Abstract:
:Magnetic resonance microscopy of skin from hairless rats under the influence of electrical fields was conducted for two cases: 1) low voltage constant electrical fields and 2) high-voltage short pulse, electrical fields. Under conditions of the low voltage and low current iontophoresis, i.e., 0 to 20 V, and 0 to 0.5 mA/cm2, it was found that the skin structure, as observed by magnetic resonance microscopy, did not significantly change until 20 Volts were applied across the 0.1 cm thick skin. Under these conditions, the viable epidermis appeared to swell, and this result corresponded to observations from scanning electron microscopy and other research from the literature. High voltage electrical fields, i.e., 220 V 1 ms pulses repeated once per second, appeared to hydrate the stratum corneum as is consistent with published literature on electroporation. In the case of iontophoresis, water self-diffusion coefficients in the epidermis and hair follicle regions at all voltages were affected by the electrical field. Statistical analysis at the 95% confidence level for the comparison of the average differences between diffusion coefficients with the electrical field on and with the electrical field off for pair matched pixels for the viable epidermis show that for 5 V (p = 0.00377), 10 V (p = 0.0108), 20 V (p = 0.0219) regimes there are statistically significant (p < or = 0.05) changes due to the applied electric field. The same analysis for the hair follicle region at 5 V (p = 6.89 x 10(-7)), 10 V (p = 1.42 x 10(-5)), 20 V (p = 3.23 x 10(-3)) also show statistically significant changes (p < or = 0.05). When the electroporation pulse was applied, the water diffusion coefficients increased by about 30% to 6.6 x 10(-6) cm2/s +/- 2.4 x 10(-7) cm2/s and 8.3 x 10(-6) cm2/s +/- 3.7 x 10(-7) cm2/s, for the epidermis and hair follicle regions, respectively. Significant differences were noted between diffusion coefficients in the viable epidermis and the hair follicles for all cases.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Caban JB,Moerland TS,Gibbs SJ,McFadden L,Locke BRdoi
10.1016/s0730-725x(99)00067-3subject
Has Abstractpub_date
1999-10-01 00:00:00pages
1183-91issue
8eissn
0730-725Xissn
1873-5894pii
S0730725X99000673journal_volume
17pub_type
杂志文章abstract::A model of MRI signal intensity which is a function of perfusion is developed based upon the assumption that biological tissue can be represented by a blood and tissue compartment. The longitudinal magnetization is derived from the Bloch equations which are modified to model the magnetization in both the blood and tis...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(91)90095-4
更新日期:1991-01-01 00:00:00
abstract:BACKGROUND:The molecular structure, charge, thermodynamic and kinetic stability are approximately the same for gadodiamide and gadoversetamide, the main substantive difference is that gadodiamide is manufactured with 5% free ligand to form Omniscan® and gadoversetamide with 10% free ligand to form OptiMARK®. PURPOSE:T...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2018.11.015
更新日期:2019-05-01 00:00:00
abstract:PURPOSE:To assess the value of semi-automated segmentation applied to diffusion MRI for predicting the therapeutic response of liver metastasis. METHODS:Conventional diffusion weighted magnetic resonance imaging (MRI) was performed using b-values of 0, 150, 300 and 450s/mm(2) at baseline and days 4, 11 and 39 followin...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.08.006
更新日期:2015-12-01 00:00:00
abstract:PURPOSE:Diffusional kurtosis imaging (DKI) is sensitive to the effects of signal noise due to strong diffusion weightings and higher order modeling of the diffusion weighted signal. A simple noise correction scheme is proposed to remove the majority of the noise bias in the estimated diffusional kurtosis. METHODS:Weig...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.08.028
更新日期:2015-01-01 00:00:00
abstract::In porous material research, one main interest of nuclear magnetic resonance diffusion (NMR) experiments is the determination of the shape of pores. While it has been a longstanding question if this is in principle achievable, it has been shown recently that it is indeed possible to perform NMR-based diffusion pore im...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2013.03.027
更新日期:2013-09-01 00:00:00
abstract::Biexponential T(2) relaxation of the localized water signal can be used for segmentation of spectroscopic volumes. To assess the specificity of the components an iterative relaxation measurement of the localized water signal (STEAM, 12 echo times, geometric spacing from 30 ms to 2000 ms) was combined with magnetizatio...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(01)00396-4
更新日期:2001-07-01 00:00:00
abstract::The purpose of this study was to develop a method to determine time discrepancies between input and myocardial time-signal intensity (TSI) curves for accurate estimation of myocardial perfusion with first-pass contrast-enhanced MRI. Estimation of myocardial perfusion with contrast-enhanced MRI using kinetic models req...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.06.015
更新日期:2015-11-01 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: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:PURPOSE:While PRESS is often employed to measure glutamate concentrations, MEGA-PRESS enables simultaneous Glx (glutamate and glutamine) and GABA measurements. This study aimed to compare validation, repeatability, and concordance of different approaches for glutamate quantification at 3T to aid future studies in their...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2017.12.029
更新日期:2018-05-01 00:00:00
abstract:PURPOSE:To identify quantitative dynamic contrast-enhanced (DCE)-MRI perfusion parameters indicating tumor response of hepatocellular carcinoma (HCC) to transarterial chemoembolization (TACE). MATERIALS AND METHODS:This prospective pilot study was approved by our institutional review board; written and informed consen...
journal_title:Magnetic resonance imaging
pub_type: 临床试验,杂志文章
doi:10.1016/j.mri.2019.06.017
更新日期:2019-10-01 00:00:00
abstract::Parallel excitation using multiple transmit channels has emerged as an effective method to shorten multidimensional spatially selective radiofrequency (RF) pulses, which have a number of important applications, including B1 field inhomogeneity correction in high-field MRI. The specific absorption rate (SAR) is a prima...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2008.02.003
更新日期:2008-10-01 00:00:00
abstract::The proton spin-lattice relaxation measured at several frequencies leads to a resolved distribution of four Tli for reactive powder concrete (RPC). The typical Tli frequency dependences are quantitatively interpreted by a biphasic fast exchange model and a proton nuclear relaxation of hydrated paramagnetic ions at the...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00063-0
更新日期:1998-06-01 00:00:00
abstract::The presence of metallic compounds in facial cosmetics and permanent tattoos may affect the quality of magnetic resonance imaging. We report a case study describing a signal artifact due to the use of a leave-on powdered hair dye. On reviewing the ingredients of the product, it was found to contain several metallic co...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.08.023
更新日期:2017-01-01 00:00:00
abstract::Within the magnetic resonance imaging (MRI) community the trend is going to higher and higher magnetic fields, ranging from 1.5 T to 7 T, corresponding to Larmor frequencies of 63.8-298 MHz. Since for high-field MRI the magnetization increases with the applied magnetic field, the signal-to-noise-ratio increases as wel...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.06.014
更新日期:2013-02-01 00:00:00
abstract::Laplace inversion has been widely used in analyzing nuclear magnetic resonance data to obtain a spectrum of decay time constant, such as the T(2) spectrum. However, due to the ill-conditioned nature of such inversion, it is difficult to determine the reliability and error of the resulting spectrum. This article descri...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,评审
doi:10.1016/j.mri.2006.11.023
更新日期:2007-05-01 00:00:00
abstract::A 24-year-old woman (Gravida I, Para I) at estimated 32 weeks of pregnancy was referred to our department for evaluation of a suspected fetal gastroschisis. Ultrasound scan revealed multiple loops of dilated bowel outside the fetal abdomen and absence of membrane surrounding the herniated loops of the intestines. Thre...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2005.10.006
更新日期:2006-02-01 00:00:00
abstract::Tumor aggressiveness and response to therapy are influenced by the extravascular extracellular space fraction (EESF) of the malignant tissue. The EESF may, therefore, be an important prognostic parameter for cancer patients. The aim of this study was to investigate whether gadopentetate dimeglumine (Gd-DTPA)-based dyn...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.06.003
更新日期:2008-02-01 00:00:00
abstract::A new approach is introduced for non-rigid registration of a pair of magnetic resonance images (MRI). It is a generalization of the demons algorithm with low computational cost, based on local information augmentation (by integrating multiple images) and balanced implementation. Specifically, a single deformation that...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2020.09.013
更新日期:2020-12-01 00:00:00
abstract::It is a big challenge to segment magnetic resonance (MR) images with intensity inhomogeneity. The widely used segmentation algorithms are region based, which mostly rely on the intensity homogeneity, and could bring inaccurate results. In this paper, we propose a novel region-based active contour model in a variationa...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2012.10.010
更新日期:2013-05-01 00:00:00
abstract::1H-nuclear magnetic resonance (NMR) measurements have been carried out on a banded sandstone to investigate the effects of structural inhomogeneities on the fluid dynamics of the sample as a whole. The results obtained from average propagator measurements (the probability of a displacement z in a time delta or P delta...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(98)00043-5
更新日期:1998-06-01 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::The purpose of this study is to illustrate motion correction in Musculoskeletal (MSK) Magnetic Resonance Imaging (MRI) through utilization of information from an optical tracker to capture the extent and instant of motion. A Digital Single Lens Reflexive camera is employed as the optical tracker to capture the extent ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2017.12.031
更新日期:2018-05-01 00:00:00
abstract::The purpose of the study was to determine whether diffusion-weighted magnetic resonance imaging (DWI) could identify focal lesions that develop in ischemia-sensitive cerebral tissues during reperfusion following global brain ischemia. Localized 1H-Magnetic Resonance Spectroscopy (1H-MRS) measurements were also obtaine...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(96)00094-x
更新日期:1996-01-01 00:00:00
abstract::Functional MR imaging of the alert, behaving monkey is being used more and more often to detect activation patterns and guide electrophysiological research investigating the neural basis of behavior. Several labs have reported fMRI data from the awake monkey, but none of them has studied and systematically corrected t...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.03.002
更新日期:2007-07-01 00:00:00
abstract:OBJECTIVE:To perform non-enhanced (NE) magnetic resonance imaging (MRI) of the small bowel at 7 Tesla (7T) and to compare it with 1.5 Tesla (1.5T). MATERIAL AND METHODS:Twelve healthy subjects were prospectively examined using a 1.5T and 7T MRI system. Coronal and axial true fast imaging with steady-state precession (...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2015.11.012
更新日期:2016-06-01 00:00:00
abstract::This study describes the appearance of Brenner tumors on MR imaging and compares quantitative signal intensity measurements of Brenner tumors with that of other ovarian tumors. A search of pathologic and MR records disclosed patients who had MRIs showing Brenner tumors prior to surgical excision. Patients (21) with ot...
journal_title:Magnetic resonance imaging
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/s0730-725x(98)00136-2
更新日期:1998-12-01 00:00:00
abstract::An inductively coupled surface coil for imaging the rat spine at 7 T is described. This planar circular probe was made from microwave substrate to limit the size of the coil and to minimize the magnetic susceptibility. The surface coil was used as a single transmit/receive coil and as a receive-only coil with a birdca...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(92)90447-8
更新日期:1992-01-01 00:00:00
abstract::Postero-anterior radiographs and magnetic resonance imaging (MRI) of the chest were performed in nine biopsy proven cases of sarcoidosis. MRI was more sensitive than a postero-anterior chest roentgenogram in detecting hilar and mediastinal adenopathy but less informative in detecting pleural and parenchymal disease. ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90131-2
更新日期:1988-09-01 00:00:00
abstract::A magnetic resonance imaging cardiac magnetic susceptometry (MRI-CS) technique for assessing cardiac tissue iron concentration based on phase mapping was developed. Normal control subjects (n=9) and thalassemia patients (n=13) receiving long-term blood transfusion therapy underwent MRI-CS and MRI measurements of the c...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.12.001
更新日期:2010-04-01 00:00:00