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. Simulations were conducted to assess the precision of T2 estimates from decay curves comprising varying numbers and ranges of TE points. Mean and standard errors for T2s of NAA, creatine and choline-containing compounds were 300(8), 169(3) and 239(4) ms in posterior frontal white matter and 256(6), 159(8) and 249(8) ms in occipital grey matter. In vivo T2s found for choline and NAA were shorter than the T2s in the literature. The elevation of literature T2s is accounted for by the simulation results, which demonstrated that there is a bias towards lengthened T2s when T2 is measured with a maximum TE approximately T2. Concentration estimates are at risk of being underestimated if previously reported T2 corrections are used.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Brief EE,Whittall KP,Li DK,MacKay ALdoi
10.1002/nbm.916subject
Has Abstractpub_date
2005-02-01 00:00:00pages
14-8issue
1eissn
0952-3480issn
1099-1492journal_volume
18pub_type
临床试验,杂志文章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::Here, we show that the sensitivity of (31)P MRSI of (31)P spins J-coupled to protons can be increased by almost a factor of three when compared with an optimal direct detection free induction decay. By direct detection integrated with multi-echo polarization transfer (DIMEPT), multiple signals from polarization transf...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3183
更新日期:2014-10-01 00:00:00
abstract::Spin-exchange NMR techniques enable the measurement of the rates of exchange of solutes between chemically or physically distinct sites in reactions taking place at chemical equilibrium. The time scale of the events that are able to be investigated lies in the neighbourhood of 1 s. The earliest studies in this area of...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940030303
更新日期:1990-06-01 00:00:00
abstract::Understanding typical, healthy brain development provides a baseline from which to detect and characterize brain anomalies associated with various neurological or psychiatric disorders and diseases. Diffusion MRI is well suited to study white matter development, as it can virtually extract individual tracts and yield ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.3778
更新日期:2019-04-01 00:00:00
abstract::The progression of Parkinson's disease (PD) seems to vary according to the disease stage, which greatly influences the management of PD patients. However, the underlying mechanism of progression in PD remains unclear. This study was designed to explore the progressive pattern of iron accumulation at different stages i...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3489
更新日期:2017-04-01 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::Several obstacles usually confound a straightforward perfusion analysis using dynamic-susceptibility contrast-based magnetic resonance imaging (DSC-MRI). In this work, it became possible to eliminate some of these sources of error by combining a multiple gradient-echo technique with parallel imaging (PI): first, the l...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1107
更新日期:2007-06-01 00:00:00
abstract::Biomarkers of early response to treatment have the potential to improve cancer therapy by allowing treatment to be tailored to the individual. Alterations in lipids detected by in vivo MRS have been suggested as noninvasive biomarkers of cell stress and early indicators of cell death. An improved understanding of the ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2796
更新日期:2012-11-01 00:00:00
abstract::The emergence and rapid development of activatable contrast agents (CAs), whose relaxivity changes in response to the variation of a specific marker in the surrounding physiological microenvironment, have expanded the scope of MRI beyond anatomical and functional imaging to also convey information at the cellular and ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.2870
更新日期:2013-07-01 00:00:00
abstract::We review several methods that have been developed to infer microstructural and physiological information about isotropic and anisotropic tissues from diffusion weighted images (DWIs). These include Diffusion Imaging (DI), Diffusion Tensor Imaging (DTI), isotropically weighted imaging, and q-space imaging. Just as DI ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940080707
更新日期:1995-11-01 00:00:00
abstract::In this work we introduce the concept of correlation chemical shift imaging (CCSI). Novel CCSI pulse sequences are demonstrated on clinical scanners for two-dimensional Correlation Spectroscopy (COSY) and Total Correlation Spectroscopy (TOCSY) imaging experiments. To date there has been limited progress reported towar...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1730
更新日期:2012-02-01 00:00:00
abstract::The aim of this study was to investigate proton changes of the parotid gland after gustatory stimulation by semi-quantitative parameters and an empirical mathematical model (EMM) using high-temporal-resolution, double-echo, echo-planar imaging (EPI). Approved by a local institutional review board, this study examined ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3885
更新日期:2018-03-01 00:00:00
abstract::Standard functional MRI (fMRI), which includes resting-state or paradigm-driven designs, is widely used in studies of brain function, aging, and disease. These fMRI studies typically use two-dimensional gradient echo-planar imaging, which inherently contains phase data that enables quantitative susceptibility mapping ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3619
更新日期:2017-04-01 00:00:00
abstract::Increased lactate production through glycolysis in aerobic conditions is a hallmark of cancer. Some anticancer drugs have been designed to exploit elevated glycolysis in cancer cells. For example, lonidamine (LND) inhibits lactate transport, leading to intracellular acidification in cancer cells. Chemical exchange sat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3287
更新日期:2015-05-01 00:00:00
abstract::During the measurement of hyperpolarized 129 Xe magnetic resonance imaging (MRI), the diffusion-weighted imaging (DWI) technique provides valuable information for the assessment of lung morphometry at the alveolar level, whereas the chemical shift saturation recovery (CSSR) technique can evaluate the gas exchange func...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3730
更新日期:2017-08-01 00:00:00
abstract::The main aim of this study was to employ high-resolution MRI to investigate the spatiotemporal development of pathological features associated with contusive spinal cord injury (SCI) in mice. Experimental mice were subjected to either sham surgery or moderate contusive SCI. A 16.4-T small-animal MR system was employed...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2829
更新日期:2013-02-01 00:00:00
abstract::The temporary or permanent storage of human bodies in freezers following a homicide is a documented method for criminal disposal of human corpses. In these cases, the detection of characteristics which indicate that a thawed cadaver or body part was previously frozen provides crucial information for forensic casework....
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4220
更新日期:2020-02-01 00:00:00
abstract::MR spectroscopic imaging (MRSI) at ultra-high field (≥7 T) benefits from improved sensitivity that allows the detection of low-concentration metabolites in the brain. However, optimized acquisition techniques are required to overcome inherent limitations of MRSI at ultra-high field. This work describes an optimized me...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3950
更新日期:2018-11-01 00:00:00
abstract::Magnetic resonance elastography (MRE) is a non-invasive imaging technique used to visualise and quantify mechanical properties of tissue, providing information beyond what can be currently achieved with standard MR sequences and could, for instance, provide new insight into pathological processes in the brain. This st...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1254
更新日期:2008-08-01 00:00:00
abstract::The sodium-calcium exchanger (NCX) is one of the transporters contributing to the control of intracellular calcium (Ca(2+)) concentration by normally mediating net Ca(2+) efflux. However, the reverse mode of the NCX can cause intracellular Ca(2+) concentration overload, which exacerbates the myocardial tissue injury r...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1414
更新日期:2009-10-01 00:00:00
abstract::(1) H-MRS is regularly applied to determine lipid content in ectopic tissue - mostly skeletal muscle and liver - to investigate physiological and/or pathologic conditions, e.g. insulin resistance. Technical developments also allow non-invasive in vivo assessment of cardiac lipids; however, basic data about methodologi...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3186
更新日期:2014-11-01 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::This study aimed to demonstrate a reliable automatic segmentation method for independently separating reduced diffusion and decreased perfusion areas in ischemic stroke brains using constrained nonnegative matrix factorization (cNMF) pattern recognition in directional intravoxel incoherent motion MRI (IVIM-MRI). First...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4268
更新日期:2020-05-01 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
abstract::Qualitative and quantitative (1) H NMR analysis of lipid extracts of gallbladder tissue in chronic cholecystitis (CC, benign) (n = 14), xanthogranulomatous cholecystitis (XGC, intermediate) (n = 9) and gallbladder cancer (GBC, malignant) (n = 8) was carried out to understand the mechanisms involved in the transformati...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1594
更新日期:2011-05-01 00:00:00
abstract::A novel and fast time-domain quantitation algorithm--quantitation based on semi-parametric quantum estimation (QUEST)--invoking optimal prior knowledge is proposed and tested. This nonlinear least-squares algorithm fits a time-domain model function, made up from a basis set of quantum-mechanically simulated whole-meta...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.895
更新日期:2005-02-01 00:00:00
abstract::Both post-contrast myocardial T1 and extracellular volume (ECV) have been reported to be associated with diffuse interstitial fibrosis. Recently, the cardiovascular magnetic resonance (CMR) field is recognizing that post-contrast myocardial T1 is sensitive to several confounders and migrating towards ECV as a measure ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3221
更新日期:2014-11-01 00:00:00
abstract::Renal urea handling is central to the urine concentrating mechanism, and as such the ability to image urea transport in the kidney is an important potential imaging biomarker for renal functional assessment. Glucagon levels associated with changes in dietary protein intake have been shown to influence renal urea handl...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4028
更新日期:2019-01-01 00:00:00
abstract::1H NMR spin-echo spectroscopy has been used to study the metabolism of exogenous compounds in human erythrocytes. The non-invasive nature of the technique and the continuous monitoring makes it ideal to investigate both the conversion of substrates and the occurrence and the nature of the products. Hydrolysis rates ma...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940030603
更新日期:1990-12-01 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