Predicting RF field penetration in heterogeneous bodies using a 3-D finite element approach: preliminary results.

abstract：:The authors describe a method for accurate in vivo multislice imaging of the active component of the B1 field which is based on a previously proposed method, which uses the signal intensity ratio of two images measured with different excitation angles, and a repetition time TR 5 > or = 5 T1. The new method essentially...

journal_title：Magnetic resonance in medicine

authors： Stollberger R,Wach P

更新日期：1996-02-01 00:00:00

abstract：:Cell death by apoptosis is critical in myocardial diseases, and noninvasive detection of early, reversible apoptosis might be useful clinically. Exogenous Annexin-V (ANX) protein binds membrane phosphatidylserine, which is externalized in early apoptosis. A molecular MRI probe was constructed with superparamagnetic ir...

journal_title：Magnetic resonance in medicine

authors： Dash R,Chung J,Chan T,Yamada M,Barral J,Nishimura D,Yang PC,Simpson PC

更新日期：2011-10-01 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：:In order to obtain proton magnetic resonance spectra from the normal human kidney in vivo, we employed a STEAM sequence with delay times TE = 10 ms and TM = 30 ms. Signals are attenuated during STEAM sequences by J-coupling effects and by macroscopic movement of the sample. The combination of short echo times and resp...

journal_title：Magnetic resonance in medicine

authors： Dixon RM,Frahm J

更新日期：1994-05-01 00:00:00

abstract：:A new fully automatic algorithm for the segmentation of the brain and total intracranial cerebrospinal fluid (CSF) from T(1)-weighted volume MRI scans of the head, called Exbrain v.2, is described. The algorithm was developed in the context of serial intracranial volumetry. A brain mask obtained using a previous versi...

journal_title：Magnetic resonance in medicine

authors： Lemieux L,Hammers A,Mackinnon T,Liu RS

更新日期：2003-05-01 00:00:00

abstract：PURPOSE:To determine the feasibility of employing the prior knowledge of well-separated chemical exchange saturation transfer (CEST) signals in the 9.4 T Z-spectrum to separate overlapping CEST signals acquired at 3 T, using a deep learning approach trained with 3 T and 9.4 T CEST spectral data from brains of the same ...

journal_title：Magnetic resonance in medicine

authors： Zaiss M,Deshmane A,Schuppert M,Herz K,Glang F,Ehses P,Lindig T,Bender B,Ernemann U,Scheffler K

更新日期：2019-06-01 00:00:00

abstract：:A new volume selection/spectral editing pulse sequence (VOSING) is presented. The features specific to the technique are that the volume selection and the editing intervals coincide and that no decoupling is necessary. The pulse sequence can be applied under both homo- and heteronuclear conditions. Phantom experiments...

journal_title：Magnetic resonance in medicine

authors： Knüttel A,Rommel E,Clausen M,Kimmich R

更新日期：1988-09-01 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：:Velocity-encoded phase contrast imaging is being used increasingly in clinical imaging for quantization of blood flow. In this study, the accuracy and precision of ascending aorta flow measurements were found to depend on several subtle aspects of the scan prescription and image analysis. While the usual scan paramete...

journal_title：Magnetic resonance in medicine

authors： Buonocore MH,Bogren H

更新日期：1992-07-01 00:00:00

abstract：:Quantification of cerebral blood flow using QUIPSSII pulsed arterial spin labeling requires that the QUIPSS saturation delay TI1 is shorter than the natural temporal bolus width. Yet the duration of the bolus of tagged spins entering the region of interest varies during vasoactive stimuli such as gaseous challenges or...

journal_title：Magnetic resonance in medicine

authors： Villien M,Chipon E,Troprès I,Bouvier J,Cantin S,Chechin D,Le Bas JF,Krainik A,Warnking JM

更新日期：2013-06-01 00:00:00

abstract：:A common type of motion present in clinical magnetic resonance imaging examinations is rotational motion, such as that due to voluntary motion during head examinations. The correction scheme presented in this work offers a method for eliminating the effects of rotations within the imaging plane. Integral to the implem...

journal_title：Magnetic resonance in medicine

authors： Korin HW,Felmlee JP,Riederer SJ,Ehman RL

更新日期：1995-05-01 00:00:00

abstract：PURPOSE:We demonstrate the feasibility of MRI with missing-pulse steady-state free precession (MP-SSFP) in a 4T magnet with artificially degraded homogeneity. METHODS:T1 , T2 , and diffusion contrast of MP-SSFP was simulated with constant and alternate radiofrequency (RF) phase using an extended phase graph. To valida...

journal_title：Magnetic resonance in medicine

authors： Kobayashi N,Parkinson B,Idiyatullin D,Adriany G,Theilenberg S,Juchem C,Garwood M

更新日期：2021-02-01 00:00:00

abstract：:Time-dependent changes of T1 in the rotating frame (T1rho), diffusion, T2, and magnetization transfer contrast on cardiac arrest-induced global ischemia in rat were investigated. T1rho, as acquired with spin lock amplitudes >0.6 G, started to increase 10-20 sec after cardiac arrest followed by an increase within 3-4 m...

journal_title：Magnetic resonance in medicine

authors： Kettunen MI,Gröhn OH,Penttonen M,Kauppinen RA

更新日期：2001-09-01 00:00:00

abstract：:ECG-gated cardiac MRI in the mouse is hindered by many technical difficulties in ECG signal recording inside static and variable high magnetic scanner fields. The present study proposes an alternative robust method of acquiring auto-gated cardiac and respiratory cine images in mouse heart. In our approach, a motion sy...

journal_title：Magnetic resonance in medicine

authors： Hiba B,Richard N,Janier M,Croisille P

更新日期：2006-03-01 00:00:00

abstract：:Magnetization transfer imaging (MT) and localized proton spectroscopy (1H-MRS) were utilized in the evaluation of lesions (high signal abnormalities on T2-weighted images) and normal-appearing white matter (NAWM) in multiple sclerosis (MS). Eleven patients with a clinical diagnosis of MS were independently evaluated w...

journal_title：Magnetic resonance in medicine

authors： Hiehle JF Jr,Lenkinski RE,Grossman RI,Dousset V,Ramer KN,Schnall MD,Cohen JA,Gonzalez-Scarano F

更新日期：1994-09-01 00:00:00

abstract：PURPOSE:To achieve rapid, high resolution whole-brain gray matter (GM) imaging by developing a novel, single-slab three-dimensional dual-echo fast-spin-echo pulse sequence and GM-selective reconstruction. METHODS:Unlike conventional GM imaging that uses time-consuming double-inversion-recovery preparation, the propose...

journal_title：Magnetic resonance in medicine

authors： Lee H,Kim EY,Sohn CH,Park J

更新日期：2017-11-01 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：:Human mesenchymal stem cells (hMSCs) were labeled with Ferucarbotran by simple incubation and cultured for up to 14 d. Iron content was determined by spectrometry and the intracellular localization of the contrast agent uptake was studied by electron and confocal microscopy. At various time points after labeling, rang...

journal_title：Magnetic resonance in medicine

authors： Henning TD,Wendland MF,Golovko D,Sutton EJ,Sennino B,Malek F,Bauer JS,McDonald DM,Daldrup-Link H

更新日期：2009-08-01 00:00:00

abstract：:In active catheter tracking, small RF coils are attached to the catheter for localization. For interactive catheter steering at vessel branchings, it is necessary to visualize not only a single point near the catheter tip but also the entire shape and orientation of the catheter's distal end. Therefore, a 35-mm-long t...

journal_title：Magnetic resonance in medicine

authors： Zuehlsdorff S,Umathum R,Volz S,Hallscheidt P,Fink C,Semmler W,Bock M

更新日期：2004-07-01 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：:A MultiEcho Segmented EPI with z-shimmed BAckground gradient Compensation (MESBAC) pulse sequence is proposed and validated for functional MRI (fMRI) study in regions suffering from severe susceptibility artifacts. This sequence provides an effective tradeoff between spatial and temporal resolution and reduces image d...

journal_title：Magnetic resonance in medicine

authors： Li Z,Wu G,Zhao X,Luo F,Li SJ

更新日期：2002-08-01 00:00:00

abstract：:The reconstruction of MR images from nonrectilinearly sampled data is complicated by the fact that the inverse 2D Fourier transform (FT) cannot be performed directly on the acquired k-space data set. k-Space gridding is commonly used because it is an efficient reconstruction method. However, conventional gridding requ...

journal_title：Magnetic resonance in medicine

authors： Moriguchi H,Duerk JL

更新日期：2004-02-01 00:00:00

abstract：PURPOSE:Diffusion magnetic resonance imaging (MRI) microstructure imaging provides a unique noninvasive probe into tissue microstructure. The technique relies on biophysically motivated mathematical models, relating microscopic tissue features to the magnetic resonance (MR) signal. This work aims to determine which com...

journal_title：Magnetic resonance in medicine

authors： Ferizi U,Schneider T,Panagiotaki E,Nedjati-Gilani G,Zhang H,Wheeler-Kingshott CA,Alexander DC

更新日期：2014-12-01 00:00:00

abstract：:A combined carbogen ultrasmall superparamagnetic iron oxide (USPIO) imaging protocol was developed and applied in vivo in two murine colorectal tumor xenograft models, HCT116 and SW1222, with established disparate vascular morphology, to investigate whether additional information could be extracted from the combinatio...

journal_title：Magnetic resonance in medicine

authors： Burrell JS,Walker-Samuel S,Baker LC,Boult JK,Ryan AJ,Waterton JC,Halliday J,Robinson SP

更新日期：2011-07-01 00:00:00

abstract：:Maximal intensity projection (MIP) is routinely used to view MRA and other volumetric angiographic data. The straightforward implementation of MIP is ray casting that traces a volumetric data set in a computationally expensive manner. This article reports a fast MIP algorithm using shear warp factorization and reduced...

journal_title：Magnetic resonance in medicine

authors： Fang L,Wang Y,Qiu B,Qian Y

更新日期：2002-04-01 00:00:00

abstract：PURPOSE:To develop a fast protocol for measuring T1 values in the internal carotid artery (ICA), to validate this technique with in vitro measurements, and to evaluate its reproducibility. METHODS:A modified Look-Locker sequence was optimized to enable rapid determination of T1 in the ICA at 3T. T1 values from the ICA...

journal_title：Magnetic resonance in medicine

authors： Li W,Liu P,Lu H,Strouse JJ,van Zijl PCM,Qin Q

更新日期：2017-06-01 00:00:00

abstract：:Dextran-magnetite, a superparamagnetic compound, is a powerful relaxation reagent for sodium. Administered intravenously, it is confined mainly to the vasculature and eliminates the signal from plasma sodium, a significant component of the tissue sodium signal. Applications of dextran-magnetite for in vivo sodium imag...

journal_title：Magnetic resonance in medicine

authors： Summers RM,Joseph PM,Renshaw PF,Kundel HL

更新日期：1988-12-01 00:00:00

abstract：:When using tracer kinetic modeling to analyze dynamic contrast-enhanced MRI (DCE-MRI) it is necessary to identify an appropriate arterial input function (AIF). The measured AIF is often poorly sampled in both clinical and preclinical MR systems due to the initial rapid increase in contrast agent concentration and the ...

journal_title：Magnetic resonance in medicine

authors： McGrath DM,Bradley DP,Tessier JL,Lacey T,Taylor CJ,Parker GJ

更新日期：2009-05-01 00:00:00

abstract：PURPOSE:To develop and validate a method for acquiring helium-3 ((3) He) and proton ((1) H) three-dimensional (3D) image sets of the human lung with isotropic spatial resolution within a 10-s breath-hold by using compressed sensing (CS) acceleration, and to assess the fidelity of undersampled images compared with fully...

journal_title：Magnetic resonance in medicine

authors： Qing K,Altes TA,Tustison NJ,Feng X,Chen X,Mata JF,Miller GW,de Lange EE,Tobias WA,Cates GD Jr,Brookeman JR,Mugler JP 3rd

更新日期：2015-10-01 00:00:00

abstract：:Flow measurement methods for functional MRI (fMRI) are desirable as they are more closely tied to neuronal activity than the commonly used blood oxygenation techniques. In this work we introduce a flow-based functional imaging method. The method, called flow enhancement of signal intensity (FENSI), is an extension of ...

journal_title：Magnetic resonance in medicine

authors： Sutton BP,Ouyang C,Ching BL,Ciobanu L

更新日期：2007-08-01 00:00:00