Flow-gated phase-contrast MRI using radial acquisitions.

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：PURPOSE:To design short parallel transmission (pTx) pulses for excitation of arbitrary three-dimensional (3D) magnetization patterns. METHODS:We propose a joint optimization of the pTx radiofrequency (RF) and gradient waveforms for excitation of arbitrary 3D magnetization patterns. Our optimization of the gradient wav...

journal_title：Magnetic resonance in medicine

authors： Davids M,Schad LR,Wald LL,Guérin B

更新日期：2016-10-01 00:00:00

abstract：:Vascular-space-occupancy (VASO) MRI exploits the difference between blood and tissue T1 to null blood signal and measure cerebral blood volume changes using the residual tissue signal. VASO imaging is more difficult at higher field because of sensitivity loss due to the convergence of tissue and blood T1 values and in...

journal_title：Magnetic resonance in medicine

authors： Hua J,Jones CK,Qin Q,van Zijl PC

更新日期：2013-04-01 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:The heterogeneous tumor cell population and dynamic microenvironment within a tumor lead to regional variations in cell proliferation, migration, and differentiation. In this work, MRI and optical projection tomography were used to examine and compare the redistribution of a cellular label in two mouse glioma m...

journal_title：Magnetic resonance in medicine

authors： Gazdzinski LM,Nieman BJ

更新日期：2014-04-01 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：PURPOSE:Undiagnosed dehydration compromises health outcomes across many populations. Existing dehydration diagnostics require invasive bodily fluid sampling or are easily confounded by fluid and electrolyte intake, environment, and physical activity limiting widespread adoption. We present a portable MR sensor designed...

journal_title：Magnetic resonance in medicine

authors： Bashyam A,Frangieh CJ,Li M,Cima MJ

更新日期：2020-04-01 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：PURPOSE:In this work, 22 configurations for remote radiofrequency (RF) coil arrays consisting of different transmit element designs for 7 Tesla (T) ultrahigh-field MRI are compared by numerical simulations. METHODS:Investigated transmit RF element types are rectangular loops, micro striplines, micro striplines with me...

journal_title：Magnetic resonance in medicine

authors： Rietsch SHG,Orzada S,Bitz AK,Gratz M,Ladd ME,Quick HH

更新日期：2018-02-01 00:00:00

abstract：:Phase contrast flow velocity measurements were performed in six healthy volunteers and 30 patients with arteriosclerotic disease. The iliac arteries were investigated in 8 cases and the femoral arteries in 28 cases. In the first 24 patients, 16 evenly distributed data sets were acquired during one cardiac cycle. In th...

journal_title：Magnetic resonance in medicine

authors： Krug B,Kugel H,Harnischmacher U,Heindel W,Schmidt R,Krings F

更新日期：1995-11-01 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：:Quantitative estimation of T1 is a challenging but important task inherent to many clinical applications. The most commonly used paradigm for estimating T1 in vivo involves performing a sequence of spoiled gradient-recalled echo acquisitions at different flip angles, followed by fitting of an exponential model to the ...

journal_title：Magnetic resonance in medicine

authors： Trzasko JD,Mostardi PM,Riederer SJ,Manduca A

更新日期：2013-06-01 00:00:00

abstract：:Functional magnetic resonance imaging in real time is an emerging tool for the assessment of dynamic changes in brain activation. The short response latency (tens of seconds) renders the technique more sensitive to motion artifacts. Motion correction in real time requires computationally efficient algorithms which can...

journal_title：Magnetic resonance in medicine

authors： Mathiak K,Posse S

更新日期：2001-01-01 00:00:00

abstract：:Higher field strengths entail less homogeneous RF fields. This may influence quantitative MRI and MRS. A method for rapidly mapping the RF field in the human head with minimal distortion was developed on the basis of a single-shot stimulated echo acquisition mode (STEAM) sequence. The flip angle of the second RF pulse...

journal_title：Magnetic resonance in medicine

authors： Helms G,Finsterbusch J,Weiskopf N,Dechent P

更新日期：2008-09-01 00:00:00

abstract：:A fast, two-coil, pseudo-continuous labeling scheme is presented. This new scheme permits the collection of a multislice subtraction pair in <3 s, depending on the subject's arterial transit times. The method consists of acquiring both control and tag images immediately after a labeling period that matches the arteria...

journal_title：Magnetic resonance in medicine

authors： Hernandez-Garcia L,Lee GR,Vazquez AL,Noll DC

更新日期：2004-03-01 00:00:00

abstract：:The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

journal_title：Magnetic resonance in medicine

authors： Zheng S,Xia Y

更新日期：2010-01-01 00:00:00

abstract：:High-quality, high-resolution, proton-decoupled natural-abundance 13C NMR spectra have been obtained in vitro at 100.6 MHz from unprocessed human pathology specimens of tumors and adjacent nonneoplastic control tissues from lung, colon, and prostate. In these preliminary studies, specific molecular parameters were ide...

journal_title：Magnetic resonance in medicine

authors： Halliday KR,Fenoglio-Preiser C,Sillerud LO

更新日期：1988-08-01 00:00:00

abstract：:Healthy human brain diffusion anisotropy maps derived from standard spin echo diffusion tensor imaging (DTI) were compared with those using fluid-attenuated inversion recovery (FLAIR) preparation prior to DTI to null the signal from cerebrospinal fluid (CSF). Consistent comparisons entailed development of DTI postproc...

journal_title：Magnetic resonance in medicine

authors： Papadakis NG,Martin KM,Mustafa MH,Wilkinson ID,Griffiths PD,Huang CL,Woodruff PW

更新日期：2002-08-01 00:00:00

abstract：:In in vivo (1)H spectroscopy, the signal at 1.32 ppm is usually assigned to lactate. This resonance position is shared with threonine at physiological pH. The similarity of spectral patterns of lactate and threonine renders the separate measurement of either threonine or lactate without and even with editing technical...

journal_title：Magnetic resonance in medicine

authors： Marjanska M,Henry PG,Uğurbil K,Gruetter R

更新日期：2008-02-01 00:00:00

abstract：:The purpose of this study is (1) to determine the correlation between T(1rho) and T(2) and degenerative grade in intervertebral discs using in vivo 3.0-T MRI, and (2) to determine the association between T(1rho) and T(2) and clinical findings as quantified by the SF-36 Questionnaire and Oswestry Disability Index. Sixt...

journal_title：Magnetic resonance in medicine

authors： Blumenkrantz G,Zuo J,Li X,Kornak J,Link TM,Majumdar S

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements. THEORY AND METHODS:An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into ...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Yan X,Gore JC,Grissom WA

更新日期：2020-06-01 00:00:00

abstract：:Measurements of the volume magnetic susceptibility of solids using the classical Gouy balance approach are hampered by variations in apparent density of the packed powder. In this paper a quantitative NMR measurement of the volume magnetic susceptibility of powdered solids is described and the volume susceptibility of...

journal_title：Magnetic resonance in medicine

authors： Hopkins JA,Wehrli FW

更新日期：1997-04-01 00:00:00

abstract：:A precise understanding of human blood spin-spin relaxation is of major importance for numerous applications, particularly functional magnetic resonance imaging (fMRI), which is increasingly performed at 3 Tesla. It is well known that T2 measured from partially deoxygenated blood depends on the Carr-Purcell Meiboom-Gi...

journal_title：Magnetic resonance in medicine

authors： Chen JJ,Pike GB

更新日期：2009-02-01 00:00:00

abstract：:The combination of cardiac viability and functional information enhances the identification of different heart tissues in the setting of ischemic heart disease. A method has recently been proposed for obtaining black-blood delayed-enhancement (DE) viability images using the stimulated-echo acquisition mode (STEAM) MRI...

journal_title：Magnetic resonance in medicine

authors： Ibrahim el-SH,Stuber M,Kraitchman DL,Weiss RG,Osman NF

更新日期：2007-10-01 00:00:00

abstract：:A method for evaluating the sensitivity of MRI protocols to changes in an arbitrary number of tissue parameters over a broad range of parameter values is presented. This analysis is useful for choosing an optimal basis set of images for either a "survey" protocol or tissue segmentation algorithms. A survey protocol is...

journal_title：Magnetic resonance in medicine

authors： McVeigh ER,Henkelman RM,Bronskill MJ

更新日期：1990-02-01 00:00:00

abstract：:Activity-induced manganese-dependent contrast (AIM) MRI is a hemodynamic-independent functional MRI method that used manganese ion as an MR-detectable contrast agent. In AIM, MnCl(2) is infused intra-arterially after the blood-brain barrier (BBB) is opened with a hyperosmolar agent. Upon functional stimulation of the ...

journal_title：Magnetic resonance in medicine

authors： Aoki I,Tanaka C,Takegami T,Ebisu T,Umeda M,Fukunaga M,Fukuda K,Silva AC,Koretsky AP,Naruse S

更新日期：2002-12-01 00:00:00

abstract：:A birdcage coil possesses various intrinsic resonant modes. One of the modes produces sinusoidal current distribution around the rung elements of the birdcage and generates a highly uniform B(1) field in the transverse plane. Another mode is the end-ring resonant mode, in which there are no currents in the rungs of th...

journal_title：Magnetic resonance in medicine

authors： Fujita H,Braum WO,Morich MA

更新日期：2000-10-01 00:00:00

abstract：PURPOSE:To investigate the relative gain in sensitivity of five histology coils designed in-house to accommodate tissue sections of various sizes and compare with commercial mouse head coils. METHODS:The coil set was tailored to house tissue sections ranging from 5 to1000 µm encased in either glass slides or coverslip...

journal_title：Magnetic resonance in medicine

authors： Hoang DM,Voura EB,Zhang C,Fakri-Bouchet L,Wadghiri YZ

更新日期：2014-05-01 00:00:00

abstract：PURPOSE:Phosphomono- and diesters, the major components of the choline peak in (1) H magnetic resonance spectroscopy, are associated with membrane anabolic and catabolic mechanisms. With the refocused insensitive nuclei-enhanced polarization transfer technique, these phospholipids are edited and enhanced in the (31) P ...

journal_title：Magnetic resonance in medicine

authors： Biedermann SV,Weber-Fahr W,Demirakca T,Tunc-Skarka N,Hoerst M,Henn F,Sartorius A,Ende G

更新日期：2015-04-01 00:00:00

abstract：:Sequential albumin-Gd-DTPA and Gd-DTPA dynamic enhancement studies were performed in an animal tumor model for the comparison of regional vascularity and permeability parameters measured by these two different sizes of contrast agents. The early albumin-Gd-DTPA enhancement arises from the vascular compartment, and the...

journal_title：Magnetic resonance in medicine

authors： Su MY,Najafi AA,Nalcioglu O

更新日期：1995-09-01 00:00:00