Trading off SNR and resolution in MR images.

abstract：:The goals of this study were to develop an acquisition protocol and the analysis tools for Meshcher-Garwood point-resolved spectroscopy (MEGA-PRESS) in mouse brain at 9.4 T, to allow the in vivo detection of γ-aminobutyric acid (GABA) and to examine whether isoflurane alters GABA levels in the thalamus during anesthes...

journal_title：NMR in biomedicine

authors： Guo J,Gang Z,Sun Y,Laine A,Small SA,Rothman DL

更新日期：2018-01-01 00:00:00

abstract：:By quantification of brain metabolites, localized brain proton MRS can non-invasively provide biochemical information from distinct regions of the brain. Quantification of short-TE signals is usually based on a metabolite basis set. The basis set can be obtained by two approaches: (1) by measuring the signals of metab...

journal_title：NMR in biomedicine

authors： Cudalbu C,Cavassila S,Rabeson H,van Ormondt D,Graveron-Demilly D

更新日期：2008-07-01 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

authors： Ratiney H,Sdika M,Coenradie Y,Cavassila S,van Ormondt D,Graveron-Demilly D

更新日期：2005-02-01 00:00:00

abstract：:Traditional methods of measuring magnetization in magnetic fluid samples, such as vibrating sample magnetometry (VSM), are typically limited to maximum field strengths of about 1 T. This work demonstrates the ability of MRI to measure the magnetization associated with two commercial MRI contrast agents at 3 T by compa...

journal_title：NMR in biomedicine

authors： Cantillon-Murphy P,Wald LL,Zahn M,Adalsteinsson E

更新日期：2009-10-01 00:00:00

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

authors： Vaupel P

更新日期：1992-09-01 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

authors： Blomster LV,Cowin GJ,Kurniawan ND,Ruitenberg MJ

更新日期：2013-02-01 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

authors： Choi C,Dimitrov IE,Douglas D,Patel A,Kaiser LG,Amezcua CA,Maher EA

更新日期：2010-11-01 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

authors： Landheer K,Gajdošík M,Juchem C

更新日期：2020-09-01 00:00:00

abstract：:γ-Aminobutyric acid (GABA) and glutamate (Glu), major neurotransmitters in the brain, are recycled through glutamine (Gln). All three metabolites can be measured by magnetic resonance spectroscopy in vivo, although GABA measurement at 3 T requires an extra editing acquisition, such as Mescher-Garwood point-resolved sp...

journal_title：NMR in biomedicine

authors： Sanaei Nezhad F,Anton A,Michou E,Jung J,Parkes LM,Williams SR

更新日期：2018-01-01 00:00:00

abstract：:In this study, Blood Oxygenation Level Dependent (BOLD) contrast in the detection of human brain activation was compared between spin-echo and gradient-echo echo-planar sequences at 1.5 T. Time course series of spin-echo and gradient-echo images containing the primary motor cortex were collected during rest (no finger...

journal_title：NMR in biomedicine

authors： Bandettini PA,Wong EC,Jesmanowicz A,Hinks RS,Hyde JS

更新日期：1994-03-01 00:00:00

abstract：:Metabolic activity in the lung is known to change in response to external insults, inflammation, and cancer. We report measurements of metabolism in the isolated, perfused rat lung of healthy controls and in diseased lungs undergoing acute inflammation using hyperpolarized 1-(13) C-labeled pyruvate. The overall appare...

journal_title：NMR in biomedicine

authors： Shaghaghi H,Kadlecek S,Deshpande C,Siddiqui S,Martinez D,Pourfathi M,Hamedani H,Ishii M,Profka H,Rizi R

更新日期：2014-08-01 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

authors： Mirbahai L,Wilson M,Shaw CS,McConville C,Malcomson RD,Kauppinen RA,Peet AC

更新日期：2012-11-01 00:00:00

abstract：:To understand and predict the blood-oxygenation level-dependent (BOLD) fMRI signal, an accurate knowledge of the relationship between cerebral blood flow (DeltaCBF) and volume (DeltaCBV) changes is critical. Currently, this relationship is widely assumed to be characterized by Grubb's power-law, derived from primate d...

journal_title：NMR in biomedicine

authors： Chen JJ,Pike GB

更新日期：2009-12-01 00:00:00

abstract：:A short-echo spectroscopic imaging sequence extended with a frequency-selective multiple-quantum- coherence technique (Sel-MQC) is presented. The method enables acquisition of a complete water-suppressed proton spectrum with a short echo time and filtering of the J-coupling metabolite, lactate, from co-resonant lipids...

journal_title：NMR in biomedicine

authors： Melkus G,Mörchel P,Behr VC,Kotas M,Flentje M,Jakob PM

更新日期：2008-11-01 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

authors： Kaiser LG,Schuff N,Cashdollar N,Weiner MW

更新日期：2005-02-01 00:00:00

abstract：:A review of the theory, technology, and use of radio frequency (RF) coils for small-animal MRI is presented. It includes a brief overview of MR signal-to-noise (S/N) analysis and discussions of the various coils commonly used in small-animal MR: surface coils, linear volume coils, birdcages, and their derivatives. The...

journal_title：NMR in biomedicine

authors： Doty FD,Entzminger G,Kulkarni J,Pamarthy K,Staab JP

更新日期：2007-05-01 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

authors： Walker SC,Asadi AK,Hopkins SR,Buxton RB,Prisk GK

更新日期：2015-09-01 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

authors： Goerke U,Möller HE,Norris DG,Schwarzbauer C

更新日期：2005-12-01 00:00:00

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

authors： McSheehy PM,Maxwell RJ,Griffiths JR

更新日期：1991-12-01 00:00:00

abstract：:Quantitative magnetisation transfer imaging (qMTI) is an extension of conventional MT techniques and allows the measurement of parameters that reflect tissue ultrastructure through the properties of macromolecule-bound protons; these include the bound proton fraction and the relaxation times of free and bound proton p...

journal_title：NMR in biomedicine

authors： Tozer DJ,Rees JH,Benton CE,Waldman AD,Jäger HR,Tofts PS

更新日期：2011-06-01 00:00:00

abstract：:In many studies, it has been demonstrated that (1)H MRSI of the human prostate has great potential to aid prostate cancer management, e.g. in the detection and localisation of cancer foci in the prostate or in the assessment of its aggressiveness. It is particularly powerful in combination with T2 -weighted MRI. Never...

journal_title：NMR in biomedicine

authors： Kobus T,Wright AJ,Scheenen TW,Heerschap A

更新日期：2014-01-01 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

authors： Lee J,Choi SH,Kim JH,Sohn CH,Lee S,Jeong J

更新日期：2014-09-01 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

authors： Coello E,Noeske R,Burns BL,Gordon JW,Jakary A,Menze B,Haase A,Larson PEZ,Li Y,Schulte RF

更新日期：2018-11-01 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

authors： Liu YJ,Lee YH,Chang HC,Chiu HC,Chiu TW,Hsu K,Pen CM,Hsu HH,Juan CJ

更新日期：2018-03-01 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

authors： Fujii H,Berliner LJ

更新日期：2004-08-01 00:00:00

abstract：:Evaluation of high intensity focused ultrasound (HIFU) treatment with MRI is generally based on assessment of the non-perfused volume from contrast-enhanced T1-weighted images. However, the vascular status of tissue surrounding the non-perfused volume has not been extensively investigated with MRI. In this study, clus...

journal_title：NMR in biomedicine

authors： Jacobs I,Hectors SJ,Schabel MC,Grüll H,Strijkers GJ,Nicolay K

更新日期：2015-11-01 00:00:00

abstract：OBJECTIVES:Quantitative MRI (qMRI) of muscles is a promising tool to measure disease progression or to assess therapeutic effects in neuromuscular diseases. Longitudinal imaging studies are needed to show sensitivity of qMRI in detecting disease progression in spinal muscular atrophy (SMA). In this pilot study we there...

journal_title：NMR in biomedicine

authors： Otto LAM,Froeling M,van Eijk RPA,Asselman FL,Wadman R,Cuppen I,Hendrikse J,van der Pol WL

更新日期：2021-01-22 00:00:00

abstract：:The accuracy and precision of the quantification of metabolite concentrations in in vivo (1) H NMR spectroscopy are affected by linewidth and signal-to-noise ratio (SNR). To study the effect of both factors in in vivo (1) H NMR spectra acquired at ultrahigh field, a reference spectrum was generated by summing nine in ...

journal_title：NMR in biomedicine

authors： Hong ST,Pohmann R

更新日期：2013-01-01 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

authors： Cowie AG,Bastin ME,Manners DN,Hands LJ,Styles P,Radda GK

更新日期：1996-08-01 00:00:00

abstract：:In this methodological paper I report the stereotactic correlation of different magnetic resonance imaging (MRI) techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), functional MRI, and high-resolution BOLD venography (HRBV)] in patients with cerebral arterio-venous malformations (AVM) and brain tumors. ...

journal_title：NMR in biomedicine

authors： Schad LR

更新日期：2001-11-01 00:00:00