Reduction of B1 sensitivity in selective single-slab 3D turbo spin echo imaging with very long echo trains.

abstract：:Phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMR) was used to assess the temporal changes of high-energy phosphate metabolites in the region of acute myocardial ischemia of open-chest cats. Eight anesthetized cats were studied following ligation of the left anterior descending coronary artery. Creatine p...

journal_title：Magnetic resonance in medicine

authors： Stein PD,Goldstein S,Sabbah HN,Liu ZQ,Helpern JA,Ewing JR,Lakier JB,Chopp M,LaPenna WF,Welch KM

更新日期：1986-04-01 00:00:00

abstract：PURPOSE:To investigate and compare several quantification methods of myocardial perfusion measurements, paying special attention to the relation between the techniques and the required measurement duration. METHODS:Seven patients underwent contrast-enhanced rest and stress cardiac perfusion measurements at 3T. Three s...

journal_title：Magnetic resonance in medicine

authors： Schwab F,Ingrisch M,Marcus R,Bamberg F,Hildebrandt K,Adrion C,Gliemi C,Nikolaou K,Reiser M,Theisen D

更新日期：2015-03-01 00:00:00

abstract：:We have developed a method for measuring the electrocardiogram (ECG) continuously during MR examinations. In contrast to ECG acquisition by wires, our new method is to amplify and convert the ECG into an optical signal directly above the patient's heart. The optical signal is transmitted out of the magnet bore by opti...

journal_title：Magnetic resonance in medicine

authors： Felblinger J,Lehmann C,Boesch C

更新日期：1994-10-01 00:00:00

abstract：:The authors addressed the hypothesis that interactions with creatine kinase (CK) play a role in the off-resonance magnetization transfer (MT) effect of creatine in skeletal muscle. Toward that aim, (1)H MT studies were done on hindleg muscle in wild-type mice and in transgenic mice, lacking cytoplasmic CK and/or mitoc...

journal_title：Magnetic resonance in medicine

authors： Kruiskamp MJ,van Vliet G,Nicolay K

更新日期：2000-05-01 00:00:00

abstract：:MRI has become an important tool to noninvasively assess global and regional cardiac function, infarct size, or myocardial blood flow in surgically or genetically modified mouse models of human heart disease. Constraints on scan time due to sensitivity to general anesthesia in hemodynamically compromised mice frequent...

journal_title：Magnetic resonance in medicine

authors： Schneider JE,Lanz T,Barnes H,Stork LA,Bohl S,Lygate CA,Ordidge RJ,Neubauer S

更新日期：2011-01-01 00:00:00

abstract：:We describe a doubly tuned radiofrequency (RF) local coil probe designed specifically for performing in vivo image-localized spectroscopy. The probe was designed using principles developed in connection with the counter-rotating-current (CRC) and planar-pair loop gap resonators for magnetic resonance imaging (MRI). Th...

journal_title：Magnetic resonance in medicine

authors： Grist TM,Jesmanowicz A,Kneeland JB,Froncisz W,Hyde JS

更新日期：1988-03-01 00:00:00

abstract：:It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...

journal_title：Magnetic resonance in medicine

authors： Williamson DS,Mulken RV,Jakab PD,Jolesz FA

更新日期：1996-04-01 00:00:00

abstract：PURPOSE:To investigate the heating induced by (pseudo)-continuous arterial spin labeling ((p)CASL) sequences in vivo at 9.4T and to evaluate the benefit of a dedicated labeling coil. METHODS:Temperature was measured continuously in the brain, neck, and rectum of 9 rats with fiber-optic temperature probes while running...

journal_title：Magnetic resonance in medicine

authors： Hirschler L,Collomb N,Voiron J,Köhler S,Barbier EL,Warnking JM

更新日期：2020-01-01 00:00:00

abstract：PURPOSE:Spiral-based trajectories for magnetic resonance imaging can be advantageous, but are often cumbersome to design or create. This work presents a flexible numerical algorithm for designing trajectories based on explicit definition of radial undersampling, and also gives several analytical expressions for charact...

journal_title：Magnetic resonance in medicine

authors： Pipe JG,Zwart NR

更新日期：2014-01-01 00:00:00

abstract：:For clinical 31P MR spectroscopic imaging (MRSI) studies, where signal averaging is necessary, some improvement of sensitivity and spatial response function may be achieved by acquiring data over a spherical k-space volume and varying the number of averages acquired in proportion to the desired spatial filter. Eight d...

journal_title：Magnetic resonance in medicine

authors： Hugg JW,Maudsley AA,Weiner MW,Matson GB

更新日期：1996-09-01 00:00:00

abstract：PURPOSE:The purpose of this project was to construct a physical brain phantom for MRI, mimicking structure and T1 relaxation properties of white matter (WM) and gray matter (GM). METHODS:The phantom design comprised 2 compartments, 1 resembling the WM and 1 resembling the GM. Their T1 relaxation times, as assessed usi...

journal_title：Magnetic resonance in medicine

authors： Altermatt A,Santini F,Deligianni X,Magon S,Sprenger T,Kappos L,Cattin P,Wuerfel J,Gaetano L

更新日期：2019-02-01 00:00:00

abstract：:In the present work, diffusion-weighted (DW)-NMR spectroscopy of glutamate was performed during a (13)C-labeled glucose infusion in monkey brain (six experiments). It is shown that glutamate (13)C labeling occurs significantly faster at higher diffusion weightings-slightly for glutamate in position C4, and more marked...

journal_title：Magnetic resonance in medicine

authors： Valette J,Chaumeil M,Guillermier M,Bloch G,Hantraye P,Lebon V

更新日期：2008-08-01 00:00:00

abstract：:MR images acquired by using an arterial spin-labeling technique showed spatial and temporal variations of perfusion in the skeletal muscle of exercising humans. Perfusion measurements made during plantar flexion exercise in normal volunteers were consistent with those obtained by traditional techniques reported in the...

journal_title：Magnetic resonance in medicine

authors： Frank LR,Wong EC,Haseler LJ,Buxton RB

更新日期：1999-08-01 00:00:00

abstract：:The suppression of water signals in in vivo proton spectra by means of multiple-quantum filtering can be brought about in several ways. This communication exposes the shortcomings of using purely subtractive filtering techniques to observe signals from metabolites that contain proton couplings of the form AX3. ...

journal_title：Magnetic resonance in medicine

authors： Nosel W,Trimble LA,Shen JF,Allen PS

更新日期：1989-09-01 00:00:00

abstract：PURPOSE:Amide-proton transfer (APT) and amine-water proton exchange (APEX) MRI can be viable to map pH-decreasing ischemic regions. However, their exact contributions are unclear. METHODS:We measured APEX- and APT-weighted magnetization transfer ratio asymmetry (denoted as APEXw and APTw), apparent diffusion coefficie...

journal_title：Magnetic resonance in medicine

authors： Zong X,Wang P,Kim SG,Jin T

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:To develop a method to use information from multiple MRI contrasts to produce a composite angiogram with reduced sequence-specific artifacts and improved vessel depiction. METHODS:Bayesian posterior vessel probability was determined as a function of black blood (BB), contrast enhanced angiography (CE-MRA), and...

journal_title：Magnetic resonance in medicine

authors： Kim D,Edjlali M,Turski P,Johnson KM

更新日期：2020-03-01 00:00:00

abstract：PURPOSE:Applications of dynamic shimming require high field fidelity, and characterizing the shim field dynamics is therefore necessary. Modeling the system as linear and time-invariant, the purpose of this work was to measure the impulse response function with optimal sensitivity. THEORY AND METHODS:Frequency-swept p...

journal_title：Magnetic resonance in medicine

authors： Vannesjo SJ,Dietrich BE,Pavan M,Brunner DO,Wilm BJ,Barmet C,Pruessmann KP

更新日期：2014-08-01 00:00:00

abstract：:The feasibility of reconstructing three-dimensional (3D) MRI data sets from limited-view projections is investigated in phantom and in vivo animal studies to improve the temporal resolution of magnetic resonance angiography without sacrificing spatial resolution. Thirty-two pairs of orthogonal biplane projections are ...

journal_title：Magnetic resonance in medicine

authors： Huang Y,Gurr D,Wright GA

更新日期：2006-01-01 00:00:00

abstract：PURPOSE:To improve ultrahigh field diffusion-weighted imaging (DWI) in the presence of inhomogeneous transmit B1 field by designing a novel semi-adiabatic single-refocused DWI technique. METHODS:A 180° slice-selective, adiabatic radiofrequency (RF) pulse of 4 ms duration was designed using the adiabatic Shinnar-Le Rou...

journal_title：Magnetic resonance in medicine

authors： Dyvorne H,O'Halloran R,Balchandani P

更新日期：2016-05-01 00:00:00

abstract：PURPOSE:Magnetic resonance (MR) cholangiopancreatography (MRCP) is an established specialist method for imaging the upper abdomen and biliary/pancreatic ducts. Due to limitations of either MR image contrast or low through-plane resolution, patients may require further evaluation with contrast-enhanced computed tomograp...

journal_title：Magnetic resonance in medicine

authors： Ebner M,Patel PA,Atkinson D,Caselton L,Firmin L,Amin Z,Bainbridge A,De Coppi P,Taylor SA,Ourselin S,Chouhan MD,Vercauteren T

更新日期：2019-11-01 00:00:00

abstract：:It has been suggested that orientational changes in the collagen network of articular cartilage account for the depthwise T2 anisotropy of MRI through the magic angle effect. To investigate the relationship between laminar T2 appearance and collagen organization (anisotropy), bovine osteochondral plugs (N = 9) were T2...

journal_title：Magnetic resonance in medicine

authors： Nieminen MT,Rieppo J,Töyräs J,Hakumäki JM,Silvennoinen J,Hyttinen MM,Helminen HJ,Jurvelin JS

更新日期：2001-09-01 00:00:00

abstract：PURPOSE:To study the feasibility of black-blood contrast in native T1 mapping for reduction of partial voluming at the blood-myocardium interface. METHODS:A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) b...

journal_title：Magnetic resonance in medicine

authors： Weingärtner S,Meßner NM,Zöllner FG,Akçakaya M,Schad LR

更新日期：2017-08-01 00:00:00

abstract：:Noninvasive molecular imaging of angiogenesis could play a critical role in the clinical management of peripheral vascular disease patients. The alpha(nu)beta(3)-integrin, a well-established biomarker of neovascular proliferation, is an ideal target for molecular imaging of angiogenesis. This study investigates whethe...

journal_title：Magnetic resonance in medicine

authors： Winter PM,Caruthers SD,Allen JS,Cai K,Williams TA,Lanza GM,Wickline SA

更新日期：2010-08-01 00:00:00

abstract：PURPOSE:To assess the risk of radiofrequency (RF)-induced heating in patients with MR-conditional pacemaker (PM) systems, in the presence of another lead abandoned from a previous implant. METHODS:Four commercial pacemaker leads were placed beside a MR-conditional PM system, inside a human trunk simulator. The phantom...

journal_title：Magnetic resonance in medicine

authors： Mattei E,Gentili G,Censi F,Triventi M,Calcagnini G

更新日期：2015-01-01 00:00:00

abstract：:Standard MRI cine exams for the study of cardiac function are segmented over several heartbeats and thus require a breath-hold to minimize breathing motion artifacts, which is a current limitation of this approach. The purpose of this study was to develop a method for the measurement and correction of respiratory moti...

journal_title：Magnetic resonance in medicine

authors： Leung AO,Paterson I,Thompson RB

更新日期：2008-09-01 00:00:00

abstract：:Image contrast with gradient-recalled echo sequences (GRE) used for fMRI can have both blood oxygen level-dependent (BOLD) and inflow components, and the latter is often undesirable. A dual-echo technique can be used to differentiate these mechanisms, because modulation of signal from inflow is common to both echoes, ...

journal_title：Magnetic resonance in medicine

authors： Glover GH,Lemieux SK,Drangova M,Pauly JM

更新日期：1996-03-01 00:00:00

abstract：:Phase-contrast (PC) MRI is a noninvasive method for imaging blood and tissue velocity. PC experiments are typically segmented into many cardiac cycles in order to obtain sufficient spatial and temporal resolution, and thus require a gating signal to properly combine the data from multiple cardiac cycles. Although the ...

journal_title：Magnetic resonance in medicine

authors： Thompson RB,McVeigh ER

更新日期：2004-09-01 00:00:00

abstract：PURPOSE:To evaluate the use of variable flip angle refocusing pulse trains in single-shot three-dimensional gradient and spin-echo (3D-GRASE) to reduce blurring and increase the spatial coverage for high spatial resolution T2 -weighted functional MRI at 7 Tesla. METHODS:Variable flip angle refocusing schemes in 3D-GRA...

journal_title：Magnetic resonance in medicine

authors： Kemper VG,De Martino F,Yacoub E,Goebel R

更新日期：2016-09-01 00:00:00

abstract：:To investigate the dependency of T(1) relaxation on mechanical strain in articular cartilage, quantitative magnetic resonance T(1) imaging experiments were carried out on cartilage before/after the tissue was immersed in gadolinium contrast agent and when the tissue was being compressed (up to ∼ 48% strains). The spat...

journal_title：Magnetic resonance in medicine

authors： Xia Y,Wang N,Lee J,Badar F

更新日期：2011-06-01 00:00:00

abstract：:A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equatio...

journal_title：Magnetic resonance in medicine

authors： Olsson MB,Wirestam R,Persson BR

更新日期：1995-10-01 00:00:00