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 the decay time. A simple base line correction is no solution since this yields an equally large underestimation due to overcorrection of the first part of the curve. The use of squared data does yield reliable results, but only in the case of monoexponential decays. The best fitting algorithm under all experimentally occurring conditions turns out to be using real data after phase correction. A phase correction scheme is proposed, which applies to all imaging experiments for which the phase of the pixels is constant over the echo train. This scheme is validated for a phantom and for a tulip bulb.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
van der Weerd L,Vergeldt FJ,Adrie de Jager P,Van As Hdoi
10.1016/s0730-725x(00)00200-9subject
Has Abstractpub_date
2000-11-01 00:00:00pages
1151-8issue
9eissn
0730-725Xissn
1873-5894pii
S0730-725X(00)00200-9journal_volume
18pub_type
杂志文章abstract：PURPOSE:Only a few studies have investigated the brain morphology abnormalities in structural MRI in patients with drug-naïve idiopathic generalized epilepsy (IGE) and mainly focused on brain volume changes. In the present study, we aimed to investigate the changes in three morphologic measurement differences including...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2019.05.035
更新日期：2019-09-01 00:00:00
abstract：:Stimulated spin-echo and Carr-Purcell pulse sequences, with pulsed magnetic field gradients, have been used to study the self-diffusion processes of the water in swollen and in supercoiled polyacrylamide gels and in polysaccharides agarose gels, for different polymer concentrations. Restricted diffusion effects are ev...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00202-0
更新日期：1996-01-01 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：:The purpose of this study was to evaluate the effect of gadoxetic acid (Gd-EOB-DTPA) on measurements of liver stiffness by using magnetic resonance elastography (MRE). In this study, 104 consecutive patients (mean age, 67.7±9.4 years) underwent MRE using a 1.5-T MR scanner equipped with a cylindrical passive driver th...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2011.08.005
更新日期：2012-01-01 00:00:00
abstract：:Renal transplant patients often require imaging to ensure appropriate graft placement, to assess integrity of transplant vessel anastomosis and to evaluate for stenosis that can be a cause of graft failure. Because there is risk for nephrogenic systemic fibrosis in the setting of renal insufficiency, the use of non-co...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.10.004
更新日期：2014-02-01 00:00:00
abstract：:A parametric method is proposed to examine the relationship between neuronal activity, measured with event related potentials (ERPs), and the hemodynamic response, observed with functional magnetic resonance imaging (fMRI), during an auditory oddball paradigm. After verifying that the amplitude of the evoked response ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(02)00496-4
更新日期：2002-05-01 00:00:00
abstract：:Qualitative and quantitative proton magnetic resonance imaging techniques were applied to persimmon (Diospyros kaki cv 'Fuyu') fruit during development and post-harvest ripening. Spin-lattice (T(1)) relaxation times in mesocarp parenchyma and vascular tissue exhibited a sigmoidal pattern of increase leading to commerc...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(03)00082-1
更新日期：2003-07-01 00:00:00
abstract：:With the conventional 3D MR angiographic sequences, it is difficult to prescribe multiple phases in different orientations, though multiple phases may be prescribed in the same orientation as the initial scan. Magnetic resonance angiography (MRA) was performed in which three slabs were prescribed in different orientat...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(99)00003-x
更新日期：1999-07-01 00:00:00
abstract：BACKGROUND:The diagnosis and management of mild traumatic brain injury (MTBI) continue to be subjects of debate, with varying opinions regarding the extent to which tissue-based impairments versus the impacts of other stressors cause ongoing disability. Detecting areas of the brain with abnormalities that can explain s...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2011.12.018
更新日期：2012-05-01 00:00:00
abstract：PURPOSE:To describe the MR appearances of hepatic sarcoidosis in patients with chronic liver disease and correlate the results with clinical stage of disease as measured with the Mayo end-stage liver disease (MELD) score. MATERIALS AND METHODS:Twenty patients with chronic liver disease and histopathological diagnosis ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.08.005
更新日期：2013-04-01 00:00:00
abstract：PURPOSE:This study aims to develop and evaluate a robust conductivity imaging method that combines total variation and wavelet regularization to enhance the accuracy of conductivity maps. THEORY AND METHODS:The proposed approach is based on a gradient-based method. The central equation is derived from Maxwell's equati...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.02.015
更新日期：2020-06-01 00:00:00
abstract：:The application of MRI-visible paramagnetic tracers to reveal in vivo connectivity can provide important subject-specific information for multisite, multielectrode intracortical recordings in combined behavioral and physiology experiments. To establish the use of such tracers in the nonhuman primate, we recently compa...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2005.12.031
更新日期：2006-05-01 00:00:00
abstract：:An efficient method for obtaining longitudinal relaxation time (T1) maps is based on acquiring two spoiled gradient recalled echo (SPGR) images in steady states with different flip angles, which has also been extended, with additional acquisitions, to obtain a tissue water content (M0) map. Several factors, including ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.08.001
更新日期：2013-12-01 00:00:00
abstract：:Radio frequency magnetic fields from 5 to 100 kHz off resonance reduce longitudinal magnetization of water in some tissues without affecting the magnetization of simple solutions (Wolff, S.D.; Balaban, R.S. Magnetization transfer contrast (MTC) and tissue water proton relaxation in vivo. Magn. Reson. Med. 10:135-144; ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90050-c
更新日期：1990-01-01 00:00:00
abstract：:Glutamate plays a double role in (13)C-nuclear magnetic resonance (NMR) spectroscopic determination of glucose metabolism in the brain. Bidirectional exchange between initially unlabeled glutamate and labeled α-ketoglutarate, formed from pyruvate via pyruvate dehydrogenase (PDH), indicates the rate of energy metabolis...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2011.04.013
更新日期：2011-12-01 00:00:00
abstract：:The hippocampal formation is a brain system that is implicated in learning and memory. The major input to the hippocampus arrives from the entorhinal cortex (EC) to the dentate gyrus (DG) through the perforant path. In the present work, we have investigated the functional properties of this connection by concomitantly...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.02.018
更新日期：2008-09-01 00:00:00
abstract：:Brain vascular damage accumulate in aging and often manifest as white matter hyperintensities (WMHs) on MRI. Despite increased interest in automated methods to segment WMHs, a gold standard has not been achieved and their longitudinal reproducibility has been poorly investigated. The aim of present work is to evaluate...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.11.008
更新日期：2021-02-01 00:00:00
abstract：:Susceptibility-weighted imaging (SWI) is a valuable technique for high-resolution imaging of brain vasculature that greatly benefits from the emergence of higher field strength MR scanners. Autocalibrating partially parallel imaging techniques can be employed to reduce lengthy acquisition times as long as the decrease...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.08.003
更新日期：2009-05-01 00:00:00
abstract：:Atherosclerotic plaques in the bifurcation of the carotid arteries can pose a significant health risk due to possible plaque rupture and subsequent stroke. The assessment of plaques, and evaluation of the risk they pose, can be performed with Black-Blood (BB) vessel wall magnetic resonance imaging. However, resolution...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2017.04.011
更新日期：2017-07-01 00:00:00
abstract：:Etched particle tracks produced after heavy ion irradiation of polymer foils are used as model systems to test the performance of NMR in a newly developed ultrahigh magnetic field gradient system. The stimulated NMR echo decay of molecules diffusing in the channels, formulated in terms of the self part of the intermed...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)91527-x
更新日期：1994-01-01 00:00:00
abstract：:This work addresses the special problems of measuring flow velocity distributions in rock by NMR methods. Specifically, these problems are to measure very slow flows as well as flows in the presence of background magnetic field gradients caused by heterogeneities of the rock. We modify a stimulated echo sequence for u...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00110-5
更新日期：1996-01-01 00:00:00
abstract：:Thoracic and abdominal magnetic resonance imaging studies generally require some type of compensation for respiratory and cardiac motions in order to yield artifact-free images with good signal-to-noise ratio. Most techniques for respiratory compensation require the use of a non-NMR sensing device to monitor the subje...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(01)00403-9
更新日期：2001-07-01 00:00:00
abstract：:We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate the translational and rotational mobility of adsorbents on quartz and calcite mineral surfaces. On both surfaces it was found that water is the dominant molecule. On the quartz surface the majority of water molecules have a ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2018.10.002
更新日期：2019-02-01 00:00:00
abstract：:The advantages of the application of NMR imaging to the studies of enhanced oil recovery methods that include polymer slug flooding, combination slug flooding, and thermal soaking are described. ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00192-0
更新日期：1996-01-01 00:00:00
abstract：:Constrained energy minimization (CEM) has proven highly effective for hyperspectral (or multispectral) target detection and classification. It requires a complete knowledge of the desired target signature in images. This work presents "Unsupervised CEM (UCEM)," a novel approach to automatically target detection and cl...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2010.03.009
更新日期：2010-06-01 00:00:00
abstract：OBJECTIVE:In magnetic resonance-guided breast vacuum biopsies, the contrast agent for targeting suspicious lesions can typically be applied only once during an intervention, due to the slow elimination of the gadolinium chelate from the extracellular fluid space. This study evaluated the feasibility of diffusion-weight...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2016.12.006
更新日期：2017-05-01 00:00:00
abstract：:The anticancer effect of thiacarpine, a synthetic analogue of the known cytotoxic alkaloid polycarpine isolated from the Pacific ascidian Polycarpa aurata, was investigated in vivo in experiments using mouse solid Ehrlich carcinoma tumor as the target. A high-resolution magnetic resonance imaging (MRI) technique using...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2008.01.014
更新日期：2008-07-01 00:00:00
abstract：:The spin-echo nuclear magnetic resonance (NMR) technique together with paramagnetic ion doping are used to study structural parameters of plant samples, such as restricted dimensions, and cell interconnection both through membranes and by cell contact by studying simultaneous restricted diffusion and intercellular wat...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(98)00053-8
更新日期：1998-06-01 00:00:00
abstract：:Neurovascular coupling describes the cascade between neuronal activity and subsequent Blood-Oxygenation-Level-Dependent (BOLD) signal increase. Based on this premise, the correlation of this BOLD signal increase with a particular task, such as finger-tapping, is used to map neuronal activation. This signal increase ma...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2018.02.002
更新日期：2018-06-01 00:00:00
abstract：:Cross-terms between imaging and diffusion gradients, unaccounted for during tensor calculations, can lead to erroneous estimation of diffusivity and fractional anisotropy (FA) in regions of isotropic and anisotropic diffusion. Cross-term of magnitude 136.8±1.6 s/mm(2), artificially introduced in the slice-encode direc...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.02.021
更新日期：2012-07-01 00:00:00
