Abstract:
:We propose a very high-resolution, three-dimensional (3D) gradient-echo technique with a twofold parallel imaging acceleration using a specialized occipital receiver coil at 3 T to perform functional MRI (fMRI) of the visual cortex. This configuration makes it possible to acquire 3D fMRI data within a timescale compatible with a block design. Without further processing, the functional maps at an isotropic 3D resolution of 0.42 microL (0.75 mm voxel size) and near-isotropic resolution of 1.2 microL (1 mm voxel size) show very robust activation in visual areas, but with clear contamination from larger veins. As this technique allows direct identification of veins in the functional scan, it permits removal of their effect from the activation maps. In our study, elimination of veins qualitatively improves the spatial specificity of activation maps, while reducing the activated volume by about 25%. The proposed technique provides functional information at the resolution of anatomical scans, is localized to gray matter, and facilitates functional to anatomical co-registration because of minimal distortions.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Barth M,Norris DGdoi
10.1002/nbm.1158subject
Has Abstractpub_date
2007-08-01 00:00:00pages
477-84issue
5eissn
0952-3480issn
1099-1492journal_volume
20pub_type
杂志文章abstract::The physiological status of anesthetized rats greatly influences blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI). Monitoring of physiological parameters, particularly partial pressure of carbon dioxide (pCO(2)) levels in the blood, is therefore an important part in the design and ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.978
更新日期:2005-11-01 00:00:00
abstract::In recent years considerable effort has been devoted to applying pattern recognition techniques to the complex task of data analysis in magnetic resonance spectroscopy. It may be argued that such techniques will facilitate putting MRS technology to practical clinical use. This paper reviews approaches of pattern recog...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199705)10:3<99::aid-nbm461
更新日期:1997-05-01 00:00:00
abstract::Management of brain tumours in children would benefit from improved non-invasive diagnosis, characterisation and prognostic biomarkers. Metabolite profiles derived from in-vivo MRS have been shown to provide such information. Studies indicate that using optimum a priori information on metabolite contents in the constr...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1432
更新日期:2010-01-01 00:00:00
abstract::In vitro (1)H MRS of human bile has shown potential in the diagnosis of various hepatopancreatobiliary (HPB) diseases. Previously, in vivo (1)H MRS of human bile in gallbladder using a 1.5 T scanner demonstrated the possibility of quantification of choline-containing phospholipids (chol-PLs). However, other lipid comp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3173
更新日期:2014-10-01 00:00:00
abstract::This paper describes the use of off-resonance saturation to further manipulate the blood oxygenation level dependent (BOLD) contrast of fMRI. A customized narrow bandwidth radiofrequency pulse, applied with a range of frequency offsets prior to selection of each slice, was designed and incorporated into a gradient ech...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199706/08)10:4/5<208::aid-
更新日期:1997-06-01 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::Natural abundance proton-decoupled (13)C magnetic resonance spectroscopy was used to establish the in vivo lipid composition of normal adipose tissue and the corresponding effects of altered lipid diets. Experiments were performed on a standard 1.5 T clinical MR scanner using a double-tuned (1)H-(13)C coil. Peaks from...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.824
更新日期:2003-05-01 00:00:00
abstract::The parameters that characterize the intricate water diffusion in tumors may serve to reveal their distinct pathology. Specifically, the application of diffusion magnetic resonance imaging (MRI) can aid in characterizing breast cancer, as well as monitoring response to therapy. We present here a non-invasive, quantita...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.882
更新日期:2004-06-01 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::Obesity causes damage to several organs, including the brain. Recent studies have been focusing on understanding the mechanisms through which obesity affects brain structure and function using neuroimaging techniques. A functional biomarker, such as cerebral blood flow (CBF), is a powerful tool that can be used to exp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4375
更新日期:2020-10-01 00:00:00
abstract::We describe and discuss the application of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) to visualize non-invasively the cerebral vasculature of the rat. MR angiograms of healthy spontaneously hypertensive rats were obtained without the use of contrast agents. Total imaging time rang...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199906)12:4<189::aid-nbm55
更新日期:1999-06-01 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::Wilms' tumours (WTs) are large heterogeneous tumours, which typically consist of a mixture of histological cell types, together with regions of chemotherapy-induced regressive change and necrosis. The predominant cell type in a WT is assessed histologically following nephrectomy, and used to assess the tumour subtype ...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.3337
更新日期:2015-08-01 00:00:00
abstract::The phosphorus NMR spectra of isolated perfused rat liver displays a prominent inorganic phosphate peak at 2.76 +/- 0.05 ppm relative to liver glycerolphosphocholine at 0.49 ppm. From titration curves of phosphorus-containing compounds this corresponds to a pH of 7.4. The spectra also display a shoulder on the promine...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940010207
更新日期:1988-04-01 00:00:00
abstract::Following the development of parallel imaging, parallel transmission describes the use of multiple RF transmit coils. Parallel transmission can be applied to improve RF excitation, in particular, multidimensional, spatially selective RF excitation. For instance, parallel transmission is able to shorten spatially selec...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1049
更新日期:2006-05-01 00:00:00
abstract::Net ATP production rates in exercising human muscle were calculated from 31P MRS kinetic data collected with 1-8 s time resolution. During the exercise, the muscle output was measured using a force transducer. Muscle output (force/unit volume) is then divided by the calculated net ATP used to estimate the ATP cost of ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940040404
更新日期:1991-08-01 00:00:00
abstract::Development and evaluation of new anticancer drugs are expedited when minimally invasive biomarkers of pharmacokinetic and pharmacodynamic behaviour are available. Gene-directed enzyme prodrug therapy (GDEPT) is a suicide gene therapy in which the anticancer drug is activated in the tumor by an exogenous enzyme previo...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1375
更新日期:2009-06-01 00:00:00
abstract::Free cytosolic [Mg2+] can be assessed in vivo by 31P MRS from the chemical shift of beta-ATP which in turn depends on the fraction of total ATP complexed to Mg2+ ions. The reliability of these in vivo measurements depends on the availability of an appropriate in vitro calibration to determine the limits of chemical sh...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199602)9:1<24::AID-NBM392>
更新日期:1996-02-01 00:00:00
abstract::The purpose of this paper is to facilitate the comparison of magnetic resonance (MR) spectra acquired from unknown brain lesions with published spectra in order to help identify unknown lesions in clinical settings. The paper includes lists of references for published MR spectra of various brain diseases, including py...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1039
更新日期:2006-06-01 00:00:00
abstract::This review assesses the progress of NMR in the field of hemorheology, i.e., the assessment of the mechanical and physical characteristics of flowing blood. The review deals with the intrinsic rheological properties of the red cell and its constituents (membrane, cytoplasm), which are dominant in the microcirculation,...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940020102
更新日期:1989-06-01 00:00:00
abstract::The management and treatment of high-grade glioblastoma multiforme (GBM) and solitary metastasis (MET) are very different and influence the prognosis and subsequent clinical outcomes. In the case of a solitary MET, diagnosis using conventional radiology can be equivocal. Currently, a definitive diagnosis is based on h...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3163
更新日期:2014-09-01 00:00:00
abstract::Acute kidney injury (AKI) in mice caused by sustained ischemia followed by reperfusion is associated with acute tubular necrosis and renal dysfunctional blood flow. Although the principal role of the kidney is the maintenance of acid-base balance, current imaging approaches are unable to assess this important paramete...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3720
更新日期:2017-07-01 00:00:00
abstract::Owing to the small quantity of tissue available in human biopsy specimens, aqueous and lipid components often have to be determined in the same tissue sample. Perchloric acid (PCA) used for the extraction of aqueous metabolites has a deleterious effect on lipid components; the severity of the damage is not known. In t...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1159
更新日期:2008-02-01 00:00:00
abstract::Cerebral ischemia provokes tissue damage by two major patho-physiological mechanisms. Direct cell necrosis is induced by diminished access of neurons and glia to essential nutrients such as glucose and oxygen leading to energy failure. A second factor of cellular loss is related to the activation of immune-competent c...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.770
更新日期:2002-06-01 00:00:00
abstract::An often-employed strategy to enhance signals in (31) P MRS is the generation of the nuclear Overhauser effect (NOE) by saturation of the water resonance. However, NOE allegedly increases the variability of the (31) P data, because variation is reported in NOE enhancements. This would negate the signal-to-noise (SNR) ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3455
更新日期:2016-03-01 00:00:00
abstract::The present work aims to show the applicability of an analytical model for the optimisation of the STEAM sequence timing parameters for lactate detection at ultra high-field. The effects of the chemical shift displacement artefact on the J-modulated signal for a weakly-coupled spin system were considered in the three ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4440
更新日期:2020-11-02 00:00:00
abstract::In the unstimulated brain energy is primarily supplied by the oxidation of glucose. However the oxygen-to-glucose index (OGI), which is the ratio of metabolic rates of oxygen to glucose, CMR(O2)/CMR(glc), diverges from the theoretical value of 6 as activity is increased. In vivo measurements of brain lactate show its ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.741
更新日期:2001-11-01 00:00:00
abstract::The performance of multichannel transmit coil layouts and parallel transmission (pTx) RF pulse design was evaluated with respect to transmit B1 (B1 (+)) homogeneity and specific absorption rate (SAR) at 3 T for a whole body coil. Five specific coils were modeled and compared: a 32-rung birdcage body coil (driven eithe...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3378
更新日期:2015-10-01 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::Proton NMR spectroscopy of biological fluids has produced interesting results lately. We used the technique to investigate the effects of cryopreservation on primary porcine hepatocytes as successful cryopreservation of primary porcine hepatocytes is of importance to the development of bioartificial liver support syst...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.765
更新日期:2002-05-01 00:00:00