Abstract:
PURPOSE:To test the hypothesis that a noninvasive dynamic contrast enhanced MRI (DCE-MRI) derived interstitial volume fraction (ve ) and/or distribution volume (VD ) were correlated with tumor cellularity in cerebral tumor. METHODS:T1 -weighted DCE-MRI studies were performed in 18 athymic rats implanted with U251 xenografts. After DCE-MRI, sectioned brain tissues were stained with Hematoxylin and Eosin for cell counting. Using a Standard Model analysis and Logan graphical plot, DCE-MRI image sets during and after the injection of a gadolinium contrast agent were used to estimate the parameters plasma volume (vp ), forward transfer constant (K(trans) ), ve , and VD . RESULTS:Parameter values in regions where the standard model was selected as the best model were: (mean ± S.D.): vp = (0.81 ± 0.40)%, K(trans) = (2.09 ± 0.65) × 10(-2) min(-1) , ve = (6.65 ± 1.86)%, and VD = (7.21 ± 1.98)%. The Logan-estimated VD was strongly correlated with the standard model's vp + ve (r = 0.91, P < 0.001). The parameters, ve and/or VD , were significantly correlated with tumor cellularity (r ≥ -0.75, P < 0.001 for both). CONCLUSION:These data suggest that tumor cellularity can be estimated noninvasively by DCE-MRI, thus supporting its utility in assessing tumor pathophysiology.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Aryal MP,Nagaraja TN,Keenan KA,Bagher-Ebadian H,Panda S,Brown SL,Cabral G,Fenstermacher JD,Ewing JRdoi
10.1002/mrm.24873subject
Has Abstractpub_date
2014-06-01 00:00:00pages
2206-14issue
6eissn
0740-3194issn
1522-2594journal_volume
71pub_type
杂志文章abstract::Susceptibility artifacts and transmission radio frequency (RF) field (B(1) +) inhomogeneity are major limitations in high-field gradient echo MRI. Previously proposed numerical 2D spectral-spatial RF pulses have been shown to be promising for reducing the through-plane signal loss susceptibility artifact by incorporat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22725
更新日期:2011-02-01 00:00:00
abstract:PURPOSE:To achieve artifact-suppressed whole-brain pass-band-balanced steady-state free precession functional MRI from a single functional magnetic resonance imaging (fMRI) scan. METHODS:A complete and practical data acquisition sequence for alt-SSFP fMRI was developed. First, multishot flyback-echo-planar imaging (EP...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25797
更新日期:2016-05-01 00:00:00
abstract:PURPOSE:A method for the quantification of perfusion in murine myocardium is demonstrated. The method allows for the reconstruction of perfusion maps on arbitrary time points in the heart cycle while addressing problems that arise due to the irregular heart beat of mice. METHODS:A flow-sensitive alternating inversion ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25526
更新日期:2015-12-01 00:00:00
abstract::The aim of this study was to detect salvageable peri-infarction myocardium by MRI in rats after infarction, using with a double contrast agent (CA) protocol at 7 Tesla. Intravascular superparamagnetic iron oxide (SPIO) nanoparticles and an extracellular paramagnetic CA (Gd-DOTA) were used to characterize the peri-infa...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20210
更新日期:2004-10-01 00:00:00
abstract::At high magnetic fields the performance of a volume-type body coil inside a human sized MR-scanner is influenced by the waveguide action of the scanner's bore. This can result in undesirable strong radio frequency fields B1+) outside the coil's target volume. A radio frequency (RF) transmit system, exploiting this wav...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24496
更新日期:2013-09-01 00:00:00
abstract::A method is presented for the detection of quadrupole splitting in tissue, where the spectral line splittings are typically unobservable. The method used is a study of the rate of rotation of the flip angle as a function of radiofrequency (rf) amplitude. Our results with samples of skeletal muscle and cat brain indica...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910040108
更新日期:1987-01-01 00:00:00
abstract:PURPOSE:To develop a flexible fast spin echo (FSE) triple-echo Dixon (FTED) technique. METHODS:An FSE pulse sequence was modified by replacing each readout gradient with three fast-switching bipolar readout gradients with minimal interecho dead time. The corresponding three echoes were used to generate three raw image...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26186
更新日期:2017-03-01 00:00:00
abstract::A new contrast preparation based on modified driven equilibrium Fourier transfer is introduced and evaluated for generation of T1-weighted images for assessment of the myocardial perfusion with contrast agent first-pass kinetics. The new preparation scheme produces T1 contrast with insensitivity to arrhythmias in pros...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910340408
更新日期:1995-10-01 00:00:00
abstract:PURPOSE:Blood flow causes induced voltages via the magnetohydrodynamic (MHD) effect distorting electrograms (EGMs) made during magnetic resonance imaging. To investigate the MHD effect in this context MHD voltages occurring inside the human heart were simulated in an in vitro model system inside a 1.5 T MR system. MET...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25456
更新日期:2015-09-01 00:00:00
abstract::We constructed a device to compress small samples of articular cartilage while the samples were imaged in a 1.5 T imager. With the use of a piezoelectric piston, the device compressed 1-cm-diameter cylindrical samples of articular cartilage (200 microm) at a rate of 2 Hz. Simultaneously, we imaged the samples with a d...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20439
更新日期:2005-05-01 00:00:00
abstract:PURPOSE:To design, construct, and evaluate quantitative MR phantoms that mimic MRI signals from the liver with simultaneous control of three parameters: proton-density fat fraction (PDFF), R 2 ∗ ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28452
更新日期:2021-02-01 00:00:00
abstract::A novel method, called relaxo-oximetry, for rapid spatially resolved in vivo measurements of oxygen concentration using time-domain radiofrequency (RF) electron paramagnetic resonance (EPR) is described. Time-domain data from triaryl methyl (TAM)-based single-electron contrast agents were processed by systematic delet...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10133
更新日期:2002-05-01 00:00:00
abstract::Activity-induced manganese-dependent contrast (AIM) MRI is a hemodynamic-independent functional MRI method that used manganese ion as an MR-detectable contrast agent. In AIM, MnCl(2) is infused intra-arterially after the blood-brain barrier (BBB) is opened with a hyperosmolar agent. Upon functional stimulation of the ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10320
更新日期:2002-12-01 00:00:00
abstract::Diffusion tensor imaging (DTI) is a new imaging modality that can provide unique information on brain white matter anatomy. Measurements of water diffusion constant along multiple axes are fitted to a tensor model, from which the diffusion anisotropy and dominant fiber orientation can be estimated. Even though the ten...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20767
更新日期:2006-02-01 00:00:00
abstract::For sodium imaging of the human brain, Gibbs' ringing can degrade image appearance and confound image analysis; k-space filtering is generally required. In this work, the signal to noise ratio (SNR) advantage of sampling density weighted apodization (SDWA) over uniform k-space sampling with postacquisition filtering a...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21738
更新日期:2008-10-01 00:00:00
abstract::Patient-specific radiofrequency shimming in high-field MRI strengthens the need for online, patient-specific specific absorption rate (SAR) monitoring. Numerical simulation is currently most effective for this purpose but may require a patient-specific dielectric model. To investigate whether a generic model may be co...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24378
更新日期:2013-05-01 00:00:00
abstract::In this article, we determined the relative accuracy of semiautomated spleen volumetry with diffusion-weighted (DW) MR images compared to standard manual volumetry with DW-MR or CT images. Semiautomated spleen volumetry using simple thresholding followed by 3D and 2D connected component analysis was performed with DW-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.23204
更新日期:2012-07-01 00:00:00
abstract:PURPOSE:The purpose of the present study was to apply noninvasive methods for monitoring regeneration and mechanical properties of tissue-engineered cartilage in vivo at different growth stages using MR elastography (MRE). METHODS:Three types of scaffolds, including silk, collagen, and gelatin seeded by human mesenchy...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25745
更新日期:2016-03-01 00:00:00
abstract:PURPOSE:For the application of compressive sensing to parallel MRI, Poisson disk sampling (PDS) has been shown to generate superior results compared with random sampling methods. However, due to its limited flexibility to incorporate additional constraints, PDS is not readily extendible to dynamic applications. Here, w...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25507
更新日期:2015-11-01 00:00:00
abstract::This study investigates the potential of in vivo 31P magnetic resonance spectroscopy (MRS) to characterize musculoskeletal tumors and to determine preoperative levels of histological necrosis, which is an important clinical indicator of patient response. Pretherapy MRS was performed on 28 patients with large musculosk...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910270204
更新日期:1992-10-01 00:00:00
abstract::The experiments reported herein are the first MRI investigations of the orientational dependence of T(2) relaxation in articular cartilage at microscopic resolution over the 360 degrees angular space. For each of six canine cartilage specimens, 48 independent T(2)-weighted proton images were acquired for 12 different ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10216
更新日期:2002-09-01 00:00:00
abstract::Sensitivity encoding is used to improve the performance of real-time MRI. The encoding efficiency of single-shot and segmented echo-planar imaging is tripled by means of a 6-element receiver coil array. The feasibility of this approach is verified for double oblique cardiac real-time imaging of human subjects at rest ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(200002)43:2<177::aid-mrm3>
更新日期:2000-02-01 00:00:00
abstract::Function and morphology of the cerebral vasculature were studied in the amyloid (Abeta) plaque-containing double-transgenic (TG) B6.PS2APP Alzheimer's disease (AD) mouse model with MRI at an age range of 10 to 17 months. Perfusion, blood volume, and average vessel geometry were assessed in the brain and compared to ag...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21985
更新日期:2009-07-01 00:00:00
abstract:PURPOSE:To develop a postprocessing algorithm that corrects geometric distortions due to spatial variations of the static magnetic field amplitude, B0 , and effects from relaxation during signal acquisition in EPI. THEORY AND METHODS:An analytic, complex point-spread function is deduced for k-space trajectories of EPI...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28591
更新日期:2020-11-21 00:00:00
abstract:PURPOSE:To compare the performance of an 8-channel surface coil/clamshell transmitter and 32-channel head array coil/birdcage transmitter for hyperpolarized 13 C brain metabolic imaging. METHODS:To determine the field homogeneity of the radiofrequency transmitters, B1 + mapping was performed on an ethylene glycol head...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27743
更新日期:2019-08-01 00:00:00
abstract::A new decoupling sequence, PBAR, is described for broadband heteronuclear decoupling in vivo in humans at 1.5T. The sequence uses non-adiabatic, frequency- and amplitude-modulated inversion pulses designed to minimize decoupling sidebands at low applied gammaB(2) RF field levels and to cover only the narrow range of r...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200102)45:2<226::aid-mrm1031>3.0
更新日期:2001-02-01 00:00:00
abstract::A non-invasive method for studying the modifications induced in lipid depots by hormonal stimulation could extend knowledge of adipose tissues. We studied the effect of adrenergic stimulation on interscapular brown adipose tissue (IBAT) of rats using contrast-enhanced MRI. Controls and rats pre-treated with adrenaline...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20851
更新日期:2006-04-01 00:00:00
abstract::Adipose tissue as well as other depots of fat (triglycerides) are increasingly being recognized as active contributors to the human function and metabolism. In addition to the fat concentration, also the fatty acid chemical composition (FAC) of the triglyceride molecules may play an important part in diseases such as ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章,评审
doi:10.1002/mrm.28471
更新日期:2021-01-01 00:00:00
abstract::Quantification of peak velocity is important in the assessment of stenotic flow jets in patients with congenital heart disease. Phase-contrast magnetic resonance underestimates peak velocities. Hence, clinically Doppler ultrasound is used as the reference standard for assessing stenoses. It is possible to accurately m...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24293
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:To determine the feasibility of employing the prior knowledge of well-separated chemical exchange saturation transfer (CEST) signals in the 9.4 T Z-spectrum to separate overlapping CEST signals acquired at 3 T, using a deep learning approach trained with 3 T and 9.4 T CEST spectral data from brains of the same ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27690
更新日期:2019-06-01 00:00:00