Abstract:
:An indirect method for in vivo T2 mapping of 13 C-labeled metabolites using T2 and T2 * information of water protons obtained a priori is proposed. The T2 values of 13 C metabolites are inferred using the relationship to T2 ' of coexisting 1 H and the T2 * of 13 C metabolites, which is measured using routine hyperpolarized 13 C CSI data. The concept is verified with phantom studies. Simulations were performed to evaluate the extent of T2 estimation accuracy due to errors in the other measurements. Also, bias in the 13 C T2 * estimation from the 13 C CSI data was studied. In vivo experiments were performed from the brains of normal rats and a rat with C6 glioma. Simulation results indicate that the proposed method provides accurate and unbiased 13 C T2 values within typical experimental settings. The in vivo studies found that the estimated T2 of [1-13 C] pyruvate using the indirect method was longer in tumor than in normal tissues and gave values similar to previous reports. This method can estimate localized T2 relaxation times from multiple voxels using conventional hyperpolarized 13 C CSI and can potentially be used with time resolved fast CSI.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Joe E,Lee H,Lee J,Yang S,Choi YS,Wang E,Song HT,Kim DHdoi
10.1002/nbm.3690subject
Has Abstractpub_date
2017-05-01 00:00:00issue
5eissn
0952-3480issn
1099-1492journal_volume
30pub_type
杂志文章abstract::The aim of this study was to evaluate the change of breast density in the normal breast of patients receiving neoadjuvant chemotherapy (NAC). Forty-four breast cancer patients were studied. MRI acquisition was performed before treatment (baseline), and 4 and 12 weeks after treatment. A computer-algorithm-based program...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3006
更新日期:2013-12-01 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::Spatiotemporally structured noise, such as physiological noise, is a potential source of artifacts in functional magnetic resonance imaging (fMRI) and is the main limiting factor for the detection of small blood oxygen level-dependent (BOLD) signal variations. fMRI was employed to detect low-frequency BOLD signal fluc...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.987
更新日期:2005-12-01 00:00:00
abstract::Given the importance of genetically modified mice in studies of mammalian brain development and human congenital brain diseases, MRI has the potential to provide an efficient in vivo approach for analyzing mutant phenotypes in the early postnatal mouse brain. The combination of reduced tissue contrast at the high magn...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.932
更新日期:2004-12-01 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::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::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::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::In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by im...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4298
更新日期:2020-07-01 00:00:00
abstract::The possibility of quantifying the superimposed signal of glutamate and glutamine (Glx) and its components by ¹H magnetic resonance spectroscopy (MRS) in the spinal cord is an exciting challenge with important clinical applications in neurological conditions. The spinal cord is a particularly difficult region of inter...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2867
更新日期:2013-03-01 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::The aim of this study was to measure choline/creatine (Ch/Cr) levels through (1)H-MRS and apparent diffusion coefficient (ADC) values through diffusion-weighted MRI, and to correlate these values with the prognostic parameters of head and neck squamous cell carcinoma (HNSCC). The institutional review board approved th...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3472
更新日期:2016-04-01 00:00:00
abstract::Human tumor and skeletal muscle tissue was studied by means of in vivo 1H, 31P, and 13C MRS. The examinations were performed with a 1.5 T whole-body MR scanner equipped with a second RF system. Localized 1H and broadband proton-decoupled 31P and 13C MR spectra were obtained in measurement times of 5, 10 and 33 min, re...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940050402
更新日期:1992-07-01 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::Recent work has shown that solid-state (1) H and (31) P MRI can provide detailed insight into bone matrix and mineral properties, thereby potentially enabling differentiation of osteoporosis from osteomalacia. However, (31) P MRI of bone mineral is hampered by unfavorable relaxation properties. Hence, accurate knowled...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2930
更新日期:2013-09-01 00:00:00
abstract::The measurement of pulmonary perfusion (blood delivered to the capillary bed within a voxel) using arterial spin labeling (ASL) magnetic resonance imaging is often complicated by signal artifacts from conduit vessels that carry blood destined for voxels at a distant location in the lung. One approach to dealing with c...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3358
更新日期:2015-09-01 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 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: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::A special characteristic of the brain is the usage of lactate as alternative fuel instead of glucose to preserve its energy homeostasis. This physiological function is valid for sufficient cerebral glucose supply, as well as presumably during hypoglycemia, given that exogenous lactate infusion suppresses hormonal coun...
journal_title:NMR in biomedicine
pub_type: 杂志文章,随机对照试验
doi:10.1002/nbm.4167
更新日期:2019-11-01 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 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::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::An MR thermometry method is proposed for measuring in vivo small temperature changes engendered by external RF heat sources. The method relies on reproducible and stable respiration and therefore currently applies to ventilated animals whose breathing is carefully controlled. It first consists in characterizing the st...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3232
更新日期:2015-01-01 00:00:00
abstract::Detailed (1)H and (13)C NMR spectroscopy of lipid extracts from 12 human intracranial tuberculomas and two control brain tissue samples was performed to assess the role of lipids in the disease process. One-dimensional and two-dimensional NMR techniques were used to resolve the mixture of lipid components and make res...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1191
更新日期:2008-03-01 00:00:00
abstract::Citicoline supplementation has been used to ameliorate memory disturbances in older people and those with Alzheimer's disease. This study used MRS to characterize the effects of citicoline on high-energy phosphate metabolites and constituents of membrane synthesis in the frontal lobe. Phosphorus ((31)P) metabolite dat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1281
更新日期:2008-11-01 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::Perfusion is an important biomarker of tissue function and has been associated with tumor pathophysiology such as angiogenesis and hypoxia. Arterial spin labeling (ASL) MRI allows noninvasive and quantitative imaging of perfusion; however, the application in mouse xenograft tumor models has been challenging due to the...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3330
更新日期:2015-08-01 00:00:00
abstract::In this study the conjugated macromolecular ligand, diethylenetriaminepentaacetic acid (DTPA)-amide-dextran, was synthesized by attaching DTPA to the dextran macromolecule (M(r) approximately 6000) by a covalent amide bond. Subsequently, DTPA-amide-dextran was complexed with either of the two lanthanide metal ions dys...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940080404
更新日期:1995-06-01 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