Abstract：
:The non-Einstein diffusion behavior of water in a model biological tissue system, intact duck embryos, has been investigated by the use of an in vivo proton pulsed-gradient spin-echo (PGSE) MR imaging technique. Multiple-frame MR images of the intact duck embryos and control solution (0.5 mM CuSO4 doped water) were acquired systematically at different diffusion times and strengths of the diffusion-sensitizing magnetic field gradients of the PGSE sequence. These raw images were then used to generate various dynamic (self-diffusion coefficient) and structural (fractal, residual attenuation, and compartment fraction) diffusion parameter maps of water in the imaging objects on the basis of different Einstein and higher order (non-Brownian, Residual, and 2-compartment) diffusion models. The self-diffusion coefficients of the body tissues of the embryos obtained from all diffusion models were significantly lower than those of the surrounding embryonic fluid. The structural diffusion parameter maps obtained from the higher order diffusion models revealed that water molecules exhibited either non-Brownian, restricted, or compartmentalized diffusion behavior in the embryonic tissues, but Einstein or Brownian diffusion behavior in the embryonic fluid and control solution. The diffusion parameter maps, both dynamic and structural, were found to provide much better contrasts than the conventional relaxation time (T1, T2, and biexponential T2) maps in separating the tissues from the surrounding embryonic fluid in the duck embryos. The mathematical models and procedures for generating the dynamic and structural diffusion parameter maps are also presented in this paper.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Cheng KHdoi
10.1016/0730-725x(93)90476-tsubject
Has Abstractpub_date
1993-01-01 00:00:00pages
569-83issue
4eissn
0730-725Xissn
1873-5894pii
0730-725X(93)90476-Tjournal_volume
11pub_type
杂志文章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：:Myelin water fraction (MWF) images in brain tend to be spatially noisy with unknown or no apparent spatial patterns structure, so values are therefore typically averaged over large white matter (WM) volumes. We investigated the existence of an inherent spatial structure in MWF maps and explored the benefits of examini...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2019.09.012
更新日期：2020-04-01 00:00:00
abstract：:Autoradiographic studies have shown that low dose ketamine produces increases in regional glucose utilisation and blood flow in the hippocampus, cerebral cortex, and olfactory lobe in the rat brain, probably due to antagonism at the NMDA receptor. Functional MRI using deoxyhaemoglobin contrast can be used to study cha...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)00010-e
更新日期：1995-01-01 00:00:00
abstract：:Functional T1ρ mapping has been proposed as a method to assess pH and metabolism dynamics in the brain with high spatial and temporal resolution. The purpose of this work is to describe and evaluate a variant of the spin-locked echo-planar imaging sequence for functional T1ρ mapping at 3T. The proposed sequence rapidl...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2014.07.010
更新日期：2014-11-01 00:00:00
abstract：:The optics of the ocular lens are determined by its geometry (shape and volume) and its inherent gradient of refractive index (water to protein ratio), which are in turn maintained by unique cellular physiology known as the lens internal microcirculation system. Previously, magnetic resonance imaging (MRI) has been us...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.04.015
更新日期：2020-07-01 00:00:00
abstract：PURPOSE:To perform comprehensive in vitro experiments using six-directional icosahedral flow encoding (ICOSA6) 4D flow magnetic resonance imaging (MRI) under various scan conditions to analyze the robustness of velocity and turbulence quantification. MATERIALS AND METHODS:In vitro flow phantoms with steady flow rates ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.06.020
更新日期：2020-10-01 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：:The CNS involvement is frequently found in human immunodeficiency virus (HIV) infection. The purpose of our study was to determine whether proton magnetic resonance spectroscopy (MRS) could detect early brain involvement in neurologically asymptomatic HIV-infected patients with normal MR imagings and to find the corre...
journal_title：Magnetic resonance imaging
pub_type： 临床试验,杂志文章
doi：10.1016/s0730-725x(00)00173-9
更新日期：2000-09-01 00:00:00
abstract：PURPOSE:The purpose was to study the effect of estrogen deficiency on contrast agent diffusion into intervertebral disc in a rat model. MATERIALS AND METHODS:Seven-month-old female Sprague-Dawley rats were used. Fourteen rats had ovariectomy, and nine rats had sham surgery. Magnetic resonance imaging (MRI) of sagittal...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2012.01.001
更新日期：2012-06-01 00:00:00
abstract：:Respiratory motion and capnometry monitoring were performed during blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) of the brain while a series of paced hyperventilation tasks were performed that caused significant hypocapnia. Respiration volume per time (RVT) and end-tidal carbon dioxi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2011.07.011
更新日期：2011-11-01 00:00:00
abstract：BACKGROUND AND PURPOSE:Slice-encoding metal artifact corrections (SEMAC)-view-angle tilting (VAT) sequences have recently been used in clinical protocols to reduce metal artifacts in MR scans of patients with spinal instrumentation. The objective of this study was to compare the SEMAC-VAT sequence with the conventional...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2018.08.002
更新日期：2018-12-01 00:00:00
abstract：:A technique for obtaining quantitative longitudinal saturation/porosity profiles of rock cores which are longer than the NMR coil has been developed. The slice-selected experiment uses a prefocused pulse in conjunction with a magnetic field gradient for the localization and a CPMG sequence to sample the data. A variet...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)91547-4
更新日期：1994-01-01 00:00:00
abstract：:The performance evaluation of a semi-supervised fuzzy c-means (SFCM) clustering method for monitoring brain tumor volume changes during the course of routine clinical radiation-therapeutic and chemo-therapeutic regimens is presented. The tumor volume determined using the SFCM method was compared with the volume estima...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00386-4
更新日期：1997-01-01 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：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：:The radiologic findings from 60 patients with 86 internally deranged temporomandibular joints (TMJ) upon whom sequential imaging procedures had been performed over a period of two months to ten years were analyzed and correlated with clinical, surgical (72 joints), and pathological observations. Internal derangement o...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(89)90404-9
更新日期：1989-09-01 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：:Superparamagnetic iron oxide particles (SPIOs) are usually referred to as T2 MR contrast agents, reducing signal intensity (SI) on T2-weighted MR images (negative enhancement). This study reports the original use of SPIOs as T1-enhancing contrast agents, primarily assessed in vitro, and then applied to an in vivo inve...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(93)90241-5
更新日期：1993-01-01 00:00:00
abstract：:Obstructive sleep apnea syndrome (OSAS) is caused by multi-level upper airway obstruction. Anatomic changes at the sites of obstruction may modify the physical or acoustic properties of snores. The surgical success of OSA depends upon precise localization of obstructed levels. We present a case of OSAS who received si...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.08.004
更新日期：2015-12-01 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：:Magnetic resonance imaging (MRI) and localized proton MR spectroscopy (MRS) techniques have been applied for studying different maturation processes in the histochemistry of coconut (Cocos nucifera). Images of the tender and mature coconut are characterized by protons of the aqueous solution present in the cavity and ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(95)00033-d
更新日期：1995-01-01 00:00:00
abstract：:Quantitative longitudinal brain magnetic resonance (MR) studies may be confounded by scanner-related drifts in voxel sizes. Total intracranial volume (TIV) normalisation is commonly used to correct serial cerebral volumetric measurements for these drifts. We hypothesised that automated rigid-body registration of whole...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2004.01.057
更新日期：2004-09-01 00:00:00
abstract：PURPOSE:Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating moto...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.02.015
更新日期：2015-06-01 00:00:00
abstract：:In ultrashort TE (UTE) imaging, the short T2 values of the tissues of interest are comparable to the k-space readout duration, which result in significant T2 decay during k-space readout. This decay consequently causes significant effects on signal and contrast in UTE sequences, which we evaluate in this paper using m...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.11.002
更新日期：2014-04-01 00:00:00
abstract：:Susceptibility differences are common causes for artifacts in magnetic resonance (MR); therefore, it is important to choose phantom materials in a way that these artifacts are kept at a minimum. In this study, a previously proposed MR imaging (MRI) method [Beuf O, Briguet A, Lissac M, Davis R. Magnetic resonance imagi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2006.07.005
更新日期：2006-11-01 00:00:00
abstract：:The purpose of this study was to evaluate the value of Ferumoxide-enhanced magnetic resonance (MR) imaging in the detection of hepatic metastases in high-risk patients treated for colorectal cancer that have rising CEA. We used 19 patients treated previously for colorectal cancer with rising CEA levels underwent an un...
journal_title：Magnetic resonance imaging
pub_type： 临床试验,杂志文章
doi：10.1016/s0730-725x(99)00134-4
更新日期：2000-04-01 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：:Type A acute aortic dissection (TAAAD) sometimes presents with acute stroke-like symptoms. When intravenous tissue plasminogen activator (IV-tPA) therapy is considered for acute ischemic stroke, TAAAD must be excluded. Painless TAAAD presenting with acute stroke may be easily missed. Two cases of painless TAAAD presen...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2016.04.021
更新日期：2016-09-01 00:00:00
abstract：:Flattened representations are a useful approach to represent the convoluted complex surface of the neocortex of primates and other large-brained mammals. In this study, we compared the flattened representation of neocortical areas obtained from the recently published MRI and histology atlas of the rhesus monkey brain ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2010.03.023
更新日期：2010-10-01 00:00:00
abstract：:Positive contrast imaging methods produce enhanced signal at large magnetic field gradient in magnetic resonance imaging. Several postprocessing algorithms, such as susceptibility gradient mapping and phase gradient mapping methods, have been applied for positive contrast generation to detect the cells targeted by sup...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2011.04.011
更新日期：2011-09-01 00:00:00
