Abstract:
:Vessel size index (VSI), a parameter related to the distribution of vessel diameters, may be estimated using two MRI approaches: (i) dynamic susceptibility contrast (DSC) MRI following the injection of a bolus of Gd-chelate. This technique is routinely applied in the clinic to assess intracranial tissue perfusion in patients; (ii) steady-state susceptibility contrast with USPIO contrast agents, which is considered here as the standard method. Such agents are not available for human yet and the steady-state approach is currently limited to animal studies. The aim is to compare VSI estimates obtained with these two approaches on rats bearing C6 glioma (n = 7). In a first session, VSI was estimated from two consecutive injections of Gd-Chelate (Gd(1) and Gd(2)). In a second session (4 hours later), VSI was estimated using USPIO. Our findings indicate that both approaches yield comparable VSI estimates both in contralateral (VSI{USPIO} = 7.5 ± 2.0 µm, VSI{Gd(1)} = 6.5 ± 0.7 µm) and in brain tumour tissues (VSI{USPIO} = 19.4 ± 7.1 µm, VSI{Gd(1)} = 16.6 ± 4.5 µm). We also observed that, in the presence of BBB leakage (as it occurs typically in brain tumours), applying a preload of Gd-chelate improves the VSI estimate with the DSC approach both in contralateral (VSI{Gd(2)} = 7.1 ± 0.4 µm) and in brain tumour tissues (VSI{Gd(2)} = 18.5 ± 4.3 µm) but is not mandatory. VSI estimates do not appear to be sensitive to T(1) changes related to Gd extravasation. These results suggest that robust VSI estimates may be obtained in patients at 3 T or higher magnetic fields with the DSC approach.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Pannetier N,Lemasson B,Christen T,Tachrount M,Troprès I,Farion R,Segebarth C,Rémy C,Barbier ELdoi
10.1002/nbm.1734subject
Has Abstractpub_date
2012-02-01 00:00:00pages
218-26issue
2eissn
0952-3480issn
1099-1492journal_volume
25pub_type
杂志文章abstract::MR Z-spectroscopy allows enhanced imaging contrast on the basis of saturation transfer between the proton pools of cellular compounds and water, occurring via chemical exchange (chemical exchange saturation transfer, CEST) or dipole-dipole coupling (nuclear Overhauser effect, NOE). In previous studies, signals observe...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3021
更新日期:2013-12-01 00:00:00
abstract::In imaging of human lungs with hyperpolarised noble gases, measurements of apparent diffusion coefficient (ADC) and relaxation time provide valuable information for the assessment of lung microstructure. In this work, a sequence was developed for interleaved acquisition of ventilation images, ADC, T(2)* and flip angle...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1710
更新日期:2012-01-01 00:00:00
abstract::The aim of this study was to analyze Na+ fluxes in whole perfused hearts using Li+ as a Na+ congener and 7Li-nuclear magnetic resonance as a detection method. Hearts were equilibrated for 32 min with 15 mM LiCl added to P1-free Krebs-Henseleit buffer (intracellular space (ICS) [Li+] = 21.5 +/- 3.4 mM). Li+ efflux was ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199709)10:6<271::aid-nbm47
更新日期:1997-09-01 00:00:00
abstract::An outline is presented of metabolite-specific in vivo NMR spectroscopy (particularly in brain). It reviews from a physical spectroscopist's perspective, the need for and the methods of observation of, individual metabolite resonances. ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199712)10:8<435::aid-nbm48
更新日期:1997-12-01 00:00:00
abstract::The accurate diagnosis of glioma subtypes is critical for appropriate treatment, but conventional histopathologic diagnosis often exhibits significant intra-observer variability and sampling error. The aim of this study was to investigate whether histogram analysis using an automatically segmented region of interest (...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3153
更新日期:2014-09-01 00:00:00
abstract::The background underpinning the clinical use of ultrashort echo time, SPRITE and other pulse sequences for imaging bone and other connective tissues with short T2 is reviewed. Features of the basic physics relevant to UTE imaging are described, including the consequences when the radiofrequency pulse duration is of th...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1100
更新日期:2006-11-01 00:00:00
abstract::One of the most commonly used methods for in vivo MRS detection of γ-aminobutyric acid (GABA) is the MEGA-point-resolved spectroscopy (MEGA-PRESS) technique. However, accurate quantification of GABA using MEGA-PRESS is complicated by spectral co-editing of macromolecular resonances. In this article, a new pulse sequen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1688
更新日期:2011-12-01 00:00:00
abstract:PURPOSE:To develop a novel respiratory motion compensated three-dimensional (3D) cardiac magnetic resonance fingerprinting (cMRF) approach for whole-heart myocardial T1 and T2 mapping from a free-breathing scan. METHODS:Two-dimensional (2D) cMRF has been recently proposed for simultaneous, co-registered T1 and T2 mapp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4370
更新日期:2020-10-01 00:00:00
abstract::Reconstruction of MRI data is based on exact knowledge of all magnetic field dynamics, since the interplay of RF and gradient pulses generates the signal, defines the contrast and forms the basis of resolution in spatial and spectral dimensions. Deviations caused by various sources, such as system imperfections, delay...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3359
更新日期:2016-09-01 00:00:00
abstract::Diffusion tensor imaging (DTI) provides an indirect measure of tissue structure on a microscopic scale. To date, DTI is the only imaging method that provides such information in vivo, and has proven to be a valuable tool in both research and clinical settings. In this study, we investigated the relationship between wh...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1810
更新日期:2012-07-01 00:00:00
abstract::A noise figure and noise parameter measurement system was developed that consists of a combination spectrum and network analyzer, preamplifier, programmable power supply, noise source, tuning board, and desktop computer. The system uses the Y-factor method for noise figure calculation and allows calibrations to correc...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3138
更新日期:2014-08-01 00:00:00
abstract::The myeloproliferative leukemic virus (MPLV) induces within 2-3 weeks a massive infiltration of the adult mouse liver by hematopoietic leukemic cells. Since the metabolism of the infiltrated organ might be correlated with an interaction of two cell populations, it was decided to study the isolated hematopoietic cells ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940020106
更新日期:1989-06-01 00:00:00
abstract::The purpose of the present study was to characterize the metabolic profile of the visual cortex in streptozotocin-induced Type 1 diabetic rats by means of in vivo proton MRS. Several metabolite concentration ratios in the visual cortex were calculated. In addition, postmortem histologic analyses for retinal ganglion c...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3783
更新日期:2017-11-01 00:00:00
abstract::Balanced steady-state free precession imaging has recently been suggested for chemical exchange detection (bSSFPX). The objective of this work is to investigate the contributions of microstructural, chemical shift and chemical exchange effects to the asymmetry of the bSSFP profile at field strengths of 3 T and 9.4 T. ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4200
更新日期:2020-03-01 00:00:00
abstract::Structural high-resolution imaging of the brainstem can be of high importance in clinical practice. However, ultra-high field magnetic resonance imaging (MRI) is still restricted in use due to limited availability. Therefore, quantitative MRI techniques (quantitative susceptibility mapping [QSM], relaxation measuremen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4118
更新日期:2019-09-01 00:00:00
abstract::In this study, we have performed simulations to address the effects of diffusion encoding parameters, signal-to-noise ratio (SNR) and T2 on skeletal muscle diffusion tensor indices and fiber tracts. Where appropriate, simulations were corroborated and validated by in vivo diffusion tensor imaging (DTI) of human skelet...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2959
更新日期:2013-11-01 00:00:00
abstract::Cerebrovascular reactivity (CVR) can give insight into the cerebrovascular function. CVR can be estimated by measuring a blood-oxygen-level-dependent (BOLD) response combined with breath-holding (BH). The reproducibility of this technique has been addressed and existing studies have focused on short-term reproducibili...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4195
更新日期:2020-03-01 00:00:00
abstract::In many small animals there are distinct differences in fiber-type composition among limb muscles, and these differences typically correspond to marked disparities in the oxidative capacities. However, whether there are similar differences in the oxidative capacity among leg muscles in humans is less clear. The purpos...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1413
更新日期:2009-12-01 00:00:00
abstract::13C MRS was installed on a clinical scanner at 1.5 T in order to facilitate integrated MR examinations of human brain disorders. Using a simplified protocol, (1-(13)C) glucose and/or (1-(13)C) acetate were administered orally or by intravenous infusion. (13)C spectra of diagnostic quality were acquired in more than 10...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.852
更新日期:2003-10-01 00:00:00
abstract::The cerebral blood volume (CBV) is a crucial physiological indicator of tissue viability and vascular reactivity. Thus, noninvasive CBV mapping has been of great interest. For this, ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles, including monocrystalline iron oxide nanoparticles, can be used as long-ha...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.2885
更新日期:2013-08-01 00:00:00
abstract::In this study, the upper-limit volume (gas plus partial tissue volume) as well as absolute volume (gas only) of lungs measured with hyperpolarized (3)He-MR imaging is compared with that determined by micro-computed tomography (CT) under similar ventilation conditions in normal rats. Five Brown Norway rats (210-259 g) ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1470
更新日期:2010-05-01 00:00:00
abstract::Aminoacylase 1 deficiency is a novel inborn error of metabolism. The clinical significance of the deficiency is under discussion, as well as the possible consequences of the defect for brain metabolism and function. This study includes the five originally published cases as well as three novel ones. NMR spectroscopy o...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1170
更新日期:2008-02-01 00:00:00
abstract::Quantitative susceptibility mapping (QSM) is a recently developed MRI technique that provides a quantitative measure of tissue magnetic susceptibility. To compute tissue magnetic susceptibilities based on gradient echoes, QSM requires reliable unwrapping of the measured phase images and removal of contributions caused...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3056
更新日期:2014-02-01 00:00:00
abstract::Raised concentrations of glucose for extended periods of time have detrimental effects on the insulin-producing beta-cell. As de novo synthesis of lipids has been observed under such conditions, it was hypothesized that newly formed lipids may preferentially contain saturated fatty acids, which in particular have been...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1197
更新日期:2008-05-01 00:00:00
abstract::This paper compares two spectral processing methods for obtaining quantitative measures from in vivo prostate spectra, evaluates their effectiveness, and discusses the necessary modifications for accurate results. A frequency domain analysis (FDA) method based on peak integration was compared with a time domain fittin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1008
更新日期:2006-04-01 00:00:00
abstract::T2 of NAA, creatine and choline-containing compounds were measured in posterior frontal white matter and occipital grey matter in 10 healthy human volunteers. Decay curves comprised signals from eight TE times ranging from 30 to 800 ms with TR 2000 ms acquired with a PRESS sequence on a 1.5 T clinical scanner. Simulat...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.916
更新日期:2005-02-01 00:00:00
abstract::The aim of this study was to investigate physiological variations of the water T2 relaxation time in vertebral bone marrow with respect to age, body mass index (BMI), sex and proton density fat fraction (PDFF) based on single-voxel magnetic resonance spectroscopy (MRS) at 3 T. Multi-TE single-voxel STEAM MRS data of a...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4439
更新日期:2020-11-17 00:00:00
abstract::The application of 31P MR spectroscopy in the characterization and treatment of malignant human extremity tumors is reviewed and placed in the perspective of results obtained in murine sarcomas. Despite the now widespread acquisition of gradient localized spectral maps, the low spatial resolution that can be achieved ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(1998110)11:7<341::aid-nbm5
更新日期:1998-11-01 00:00:00
abstract::The purpose of this work was to harmonize data acquisition and post-processing of single voxel proton MRS ((1) H-MRS) at 7 T, and to determine metabolite concentrations and the accuracy and reproducibility of metabolite levels in the adult human brain. This study was performed in compliance with local institutional hu...
journal_title:NMR in biomedicine
pub_type: 杂志文章,多中心研究
doi:10.1002/nbm.3252
更新日期:2015-03-01 00:00:00
abstract::Electric properties tomography (EPT) derives the patient's electric properties, i.e. conductivity and permittivity, using standard magnetic resonance (MR) systems and standard MR sequences. Thus, EPT does not apply externally mounted electrodes, currents or radiofrequency (RF) probes, as is the case in competing techn...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.3729
更新日期:2017-08-01 00:00:00