Abstract:
:The effects of motion in two-dimensional Fourier transform imaging (2DFT) are considered. Specific calculations describing the case of periodic motion are presented. The results predict the commonly seen artifact of image replication, sometimes referred to as ghosting. Expressions for both position and amplitude of these ghosts are derived. Simulated examples illustrate the image degradation for pulsatile flow and in plane motion. Several methods of reducing motion artifacts are then suggested. These include: randomization of views, averaging views, matching repeat times to the respiratory period, hybrid imaging, ROPE and COPE. The latter two methods reorder the data acquisition to destroy the coherence of the motion. They do not increase the data acquisition time and promise to be part of the standard approach to remove motion artifacts. The final step in actually recovering ideal resolution can be accomplished by using a model of the motion and a generalized transform inversion technique.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Haacke EM,Patrick JLdoi
10.1016/0730-725x(86)91046-5subject
Has Abstractpub_date
1986-01-01 00:00:00pages
359-76issue
4eissn
0730-725Xissn
1873-5894pii
0730-725X(86)91046-5journal_volume
4pub_type
杂志文章abstract::Magnetic resonance elastography (MRE) uses a phase-contrast MRI technique to image shear wave propagation in tissue followed by the mathematical inversion of the equations of motion governing tissue mechanics to noninvasively image tissue stiffness. This work investigates the impact of various MR sampling strategies d...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2010.06.016
更新日期:2010-12-01 00:00:00
abstract::The relative value of two different MRI procedures for the assessment of infratentorial extension in multiple sclerosis (MS) was studied. Multislice spin-echo techniques were used overall. Procedure A consisted of parasagittal T1-weighted images (500/30) and axial T2-weighted images (2500/30, 2500/120). Procedure B co...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(89)90547-x
更新日期:1989-05-01 00:00:00
abstract::The present trend in dynamic contrast-enhanced MRI is to increase the number of estimated perfusion parameters using complex pharmacokinetic models. However, less attention is given to the precision analysis of the parameter estimates. In this paper, the distributed capillary adiabatic tissue homogeneity pharmacokinet...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.02.003
更新日期:2014-06-01 00:00:00
abstract::Measurements of time-dependent diffusion are performed on a rock sample saturated first with water, then methane and finally ethane. The gases were selected because their increased diffusivities and relaxation times allow probing greater length scales than water and because of their practical relevance. The nuclear ma...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.01.002
更新日期:2005-02-01 00:00:00
abstract::H2O17 is a freely diffusible tracer and naturally occurring isotope of O16 detectable by MRI and has been shown to be useful for assessing cerebral perfusion in animal studies using direct and indirect MR detection techniques. However, earlier MR techniques are either not sensitive to changes in small concentrations o...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2003.09.005
更新日期:2004-02-01 00:00:00
abstract::We compared the ability of magnetic resonance imaging (MRI) using a 0.064 T permanent magnet, three-phase bone scanning, and indium-labeled white blood cell (111In-WBC) scanning, to diagnose osteomyelitis. Twenty-three patients underwent biopsy. All patients were examined at presentation with all three modalities. Sen...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90540-3
更新日期:1991-01-01 00:00:00
abstract::NMR offers, in the complex proton relaxation properties of biological tissues, a unique and potentially powerful tool of tissue characterization. The difficulties encountered so far in comparing the results of in vitro and in vivo NMR studies carried out in different laboratories inhibit NMR methodologies from fully e...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90447-x
更新日期:1988-03-01 00:00:00
abstract::In this retrospective study we tested the hypothesis that the net effect of impaired electrical conduction and therefore increased heat dissipation in multiple sclerosis (MS) results in elevated lateral ventricular (LV) cerebrospinal fluid (CSF) diffusivity as a measure of brain temperature estimated in vivo using dif...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.11.002
更新日期:2015-04-01 00:00:00
abstract::Multiparametric MRI is a remarkable imaging method for the assessment of patho-physiological processes. In particular, brain tumor characterization has taken advantage of the development of advanced techniques such as Diffusion- (DWI) and Perfusion- (PWI) Weighted Imaging, but a thorough analysis of meningiomas is sti...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.12.003
更新日期:2020-04-01 00:00:00
abstract::Signal fluctuations in functional magnetic resonance imaging (fMRI) can result from a number of sources that may have a neuronal, physiologic or instrumental origin. To determine the relative contribution of these sources, we recorded physiological (respiration and cardiac) signals simultaneously with fMRI in human vo...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.02.004
更新日期:2009-10-01 00:00:00
abstract::Magnetic resonance (MR) imaging has been shown to provide accurate measurements of right ventricular (RV) volumes and myocardial mass. The purpose of this study was to evaluate the reproducibility of MR imaging, which in clinical practice may be as important as its absolute accuracy. The reproducibility of MR imaging ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)00076-f
更新日期:1995-01-01 00:00:00
abstract::Perfusion magnetic resonance imaging (MRI) is a promising non-invasive technique providing insights regarding the brain's microvascular architecture in vivo. The scalar perfusion metrics can be used for quantitative diagnostics of various brain abnormalities, in particular, in the stroke cases and tumours. However, co...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.11.007
更新日期:2019-04-01 00:00:00
abstract::A new and simple method for precise determination of lateral opposed treatment portals was developed and used in 17 patients. Compared to CT, MRI led to significant changes of portals in 59% (10/17) of cases. Individual shielding blocks could be precisely designed by use of our new method. MRI is the procedure of choi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90007-9
更新日期:1991-01-01 00:00:00
abstract::The most recently reported magnetic resonance first-pass myocardial perfusion studies were restricted to single slice imaging or a data analysis based on interactively placed regions of interest. This study was designed to investigate a new saturation recovery TurboFLASH sequence for multisection myocardial perfusion ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00166-0
更新日期:1999-02-01 00:00:00
abstract::Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is often used to examine vascular function in malignant tumors and noninvasively monitor drug efficacy of antivascular therapies in clinical studies. However, complex numerical methods used to derive tumor physiological properties from DCE-MRI images can b...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.09.007
更新日期:2013-05-01 00:00:00
abstract::Functional MR (fMR) imaging techniques based on blood oxygenation level dependent (BOLD) effects were developed and applied to a rat brain tumor model to evaluate the potential utility of the method for characterizing tumor growth and regression following treatment. Rats bearing 9L brain tumors in situ were imaged dur...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00208-2
更新日期:1999-05-01 00:00:00
abstract::The chain dynamics of short-chain perfluoropolyether melts confined in Vycor nanoporous media has been characterized by field cycling nuclear magnetic resonance relaxometry and the dipolar correlation effect. The slowdown of motions under confinement, leading to larger residual dipolar couplings, has been probed by lo...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.11.018
更新日期:2007-05-01 00:00:00
abstract::Dynamic contrast-enhanced MRI (DCE-MRI) was used to noninvasively evaluate the effects of AG-03736, a novel inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, on tumor microvasculature in a breast cancer model. First, a dose response study was undertaken to determine the responsiveness o...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.09.041
更新日期:2007-04-01 00:00:00
abstract::The purpose of this investigation is to evaluate the positioning and to confirm the volume concept of the Lea's Shield diaphragm utilizing MR imaging. We evaluated the device in two women, one nulliparous and one multiparous. We were able to comprehensively evaluate the device in both patients and answer all questions...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00385-x
更新日期:2001-06-01 00:00:00
abstract::Conventional and spatially resolved proton NMR and relaxation measurements are used in order to study the molecular motions and the equilibrium and nonequilibrium diffusion of oils in Berea sandstone and Venezuelan reservoir rocks. In the water-saturated Berea a single line with T*2 congruent to 150 microseconds is ob...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(92)90420-5
更新日期:1992-01-01 00:00:00
abstract::The localization of critical structures within the brain is important for the planning of therapeutic strategies. Functional MRI is capable to assess functional response of cortical structures to certain stimuli. The authors present two techniques for functional MRI (fMRI) in a stereotactic set-up. The skull of the pa...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)02108-x
更新日期:1996-01-01 00:00:00
abstract::In this work an interleaved multiple-gradient-echo chemical shift imaging (IMGE-CSI) technique was designed, implemented and evaluated at 1.5 and 4T for high-resolution lipid quantification and R(2)* measurement in-vivo. The method is analogous to echo planar CSI but utilizes conventional gradient echoes, exploiting t...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00165-x
更新日期:2000-09-01 00:00:00
abstract::A magnetic resonance imaging (MRI) method is described that allows interleaved measurements of transverse (R(2)(*) and R(2)) and longitudinal (R(1)) relaxation rates of tissue water in conjunction with spin labeling. The image-contrasts are intrinsically blood oxygenation level dependent (BOLD) and cerebral blood flow...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00125-9
更新日期:2000-04-01 00:00:00
abstract::Magnetic resonance imaging (MRI) is a completely noninvasive modality that has shown significant promise for the evaluation of the cardiovascular system. Our imaging technique employed electrocardiographic (ECG) gating, which resulted in well-resolved images of the cardiac structures. Patients and animals with a varie...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(84)90002-x
更新日期:1984-01-01 00:00:00
abstract::Measurements of arterial input function (AIF) can have large systematic errors at standard contrast agent doses in dynamic contrast enhanced MRI (DCE-MRI). We compared measured AIFs from low dose (AIFLD) and standard dose (AIFSD) contrast agent injections, as well as the AIF derived from a muscle reference tissue and ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.10.025
更新日期:2016-02-01 00:00:00
abstract::Quantitative processing of NMR relaxation images depends on the characteristics of the used fitting algorithm. Therefore several common fitting algorithms are compared for decay curves with low signal-to-noise ratios. The use of magnitude data yields a non-zero base line, and is shown to result in an overestimation of...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00200-9
更新日期:2000-11-01 00:00:00
abstract:PURPOSE:Our study aimed to develop accelerated microscopic diffusional kurtosis imaging (μDKI) and preliminarily evaluated it in a rodent model of chronic epilepsy. METHODS:We investigated two μDKI acceleration schemes of reduced sampling density and angular range in a phantom and wild-type rats, and further tested μD...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.10.009
更新日期:2019-02-01 00:00:00
abstract::Until recently, NMR imaging with intermolecular multiple-quantum coherences (iMQCs) has been based on the acquisition of a single echo. In vivo studies of iMQC image contrast would greatly benefit from a method that could acquire several orders of quantum coherence during the same acquisition. This would enable compar...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.10.019
更新日期:2004-12-01 00:00:00
abstract:BACKGROUND:Doppler based mitral annular velocities are an integral part of echocardiographic left ventricular diastolic function assessment. Although these measurements can be obtained by phase contrast cardiac magnetic resonance imaging (PC-CMR), this approach has limitations. The aims of this study were to assess the...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.08.018
更新日期:2019-01-01 00:00:00
abstract::Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is currently the dominant technique for non-invasive investigation of brain functions. One of the challenges with BOLD fMRI, particularly at high fields, is compensation for the effects of spatiotemporally varying magnetic field inho...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.07.005
更新日期:2010-02-01 00:00:00