Quantification of the pulse wave velocity of the descending aorta using axial velocity profiles from phase-contrast magnetic resonance imaging.

abstract：:Specific absorption rate management and excitation fidelity are key aspects of radiofrequency pulse design for parallel transmission at ultra-high magnetic field strength. The design of radiofrequency pulses for multiple channels is often based on the solution of regularized least-squares optimization problems for whi...

journal_title：Magnetic resonance in medicine

authors： Deniz CM,Alon L,Brown R,Sodickson DK,Zhu Y

更新日期：2012-01-01 00:00:00

abstract：PURPOSE:To obviate online slice-by-slice RF shim optimization and reduce B1+ mapping requirements for patient-specific RF shimming in high-field magnetic resonance imaging. THEORY AND METHODS:RF Shim Prediction by Iteratively Projected Ridge Regression (PIPRR) predicts patient-specific, SAR-efficient RF shims with a m...

journal_title：Magnetic resonance in medicine

authors： Ianni JD,Cao Z,Grissom WA

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:To develop an analytically based algorithm for rapid optimization of the local radiofrequency magnetic (B1+) field intensity for a given radiofrequency power through a transmit array. The analytical nature of the method will yield insight to optimization requirements and provides a valuable reference for numeri...

journal_title：Magnetic resonance in medicine

authors： Carluccio G,Collins CM,Erricolo D

更新日期：2014-01-01 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：:A multifocal mouse liver tumor model chemically induced with 5,9-dimethyl-7H-dibenzo[c,g]carbazole was investigated by respiratory-triggered morphological and functional MRI (fMRI) at 4.7 Tesla. The model is characterized by the presence of two tumor types: hypovascular cholangioma and vascularized hepatocellular carc...

journal_title：Magnetic resonance in medicine

authors： Thomas CD,Chenu E,Walczak C,Plessis MJ,Perin F,Volk A

更新日期：2003-09-01 00:00:00

abstract：:We report the synthesis and characterization of polyvinyl alcohol (PVA) embolic particles modified with a clinically approved magnetic resonance (MR) contrast agent. PVA particles are used during transcatheter arterial embolization (TAE) procedures and this minimally invasive technique is a widely employed treatment f...

journal_title：Magnetic resonance in medicine

authors： Cilliers R,Song Y,Kohlmeir EK,Larson AC,Omary RA,Meade TJ

更新日期：2008-04-01 00:00:00

abstract：:The mechanics of the macrocirculation are examined as a basis for imaging blood flow within the system. The macrocirculation is defined as that part of the circulation in which inertial forces are not negligible compared to viscous forces and as such in human subjects comprises the heart and large blood vessels. Becau...

journal_title：Magnetic resonance in medicine

authors： Caro CG,Parker KH

更新日期：1990-05-01 00:00:00

abstract：:When developing new techniques for NMR imaging and in vivo spectroscopy it is a major advantage to be able to calculate the magnetization slice profiles, at any point during a pulse sequence in the presence of a field gradient. While this has frequently been done by treating the problem as a number of discrete resonan...

journal_title：Magnetic resonance in medicine

authors： Bulsing JM,Galloway GJ,Brereton IM,Doddrell DM

更新日期：1987-11-01 00:00:00

abstract：PURPOSE:A ghost correction strategy for Simultaneous Multi-Slice (SMS) EPI methods that provides improved ghosting artifact reduction compared to conventional methods is presented. Conventional Nyquist ghost correction methods for SMS-EPI rely on navigator data that contain phase errors from all slices in the simultane...

journal_title：Magnetic resonance in medicine

authors： Hoge WS,Setsompop K,Polimeni JR

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:To measure the T1 and T2 relaxation times of water, metabolites, and macromolecules in the rat brain in vivo at 17.2T and achieve absolute quantification of the neurochemical profile. Relaxation times were compared with values from the literature found at lower magnetic fields. METHODS:(1) H NMR spectra were m...

journal_title：Magnetic resonance in medicine

authors： Lopez-Kolkovsky AL,Mériaux S,Boumezbeur F

更新日期：2016-02-01 00:00:00

abstract：:Surgical specimens from 22 patients with infiltrating ductal carcinoma of the breast were analyzed by high-resolution 1H NMR spectroscopy at 80 and 300 MHz. Results were compared with those obtained from 9 benign (proliferative dysplasia without atypia) breast samples. NMR spectra at 80 MHz showed well-resolved water ...

journal_title：Magnetic resonance in medicine

authors： Bradamante S,Barchiesi E,Pilotti S,Borasi G

更新日期：1988-12-01 00:00:00

abstract：:The objective of this study is to evaluate the effect of MR image resolution on trabecular bone parameters and to determine the acceptable resolution that can be accurately analyzed to assess structural parameters. Ten distal femoral condyle specimens of 1 × 1 × 1 cm(3) were scanned with a 4.7-T Bruker BioSpec MRI sca...

journal_title：Magnetic resonance in medicine

authors： Kim N,Lee JG,Song Y,Kim HJ,S Yeom J,Cho G

更新日期：2012-01-01 00:00:00

abstract：:Metabolite signals with short T(1) or T(2) are difficult to localize with full sensitivity. This limitation was overcome with the development and implementation of a single-shot, complete three-dimensional "non-echo" localization method with reduced sensitivity to spatial B(1) variation, which is suitable for measurin...

journal_title：Magnetic resonance in medicine

authors： Choi IY,Tkác I,Gruetter R

更新日期：2000-09-01 00:00:00

abstract：:Partially parallel imaging strategies such as SMASH, SENSE, and PILS rely on the sensitivity distribution of phased array RF coils to reduce MRI imaging time. Using an N-element phased array, these techniques allow maximum accelerations, L, such that L < or = N, with acceleration defined as the factor by which scan ti...

journal_title：Magnetic resonance in medicine

authors： Bankson JA,Wright SM

更新日期：2002-04-01 00:00:00

abstract：:An effective shield for the dc fringing fields produced by a large-bore, high field magnet intended for imaging and in vivo spectroscopy is presented. While limiting the extent of fringe fields, the shield has little effect on the homogeneity of the central field of the magnet. The effect of institutional safety polic...

journal_title：Magnetic resonance in medicine

authors： Ewing JR,Timms W,Williams JE,Welch KM

更新日期：1985-10-01 00:00:00

abstract：PURPOSE:This study aims to identify work-related and personal factors associated with workers' exposure to static magnetic fields (SMF) and motion-induced time-varying magnetic fields (TVMF) from MRI scanners. METHODS:Measurements of personal exposure to SMF and TVMF were performed among MRI staff during 439 work shif...

journal_title：Magnetic resonance in medicine

authors： Schaap K,Christopher-De Vries Y,Cambron-Goulet É,Kromhout H

更新日期：2016-05-01 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：:Nuclear Overhauser effect (NOE) enhancements and relaxation times of 31P metabolites in human calf were measured in 12 volunteers (4 men and 8 women) at 1.5 T using a dual tuned four-ring birdcage. The NOE enhancements of inorganic phosphate (Pi), phosphocreatine (PCr), gamma-, alpha-, and beta-nucleoside triphosphate...

journal_title：Magnetic resonance in medicine

authors： Brown TR,Stoyanova R,Greenberg T,Srinivasan R,Murphy-Boesch J

更新日期：1995-03-01 00:00:00

abstract：:To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were...

journal_title：Magnetic resonance in medicine

authors： Rose SE,Hatzigeorgiou X,Strudwick MW,Durbridge G,Davies PS,Colditz PB

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:Correlation imaging is a previously developed high-speed MRI framework that converts parallel imaging reconstruction into the estimate of correlation functions. The presented work aims to demonstrate this framework can provide a speed gain over parallel imaging by estimating k-space variant correlation function...

journal_title：Magnetic resonance in medicine

authors： Li Y,Edalati M,Du X,Wang H,Cao JJ

更新日期：2018-03-01 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：:Perfusion-based event-related functional MRI was performed by measuring flow-sensitive alternating inversion recovery (FAIR) signal changes during repeated single-trial, short visual stimulation (250 msec). In the visual cortex activation area, the blood flow increases immediately after the stimulus, reaches the maxim...

journal_title：Magnetic resonance in medicine

authors： Liu HL,Gao JH

更新日期：1999-12-01 00:00:00

abstract：PURPOSE:Single-scan two-dimensional MRI has been generally constrained to acquisitions in high quality magnets. This study introduces a methodology, cross-term spatiotemporal encoding (xSPEN), that delivers such images under much poorer external field conditions. METHODS:xSPEN departs from conventional k-space scannin...

journal_title：Magnetic resonance in medicine

authors： Zhang Z,Seginer A,Frydman L

更新日期：2017-02-01 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：: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：:At TE values of 136 ms, it has recently been shown that the lactate methyl signal, when obtained with a stimulated-echo (STE) sequence, is modulated at the zero-quantum (ZQ) frequency when TM is varied. Here we describe an additional modulation of the ZQ lactate signal, due to spin-spin coupling, that results in a 10-...

journal_title：Magnetic resonance in medicine

authors： Sotak CH,Alger JR

更新日期：1991-02-01 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

abstract：PURPOSE:Treatments using high-intensity focused ultrasound (HIFU) in the abdominal region remain challenging as a result of respiratory organ motion. A novel method is described here to achieve 3D motion-compensated ultrasound (US) MR-guided HIFU therapy using simultaneous ultrasound and MRI. METHODS:A truly hybrid US...

journal_title：Magnetic resonance in medicine

authors： Celicanin Z,Manasseh G,Petrusca L,Scheffler K,Auboiroux V,Crowe LA,Hyacinthe JN,Natsuaki Y,Santini F,Becker CD,Terraz S,Bieri O,Salomir R

更新日期：2018-05-01 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:Over the last two decades, extended criteria have promoted an increased number of donor livers available for liver transplantation. But posttransplant graft loss is still a major concern. Macrovesicular hepatic steatosis (MHS) is recognized as the most significant prognostic histologic parameter in predicting p...

journal_title：Magnetic resonance in medicine

authors： Chen G,Jiang J,Wang X,Yang M,Xie Y,Guo H,Tang H,Zhou L,Hu D,Kamel IR,Chen Z,Li Z

更新日期：2020-11-16 00:00:00