Abstract:
:The exponential clearance rate constant, (kappa), and filtration fraction (FF) have been measured for dialysis of Gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) (Magnevist, Berlex, Wayne, NJ) solutions by using a Look-Locker imaging technique under conditions of flow. The measured values of kappa for the Baxter CA-50, CA-110, and CA-210 filters were 0.0037 +/- 0.0003, 0.0057 +/- 0.0017, and 0.0092 +/- 0.0018 min-1, respectively, for dialysis of 4.0 liters of aqueous Gd-DTPA solutions. The measured values of FF for the Baxter CA-110 and CA-210 filters were 0.060 +/- 0.013 and 0.089 +/- 0.015, respectively, for dialysis of aqueous Gd-DTPA at 350 ml/min. The kappa and FF measurements agree with values that use inversion recovery (IR) on static samples obtained by drawing aliquots of solution during the course of dialysis. This in vitro experiment suggests that accurate in vivo measurements of filtration fraction and glomerular filtration rate (GFR) may be possible.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Niendorf ER,Santyr GE,Brazy PC,Grist TMdoi
10.1002/mrm.1910360412subject
Has Abstractpub_date
1996-10-01 00:00:00pages
571-8issue
4eissn
0740-3194issn
1522-2594journal_volume
36pub_type
杂志文章abstract:PURPOSE:Image-guided prostate biopsies are routinely acquired in the diagnosis and treatment monitoring of prostate cancer, yielding useful tissue for identifying metabolic biomarkers and therapeutic targets. We developed an optimized biopsy tissue culture protocol in combination with [1,6-13 C2 ]glucose labeling and q...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27739
更新日期:2019-08-01 00:00:00
abstract::Noninvasive investigation of aldose reductase activities in rat testis was performed using 3-fluoro-3-deoxy-D-glucose (3-FDG) and nuclear magnetic resonance (NMR) spectroscopy/imaging. Quantitative determination of testis aldose reductase activities, expressed as the sorbitol index, showed a value similar to that of b...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910290417
更新日期:1993-04-01 00:00:00
abstract::Flow-sensitive dephasing (FSD) magnetization preparation has been developed for black-blood vessel wall MRI and noncontrast MR angiography. The first-order gradient moment, m(1) , is a measure of the flow-sensitization imparted by an FSD preparative module. Determination of the optimal m(1) for each individual is high...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22847
更新日期:2011-04-01 00:00:00
abstract:PURPOSE:To demonstrate dynamic slice-dependent shim update as a simple method to reduce susceptibility-induced B0 inhomogeneity and associated pixel shift artifacts in diffusion-weighted echo planar imaging (DW-EPI) in 3 T breast imaging. METHODS:Dynamic slice-dependent update of linear shim and center frequency was i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24824
更新日期:2014-05-01 00:00:00
abstract::Successful radiofrequency (RF) thermal ablation was performed on VX2 tumors implanted in 23 rabbit livers under magnetic resonance (MR) guidance using a C-arm-shaped low-field 0.2 T system. RF application and immediate postprocedure MRI of all animals was performed [T2-weighted, turbo short tau inversion recovery (STI...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199907)42:1<141::aid-mrm19
更新日期:1999-07-01 00:00:00
abstract:PURPOSE:To develop a practical method for mapping macromolecule distribution in the brain using ultrashort-TE MRSI data. METHODS:An FID-based chemical shift imaging acquisition without metabolite-nulling pulses was used to acquire ultrashort-TE MRSI data that capture the macromolecule signals with high signal-to-noise...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26896
更新日期:2018-05-01 00:00:00
abstract::The acquisition of complete three-dimensional (3D), segmented gradient-echo data sets to visualize the coronary arteries can be both time consuming and sensitive to motion, even with use of multiple breath-holding or respiratory gating. An alternate hybrid approach is demonstrated here, in which real-time interactive ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400115
更新日期:1998-07-01 00:00:00
abstract::Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910400611
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:To develop a rapid imaging framework for balanced steady-state free precession (bSSFP) that jointly reconstructs undersampled data (by a factor of R) across multiple coils (D) and multiple acquisitions (N). To devise a multi-acquisition coil compression technique for improved computational efficiency. METHODS:...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26902
更新日期:2018-05-01 00:00:00
abstract:PURPOSE:To systematically evaluate the dependence of intravoxel-incoherent-motion (IVIM) parameters on the b-value threshold separating the perfusion and diffusion compartment, and to implement and test an algorithm for the standardized computation of this threshold. METHODS:Diffusion weighted images of the upper abdo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25506
更新日期:2015-11-01 00:00:00
abstract:PURPOSE:To develop a wideband cardiac perfusion pulse sequence and test whether it is capable of suppressing image artifacts in patients with a cardiac implantable electronic device (CIED), while not exceeding the specific absorption rate (SAR) limit (2.0 W/kg). METHODS:A wideband perfusion pulse sequence was develope...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27458
更新日期:2019-02-01 00:00:00
abstract::The ability to directly detect neuronal magnetic fields by MRI would help investigators achieve the "holy grail" of neuroimaging, namely both high spatial and temporal resolution. Both positive and negative findings have been reported in the literature, with no clear consensus as to the feasibility of direct detection...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21129
更新日期:2007-02-01 00:00:00
abstract:PURPOSE:A new method, called Transmit and Receive Patterns from Low-Tip-angle gradient-Echo Images (TRIPLET), is described which simultaneously maps the B1+ and B1- fields of a transmit/receive radiofrequency coil array. The input data are low-tip-angle gradient-echo images, which can be acquired in a relatively short ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24912
更新日期:2014-07-01 00:00:00
abstract:PURPOSE:To develop and evaluate a novel dynamic contrast-enhanced imaging technique called RACER-GRASP (Respiratory-weighted, Aortic Contrast Enhancement-guided and coil-unstReaking Golden-angle RAdial Sparse Parallel) MRI that extends GRASP to include automatic contrast bolus timing, respiratory motion compensation, a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27002
更新日期:2018-07-01 00:00:00
abstract::It is well known that when compared to conventional spin-echo (CSE) imaging for equivalent effective echo times, fast spin-echo (FSE) imaging experiments yield higher signal intensities for coupled spin systems, such as that for lipid. One hypothesis put forth for this phenomenon is the removal of scalar coupling-base...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910350409
更新日期:1996-04-01 00:00:00
abstract::Fitting a model to an experimental spectrum is a difficult nonlinear estimation problem. The solution presented here is to start an iterative search procedure sufficiently close to the optimal model parameter set. This is achieved by providing tissue-dependent a priori peak information and by a novel correlation metho...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910210206
更新日期:1991-10-01 00:00:00
abstract::The detection of free radical reactions in a gelatin sample irradiated by a heavy-ion beam was tested using electron paramagnetic resonance (EPR) spectroscopic and MRI methods. Geometry and the amount of free radical generation in a sample are described. A reaction mixture containing glutathione and a nitroxyl radical...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21958
更新日期:2009-05-01 00:00:00
abstract::Alternate methods to quantify mitochondrial activity or function have been extensively used for studying insulin resistance and type 2 diabetes mellitus, namely saturation transfer and phosphocreatine (PCr) recovery. As these methods are in fact determining different parameters, this study aimed to compare saturation ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23095
更新日期:2012-04-01 00:00:00
abstract::Metallic implants, such as stents, have long been a concern in magnetic resonance imaging (MRI). In addition to safety issues, they are commonly associated with image artifacts. The mechanisms of radiofrequency- (RF) and susceptibility-induced artifacts have been thoroughly investigated. However, gradient-switching-in...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20294
更新日期:2004-12-01 00:00:00
abstract::Human mesenchymal stem cells (hMSCs) were labeled with Ferucarbotran by simple incubation and cultured for up to 14 d. Iron content was determined by spectrometry and the intracellular localization of the contrast agent uptake was studied by electron and confocal microscopy. At various time points after labeling, rang...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22011
更新日期:2009-08-01 00:00:00
abstract::Accurate and fast quantification of myocardial blood flow (MBF) with MR first-pass perfusion imaging techniques on a pixel-by-pixel basis remains difficult due to relatively long calculation times and noise-sensitive algorithms. In this study, Zierler's central volume principle was used to develop an algorithm for the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21559
更新日期:2008-06-01 00:00:00
abstract::In this study undersampled projection reconstruction (PR) was used for rapid catheter imaging in the heart, employing steady-state free precession (SSFP) contrast. Active catheters and phased-array coils were used for combined imaging of anatomy and catheter position in swine. Real-time imaging of catheter position wa...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10390
更新日期:2003-02-01 00:00:00
abstract::A gradient technique to measure electron paramagnetic resonance spectra simultaneously at several different locations is described. The technique is based on the use of point probes containing paramagnetic centers. The value of the magnetic field gradient is chosen to be sufficient to separate the EPR signals from the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910300210
更新日期:1993-08-01 00:00:00
abstract:PURPOSE:To model and correct the dephasing effects in the gradient-echo signal for arbitrary RF excitation pulses with large flip angles in the presence of macroscopic field variations. METHODS:The dephasing of the spoiled 2D gradient-echo signal was modeled using a numerical solution of the Bloch equations to calcula...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28139
更新日期:2020-08-01 00:00:00
abstract:PURPOSE:The aim of this study was to develop a technique for rapid collection of chemical exchange saturation transfer images with the saturation varied to modulate signal loss transfer and enhance contrast. METHODS:Multi-echo Length and Offset VARied Saturation (MeLOVARS) divides the saturation pulse of length Tsat i...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25567
更新日期:2015-02-01 00:00:00
abstract::Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910360422
更新日期:1996-10-01 00:00:00
abstract::Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons-including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools k(mf) . This study describes the first implementation of...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22928
更新日期:2011-11-01 00:00:00
abstract::Golgi impregnation is unique in its ability to display the dendritic trees and axons of large numbers of individual neurons by histology. Here we apply magnetic resonance microscopy to visualize the neuroanatomy of animal models by combining histologic fixation chemistry with paramagnetic contrast agents. Although the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22322
更新日期:2010-05-01 00:00:00
abstract::Magnetization exchange effects between the matrix macromolecules (e. g., collagen and proteoglycan) and water were examined in normal, deuterated, and proteoglycan-depleted articular cartilage. Relaxation results (T(2), T(1rho), and T(1)) suggested that a four-site exchange scheme provided an accurate model for articu...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200012)44:6<840::aid-mrm4>3.0.co
更新日期:2000-12-01 00:00:00
abstract::A method is demonstrated for detection of magnetization from a selected region within the sensitive volume of a surface coil in a single acquisition. Composite pulses are described which eliminate signals from regions where magnetization is rotated 270 and 450 degrees. There is a loss of 1.3% or less of signal from re...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910030221
更新日期:1986-04-01 00:00:00