Single Voxel Localized Proton NMR Spectroscopy of Human Brain In Vivo

Frahm, Jens; Hänicke, W.

doi:10.1002/9780470034590.emrstm0507

Cited by 4 publications

(2 citation statements)

References 82 publications

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“…For proton MRS, these sequences are preceded by a water suppression module such as the generic CHESS method [224], that is a water-selective RF excitation pulse followed by a spoiler gradient. Relative advantages and drawbacks of MRS versus MRSI and PRESS versus STEAM have been discussed elsewhere [225][226][227][228][229]. Because all techniques may perform high-quality proton MRS in vivo when properly used, other non-technical issues such as the quantification of metabolite concentrations (rather than the observation of resonance intensity ratios) are more important in view of the achievable neurochemical insight or long-term medical impact.…”

Section: Localizationmentioning

confidence: 99%

Localized proton MRS of animal brain in vivo: Models of human disorders

Michaelis

Boretius

Frahm

2009

Progress in Nuclear Magnetic Resonance Spectroscopy

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Section: Localizationmentioning

confidence: 99%

Localized proton MRS of animal brain in vivo: Models of human disorders

Michaelis

Boretius

Frahm

2009

Progress in Nuclear Magnetic Resonance Spectroscopy

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“…Both methods provide single-shot capabilities to acquire spectroscopic data from the VOI and are particularly advantageous over multi-shot techniques like image selected in vivo spectroscopy (ISIS), which is inherently based on multiple excitation followed by phase cycling scheme (Ordidge et al, 1986). This makes ISIS vulnerable to motion and contaminated with unwanted signal outside the VOI (Frahm and Hänicke, 2000). An additional advantage of single-shot is the ability to perform localized shimming, water suppression, and RF pulse gain adjustments on the desired VOI.…”

Section: Single-voxel Mr Spectroscopymentioning

confidence: 99%

Localized Proton Magnetic Resonance Spectroscopy of Mouse Brain In Vivo at High Magnetic Field Strength

Tafresh¹

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Chapter 1 1950). Following the discovery of the spin echo (Hahn, 1950) and of spin-spin coupling (Ramsey and Purcell, 1952), NMR spectroscopy gradually developed into the most versatile technique for non-invasive probing of molecular structure, as well as molecular motions and reaction dynamics. The diagnostic value of (proton) NMR in medical applications was apprehended first by Damadian (Damadian, 1971), reporting the different magnetic relaxation times of malignant tumors from those of normal tissues.With the advent of linear magnetic field gradients (Lauterbur, 1973, Mansfield and will enable a sufficiently reliable localization to obtain adequate signals -even from the brain regions remote from the surface coil. (iii) state-of-the-art magnet and shim coils will ensure stability in B 0 . (iv) 12 cm inner diameter self-shielded gradient coil insert (Resonance Research Inc, Billerica, MA, USA) will provide sophisticated eddy current compensation, while being capable of supplying up to 400 mTm −1 in 80 μs rise time. (v) Use of only three RF pulses in water suppression scheme, in analogy to what is proposed by Ernst et al (Ernst and Hennig, 1995), will minimize the risk of unwanted echo formation. (vi) Use of oblique volume-of-interest will facilitate localization for specific brain regions.With these improvements, the primary objective of the research presented in this thesis is to implement and optimize a STEAM localization technique on a 9.4 T MRI system, to perform state-of-the-art single-voxel 1 H MRS in vivo, taking full advantage of the gain in SNR and chemical shift dispersion at higher field strengths. Further, these modifications will require, (i) systematic investigation of bandwidths and inter-pulse delays of water suppression pulses for in vitro condition as well as for mouse brain in vivo, (ii) systematic investigation of the relative detectability of strongly coupled metabolite resonances at 9.4 T compared to lower field strength.

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Single Voxel Proton MR Spectroscopy Methods and Applications in Neuropediatrics

Frahm

Hanefeld

2000

Rivista di Neuroradiologia

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The purpose of this contribution is to introduce quantitative single voxel proton MR spectroscopy of the human brain as an easy-to-use method for a noninvasive assessment of cellular c;omposition and metabolism and to demonstrate its clinical potential in the field of neuropediatrics.The chosen approach transforms fully relaxed (TR = 6000 ms) short echo time (TE = 20 ms) proton MR spectra (STEAM localization sequence) into absolute metabolite concentrations by automatically fitting the raw data with a library of model spectra comprising all metabolites at known concentration (LCModel). The procedure includes total N-acetylaspartyl compounds as a marker for viable neuroaxonal tissue and myo-inositol as a purely glial constituent as well as total creatine, choline-containing compounds, glutamate and glutamine, and lactate.Extensive studies of brain disorders in childhood suggest the use of proton MRS as a promising tool for an in vivo histopathologic characterization of brain tissue. Typical metabolite patterns are observed for pathologic processes such as lactic acidosis, loss of functioning neurons, astrocytosis, myelin breakdown, or loss of oligodendrocytes. Examples deal with the diagnostic workup of enzyme deficiencies, demyelinating white matter diseases, and focal brain lesions. Spettroscopia protonica con risonanza magnetica Metodi e applicazioni in neuropediatriaSOMMARIO -Scopo di questo contributo e quello di introdurre l'analisi quantitativa degli spettri RM acquisiti a livello cerebrate come metodo di semplice utilizzo per la determinazione non invasiva della composizione cellulare e del metabolismo e per dimostrare il potenziale clinico di questo metodo nel campo della neuro-pediatria.L'approccio scelto trasforma spettri completamente rilassati (TR = 6s), acquisiti a tempi di eco brevi (TE = 20 ms) con la sequenza STEAM, in concentrazioni assolute dei metaboliti mediante "fitting" automatico dei dati con una libreria di spettri-modello contenenti tutti i metaboliti a concentrazioni note (LCModel). Questa procedura include i composti del N-acetilaspartato come marker del tessuto neuro-assonale, il mio-inositolo come marker della glia cos'i come la creatina totale, i composti della colina, il glutammato, la glutammina e l'acido lattico.Studi estensivi su malattie neurologiche nei bambini hanno mostrato come la risonanza magnetica spettroscopica sia uno strumento molto promettente per la caratteriz zazione istopatologica del tessuto cerebrate. Spettri caratteristici sono stati osservati per processi patologici quali l'acidosi lattica, la perdita di neu-' rani, l'astrocitosi, la rottura delle catene mieliniche o la perdita di oligodendrociti. Gli esempi di applicazioni della spettroscopia riportati nel testa riguardano il deficit di enzimi, le malattie demielinizzanti della materia bianca e le lesioni cerebrali focali. 7Single Voxel Proton MR Spectroscopy

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Single Voxel Localized Proton NMR Spectroscopy of Human Brain In Vivo

Cited by 4 publications

References 82 publications

Localized proton MRS of animal brain in vivo: Models of human disorders

Localized proton MRS of animal brain in vivo: Models of human disorders

Localized Proton Magnetic Resonance Spectroscopy of Mouse Brain In Vivo at High Magnetic Field Strength

Single Voxel Proton MR Spectroscopy Methods and Applications in Neuropediatrics

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