Abstract：
:Because of their paramagnetic properties, nitroxides are potentially useful as contrast agents in magnetic resonance imaging (MRI). They are reduced in vivo to their corresponding hydroxylamines which are nonparamagnetic and have no contrast enhancing property. Nitroxides with high resistance to reduction would be advantageous as pharmaceutical contrast enhancing agents. We show that in the presence of ascorbic acid and in tissue homogenates, the reduction is faster for piperidine than for pyrrolidine nitroxides and for positively-charged than for negatively-charged derivatives. The data also suggest that nitroxide reduction in tissue homogenates is mainly due to sulfhydryl groups on proteins and that endogenous ascorbic acid plays a relatively minor role.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Couet WR,Brasch RC,Sosnovsky G,Tozer TNdoi
10.1016/0730-725x(85)90012-8subject
Has Abstractpub_date
1985-01-01 00:00:00pages
83-8issue
1eissn
0730-725Xissn
1873-5894pii
0730-725X(85)90012-8journal_volume
3pub_type
杂志文章abstract：:Dynamic contrast-enhanced magnetic resonance imaging (MRI) is widely used for measuring perfusion and blood volume, especially cerebral blood volume (CBV). In case of blood-brain barrier (BBB) disruption, the conventional techniques only partially determine the pharmacokinetic parameters of contrast medium (CM) exchan...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(00)00223-x
更新日期：2000-12-01 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：PURPOSE:To evaluate the influence of cholecystectomy on the flow dynamic pattern of bile in the extrahepatic bile duct by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively. MATERIALS AND METHODS:56 patients with cholecystectomy and 48 control subjects without cholecystectomy...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.08.016
更新日期：2020-12-01 00:00:00
abstract：:The purpose of this study was to analyze background parenchymal enhancement (BPE) in the contralateral normal breast of cancer patients during the course of neoadjuvant chemotherapy (NAC). Forty-five subjects were analyzed. Each patient had three MRIs, one baseline (B/L) and two follow-up (F/U) studies. The fibrogland...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.07.014
更新日期：2013-11-01 00:00:00
abstract：PURPOSE:Investigation of the feasibility of the R2⁎ mapping techniques by using latest theoretical models corrected for confounding factors and optimized for signal to noise ratio. THEORY AND METHODS:The improvement of the performance of state of the art magnetic resonance imaging (MRI) relaxometry algorithms is chall...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2016.08.006
更新日期：2017-01-01 00:00:00
abstract：:We retrospectively compared the diagnostic accuracy of abdominal ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) studies performed on the same individual to determine the relative performance of these modalities in the evaluation of disease processes, arising from different intra-abdomi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2003.01.001
更新日期：2004-01-01 00:00:00
abstract：PURPOSE:To evaluate the application of high-resolution MRI methodology for characterizing the fluid velocity field and evaluate fluid shear field within a simplified in vitro model of a bone-implant interface. MATERIALS AND METHODS:The study used a specific micromotion canine bone implant that has been used for over a...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2005.11.001
更新日期：2006-06-01 00:00:00
abstract：:Magnetic resonance imaging (MRI) has been applied to assess kidney function in normal rats by monitoring the passage of the extracellular contrast agent GdDOTA. High-resolution images have been obtained using either the rapid acquisition with relaxation enhancement (RARE) or the snapshot pulse sequence. The latter was...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(00)00134-x
更新日期：2000-06-01 00:00:00
abstract：BACKGROUND AND PURPOSE:The widespread propagation of synchronized neuronal firing in seizure disorders may affect cortical and subcortical brain regions. Diffusion tensor imaging (DTI) can noninvasively quantify white matter integrity. The purpose of this study was to investigate the abnormal changes of white matter in...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2010.03.046
更新日期：2010-11-01 00:00:00
abstract：:Noise estimation is a challenging task in magnetic resonance imaging (MRI), with applications in quality assessment, filtering or diffusion tensor estimation. Main noise estimators based on the Rician model are revisited and classified in this article, and new useful methods are proposed. Additionally, all the surveye...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2009.05.025
更新日期：2009-12-01 00:00:00
abstract：:A new magnetic resonance imaging technique was applied to the Taylor-Couette and spiral Poiseuille (Taylor-Couette with superposed mean axial flux) flows for the first time. The experimental technique is a combination of spatial tagging methods and a snapshot FLASH imaging sequence, which allows the full-field visuali...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(99)00121-6
更新日期：2000-02-01 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：:Peripheral magnetic resonance angiography (MRA) is growing in use. However, methods of performing peripheral MRA vary widely and continue to be optimized, especially for improvement in illustration of infrapopliteal arteries. The main purpose of this project was to identify imaging factors that can improve arterial vi...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(02)00531-3
更新日期：2002-09-01 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：:Forty-two patients with clinically suspected osteomyelitis were examined using magnetic resonance imaging (MRI). Twenty-seven patients (64%) had previous surgery or fracture, and 15 (36%) were referred for differentiation of acute osteomyelitis from bone tumors or other pathologic conditions. MRI was compared with com...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(85)90350-9
更新日期：1985-01-01 00:00:00
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...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(97)00020-9
更新日期：1997-01-01 00:00:00
abstract：:The fast Fourier flow technique offers a convenient way for extremely exact flow measurements. In combination with ECG gating, arterial flow can be studied. The total acquisition time for a single measurement is about 10 s, an ECG-gated cine sequence can be acquired in about 4 min. Fast Fourier flow can, therefore, be...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(88)90473-0
更新日期：1988-07-01 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
abstract：PURPOSE:To evaluate the use of the double-echo steady-state (DESS) sequence for acquiring high-resolution breast images with diffusion and T2 weighting. MATERIALS AND METHODS:Phantom scans were used to verify the T2 and diffusion weighting of the DESS sequence. Image distortion was evaluated in volunteers by comparing...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2013.12.014
更新日期：2014-05-01 00:00:00
abstract：:SSFP-based fMRI techniques, known for their high specificity and low geometrical distortion, look promising for high-resolution brain mapping. Nevertheless, they suffer from lack of speed and sensitivity, leading them to be exploited mostly in high-field scanners. Radial acquisition can help with these inefficiencies ...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2020.09.005
更新日期：2020-12-01 00:00:00
abstract：PURPOSE:To evaluate non-invasive imaging biomarkers for assessing renal fibrosis. DWI is used to assess renal function; intravoxel incoherent motion (IVIM) provides additional measures of perfusion-related diffusion (D*, blood flow; f, perfusion fraction). We aim to determine if reduced ADC seen in renal fibrosis is at...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2015.07.012
更新日期：2015-12-01 00:00:00
abstract：:Spiral acquisition schemes offer unique advantages such as flow compensation, efficient k-space sampling and robustness against motion that make this option a viable choice among other non-Cartesian sampling schemes. For this reason, the main applications of spiral imaging lie in dynamic magnetic resonance imaging suc...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章,评审
doi：10.1016/j.mri.2010.03.036
更新日期：2010-07-01 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：:The HASTE (half-Fourier acquisition single-shot turbo spin-echo) technique delivers images with T2-weighting in about half a second and could be ideal for fast dynamic studies when T2-weighting is needed. We evaluated cardiac-triggered HASTE to study cervical spine flexion/extension. The cervical spines of ten asympto...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(98)00176-3
更新日期：1999-04-01 00:00:00
abstract：:Various analogs of NMR and MRI are now technically possible in optics; specifically, high-resolution laser-pulse shaping and complex pulse sequence generation with well-defined phase shifts has been demonstrated. Here we summarize this technology and discuss the potential for these methods to enhance optical functiona...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2003.08.024
更新日期：2003-12-01 00:00:00
abstract：:The local determination of porosity is an extremely valuable target because of different applications in petrophysics. In fact, obtaining a reliable profile of porosity or saturations could considerably improve the evaluation of transport properties of porous media, especially if applied to multiphase flow test (i.e.,...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/s0730-725x(96)00182-8
更新日期：1996-01-01 00:00:00
abstract：:Microscopic magnetic resonance elastography is a high-resolution method for visualizing shear waves and assessing the biomechanical viscoelastic properties of small biological samples. In this work, we used error propagation to develop a simple analytical model that relates the signal-to-noise ratio of MR magnitude im...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/j.mri.2006.09.040
更新日期：2007-01-01 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：:Pellets of HeLa from suspension cultured cells in isotonic medium (300 mosmolar) were introduced into a Bruker CXP100 NMR spectrophotometer at 80 mHz within 5 min of the start of centrifugation. T1 and T2 times were measured within a total elapsed time of 20-25 min at 80 mHz and 37 degrees C, and averaged 1430 msec an...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(90)90101-7
更新日期：1990-01-01 00:00:00
abstract：:The application of a raw data-based, operator-independent MR segmentation technique to differentiate boundaries of tumor from edema or hemorrhage is demonstrated. A case of a glioblastoma multiforme with gross and histopathologic correlation is presented. The MR image data set was segmented into tissue classes based o...
journal_title：Magnetic resonance imaging
pub_type： 杂志文章
doi：10.1016/0730-725x(94)00093-i
更新日期：1995-01-01 00:00:00
