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 echo EPI sequence. This application takes advantage of the resonance frequency and linewidth differences between the oxygenated and deoxygenated state of blood in human brain during task activation and rest, and is capable of creating an enhancement in the contrast of the BOLD effect. Because of a possible contribution to the signal change from cerebro-spinal fluid, which has a much narrower linewidth and smaller frequency shift compared with the brain tissue, data were also collected using a nulling inversion pulse. The inversion pulse was applied before the off-resonance pulse and data acquisition to eliminate the CSF signal. Functional areas are thus more localized to the brain tissue.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Song AW,Wolff SD,Balaban RS,Jezzard Pdoi
10.1002/(sici)1099-1492(199706/08)10:4/5<208::aid-subject
Has Abstractpub_date
1997-06-01 00:00:00pages
208-15issue
4-5eissn
0952-3480issn
1099-1492pii
10.1002/(SICI)1099-1492(199706/08)10:4/5<208::AID-journal_volume
10pub_type
杂志文章abstract::It is generally accepted that tumour microcirculation, blood flow, oxygen and nutrient supply, tissue pH distribution, and the bioenergetic status--factors which are usually closely linked and which define the so-called metabolic microenvironment--can markedly influence the therapeutic response of malignant tumours to...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940050505
更新日期:1992-09-01 00:00:00
abstract::This review highlights various magnetic resonance image (MRI) segmentation algorithms that employ pattern recognition. The procedures are grouped into two categories: low- to intermediate-level, and high-level image processing. The former consists of grey level histogram analysis, texture definition, edge identificati...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199806/08)11:4/5<157::aid-
更新日期:1998-06-01 00:00:00
abstract::Tumor metabolism is directly coupled to tumor blood flow (TBF) and both metabolism and blood flow may be determinants of tumor response to treatment. Since NMR has been used extensively to monitor tumor metabolism noninvasively, development of NMR-based methods for TBF measurement was motivated by the desire to examin...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940050516
更新日期:1992-09-01 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::In this study, mapping of ultrashort T2 and T2* of acutely isolated porcine menisci at B0 = 9.4 T was investigated. Maps of T2 were measured from a slice through the pars intermedia with a spin echo-prepared two-dimensional ultrashort-TE T2 mapping technique published previously. T2* mapping was performed by two-dimen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2931
更新日期:2013-09-01 00:00:00
abstract::1H MR spectroscopy was used to correlate the metabolite signals in 66 untreated metastatic brain tumors with the results of Gd-DTPA enhanced MRI. Cubic volumes containing brain metastases of lung cancer (n = 17), mammary carcinoma (n = 24), melanoma (n = 12) and those originating from other tumors (n = 13) were examin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199604)9:2<65::AID-NBM397>
更新日期:1996-04-01 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
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更新日期:2017-07-01 00:00:00
abstract::MRS provides a valuable tool for the non-invasive detection of brain γ-aminobutyric acid (GABA) in vivo. GABAergic dysfunction has been observed in the aging cerebellum. The study of cerebellar GABA changes is of considerable interest in understanding certain age-related motor disorders. However, little is known about...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3381
更新日期:2015-10-01 00:00:00
abstract::A novel polarizer based on the dissolution-dynamic nuclear polarization (DNP) method has been designed, built and tested. The polarizer differs from those previously described by being designed with sterile use intent and being compatible with clinical use. The main features are: (1) an integral, disposable fluid path...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1682
更新日期:2011-10-01 00:00:00
abstract::Normal subjects performed voluntary, isometric exercise 1 s contraction, 1 s rest for 10 min) of the first dorsal interosseous (FDI) muscle with a target force of 25, 50 and 100% of the maximal voluntary contraction (MVC) force. 31P NMR spectra were collected continuously before, during and after exercise. Data were a...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940030504
更新日期:1990-10-01 00:00:00
abstract::Chemical exchange saturation transfer (CEST)-derived, pH-weighted, amide proton transfer (APT) MRI has shown promise in animal studies for the prediction of infarction risk in ischemic tissue. Here, APT MRI was translated to patients with acute stroke (1-24 h post-symptom onset), and assessments of APT contrast, perfu...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3048
更新日期:2014-02-01 00:00:00
abstract::The applications of in vivo electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy have been impressive over a relatively short period despite the many obstacles which had to be overcome, such as dielectric absorption and biodestruction. The loop-gap resonators and modified loop coil syste...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.898
更新日期:2004-08-01 00:00:00
abstract::Diffusion tensor imaging (DTI) has been employed for over 2 decades to noninvasively quantify central nervous system diseases/injuries. However, DTI is an inadequate simplification of diffusion modeling in the presence of coexisting inflammation, edema and crossing nerve fibers. We employed a tissue phantom using fixe...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4414
更新日期:2021-01-01 00:00:00
abstract::Patients with different types of mucopolysaccharidoses (MPS) lack specific lysosomal enzymes, which leads to tissue accumulation and urinary excretion of glycosaminoglycans (GAGs). Since little is known about the molecular composition of the excreted GAG fragments, we used two-dimensional [1H,13C]-correlation nuclear ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.833
更新日期:2003-06-01 00:00:00
abstract::The development and implementation of novel MRI pulse sequences remains challenging and laborious. Gradient waveforms are typically designed using a combination of analytical and ad hoc methods to construct each gradient waveform axis independently. This strategy makes coding the pulse sequence complicated, in additio...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4308
更新日期:2020-12-01 00:00:00
abstract::The purpose of this study was to identify the optimal tracer kinetic model from T1 -weighted dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data and evaluate whether parameters estimated from the optimal model predict tumor aggressiveness determined from histopathology in patients with papillary thyroi...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4166
更新日期:2020-01-01 00:00:00
abstract::Mice are used in many studies to determine the role of genetic and molecular factors in mammalian development and human congenital diseases. MRI has emerged as a major method for analyzing mutant and transgenic phenotypes in developing mice, at both embryonic and neonatal stages. Progress in this area is reviewed, wit...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1146
更新日期:2007-05-01 00:00:00
abstract::The combination of hyperpolarized Xe with chemical exchange saturation transfer (Hyper-CEST) is a powerful NMR technique to detect highly dilute concentrations of Xe binding sites using RF saturation pulses. Crucially, that combination of saturation pulse strength and duration that generates the maximal Hyper-CEST eff...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3307
更新日期:2015-06-01 00:00:00
abstract::Increased sensitivity and chemical shift dispersion at ultra-high magnetic fields enable the precise quantification of an extended range of brain metabolites from (1)H MRS. However, all previous neurochemical profiling studies using single-voxel MRS at 7 T have been limited to data acquired from the occipital lobe wit...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1727
更新日期:2012-01-01 00:00:00
abstract::Results are presented from an in vivo study of human skin in which a zig-zag surface coil together with a three-pulse Fourier Series Window (FSW) protocol have been used to obtain minimally contaminated 31P skin spectra of the posterior calf. Phantom experiments indicate that while the fall-off in the B1 field profile...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199608)9:5<195::AID-NBM416
更新日期:1996-08-01 00:00:00
abstract::Chemical exchange saturation transfer (CEST) can offer information about protons associated with mobile proteins through the amide proton transfer (APT) effect, which has been shown to discriminate tumor from healthy tissue and, more recently, has been suggested as a prognosticator of response to therapy. Despite this...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2947
更新日期:2013-10-01 00:00:00
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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 leakage of metabolites from frozen and thawed tissue biopsies was measured semi-quantitatively by high-field (8.5 T) proton MRS. Human prostate and rat brain tissue specimens, frozen within 1 min of collection, lost significant and variable amounts of diagnostic metabolites immediately upon thawing. For prostate t...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.815
更新日期:2003-04-01 00:00:00
abstract::A novel iodoacetamide label 4-perfluoro-tert-butyl-phenyliodoacetamide (PFP) containing nine fluorine atoms in equivalent positions has been synthesized. It provides a homogeneous 19F NMR resonance line which can be detected with high sensitivity when coupled to proteins. As an example, the sulfhydryl groups of actin ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940050605
更新日期:1992-11-01 00:00:00
abstract::The intimal and medial linings of the pulmonary artery consist largely of vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs), respectively. The migration of these cell types to a potential tissue-engineered pulmonary valve (TEPV) implant process is therefore of interest in understanding the val...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1642
更新日期:2012-03-01 00:00:00
abstract::One of the hallmarks of diffusion NMR and MRI is its ability to utilize restricted diffusion to probe compartments much smaller than the excited volume or the MRI voxel, respectively, and to extract microstructural information from them. Single-pulsed field gradient (s-PFG) MR methodologies have been employed with gre...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1550
更新日期:2010-08-01 00:00:00
abstract::The aim of this study was to acquire high-quality in vivo (1) H spectra concurrently from two voxels at ultra-high field (7 T) without specialized hardware. To this end, an acquisition scheme was developed in which first-order shims and flip angles are dynamically updated to acquire spectra from both of the brain's mo...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3328
更新日期:2015-07-01 00:00:00
abstract::Cross-talk between adipose tissue and liver is disturbed in the metabolic syndrome. Moreover, the relative fatty acid composition of adipose and liver fat is poorly characterized. Long-TE (1)H MRS can determine the unsaturation and polyunsaturation of adipose tissue. The aim of this study was to use long-TE (1)H MRS t...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1580
更新日期:2011-04-01 00:00:00
abstract::The scyllo-inositol and myo-inositol concentrations of 24 normal human subjects were measured in vivo using 1H magnetic resonance spectroscopy at 4 T. Single-voxel short-echo (TE = 15 ms) metabolite spectra were collected from the white matter region of the corona radiata. Test-retest studies performed on 10 normal su...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.927
更新日期:2005-02-01 00:00:00
abstract:INTRODUCTION:Sarcoidosis is a systemic granulomatous disease affecting in particular the respiratory tract. Cardiac magnetic resonance (CMR), including a measurement of T1 relaxation time, could potentially detect early stadia of sarcoidosis of the heart. The study aims to assess T1 mapping in the detection of early ca...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4388
更新日期:2020-11-01 00:00:00