAA/Cr levels in patients with severe neurocognitive deficits due to AIDS dementia complex (ADC), also known as neuroAIDS. The relationship between the cellular changes within the brain during neuroAIDS and the role of NAA/Cr as a metabolic marker remains ...

journal_title：Magnetic resonance in medicine

authors： Lentz MR,Westmoreland SV,Lee V,Ratai EM,Halpern EF,González RG

更新日期：2008-03-01 00:00:00

abstract：:A number of techniques that recently have been used for fast NMR-imaging are based on a hybrid sequence of echo planar imaging (EPI) and FLASH imaging: after each NMR excitation several k-space lines are measured. The complete k-space is covered by performance of several excitations. It has been observed that there is...

journal_title：Magnetic resonance in medicine

authors： Deichmann R,Adolf H,Nöth U,Kuchenbrod E,Schwarzbauer C,Haase A

更新日期：1995-09-01 00:00:00

abstract：:The vascular space occupancy (VASO) method was recently proposed as a functional MRI (fMRI) method that is capable of detecting activation-related changes in blood volume (CBV), without the need for a blood-pool contrast agent. In the present work we introduce a new whole-brain VASO technique that is based on a parall...

journal_title：Magnetic resonance in medicine

authors： Poser BA,Norris DG

更新日期：2009-07-01 00:00:00

abstract：:A novel center-out 3D trajectory for sampling magnetic resonance data is presented. The trajectory set is based on a single Fermat spiral waveform, which is substantially undersampled in the center of k-space. Multiple trajectories are combined in a "stacked cone" configuration to give very uniform sampling throughout...

journal_title：Magnetic resonance in medicine

authors： Pipe JG,Zwart NR,Aboussouan EA,Robison RK,Devaraj A,Johnson KO

更新日期：2011-11-01 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：:Due to the presence of gross magnetic susceptibility artifacts, functional MRI (fMRI) has proved problematic in studies of the human inferior frontal cortex (IFC). There is a strong desire, therefore, to employ techniques that mitigate susceptibility artifacts in the IFC while preserving the imaging parameters of an f...

journal_title：Magnetic resonance in medicine

authors： Wilson JL,Jezzard P

更新日期：2003-11-01 00:00:00

abstract：:Dynamic imaging strategies often involve updating certain areas of k-space (i.e., the low spatial frequencies) more frequently than others. However, important dynamic signal changes may occur anywhere in k-space. In this study, a dynamic k-space sampling analysis method was developed to determine the energy error asso...

journal_title：Magnetic resonance in medicine

authors： Wu Y,Alexander AL

更新日期：2001-04-01 00:00:00

abstract：:The chemical shift of water and fat resonances in proton MRI allows separation of water and fat signal from chemical shift encoded data. This work describes an automatic method that produces separate water and fat images as well as quantitative maps of fat signal fraction and T2* from complex multiecho gradient-recall...

journal_title：Magnetic resonance in medicine

authors： Berglund J,Kullberg J

更新日期：2012-06-01 00:00:00

abstract：:The intra-individual and inter-individual variations of the global N-acetylaspartate (NAA) concentration were measured in a cohort of five 42+/-5 year-old normal females. The total NAA signal from the whole head was obtained with non-localized non-echo proton spectroscopy (1H-MRS) and converted into absolute mole amou...

journal_title：Magnetic resonance in medicine

authors： Gonen O,Viswanathan AK,Catalaa I,Babb J,Udupa J,Grossman RI

更新日期：1998-11-01 00:00:00

abstract：PURPOSE:To determine the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols used for dynamic contrast-enhanced MRI at 1.5 and 3 T. METHODS:A T1 phantom with 14 samples was imaged at eight centers with a common inversion-recovery spin-echo (IR-SE) protocol and...

journal_title：Magnetic resonance in medicine

authors： Bane O,Hectors SJ,Wagner M,Arlinghaus LL,Aryal MP,Cao Y,Chenevert TL,Fennessy F,Huang W,Hylton NM,Kalpathy-Cramer J,Keenan KE,Malyarenko DI,Mulkern RV,Newitt DC,Russek SE,Stupic KF,Tudorica A,Wilmes LJ,Yankeelov TE

更新日期：2018-05-01 00:00:00

abstract：:Radial MRI sequences are frequently used to obtain images with reduced sensitivity to motion. To decrease imaging time, multiple spin-echo acquisitions can be incorporated into radial sequences. In this case, different radial lines of Fourier data have different TE times and the resulting images can contain streaking ...

journal_title：Magnetic resonance in medicine

authors： Theilmann RJ,Gmitro AF,Altbach MI,Trouard TP

更新日期：2004-04-01 00:00:00

abstract：PURPOSE:To develop and validate closed form mathematical expressions that predict the optimal contrast agent concentration for the maximum T1-weighted spoiled gradient echo (SGRE) signal. THEORY AND METHODS:Gadolinium and iron-based contrast agents can have significant transverse relaxivity that leads to signal dropou...

journal_title：Magnetic resonance in medicine

authors： Reeder SB,Smith MR,Hernando D

更新日期：2016-04-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 00:00:00

abstract：:High permittivity "dielectric pads" have been shown to increase image quality at high magnetic fields in regions of low radiofrequency transmit efficiency. This article presents a series of electromagnetic simulations to determine the effects of pad size and geometry, relative permittivity value, as well as thickness ...

journal_title：Magnetic resonance in medicine

authors： Teeuwisse WM,Brink WM,Haines KN,Webb AG

更新日期：2012-04-01 00:00:00

abstract：PURPOSE:The goal of this study was to conduct an exposure assessment for workers moving through the stray stationary field of common MRI scanners, performed according to the recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, which aim at avoiding annoying sensory effects. THEORY ...

journal_title：Magnetic resonance in medicine

authors： Zilberti L,Bottauscio O,Chiampi M

更新日期：2016-10-01 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：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：:Choline-containing compounds (CCCs) are elevated in breast cancer, and detected in vivo by the (1)H MRS total choline (tCho) resonance (3.25 ppm) and the (31)P MRS phosphomonoester (PME) resonance (3.8 ppm). Both the tCho and PME resonances decrease early after initiation of successful therapy. The single major compon...

journal_title：Magnetic resonance in medicine

authors： Morse DL,Raghunand N,Sadarangani P,Murthi S,Job C,Day S,Howison C,Gillies RJ

更新日期：2007-08-01 00:00:00

abstract：PURPOSE:To obtain three-dimensional (3D) MR angiography having high contrast between vessel and stationary background tissue, a novel technique called sliding time of flight (TOF) is proposed. METHODS:The proposed method relies on the property that flow-related enhancement (FRE) is maximized at the blood-entering slic...

journal_title：Magnetic resonance in medicine

authors： Choi J,Seo H,Lim Y,Han Y,Park H

更新日期：2015-03-01 00:00:00

abstract：:Proton-observed carbon-edited (POCE) NMR spectroscopy is commonly used to measure 13C labeling with higher sensitivity compared to direct 13C NMR spectroscopy, at the expense of spectral resolution. For weakly coupled first-order spin systems, the multiplet signal at a specific proton chemical shift in POCE spectra di...

journal_title：Magnetic resonance in medicine

authors： Henry PG,Marjanska M,Walls JD,Valette J,Gruetter R,Ugurbil K

更新日期：2006-02-01 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：:This study examines the effect of feature extraction methods prior to automated pattern recognition based on magnetic resonance spectroscopy (MRS) for brain tumor diagnosis. Since individual inspection of spectra is time-consuming and requires specific spectroscopic expertise, the introduction of clinical decision sup...

journal_title：Magnetic resonance in medicine

authors： Luts J,Poullet JB,Garcia-Gomez JM,Heerschap A,Robles M,Suykens JA,Van Huffel S

更新日期：2008-08-01 00:00:00

abstract：:A stereotaxic restraining assembly was designed and developed for simultaneous electrophysiological recordings and functional MRI (fMRI) data acquisition from a conscious rat. The design of the nonmagnetic stereotaxic apparatus facilitated the restraining of head and body of the unanesthetized conscious animal during ...

journal_title：Magnetic resonance in medicine

authors： Khubchandani M,Mallick HN,Jagannathan NR,Mohan Kumar V

更新日期：2003-05-01 00:00:00

abstract：:The purpose of the present study was to examine whether single human carcinoma cells labeled with iron oxide nanoparticles could be detected by magnetic resonance (MR) imaging on a clinical 3-T scanner using a surface coil only. WiDr human colon carcinoma cells were loaded with two kinds of iron oxide nanoparticles di...

journal_title：Magnetic resonance in medicine

authors： Pinkernelle J,Teichgräber U,Neumann F,Lehmkuhl L,Ricke J,Scholz R,Jordan A,Bruhn H

更新日期：2005-05-01 00:00:00

abstract：:A new approach to spin-echo imaging is presented in which the 180 degrees RF pulse refocuses two or more spin-echoes at different positions in the readout period. When simultaneous echo refocusing (SER) is implemented using multiple 180 degrees pulses, an undesirable mixing of stimulated echoes and primary echoes from...

journal_title：Magnetic resonance in medicine

authors： Günther M,Feinberg DA

更新日期：2005-09-01 00:00:00

abstract：:Ferumoxytol is an ultrasmall superparamagnetic iron oxide agent marketed for the treatment of anemia. There has been increasing interest in its properties as an MRI contrast agent as well as greater awareness of its adverse event profile. This mini-review summarizes the current state of knowledge of the risks of ferum...

journal_title：Magnetic resonance in medicine

authors： Vasanawala SS,Nguyen KL,Hope MD,Bridges MD,Hope TA,Reeder SB,Bashir MR

更新日期：2016-05-01 00:00:00

abstract：:A 3D sequence for dynamic susceptibility imaging is proposed which combines echo-shifting principles (such as PRESTO), sensitivity encoding (SENSE), and partial-Fourier acquisition. The method uses a moderate SENSE factor of 2 and takes advantage of an alternating partial k-space acquisition in the "slow" phase encode...

journal_title：Magnetic resonance in medicine

authors： Klarhöfer M,Dilharreguy B,van Gelderen P,Moonen CT

更新日期：2003-10-01 00:00:00

abstract：:With standard spectroscopic imaging, high spatial resolution is achieved at the price of a large number of phase-encoding steps, leading to long acquisition times. Fast spatial encoding methods reduce the minimum total acquisition time. In this article, a k-space scanning scheme using a continuous series of growing an...

journal_title：Magnetic resonance in medicine

authors： Hiba B,Faure B,Lamalle L,Décorps M,Ziegler A

更新日期：2003-12-01 00:00:00

abstract：:Leakage of Gd-DTPA through a defective blood-brain barrier is measured quantitatively using dynamic MRI scanning, in which repeated scans are made after a bolus injection. Image registration artifacts are minimized; a dose of 0.1 mM/kg and an IR sequence enable enhancement to be measured quantitatively. The triexponen...

journal_title：Magnetic resonance in medicine

authors： Tofts PS,Kermode AG

更新日期：1991-02-01 00:00:00