Abstract:
:The cuprizone mouse model of demyelination was used to investigate the influence that white matter changes have on different magnetic resonance imaging results. In vivo T2 -weighted and magnetization transfer images (MTIs) were acquired weekly in control (n = 5) and cuprizone-fed (n = 5) mice, with significant increases in signal intensity in T2 -weighted images (p < 0.001) and lower magnetization transfer ratio (p < 0.001) in the corpus callosum of the cuprizone-fed mice starting at 3 weeks and peaking at 4 and 5 weeks, respectively. Diffusion tensor imaging (DTI), quantitative MTI (qMTI), and T1/T2 measurements were used to analyze freshly excised tissue after 6 weeks of cuprizone administration. In multicomponent T2 analysis with 10 ms echo spacing, there was no visible myelin water component associated with the short T2 value. Quantitative MTI metrics showed significant differences in the corpus callosum and external capsule of the cuprizone-fed mice, similar to previous studies of multiple sclerosis in humans and animal models of demyelination. Fractional anisotropy was significantly lower and mean, axial, and radial diffusivity were significantly higher in the cuprizone-fed mice. Cellular distributions measured in electron micrographs of the corpus callosum correlated strongly to several different quantitative MRI metrics. The largest Spearman correlation coefficient varied depending on cellular type: T1 versus the myelinated axon fraction (ρ = -0.90), the bound pool fraction (ƒ) versus the myelin sheath fraction (ρ = 0.93), and axial diffusivity versus the non-myelinated cell fraction (ρ = 0.92). Using Pearson's correlation coefficient, ƒ was strongly correlated to the myelin sheath fraction (r = 0.98) with a linear equation predicting myelin content (5.37ƒ - 0.25). Of the calculated MRI metrics, ƒ was the strongest indicator of myelin content, while longitudinal relaxation rates and diffusivity measurements were the strongest indicators of changes in tissue structure.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Thiessen JD,Zhang Y,Zhang H,Wang L,Buist R,Del Bigio MR,Kong J,Li XM,Martin Mdoi
10.1002/nbm.2992subject
Has Abstractpub_date
2013-11-01 00:00:00pages
1562-81issue
11eissn
0952-3480issn
1099-1492journal_volume
26pub_type
杂志文章abstract::Quantitative analysis of extracts from two Ehrlich ascites tumour cell lines (Lettre cells) by 19F NMR in vitro demonstrated that one Lettre cell line (designated LLM) metabolized 30-50% less 5-fluorouracil to 5-fluoronucleotides when compared to the other cell line (designated LHM). HPLC analysis of these cellular ex...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940040605
更新日期:1991-12-01 00:00:00
abstract::31P Nuclear magnetic resonance spectroscopy has been used to investigate the combined effect of 70 mM ethanol administration and hypoxia on the energetic metabolism and cytosolic pH of the perfused liver isolated from naive, fasted or chronically ethanol-treated rats. Ethanol-treatment or fasting induce a similar 25% ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940030306
更新日期:1990-06-01 00:00:00
abstract::In vivo 1H MRS is rapidly developing as a clinical tool for diagnosing and characterizing breast cancers. Many in vivo and in vitro experiments have demonstrated that alterations in concentrations of choline-containing metabolites are associated with malignant transformation. In recent years, considerable efforts have...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1217
更新日期:2009-01-01 00:00:00
abstract::Glycine (Gly) has been implicated in several neurological disorders, including malignant brain tumors. The precise measurement of Gly is challenging largely as a result of the spectral overlap with myo-inositol (mI). We report a new triple-refocusing sequence for the reliable co-detection of Gly and mI at 3 T and for ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3747
更新日期:2017-09-01 00:00:00
abstract::MRI detects changes in blood-oxygenation-level dependent (BOLD) contrast in tumors caused by tumor oxygenating agents. These changes can be used to guide the design of improved tumor oxygenating treatments (TOXs). The conventional approach to detection of BOLD effects assumes that the water resonance is a single, homo...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.728
更新日期:2002-02-01 00:00:00
abstract::The availability of high-field-strength magnetic resonance imaging (MRI) systems has brought about the development of techniques that aim to map myelination via the exploitation of various contrast mechanisms. Myelin mapping techniques have the potential to provide tools for the diagnosis and treatment of diseases, su...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3877
更新日期:2018-03-01 00:00:00
abstract::Boiling histotripsy (BH) is a new high intensity focused ultrasound (HIFU) ablation technique to mechanically fragmentize soft tissue into submicrometer fragments. So far, ultrasound has been used for BH treatment guidance and evaluation. The in vivo histopathological effects of this treatment are largely unknown. Her...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3520
更新日期:2016-06-01 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::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::The detection of Parkinson's disease (PD) in its preclinical stages prior to outright neurodegeneration is essential to the development of neuroprotective therapies and could reduce the number of misdiagnosed patients. However, early diagnosis is currently hampered by lack of reliable biomarkers. (1) H magnetic resona...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2817
更新日期:2013-01-01 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::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::The application of diffusion tensor imaging (DTI) to the evaluation of developing brain remains an area of active investigation. This review focuses on the changes in DTI parameters which accompany both brain maturation and injury. The two primary pieces of information available from DTI studies-water apparent diffusi...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.784
更新日期:2002-11-01 00:00:00
abstract::The elimination of so-called background fields is an essential step in phase MRI and quantitative susceptibility mapping (QSM). Background fields, which are caused by sources outside the region of interest (ROI), are often one to two orders of magnitude stronger than tissue-related field variations from within the ROI...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.3604
更新日期:2017-04-01 00:00:00
abstract::Resolution enhancement for glutamate (Glu), glutamine (Gln) and glutathione (GSH) in the human brain by TE-optimized point-resolved spectroscopy (PRESS) at 7 T is reported. Sub-TE dependences of the multiplets of Glu, Gln, GSH, γ-aminobutyric acid (GABA) and N-acetylaspartate (NAA) at 2.2-2.6 ppm were investigated wit...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1529
更新日期:2010-11-01 00:00:00
abstract::Progress in the development of non-proton NMR applications in medical research has been hampered by the generally low sensitivity of these nuclides as well as the lack of instrumentation readily available for studying these spins. For example, custom head coils suitable for sodium imaging of the human head are either ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940020308
更新日期:1989-09-01 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::The intrinsic nonuniformities in the transmit radiofrequency field from standard quadrature volume resonators at high field are particularly problematic for localized MRS in areas such as the temporal lobe, where a low signal-to-noise ratio and poor metabolite quantification result from destructive B₁⁺ field interfere...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1638
更新日期:2011-08-01 00:00:00
abstract::T2 relaxation time is a quantitative MRI in vivo surrogate of cerebral tissue damage in multiple sclerosis (MS) patients. Cortical T2 prolongation is a known feature in later disease stages, but has not been demonstrated in the cortical normal appearing gray matter (NAGM) in early MS. This study centers on the quantit...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3486
更新日期:2016-04-01 00:00:00
abstract::The current study aims to evaluate the feasibility of creatine (Cr) chemical exchange saturation transfer (CEST)-weighted MRI at 7 T in the human brain by optimizing the saturation pulse parameters and computing contrast using a Z-spectral fitting approach. The Cr-weighted (Cr-w) CEST contrast was computed from phanto...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4176
更新日期:2019-12-01 00:00:00
abstract::The goal of this study was to validate metabolite quantification at short TE, with particular focus on how to best account for the macromolecular signal contribution. A robust, short-TE PRESS protocol is presented, which allows reliable quantification, in vivo, of metabolite signals at 3 T in human brain. Water suppre...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1219
更新日期:2008-06-01 00:00:00
abstract::Acute hypoxia (transient cycles of hypoxia-reoxygenation) is known to occur in solid tumors and is generally believed to be caused by tumor blood flow instabilities. It was recently demonstrated that T2*-weighted (T2*w) gradient echo (GRE) MRI is a powerful non-invasive method for investigating periodic changes in tum...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1002
更新日期:2006-02-01 00:00:00
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::Hyperglycemia (blood glucose concentration >150 mg/dL) is common in extremely low gestational age newborns (ELGANs; birth at <28 week gestation). Hyperglycemia increases the risk of brain injury in the neonatal period. The long-term effects are not well understood. In adult rats, hyperglycemia alters hippocampal energ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3910
更新日期:2018-05-01 00:00:00
abstract::In vivo metabolic imaging using hyperpolarized [1-(13)C]pyruvate provides localized biochemical information and is particularly useful in detecting early disease changes, as well as monitoring disease progression and treatment response. However, a major limitation of hyperpolarized magnetization is its unrecoverable d...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3346
更新日期:2015-08-01 00:00:00
abstract::Transceiver surface coil arrays improve transmit performance (B1/√kW) and B1 homogeneity for head imaging up to 9.4 T. To further improve reception performance and parallel imaging, the number of array elements must be increased with a corresponding decrease in their size. With a large number of small interacting ante...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2989
更新日期:2013-11-01 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::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::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::An optimized semi-LASER sequence that is capable of acquiring artefact-free data with an echo time (TE) of 20.1 ms on a standard clinical 3 T MR system was developed. Simulations were performed to determine the optimal TEs that minimize the expected Cramér-Rao lower bound (CRLB) as proxy for quantification accuracy of...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4324
更新日期:2020-09-01 00:00:00