Abstract:
:In recent years considerable effort has been devoted to applying pattern recognition techniques to the complex task of data analysis in magnetic resonance spectroscopy. It may be argued that such techniques will facilitate putting MRS technology to practical clinical use. This paper reviews approaches of pattern recognition commonly used in the analysis of MR spectra for biomedical applications. It briefly introduces the mathematical and algorithmic formulation of each of the techniques, noting their developmental background and their relationship to each other, and discusses their strengths and limitations. It then reviews how these techniques have been implemented in MRS applications. In doing so the paper also highlights a number of problems related to the design and testing of MRS/pattern recognition applications which currently prevent these techniques from being in wide practical clinical use, and suggests ways to avoid those pitfalls.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
el-Deredy Wdoi
10.1002/(sici)1099-1492(199705)10:3<99::aid-nbm461subject
Has Abstractpub_date
1997-05-01 00:00:00pages
99-124issue
3eissn
0952-3480issn
1099-1492pii
10.1002/(SICI)1099-1492(199705)10:3<99::AID-NBM461journal_volume
10pub_type
杂志文章,评审abstract::Natural abundance proton-decoupled (13)C magnetic resonance spectroscopy was used to establish the in vivo lipid composition of normal adipose tissue and the corresponding effects of altered lipid diets. Experiments were performed on a standard 1.5 T clinical MR scanner using a double-tuned (1)H-(13)C coil. Peaks from...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.824
更新日期:2003-05-01 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::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::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::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
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::Vessel size index (VSI), a parameter related to the distribution of vessel diameters, may be estimated using two MRI approaches: (i) dynamic susceptibility contrast (DSC) MRI following the injection of a bolus of Gd-chelate. This technique is routinely applied in the clinic to assess intracranial tissue perfusion in p...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1734
更新日期:2012-02-01 00:00:00
abstract::Organs consist of several types of cells with specialized functions. This cellular localization of function is often referred to as compartmentation. Due to the intrinsic low sensitivity of MR methods it is generally not possible in vivo to obtain images or spectra of single cells. Instead the MRS signal is the sum of...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.692
更新日期:2001-04-01 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
pub_type: 杂志文章
doi:10.1002/nbm.1614
更新日期:2011-06-01 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::The background underpinning the clinical use of ultrashort echo time, SPRITE and other pulse sequences for imaging bone and other connective tissues with short T2 is reviewed. Features of the basic physics relevant to UTE imaging are described, including the consequences when the radiofrequency pulse duration is of th...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1100
更新日期:2006-11-01 00:00:00
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 hyperpola...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3690
更新日期:2017-05-01 00:00:00
abstract::Proton magnetic resonance spectroscopy (MRS) was employed to determine the concentrations of N-acetylaspartate (NAA), total creatine (tCr), choline-containing compounds (Cho), myo-inositol (Ins), glucose (Glc), and lactate (Lac) in rat brain before and after 10 days of oral supplementation of 2.6 g Cr-monohydrate per ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199908)12:5<309::aid-nbm57
更新日期:1999-08-01 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::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::We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2883
更新日期:2013-04-01 00:00:00
abstract::A simple technique permitting long term 31P magnetic resonance spectroscopy of cultured mammalian cells is described. Cells are encapsulated in calcium alginate gels and perfused with a new phosphate-fre medium designed for maintenance of high cell viability. Intracellular pH and beta-NTP/Pi ratios, studied in three c...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940030104
更新日期:1990-02-01 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::Signal of lung parenchymal tissue from the living rat and mouse lung was detected at 4.7 T with a good signal-to-noise ratio and motion-suppressed artifacts using a short TE gradient-echo sequence. Neither cardiac nor respiratory gating were applied, and animals respired freely during data collection. Mean T(2)* relax...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.706
更新日期:2001-08-01 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::A number of NMR spectroscopic and microscopic MRI (microMRI) techniques were used to study proton dynamics in canine tendon and articular cartilage immersed in normal saline solution (NaCl solution) and high-concentration phosphate-buffered saline (PBS) solution. In a proton CPMG experiment on tendons, the T(2) relaxa...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1294
更新日期:2009-02-01 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::The majority of functional MRI studies of pain processing in the brain use the blood oxygenation level-dependent (BOLD) imaging approach. However, the BOLD signal is complex as it depends on simultaneous changes in blood flow, vascular volume and oxygen metabolism. Arterial spin labeling (ASL) perfusion imaging is ano...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2911
更新日期:2013-06-01 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 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::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 purpose of this study was to investigate the feasibility of interventional MRI-guided local agent delivery into pig common bile duct (CBD) walls using a newly designed MR-compatible, needle-integrated balloon catheter system. We first designed a needle-integrated balloon catheter system that comprised of a 22 G MR...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3308
更新日期:2015-06-01 00:00:00
abstract::In this work, we report a case study of a stroke model in animals using two methods of quantification of the deviations from Gaussian behaviour: diffusion kurtosis imaging (DKI) and log-normal distribution function imaging (LNDFI). The affected regions were predominantly in grey rather than in white matter. The parame...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2802
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
pub_type: 杂志文章
doi:10.1002/nbm.1411
更新日期:2009-12-01 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