The effect of reducing repetition time TR on the measurement of liver R2 for the purpose of measuring liver iron concentration.

abstract：PURPOSE:Dipole antennas in ultrahigh field MRI have demonstrated advantages over more conventional designs. In this study, the fractionated dipole antenna is presented: a dipole where the legs are split into segments that are interconnected by capacitors or inductors. METHODS:A parameter study has been performed on di...

journal_title：Magnetic resonance in medicine

authors： Raaijmakers AJ,Italiaander M,Voogt IJ,Luijten PR,Hoogduin JM,Klomp DW,van den Berg CA

更新日期：2016-03-01 00:00:00

abstract：PURPOSE:Conventional 31 P chemical shift imaging is time-consuming and yields only limited spatial resolution. The purpose of this study was to demonstrate feasibility of 31 P echo-planar spectroscopic imaging (EPSI) in vivo at 7T. METHODS:A 3D 31 P EPSI sequence with trapezoidal-shaped gradient pulses was implemented...

journal_title：Magnetic resonance in medicine

authors： Korzowski A,Bachert P

更新日期：2018-03-01 00:00:00

abstract：:Noise in the composite magnitude signal from multiple-coil systems is usually assumed to follow a noncentral χ distribution when sum of squares is used to combine images sensed at different coils. However, this is true only if the variance of noise is the same for all coils, and no correlation exists between them. We ...

journal_title：Magnetic resonance in medicine

authors： Aja-Fernández S,Tristán-Vega A

更新日期：2012-02-01 00:00:00

abstract：:In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit mo...

journal_title：Magnetic resonance in medicine

authors： Nakai T,Rhine WD,Okada T,Stevenson DK,Spielman DM

更新日期：1998-10-01 00:00:00

abstract：:Partial-volume effects (PVE) in stroke imaging could hinder proper delineation of normal, ischemic, and at-risk tissues. Cerebral-blood-flow (CBF) and apparent diffusion coefficient (ADC) were measured at high and low resolution (HR = 128 x 128, LR = 64 x 64) in focal ischemia in rats during the acute phase. The data ...

journal_title：Magnetic resonance in medicine

authors： Ren H,Shen Q,Bardutzky J,Fisher M,Duong TQ

更新日期：2004-12-01 00:00:00

abstract：:In spin echo imaging, magnetization is assigned to a location defined by its frequency of rotation. In the presence of a static magnetic field inhomogeneity, however, this location does not correspond to the true location of the magnetization. This paper describes a magnetic resonance imaging technique called phase co...

journal_title：Magnetic resonance in medicine

authors： Kim JK,Plewes DB,Henkelman RM

更新日期：1995-04-01 00:00:00

abstract：:This study investigated the use of peritoneal dialysis fluid (dialyzate) as a MR contrast agent to visualize the liver structure and peritoneal adhesion in rats at 7 T. Intraperitoneal injection of dialyzate (approximately 0.1 ml/g) yielded excellent and consistent intraperitoneal enhancement that delineated the liver...

journal_title：Magnetic resonance in medicine

authors： Cheung JS,Guo H,Leung JC,Man K,Lai KN,Wu EX

更新日期：2008-05-01 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：:Recently, a technique based on arterial spin labeling, called dynamic arterial spin labeling (DASL (Magn Reson Med 1999;41:299-308)), has been introduced to measure simultaneously the transit time of the labeled blood from the labeling plane to the exchange site, the longitudinal relaxation time of the tissue, and the...

journal_title：Magnetic resonance in medicine

authors： Barbier EL,Silva AC,Kim SG,Koretsky AP

更新日期：2001-06-01 00:00:00

abstract：PURPOSE:Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase ...

journal_title：Magnetic resonance in medicine

authors： Cui SX,Epstein FH

更新日期：2018-04-01 00:00:00

abstract：PURPOSE:To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS:Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI ...

journal_title：Magnetic resonance in medicine

authors： Cho GY,Moy L,Zhang JL,Baete S,Lattanzi R,Moccaldi M,Babb JS,Kim S,Sodickson DK,Sigmund EE

更新日期：2015-10-01 00:00:00

abstract：:A new decoupling sequence, PBAR, is described for broadband heteronuclear decoupling in vivo in humans at 1.5T. The sequence uses non-adiabatic, frequency- and amplitude-modulated inversion pulses designed to minimize decoupling sidebands at low applied gammaB(2) RF field levels and to cover only the narrow range of r...

journal_title：Magnetic resonance in medicine

authors： Barker PB,Golay X,Artemov D,Ouwerkerk R,Smith MA,Shaka AJ

更新日期：2001-02-01 00:00:00

abstract：PURPOSE:The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. THEORY AND METHODS:A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of ...

journal_title：Magnetic resonance in medicine

authors： Romu T,Dahlström N,Leinhard OD,Borga M

更新日期：2017-09-01 00:00:00

abstract：:An optimized multislice data acquisition scheme for phase acquisition of composite echoes (PACE) imaging is presented. This new scheme uses a repetition time equal to the mixing time and an appropriate phase cycling scheme, which allows for more efficient exploitation of all composite echoes. These modifications provi...

journal_title：Magnetic resonance in medicine

authors： Ropele S,Stollberger R,Kapeller P,Hartung HP,Fazekas F

更新日期：1999-12-01 00:00:00

abstract：:This work aimed to investigate the effects of administering Gd-DTPA on the BOLD effect, and to determine the feasibility of using this approach to measure fractional changes in blood volume and blood oxygenation on neuronal activation during a visual paradigm. A linear relationship between cortical R(2)(*) and the int...

journal_title：Magnetic resonance in medicine

authors： Pears JA,Francis ST,Butterworth SE,Bowtell RW,Gowland PA

更新日期：2003-01-01 00:00:00

abstract：:In vivo 1H MRS can be used to detect and quantify the lactate resonance at 1.3 ppm provided that overlapping lipid resonances are eliminated. A homonuclear spectral editing method was developed to acquire uncontaminated 1H spectra of lactate with adiabatic pulses. An advantage of the adiabatic pulse sequence is the ab...

journal_title：Magnetic resonance in medicine

authors： Schupp DG,Merkle H,Ellermann JM,Ke Y,Garwood M

更新日期：1993-07-01 00:00:00

abstract：:We have noninvasively produced low-resolution, quantitative nuclear magnetic resonance images of cerebral blood flow in 2-ml voxels in eight cats. Typical signal-to-noise of 4 to 1 was obtained in cerebral voxels in 16.5-s epochs. Mean flow during normocapnia (paCO2 = 39 +/- 4 mm Hg) and hypercapnia (paCO2 = 62 +/- 4 ...

journal_title：Magnetic resonance in medicine

authors： Branch CA,Ewing JR,Helpern JA,Ordidge RJ,Butt S,Welch KM

更新日期：1992-11-01 00:00:00

abstract：:Breathing motion is one of the main sources of artifacts in MRI acquisitions that can severely impair diagnosis. In MRI with continuously moving table, the application of common motion compensation approaches such as breath holding or the synchronization of the measurement with the breathing motion can be problematic....

journal_title：Magnetic resonance in medicine

authors： Honal M,Leupold J,Huff S,Baumann T,Ludwig U

更新日期：2010-03-01 00:00:00

abstract：:Radiofrequency (RF) -spoiled gradient echo sequences were developed with the aim to produce images with T(1) weighted contrast within short acquisition time. Over the past two decades, this type of sequence has proven to be a robust technique and represents a reliable workhorse in clinical MRI. This study presents an ...

journal_title：Magnetic resonance in medicine

authors： Leupold J,Hennig J,Scheffler K

更新日期：2008-07-01 00:00:00

abstract：:MRI using hyperpolarized (13) C-labeled pyruvate is a promising tool to biochemically profile tumors and monitor their response to therapy. This technique requires injection of pyruvate into tumor-bearing animals. Pyruvate is an endogenous entity but the influence of exogenously injected bolus doses of pyruvate on tum...

journal_title：Magnetic resonance in medicine

authors： Saito K,Matsumoto S,Devasahayam N,Subramanian S,Munasinghe JP,Morris HD,Lizak MJ,Ardenkjaer-Larsen JH,Mitchell JB,Krishna MC

更新日期：2012-03-01 00:00:00

abstract：:This work presents a method applied to the design of short self-shielded gradient coils of cylindrical geometry. The method uses a hybrid technique that combines the simulated annealing and target field methods to optimize the standard stream functions. The optimized stream functions were parameterized using a few deg...

journal_title：Magnetic resonance in medicine

authors： Tomasi D

更新日期：2001-03-01 00:00:00

abstract：:In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic 13C NMR techniques in the presence and absence of dichl...

journal_title：Magnetic resonance in medicine

authors： Rath DP,Zhu H,Tong X,Jiang Z,Hamlin RL,Robitaille PM

更新日期：1997-12-01 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

abstract：PURPOSE:Diffusion-weighted magnetic resonance imaging suffers from physiological noise, such as artifacts caused by motion or system instabilities. Therefore, there is a need for robust diffusion parameter estimation techniques. In the past, several techniques have been proposed, including RESTORE and iRESTORE (Chang e...

journal_title：Magnetic resonance in medicine

authors： Collier Q,Veraart J,Jeurissen B,den Dekker AJ,Sijbers J

更新日期：2015-06-01 00:00:00

abstract：:Calculations and experiments that provide support for our previously stated theorem are presented: If two coils simultaneously receiving magnetic resonance signals from the same anatomic region exhibit zero mutual inductance, there can be no correlation of the noise. It is shown that correlation does not exist even in...

journal_title：Magnetic resonance in medicine

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

更新日期：1991-07-01 00:00:00

abstract：:NMR relaxation times (T1 and T2) and the water content (WC) of in vitro rat lungs were measured during the course of endotoxin lung injury in rats. Measurements of normal lungs, untreated endotoxin-injured lungs, and endotoxin-injured lungs treated with methylprednisolone (MPSL) were compared. The untreated endotoxin ...

journal_title：Magnetic resonance in medicine

authors： Shioya S,Haida M,Tsuji C,Ono Y,Miyairi A,Fukuzaki M,Ohta Y,Yamabayashi H

更新日期：1990-08-01 00:00:00

abstract：PURPOSE:Respiratory organ motion is still the major challenge of various image-guided treatments in the abdomen. Dynamic organ motion tracking, necessary for the treatment control, can be performed with volumetric time-resolved MRI that sequentially acquires one image and one navigator slice. Here, a novel imaging meth...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Bieri O,Preiswerk F,Cattin P,Scheffler K,Santini F

更新日期：2015-02-01 00:00:00

abstract：PURPOSE:To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. METHODS:3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisit...

journal_title：Magnetic resonance in medicine

authors： Roccia E,Vidya Shankar R,Neji R,Cruz G,Munoz C,Botnar R,Goh V,Prieto C,Dregely I

更新日期：2019-03-01 00:00:00

abstract：:Diffusion-weighted single voxel experiments conducted at b-values up to 1 x 10(4) smm-2 yielded biexponential signal attenuation curves for both normal and ischemic brain. The relative fractions of the rapidly and slowly decaying components (f1, f2) are f1 = 0.80 +/- 0.02, f2 = 0.17 +/- 0.02 in healthy adult rat brain...

journal_title：Magnetic resonance in medicine

authors： Niendorf T,Dijkhuizen RM,Norris DG,van Lookeren Campagne M,Nicolay K

更新日期：1996-12-01 00:00:00

abstract：:We used high-field (13)C NMR (18.8 T) to assign unambiguously the isotopic shifts induced by the deuterium substitutions of the H3(proR) and H3(proS) hydrogens of (2-(13)C) glutamate in extracts of the brain from deuterated animals. Monodeuterated H3R or H3S glutamate diastereoisomers were produced stereospecifically ...

journal_title：Magnetic resonance in medicine

authors： Rodrigues TB,Violante IR,Cerdán S

更新日期：2010-04-01 00:00:00