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 tumor pO2 and blood flow associated with acute hypoxia. Here, the possible correlation between tumor vessel immaturity, vessel functionality and T2*w GRE signal fluctuations was investigated. Intramuscularly implanted FSa II fibrosarcoma-bearing mice were imaged at 4.7 T. Maps of spontaneous fluctuations of MR signal intensity in tumor tissue during air breathing were obtained using a T2*w GRE sequence. This same sequence was also employed during air-5% CO2 breathing (hypercapnia) and carbogen breathing (hypercapnic hyperoxia) to obtain parametric maps representing vessel maturation and vessel function, respectively. Vascular density, vessel maturation and vessel perfusion were also assessed histologically by using CD31 labeling, alpha-smooth muscle actin immunoreactivity and Hoechst 33242 labeling, respectively. About 50% of the tumor fluctuations occurred in functional tumor regions (responsive to carbogen) and 80% occurred in tumor regions with immature vessels (lack of response to hypercapnia). The proportion of hypercapnia-responsive voxels were found to be twice as great in fluctuating than in non-fluctuating tumor areas (P: 0.22 vs 0.13). Similarly, the proportion of functional voxels was somewhat greater in fluctuating tumor areas (P: 0.54 vs 0.43). The mean values of MR signal changes during hypercapnia (VD) and during carbogen breathing (VF) (significant voxels only) were also larger in fluctuating than in non-fluctuating tumor areas (P < 0.05). This study demonstrated that adequate vessel functionality and advanced vessel maturation could explain at least in part the occurrence of spontaneous T2*w GRE signal fluctuations. Functionality and maturation are not required for signal fluctuations, however, because a large fraction of fluctuations could still occur in non-perfused and/or immature vessels.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Baudelet C,Cron GO,Ansiaux R,Crokart N,DeWever J,Feron O,Gallez Bdoi
10.1002/nbm.1002subject
Has Abstractpub_date
2006-02-01 00:00:00pages
69-76issue
1eissn
0952-3480issn
1099-1492journal_volume
19pub_type
杂志文章abstract::The goal of the study was to establish early hyperpolarized (HP) 13 C MRI metabolic and perfusion changes that predict effective high-intensity focused ultrasound (HIFU) ablation and lead to improved adjuvant treatment of partially treated regions. To accomplish this a combined HP dual-agent (13 C pyruvate and 13 C ur...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3962
更新日期:2019-10-01 00:00:00
abstract::Cross-talk between adipose tissue and liver is disturbed in the metabolic syndrome. Moreover, the relative fatty acid composition of adipose and liver fat is poorly characterized. Long-TE (1)H MRS can determine the unsaturation and polyunsaturation of adipose tissue. The aim of this study was to use long-TE (1)H MRS t...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1580
更新日期:2011-04-01 00:00:00
abstract::The signal decay with increasing b-factor at fixed echo time from brain tissue in vivo has been measured using a line scan Stejskal-Tanner spin echo diffusion approach in eight healthy adult volunteers. The use of a 175 ms echo time and maximum gradient strengths of 10 mT/m allowed 64 b-factors to be sampled, ranging ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199902)12:1<51::aid-nbm546
更新日期:1999-02-01 00:00:00
abstract::High-energy phosphate metabolism, which allows the synthesis and regeneration of adenosine triphosphate (ATP), is a vital process for neuronal survival and activity. In particular, creatine kinase (CK) serves as an energy reservoir for the rapid buffering of ATP levels. Altered CK enzyme activity, reflecting compromis...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1636
更新日期:2011-08-01 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::Proton magnetic resonance spectroscopy at 1.9 T was used to quantify dolichols, cholesterols, choline-containing phospholipids and double bonds in unsaturated acyl chains in lipid extracts of four types of thyroid tissue [normal (n = 27), papillary cancer (n = 15), adenoma (n = 13) and Basedow disease (n = 6)]. In nor...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/1099-1492(200011)13:7<377::aid-nbm658>3.0.
更新日期:2000-11-01 00:00:00
abstract::The reliability, relation to whole-body maximal oxygen uptake (VO(2max)), and force-level sensitivity of (31)P MRS markers of mitochondrial function were studied in 39 normal-weight women. Following 90 s isometric plantar-flexion exercises at 45, 70 and 100% of maximum voluntary contraction, skeletal muscle mitochondr...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(200002)13:1<14::aid-nbm605
更新日期:2000-01-01 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::(31)P MRS provides a unique non-invasive window into myocardial energy homeostasis. Mouse models of cardiac disease are widely used in preclinical studies, but the application of (31)P MRS in the in vivo mouse heart has been limited. The small-sized, fast-beating mouse heart imposes challenges regarding localized sign...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3371
更新日期:2015-10-01 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::The relaxation properties of water and metabolites were measured in rat brain following the occlusion of the middle cerebral artery (MCA) with localized 1H MRS. The PRESS sequence was employed to select volumes of 39 microL in the ischemic and the contralateral hemisphere. T1 and T2 relaxation times and peak intensiti...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940080604
更新日期:1995-09-01 00:00:00
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::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 ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3594
更新日期:2016-11-01 00:00:00
abstract::In this study, the upper-limit volume (gas plus partial tissue volume) as well as absolute volume (gas only) of lungs measured with hyperpolarized (3)He-MR imaging is compared with that determined by micro-computed tomography (CT) under similar ventilation conditions in normal rats. Five Brown Norway rats (210-259 g) ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1470
更新日期:2010-05-01 00:00:00
abstract::This review highlights various magnetic resonance image (MRI) segmentation algorithms that employ pattern recognition. The procedures are grouped into two categories: low- to intermediate-level, and high-level image processing. The former consists of grey level histogram analysis, texture definition, edge identificati...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199806/08)11:4/5<157::aid-
更新日期:1998-06-01 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::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::This paper describes the use of off-resonance saturation to further manipulate the blood oxygenation level dependent (BOLD) contrast of fMRI. A customized narrow bandwidth radiofrequency pulse, applied with a range of frequency offsets prior to selection of each slice, was designed and incorporated into a gradient ech...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199706/08)10:4/5<208::aid-
更新日期:1997-06-01 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::High-resolution MR imaging (312 microns in plane resolution) and MR spectroscopy (0.36 cm3 nominal voxel) have been performed on human frontal cortex using a 3 in surface coil. Localized proton spectra have been obtained from contiguous 6 x 6 x 10 mm voxels using one-dimensional phase encoding, TR 2000 ms and TE 31 ms...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(SICI)1099-1492(199610)9:7<297::AID-NBM433
更新日期:1996-10-01 00:00:00
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 recog...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/(sici)1099-1492(199705)10:3<99::aid-nbm461
更新日期:1997-05-01 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::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::Nonbiological total disc replacement is currently being used for the treatment of intervertebral disc (IVD) disease and injury, but these implants are prone to mechanical wear, tear and possible dislodgement. Recently, tissue-engineered total disc replacement (TE-TDR) has been investigated as a possible alternative to...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1651
更新日期:2012-03-01 00:00:00
abstract::A method to extract shapes of bubble polyhedra from three-dimensional nuclear magnetic resonance image data of foam has been developed. The method consists of four steps: first, to compute series of maximum intensity projection images from the three-dimensional NMR image data of foam to visualize the network structure...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/(sici)1099-1492(199701)10:1<13::aid-nbm443
更新日期:1997-01-01 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::While phase imaging with a gradient echo (GRE) sequence is popular, phase imaging with balanced steady-state free precession (bSSFP) has been underexplored. The purpose of this study was to investigate anatomical and functional phase imaging with multiple phase-cycled bSSFP, in expectation of increasing spatial covera...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3699
更新日期:2017-06-01 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::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::Following the development of parallel imaging, parallel transmission describes the use of multiple RF transmit coils. Parallel transmission can be applied to improve RF excitation, in particular, multidimensional, spatially selective RF excitation. For instance, parallel transmission is able to shorten spatially selec...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.1049
更新日期:2006-05-01 00:00:00