Abstract:
:High grade and metastatic brain tumours exhibit considerable spatial variations in proliferation, angiogenesis, invasion, necrosis and oedema. Vascular heterogeneity arising from vascular co-option in regions of invasive growth (in which the blood-brain barrier remains intact) and neoangiogenesis is a major challenge faced in the assessment of brain tumours by conventional MRI. A multiparametric MRI approach, incorporating native measurements and both Gd-DTPA (Magnevist) and ultrasmall superparamagnetic iron oxide (P904)-enhanced imaging, was used in combination with histogram and unsupervised cluster analysis using a k-means algorithm to examine the spatial distribution of vascular parameters, water diffusion characteristics and invasion in intracranially propagated rat RG2 gliomas and human MDA-MB-231 LM2-4 breast adenocarcinomas in mice. Both tumour models presented with higher ΔR1 (the change in transverse relaxation rate R1 induced by Gd-DTPA), fractional blood volume (fBV) and apparent diffusion coefficient than uninvolved regions of the brain. MDA-MB-231 LM2-4 tumours were less densely cellular than RG2 tumours and exhibited substantial local invasion, associated with oedema, whereas invasion in RG2 tumours was minimal. These additional features were reflected in the more heterogeneous appearance of MDA-MB-231 LM2-4 tumours on T2 -weighted images and maps of functional MRI parameters. Unsupervised cluster analysis separated subregions with distinct functional properties; areas with a low fBV and relatively impermeable blood vessels (low ΔR1 ) were predominantly located at the tumour margins, regions of MDA-MB-231 LM2-4 tumours with relatively high levels of water diffusion and low vascular permeability and/or fBV corresponded to histologically identified regions of invasion and oedema, and areas of mismatch between vascular permeability and blood volume were identified. We demonstrate that dual contrast MRI and evaluation of tissue diffusion properties, coupled with cluster analysis, allows for the assessment of heterogeneity within invasive brain tumours and the designation of functionally diverse subregions that may provide more informative predictive biomarkers.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Boult JK,Borri M,Jury A,Popov S,Box G,Perryman L,Eccles SA,Jones C,Robinson SPdoi
10.1002/nbm.3594subject
Has Abstractpub_date
2016-11-01 00:00:00pages
1608-1617issue
11eissn
0952-3480issn
1099-1492journal_volume
29pub_type
杂志文章abstract::MRI and MRS in small rodents demand very high sensitivity. Cryogenic transmit/receive radiofrequency probes (CryoProbes) designed for (1) H MRI of mouse brain provide an attractive option for increasing the performance of small-animal MR systems. As the Larmor frequency of (13) C nuclei is four times lower than that f...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3110
更新日期:2014-06-01 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::Quantification of metabolites is a goal of many biomedical NMR studies. To obtain absolute measurements of metabolite concentrations is often both difficult and time-consuming. In this paper a method for determining metabolite concentrations directly is described and validated. It is applicable to studies of amphibian...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940050306
更新日期:1992-05-01 00:00:00
abstract::Diffusion measurements were performed on the N-acetyl aspartate (NAA) signal in in situ brains (in vivo and post-mortem) and on in vitro brain tissue at 37 degrees C using wide ranges of b-values (from 0 up to 4.5 x 10(6) s/cm2 and 35.8 x 10(6) s/cm2 for the in vivo and the in vitro cases, respectively). In vivo and i...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199804)11:2<67::aid-nbm503
更新日期:1998-04-01 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
pub_type: 杂志文章
doi:10.1002/nbm.1940040605
更新日期:1991-12-01 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::Exercise studies investigating the metabolic response of calf muscles using 31 P MRS are usually performed with a single knee angle. However, during natural movement, the distribution of workload between the main contributors to force, gastrocnemius and soleus is influenced by the knee angle. Hence, it is of interest ...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.3905
更新日期:2018-06-01 00:00:00
abstract::The combination of hyperpolarized Xe with chemical exchange saturation transfer (Hyper-CEST) is a powerful NMR technique to detect highly dilute concentrations of Xe binding sites using RF saturation pulses. Crucially, that combination of saturation pulse strength and duration that generates the maximal Hyper-CEST eff...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3307
更新日期:2015-06-01 00:00:00
abstract::Quantitative susceptibility mapping (QSM) is a recently developed MRI technique that provides a quantitative measure of tissue magnetic susceptibility. To compute tissue magnetic susceptibilities based on gradient echoes, QSM requires reliable unwrapping of the measured phase images and removal of contributions caused...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3056
更新日期:2014-02-01 00:00:00
abstract::Glucose metabolism in control and estrogen stimulated rat uteri was investigated using 13C NMR spectroscopy. By employing an NMR adapted perifusion system, and developing protocols and methods based on the application of [1-13C]glucose labeling, it was possible to measure, with a temporal resolution of 10 min, the kin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940070503
更新日期:1994-08-01 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 outline is presented of metabolite-specific in vivo NMR spectroscopy (particularly in brain). It reviews from a physical spectroscopist's perspective, the need for and the methods of observation of, individual metabolite resonances. ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199712)10:8<435::aid-nbm48
更新日期:1997-12-01 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
pub_type: 杂志文章
doi:10.1002/nbm.3406
更新日期:2015-11-01 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::Increased sensitivity and chemical shift dispersion at ultra-high magnetic fields enable the precise quantification of an extended range of brain metabolites from (1)H MRS. However, all previous neurochemical profiling studies using single-voxel MRS at 7 T have been limited to data acquired from the occipital lobe wit...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1727
更新日期:2012-01-01 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::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::Normal subjects performed voluntary, isometric exercise 1 s contraction, 1 s rest for 10 min) of the first dorsal interosseous (FDI) muscle with a target force of 25, 50 and 100% of the maximal voluntary contraction (MVC) force. 31P NMR spectra were collected continuously before, during and after exercise. Data were a...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940030504
更新日期:1990-10-01 00:00:00
abstract::NMR relaxometry can provide information about the relaxation of the magnetization in different tissues, increasing our understanding of molecular dynamics and biochemical composition in biological systems. In general, tissues have complex and heterogeneous structures composed of multiple pools. As a result, bulk magne...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4318
更新日期:2020-12-01 00:00:00
abstract::Studies of cholesteryl ester transfer protein (CETP) function in lipoprotein mixtures pose many difficulties by conventional biochemical methods. For instance, studies on the effects of CETP on the composition of apolipoprotein B containing lipoproteins (very low and low density lipoproteins) in lipoprotein mixtures a...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199710)10:7<303::aid-nbm48
更新日期:1997-10-01 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::The potential use of 13C multilabeled substrates has been studied in biological applications using in vivo and in vitro proton and 13C NMR spectroscopy. In 13C NMR spectroscopy, multilabeled compounds allow the simultaneous observation of several nuclei or increase distinctly the signal to noise ratio due to a higher ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940020516
更新日期:1989-12-01 00:00:00
abstract::More than 50% of cancers fail to respond to any individual treatment and tumour follow-up after treatment plays a major role in routine therapy planning and pharmacological research. Today, MRS is the only technological approach providing non-invasive access to tumour biochemistry. Ten years ago, expectations were rai...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940060602
更新日期:1993-11-01 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::Localization techniques are considered an indispensable part of the clinical spectroscopy examination. The results are often a marked improvement in diagnostic information (amplification), but because of the introduction of new artifacts and the more prolonged examination time, some of the undoubted advantage is lost ...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1940020525
更新日期:1989-12-01 00:00:00
abstract::The significance of NMR water diffusion measurements performed at short diffusion times (< 10 ms) for brain tissue is examined. An apparent restriction to diffusion for both healthy and cytotoxically edematous tissue is shown: cytotoxic edema lengthens the diffusion time at which this phenomenon is visible. The dramat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940070703
更新日期:1994-11-01 00:00:00
abstract::The dependence of apparent diffusion coefficients (ADCs) of molecules in biological tissues on an acquisition-specific timescale is a powerful mechanism for studying tissue microstructure. Unlike water, metabolites are confined mainly to intracellular compartments, thus providing higher specificity to tissue microstru...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3085
更新日期:2014-05-01 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::Electric properties tomography (EPT) derives the patient's electric properties, i.e. conductivity and permittivity, using standard magnetic resonance (MR) systems and standard MR sequences. Thus, EPT does not apply externally mounted electrodes, currents or radiofrequency (RF) probes, as is the case in competing techn...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.3729
更新日期:2017-08-01 00:00:00
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. Simulat...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.916
更新日期:2005-02-01 00:00:00