Abstract:
:A variety of shortcomings are associated with most currently used gastrointestinal contrast agents for magnetic resonance imaging (MRI). Artifacts resulting from peristalsis and other motions in the abdominal region are produced by many positive contrast agents (which increase signal intensity). Although this is not a problem for negative contrast agents (which decrease signal intensity), some negative contrast agents produce magnetic susceptibility artifacts that are especially pronounced at high field strength and with gradient echo pulse sequences. These susceptibility artifacts are produced by both paramagnetic and diamagnetic agents. It has been demonstrated in phantoms, however, that susceptibility matching can be used to produce contrast agents with desirable relaxation and contrast properties but without deleterious susceptibility artifacts. We now report results of animal tests of such an oral contrast agent, consisting of a suspension of superparamagnetic iron oxide particles and diamagnetic barium sulfate particles, compared to individual suspensions of the iron oxide and of the barium sulfate. Iron oxide was the least effective and the matched susceptibility mixture was the most effective for the intestine, which has traditionally been the most difficult region of the GI tract to visualize clearly. Matched susceptibility mixtures, which are inherently able to yield images free of susceptibility artifacts without compromising contrast, show promise of being improved oral negative contrast agents for use in gastrointestinal MRI.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Briggs RW,Wu Z,Mladinich CR,Stoupis C,Gauger J,Liebig T,Ros PR,Ballinger JR,Kubilis Pdoi
10.1016/s0730-725x(97)00020-9subject
Has Abstractpub_date
1997-01-01 00:00:00pages
559-66issue
5eissn
0730-725Xissn
1873-5894pii
S0730-725X(97)00020-9journal_volume
15pub_type
杂志文章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::A simple model for estimating temperature distribution within the frozen region during cryo ablation was tested for accuracy. Freezing experiments were conducted in both ex vivo and in vivo porcine livers. Temperature was measured during freezing using a fiber-optic temperature sensor. Three-dimensional MR images were...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00389-7
更新日期:2001-06-01 00:00:00
abstract:OBJECTIVE:3D Time-of-flight (TOF) magnetic resonance angiography is commonly used for vascular analyses. A quantification of longitudinal morphological changes usually requires the registration of TOF image sequences acquired at different time points. The aim of this study was to evaluate the precision of different 3D ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.08.011
更新日期:2014-12-01 00:00:00
abstract::Diffusion tensor imaging (DTI) constitutes the most used paradigm among the diffusion-weighted magnetic resonance imaging (DW-MRI) techniques due to its simplicity and application potential. Recently, real-time estimation in DW-MRI has deserved special attention, with several proposals aiming at the estimation of mean...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2011.12.001
更新日期:2012-05-01 00:00:00
abstract:PURPOSE:To develop a RF coil system for joint imaging of intracranial and extracranial arterial vessel wall at 3T. MATERIALS AND METHOD:The coil system consists of a 24-channel head coil combined with an 8-channel carotid coil. It is compared with a standard coil configuration (12-channel head coil+4-channel neck coil...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.10.018
更新日期:2017-02-01 00:00:00
abstract:PURPOSE:The purpose of this study was to assess relationships between intramuscular adipose tissue (IntraMAT) content determined by MRI and intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL) determined by (1)H magnetic resonance spectroscopy ((1)H MRS) or echo intensity determined by B-mode ultrasonograp...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.12.038
更新日期:2016-05-01 00:00:00
abstract::The advantages of event-related functional Magnetic Resonance Imaging (fMRI) and the increasing use of fMRI in cognitive experiments are both driving the development of techniques that allow images sensitive to the blood oxygen level-dependent effect to be acquired at ever-higher temporal resolution. Here, we present ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.12.030
更新日期:2006-05-01 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::Lipomatous tumors of the uterus are unusual, benign neoplasms seen in postmenopausal women. Although many of the mixed-type cases such as lipoleiomyoma and fibrolipoma have been reported, pure uterine lipomas are extremely rare. In the literature, a few cases with pure uterine lipoma have been reported. We first prese...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.01.116
更新日期:2007-10-01 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::Cells labeled by super paramagnetic iron-oxide (SPIO) nanoparticles are more easily seen in gradient echo MR images, but it has not been shown that the amount of nanoparticles or the number of cells can be directly quantified from MR images. This work utilizes a previously developed and improved Complex Image Summatio...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.08.003
更新日期:2017-01-01 00:00:00
abstract::We propose a deuterium diffusion tracer approach to measure diffusion coefficient in the case of very short NMR relaxation times, too short for NMR pulsed field gradient sequences (T1 or T2 below 1 ms). We also treat the case of porous media containing metallic fibers (such as reinforced concrete) strongly disturbing ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.09.010
更新日期:2019-02-01 00:00:00
abstract::The purpose of this study is to estimate the precision or statistical variability of the velocity measurements computed from MRI phase-contrast. From the analytical probability density function (PDF) of the phase in the signal we obtain the PDF of the velocity by means of an auto-convolution. This PDF allows the estim...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.08.028
更新日期:2019-11-01 00:00:00
abstract:PURPOSE:To evaluate whether semi-quantitative analysis of high temporal resolution dynamic contrast-enhanced MRI (DCE-MRI) acquired early in treatment can predict the response of locally advanced breast cancer (LABC) to neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS:As part of an IRB-approved prospective study,...
journal_title:Magnetic resonance imaging
pub_type: 临床试验,杂志文章
doi:10.1016/j.mri.2013.07.002
更新日期:2013-11-01 00:00:00
abstract::A quantitative analysis of the dependence of water proton relaxation on water content in randomly packed beds of Sephadex is undertaken. A combination of Osmotic and Capillary theory is used to describe the morphological changes occurring in the packed beds as the water content is lowered. At each water content the wa...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)92032-x
更新日期:1994-01-01 00:00:00
abstract::The value of NMR spectrometry as a way to understand the porosity and permeability of rocks is well documented. Other more esoteric parameters, such as restrictive diffusion, grain size distribution, and fluid viscosities have received less notice but are also available from the NMR measurements as laboratory studies ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(94)91537-7
更新日期:1994-01-01 00:00:00
abstract::Pathologically, hippocampal sclerosis (HS) is characterized by neuronal loss and gliosis affecting particularly the pyramidal neurons of CA1, CA3, and CA4 with relative sparing of the CA2 neurons. This can be identified in vivo with magnetic resonance (MR) imaging techniques that can reveal both morphological and sign...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
doi:10.1016/0730-725x(95)02016-m
更新日期:1995-01-01 00:00:00
abstract::Trabecular bone structure and bone density contribute to the strength of bone and are important in the study of osteoporosis. Wavelets are a powerful tool in characterizing and quantifying texture in an image. The purpose of this study was to validate wavelets as a tool in computing trabecular bone thickness directly ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.09.020
更新日期:2007-04-01 00:00:00
abstract::Fast magnetic resonance (MR) imaging provides a consistent and predictable appearance of vascular abnormalities as shown by four patients with thrombi, dissection and aneurysm. Fast MR images are obtained during breath-holding, resulting in an absence of respiratory motion artifacts. The time of MR study is much less ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90483-3
更新日期:1988-07-01 00:00:00
abstract:PURPOSE:Although functional magnetic resonance imaging (fMRI) has revealed that spinal cord injury (SCI) causes anomalous changes in task-induced brain activation, its effect during the resting state remains unclear. The aim of this study is to explore the changes of the brain resting-state function in non-human primat...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.02.001
更新日期:2014-06-01 00:00:00
abstract::Focal brain ischemia was induced by middle cerebral artery occlusion in the rat. The volume of cerebral damage was determined 2 days later by MRI in vivo and in the same animals histologically. The edema volume as measured by MRI and the histologically determined infarction was highly correlated. As a consequence, the...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(92)90411-r
更新日期:1992-01-01 00:00:00
abstract::In recent years there has been increasing interest in applying magnetic resonance (MR) techniques in areas of engineering and chemical technology. The science that underpins many of these applications is the physics and chemistry of transport and reaction processes in porous materials. Key to the exploitation of MR me...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(03)00127-9
更新日期:2003-04-01 00:00:00
abstract::Fatigue and impairment mobility are frequent problems in multiple sclerosis (MS). Despite its enormous potential, in vivo (1)H MRS of skeletal muscles for MS patients is a largely unexplored field. One fundamental question remains unanswered: whether MS can cause observable proton metabolite changes. High quality two-...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.01.005
更新日期:2004-04-01 00:00:00
abstract::The extent of reaction of 153Gd-radiolabeled Gd(L) chelates with 25 mM CO23- (25 mF), PO34-, Zn2+ and Cu2+ at pH 7 was determined for L = EDTA, DTPA, DOTA, HP-DO3A, and DO3A. Gd(EDTA)- and Gd(DTPA)2- reacted (greater than 20% in 10 min) with Cu2+ and Zn2+ in the presence of PO34-. These double replacement reactions yi...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90429-p
更新日期:1991-01-01 00:00:00
abstract:PURPOSE:To evaluate the clinical outcomes of conservative management by observation with MRI of patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). MATERIALS AND METHODS:Twenty-three consecutive patients, who were followed up by MRI with magnetic resonance cholangiopancreatography (MRCP) ove...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2010.06.026
更新日期:2010-12-01 00:00:00
abstract::We compared the ability and reproducibility of a fast fluid-attenuated inversion recovery (fast-FLAIR) sequence with and without a magnetization transfer (MT) pulse for detecting and measuring multiple sclerosis (MS)-related abnormalities on magnetic resonance imaging (MRI) scans from 20 patients. The Contrast-to-Nois...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00182-9
更新日期:1999-04-01 00:00:00
abstract::The density driven convection phenomenon is expected to have a significant and positive role in CO2 geological storage capacity and safety. The onset and development of density-driven convective on the core scale is critical to understand the mass transfer mechanism. In this paper, laboratory experiments were conducte...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2017.03.004
更新日期:2017-06-01 00:00:00
abstract::Glioblastoma Multiforme is the most common and most aggressive type of brain tumors. Although accurate prediction of Glioblastoma borders and shape is absolutely essential for neurosurgeons, there are not many in silico platforms that can make such predictions. In the current study, an automatic patient-specific simul...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.12.012
更新日期:2020-05-01 00:00:00
abstract::Wall shear stress (WSS) is a relevant hemodynamic indicator of the local stress applied on the endothelium surface. More specifically, its spatiotemporal distribution reveals crucial in the evolution of many pathologies such as aneurysm, stenosis, and atherosclerosis. This paper introduces a new solution, called PaLMA...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2020.08.017
更新日期:2020-12-01 00:00:00
abstract::Proton MR measurements were performed in lyophilized urine samples collected from 5 normals (N) and 5 idiopathic hypercalciuric recurrent stone formers (SF). T1 and T2 relaxation times were measured with a Bruker PC Multispec at 20 MHz and 37 degrees C in the lyophilized samples and in samples gradually rehydrated. Si...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90522-x
更新日期:1988-01-01 00:00:00