Pharmacological MRI of the choroid and retina: blood flow and BOLD responses during nitroprusside infusion.

abstract：:Phased-array coils distribute the high signal-to-noise ratio (SNR) performance of their small component surface coils over the larger area covered by the entire array. The inhomogeneous sensitivity profiles of the component surface coils result in images with very high signal near the phased-array and decreased signal...

journal_title：Magnetic resonance in medicine

authors： Murakami JW,Hayes CE,Weinberger E

更新日期：1996-04-01 00:00:00

abstract：PURPOSE:To design, evaluate, and apply a bow tie antenna transceiver radiofrequency (RF) coil array tailored for cardiac MRI at 7.0 Tesla (T). METHODS:The radiofrequency (RF) coil array comprises 16 building blocks each containing a bow tie shaped λ/2-dipole antenna. Numerical simulations were used for transmission fi...

journal_title：Magnetic resonance in medicine

authors： Oezerdem C,Winter L,Graessl A,Paul K,Els A,Weinberger O,Rieger J,Kuehne A,Dieringer M,Hezel F,Voit D,Frahm J,Niendorf T

更新日期：2016-06-01 00:00:00

abstract：:A transrectal probe for 1H imaging and 31P MR spectroscopy of the prostate gland is described. The probe is covered with plastic and consists of an insectional portion containing an rf coil and a handle containing a tuning and matching circuit. Using this transrectal probe, 1H MR images and the first 31P MR spectra of...

journal_title：Magnetic resonance in medicine

authors： Narayan P,Vigneron DB,Jajodia P,Anderson CM,Hedgcock MW,Tanagho EA,James TL

更新日期：1989-08-01 00:00:00

abstract：PURPOSE:Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. METHODS:Mice were inoculated orthotopically with human U87-EGFRvIII gliom...

journal_title：Magnetic resonance in medicine

authors： Xu X,Chan KW,Knutsson L,Artemov D,Xu J,Liu G,Kato Y,Lal B,Laterra J,McMahon MT,van Zijl PC

更新日期：2015-12-01 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：:We present new diffusion phantoms dedicated to the study and validation of high-angular-resolution diffusion imaging (HARDI) models. The phantom design permits the application of imaging parameters that are typically employed in studies of the human brain. The phantoms were made of small-diameter acrylic fibers, chose...

journal_title：Magnetic resonance in medicine

authors： Poupon C,Rieul B,Kezele I,Perrin M,Poupon F,Mangin JF

更新日期：2008-12-01 00:00:00

abstract：:Homogeneous soft tissue, as regards its magnetic relaxation properties, is well-modeled by solutions of cross-linked protein (see Koenig and Brown, Prog. NMR Spectr. 22, 487 (1991)). Interactions at the solute-solvent interface alter the hydrodynamics of solvent water, and also couple the solute and solvent proton Zee...

journal_title：Magnetic resonance in medicine

authors： Koenig SH,Brown RD 3rd

更新日期：1993-12-01 00:00:00

abstract：:Manganese-enhanced MRI has previously been used for visualization of brain architecture and functional mapping of neural pathways. The present work investigated the potential of manganese-enhanced MRI for noninvasive imaging of salivary glands in living subjects. Marked shortening of T(1) was observed in salivary glan...

journal_title：Magnetic resonance in medicine

authors： Seshadri M,Hoy A

更新日期：2010-09-01 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 magnetic resonance imaging (MRI) method is presented to detect, localize, and quantify myocardial kinematics by measuring the material rate-of-strain tensor at each pixel in gated NMR images of the heart. The immediate, local effect of muscular activity is self-deformation, and the strain tensor is the basic mathema...

journal_title：Magnetic resonance in medicine

authors： Wedeen VJ

更新日期：1992-09-01 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：:The preovulatory rat follicle reaches a diameter of 1 mm with no internal blood vessels. Nutrient supply to the enclosed oocyte depends solely on passive diffusion across the follicular wall and the follicular fluid. Spin-echo and stimulated-echo NMR microscopy experiments were applied here for studying modulations in...

journal_title：Magnetic resonance in medicine

authors： Tempel C,Schiffenbauer YS,Meir G,Neeman M

更新日期：1995-08-01 00:00:00

abstract：:The long readout times of single-shot acquisitions and the high field strengths desired for functional MRI (fMRI) using blood oxygenation level-dependent (BOLD) contrast make functional scans sensitive to magnetic field inhomogeneity. If it is not corrected during image reconstruction, field inhomogeneity can cause ge...

journal_title：Magnetic resonance in medicine

authors： Sutton BP,Noll DC,Fessler JA

更新日期：2004-06-01 00:00:00

abstract：:Formalin fixation of tissue is a common laboratory practice. A direct comparison of diffusion tensor imaging (DTI) parameters from mouse brains before (in vivo) and after (ex vivo) formalin fixation is reported herein. Five diffusion indices were examined in a cohort of seven mice: relative anisotropy (RA), directiona...

journal_title：Magnetic resonance in medicine

authors： Sun SW,Neil JJ,Song SK

更新日期：2003-10-01 00:00:00

abstract：PURPOSE:Spectrally selective "prewinding" radiofrequency pulses can counteract B0 inhomogeneity in steady-state sequences, but can only prephase a limited range of off-resonance. We propose spectral-spatial small-tip angle prewinding pulses that increase the off-resonance bandwidth that can be successfully prephased by...

journal_title：Magnetic resonance in medicine

authors： Williams SN,Nielsen JF,Fessler JA,Noll DC

更新日期：2018-03-01 00:00:00

abstract：:Problems with in vivo proton spectroscopy include strong water and lipid signals, and the very complicated structures of the spectra. Multiple-quantum experiments can be designed to overcome these difficulties. Using a volume selective refocusing technique, one can demonstrate how multiple-quantum experiments can be p...

journal_title：Magnetic resonance in medicine

authors： McKinnon GC,Bosiger P

更新日期：1988-03-01 00:00:00

abstract：PURPOSE:Intracranial and intraspinal compliance are parameters of interest in the diagnosis and prediction of treatment outcome in patients with normal pressure hydrocephalus and other forms of communicating hydrocephalus. A noninvasive method to estimate the spinal cerebrospinal fluid (CSF) pulse wave velocity (PWV) a...

journal_title：Magnetic resonance in medicine

authors： Sonnabend K,Brinker G,Maintz D,Bunck AC,Weiss K

更新日期：2021-01-01 00:00:00

abstract：:Localized 1H NMR homonuclear J editing spectroscopy was used to measure the concentration of 2-pyrrolidinone (PRDN) in the human occipital lobe of five normal and six epileptic subjects taking vigabatrin. PRDN is a lactam cyclization product of gamma-aminobutyric acid (GABA). From a localized volume of 13.5 cm3 in the...

journal_title：Magnetic resonance in medicine

authors： Hyder F,Petroff OA,Mattson RH,Rothman DL

更新日期：1999-05-01 00:00:00

abstract：:Prospective motion correction methods using an optical system, diffusion-weighted prospective acquisition correction, or a free induction decay navigator have recently been applied to correct for motion in diffusion tensor imaging. These methods have some limitations and drawbacks. This article describes a novel techn...

journal_title：Magnetic resonance in medicine

authors： Alhamud A,Tisdall MD,Hess AT,Hasan KM,Meintjes EM,van der Kouwe AJ

更新日期：2012-10-01 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：PURPOSE:Sickle cell anemia is a blood disorder that alters the morphology and the oxygen affinity of the red blood cells. Cerebral oxygen extraction fraction measurements using quantitative BOLD contrast have been used for assessing inadequate oxygen delivery and the subsequent risk of ischemic stroke in sickle cell an...

journal_title：Magnetic resonance in medicine

authors： Eldeniz C,Binkley MM,Fields M,Guilliams K,Ragan DK,Chen Y,Lee JM,Ford AL,An H

更新日期：2021-01-21 00:00:00

abstract：PURPOSE:To analyze the effect of B0 field drift on multivoxel MR spectroscopic imaging and to propose an approach for its correction. THEORY AND METHODS:It is shown, both theoretically and in a phantom, that for ∼30 min acquisitions a linear B0 drift (∼0.1 ppm/h) will cause localization errors that can reach several v...

journal_title：Magnetic resonance in medicine

authors： Tal A,Gonen O

更新日期：2013-10-01 00:00:00

abstract：:Function and morphology of the cerebral vasculature were studied in the amyloid (Abeta) plaque-containing double-transgenic (TG) B6.PS2APP Alzheimer's disease (AD) mouse model with MRI at an age range of 10 to 17 months. Perfusion, blood volume, and average vessel geometry were assessed in the brain and compared to ag...

journal_title：Magnetic resonance in medicine

authors： Weidensteiner C,Metzger F,Bruns A,Bohrmann B,Kuennecke B,von Kienlin M

更新日期：2009-07-01 00:00:00

abstract：:Fucose is believed to be a marker for cancer that may be detectable by the 2D proton NMR (COSY) of human plasma. However, the COSY technique is time consuming and prone to error. These problems may be alleviated by using the SUPERCOSY pulse sequence; this technique shows that there are many other cross peaks in the re...

journal_title：Magnetic resonance in medicine

authors： Phillips PS,Herring FG

更新日期：1990-07-01 00:00:00

abstract：:The complexity of biologic tissues, with multiple compartments each with its own diffusion and relaxation properties, requires complex formalisms to model water signal in most magnetic resonance imaging or magnetic resonance spectroscopy experiments. In this article, we describe a magnetic susceptibility-induced shift...

journal_title：Magnetic resonance in medicine

authors： Galons JP,Lope-Piedrafita S,Divijak JL,Corum C,Gillies RJ,Trouard TP

更新日期：2005-07-01 00:00:00

abstract：:Spinal cord (SC) motion is thought to be the dominant source of error in current diffusion and spinal functional MRI (fMRI) methods. However, until now, such motion has not been well characterized in three dimensions. While previous studies have predominantly examined motion in the superior/inferior (S/I) direction, t...

journal_title：Magnetic resonance in medicine

authors： Figley CR,Stroman PW

更新日期：2007-07-01 00:00:00

abstract：:Proteoglycan (PG) depletion-induced changes in T1rho (spin-lattice relaxation in rotating frame) relaxation and dispersion in articular cartilage were studied at 4T. Using a spin-lock cluster pre-encoded fast spin echo sequence, T1rho maps of healthy bovine specimens and specimens that were subjected to PG depletion w...

journal_title：Magnetic resonance in medicine

authors： Akella SV,Regatte RR,Gougoutas AJ,Borthakur A,Shapiro EM,Kneeland JB,Leigh JS,Reddy R

更新日期：2001-09-01 00:00:00

abstract：:To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/...

journal_title：Magnetic resonance in medicine

authors： van der Toorn A,Syková E,Dijkhuizen RM,Vorísek I,Vargová L,Skobisová E,van Lookeren Campagne M,Reese T,Nicolay K

更新日期：1996-07-01 00:00:00

abstract：PURPOSE:The purpose of this work was to develop a rapid and robust whole-body fat-water MRI (FWMRI) method using a continuously moving table (CMT) with dynamic field corrections at 3 Tesla. METHODS:CMT FWMRI was developed at 3 Tesla with a multiecho golden angle (GA) radial trajectory and dynamic B0 field shimming. Wh...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Smith DS,Gifford A,Welch EB

更新日期：2016-07-01 00:00:00

abstract：:MRI of myocardial perfusion observed with an extracellular contrast agent has proven valuable for the detection of coronary artery disease. During contrast enhancement transient dark rim artifacts are sometimes visible, complicating diagnosis and quantification. In this work a quantification of the frequency offsets c...

journal_title：Magnetic resonance in medicine

authors： Ferreira P,Gatehouse P,Bucciarelli-Ducci C,Wage R,Firmin D

更新日期：2008-10-01 00:00:00