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Vivo Proton (vivo + proton)
Selected AbstractsMetabolic changes detected in vivo by 1H MRS in the MPTP-intoxicated mouseNMR IN BIOMEDICINE, Issue 6 2010Carine Chassain Abstract We used in vivo proton (1H) Magnetic Resonance Spectroscopy (MRS) to measure the levels of the main excitatory amino acid, glutamate (Glu) and also glutamine (Gln) and GABA in the striatum and cerebral cortex in the MPTP-intoxicated mouse, a model of dopaminergic denervation, before and after dopamine (DA) replacement. The study was performed at 9.4T on control mice (n,=,8) and MPTP-intoxicated mice (n,=,8). In vivo spectra were acquired in a voxel (8,µL) centered in the striatum, and in the cortex (4.6,µL). Three days after basal MRS acquisitions new spectra were acquired in the striatum and cortex, after levodopa (200,mg.kg,1). Glu, Gln and GABA concentrations obtained in the basal state were significantly increased in the striatum of MPTP-lesioned mice (Glu: 20.2,±,0.8 vs 11.4,±,0.9,mM, p,<,0.001; Gln: 5.4,±,1.6 vs 2.0,±,0.6,mM, p,<,0.05; GABA: 3.6,±,0.8 vs 1.6,±,0.2,mM, p,<,0.05). Levodopa lowered metabolites concentrations in the striatum of MPTP-lesioned mice (Glu: 20.2,±,0.8 vs 11.2,±,0.4,mM (+ Ldopa), p,<,0.001; Gln: 5.4,±,1.6 vs 1.6,±,0.4,mM (+ Ldopa), p,<,0.05; GABA: 3.6,±,0.8 vs 1.7,±,0.4,mM (+ Ldopa), p,<,0.01). Metabolite levels in the striatum of MPTP-intoxicated mice + levodopa were not significantly different from those in the striatum of controls. No change was found in the cortex after DA denervation and after DA replacement between the two animals groups. These results strongly support a predominant change in striatal Glu synaptic activity in the cortico-striatal pathway. Acute levodopa administration reverses the increase of metabolites in the striatum. Copyright © 2010 John Wiley & Sons, Ltd. [source] In vivo proton MR spectroscopy findings specific for adenylosuccinate lyase deficiencyNMR IN BIOMEDICINE, Issue 5 2010M. Henneke Abstract Adenylosuccinate lyase (ADSL) deficiency is an inherited metabolic disorder affecting predominantly the central nervous system. The disease is characterized by the accumulation of succinylaminoimidazolecarboxamide riboside and succinyladenosine (S-Ado) in tissue and body fluids. Three children presented with muscular hypotonia, psychomotor delay, behavioral abnormalities, and white matter changes on brain MRI. Two of them were affected by seizures. Screening for inborn errors of metabolism including in vitro high resolution proton MRS revealed an ADSL deficiency that was confirmed genetically in all cases. All patients were studied by in vivo proton MRS. In vitro high resolution proton MRS of patient cerebrospinal fluid showed singlet resonances at 8.27 and 8.29,ppm that correspond to accumulated S-Ado. In vivo proton MRS measurements also revealed a prominent signal at 8.3,ppm in gray and white matter brain regions of all patients. The resonance was undetectable in healthy human brain. In vivo proton MRS provides a conclusive finding in ADSL deficiency and represents a reliable noninvasive diagnostic tool for this neurometabolic disorder. Copyright © 2010 John Wiley & Sons, Ltd. [source] An automated quantitation of short echo time MRS spectra in an open source software environment: AQSESNMR IN BIOMEDICINE, Issue 5 2007Jean-Baptiste Poullet Abstract This paper describes a new quantitation method called AQSES for short echo time magnetic resonance spectra. This method is embedded in a software package available online from www.esat.kuleuven.be/sista/members/biomed/new/ with a graphical user interface, under an open source license, which means that the source code is freely available and easy to adapt to specific needs of the user. The quantitation problem is mathematically formulated as a separable nonlinear least-squares fitting problem, which is numerically solved using a modified variable-projection procedure. A macromolecular baseline is incorporated into the fit via nonparametric modelling, efficiently implemented using penalized splines. Unwanted components such as residual water are removed with a maximum-phase FIR filter. Constraints on the phases, dampings and frequencies of the metabolites can be imposed. AQSES has been tested on simulated MR spectra with several types of disturbance and on short echo time in vivo proton MR spectra. Results show that AQSES is robust, easy to use and very flexible. Copyright © 2006 John Wiley & Sons, Ltd. [source] Differentiation of hydatid cyst from cysticercus cyst by proton MR spectroscopyNMR IN BIOMEDICINE, Issue 5 2002Monika Garg Abstract The metabolite patterns obtained by ex vivo proton MR spectroscopy of fluid from different locations of hydatid cysts of sheep and humans (n,=,16) and cysticercus cysts of swine and humans (n,=,25) were compared with an objective of differentiating the two parasites on the basis of their metabolite pattern. The spectra from hydatid fluid differed from cysticercus cyst by the absence of creatine in the former. When the hydatid cyst was fertile, malate and/or fumarate was also observed, which was absent in cysticercus cyst. The most likely explanation for the presence of creatine only in the cysticercus fluid is its active diffusion from the surrounding host tissue along with a contribution from the musculature present in the bladder wall of the cyst. Copyright © 2002 John Wiley & Sons, Ltd. [source] In vivo magnetic resonance spectroscopy of gynaecological tumours at 3.0 TeslaBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2009SJ Booth Background, Magnetic resonance spectroscopy (MRS) uses the same hardware as MR imaging and allows us to analyse the biochemistry of tissues in vivo. Published data for gynaecological lesions are limited and are largely based on MRS carried out at the lower magnetic field strength of 1.5 Tesla (T). Objective, The purpose of this study was to determine whether in vivo proton MRS could be performed at the higher magnetic field strength of 3 T to characterise the spectra of a variety of benign and malignant gynaecological lesions. Design, Prospective, non-randomised study. Setting, MRI department within a tertiary referral centre for gynaecological cancers. Sample, All women with a pelvic mass under going 3T MRI. Methods, We carried out MRS on nonrandomised women undergoing routine 3 T MRI within our MRI department during investigation for gynaecological lesions from February 2006 to April 2008. Only those women for whom histopathological data were available were included. Main outcome measures, The presence of choline detected by in vivo 3T MRS. Results, Eighty-seven women underwent MRS, 57 of whom had newly diagnosed neoplasms. MRS data for 39 of these new women (18 were excluded because of technical errors or missing data) were used to detect the presence of choline, an indicator of basement membrane turnover. Overall, choline was present in 13 of the 14 ovarian cancers, 8 of the 11 cervical tumours and all 4 of the uterine cancers. There was no statistical significant difference between choline levels in various lesion types (P= 0.735) or between benign and malignant disease (P= 0.550). Conclusions,In vivo MRS can be performed at 3 T to provide biochemical information on pelvic lesions. The way in which this information can be utilised is less clear but may be incorporated into monitoring tissue response in cancer treatments. [source] | ||||||||||