Short echo time 1 H magnetic resonance spectroscopy of childhood brain tumours

Peet, Andrew C.; Lateef, Shaheen; MacPherson, Lesley; Natarajan, K.; Sgouros, Spyridon; Grundy, Richard G.

doi:10.1007/s00381-006-0206-4

Cited by 31 publications

(27 citation statements)

References 13 publications

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“…EPEN and MED have higher concentrations of lipids and macromolecules, associated with hypoxia, apoptosis and necrosis and linked to high malignancy and poor survival [33,34]. As previously reported [35,36,37], Tau concentration is significantly higher in MED than glial tumours (p≤0.01) and further investigation of the role of this metabolite in these tumours is warranted. Low concentrations of Cr were seen in PILOA as in previous studies but remain unexplained [30].…”

Section: Discussionmentioning

confidence: 90%

Accurate classification of childhood brain tumours by in vivo 1H MRS – A multi-centre study

Vicente

Fuster–Garcia

Tortajada

et al. 2013

European Journal of Cancer

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ElsevierVicente Robledo, J.; Fuster Garcia, E.; Tortajada Velert, S.; García Gómez, JM.; Davies, N.; Natarajan, K.; Wilson, M.... (2013) Integration. Linear Discriminant Analysis was applied to this data to produce diagnostic classifiers. An evaluation of the diagnostic accuracy was performed based on resampling to measure the Balanced Accuracy Rate (BAR). Results:The accuracy of the diagnostic classifiers for discriminating the three tumour types was found to be high (BAR 0.98) when a combination of TE was used. The combination of both TE significantly improved the classification performance (p < 0.01, Tukeyʼs test) compared with the use of one TE alone. 3Other tumour types were classified accurately as glial or primitive neuroectodermal (BAR 1.00). 12 cases failed the inclusion criteria for QC mainly due to poor SNR. Conclusions Classification and evaluation 9The diagnostic classification problem of discriminating between EPEN, PILOA and MED, the three most common pediatric tumour types, is addressed in this study. Since EPEN and PILOA tumours can be found in brain locations other than the PF whereas MED are found only in the PF, training was undertaken twice, once using the tumour cases located in the PF and then with those in any brain location. Classifiers were designed and evaluated using features from Short-TE and Long-TE alone and a combination of both TEs, ShortTE+Long-TE. Our results were compared with those in previous studies [27][28][29][30].Based on the results of previous studies [15,20,26,29 Results Spectral featuresSeveral key features allow visual discrimination of PILOA, EPEN and MED. Figures 1 and 2 show the Short-TE and Long-TE mean spectra of the tumour types. Minimum differences are found between the mean spectra of the tumours in the PF and those in any location. All tumour spectra display an increase in Cho peak (3.2ppm) with respect to Cr peak (3.0ppm). NAA (2.0ppm) presents a less prominent peak in MED and EPEN compared with 10 PILOA. Elevation of macromolecules and lipids (0.9ppm and 1.3ppm) is observed in Short-TE. Regarding Long-TE, the inverted peak of Lac at 1.3ppm is distinguished in PILOA and EPEN but not in MED. Tables 2 and 3 show the metabolite concentrations estimated with TARQUIN in Short-TE and Long-TE for the three tumour types found in any brain location. The Kruskal-Wallis test for the analysis of the variance (α=0.05) was applied to determine the significant differences in metabolite concentrations of PILOA, EPEN and MED. Both Cho components, Glycerophosphocholine (GPC) and Phosphocholine (PCh) (p≤0.01) showed significant differences. Cr and Tau concentrations were significantly different in both TEs (p≤0.01). Univariate metabolite comparisonDifferences in the mI concentrations (p≤0.01) were significant in Short-TE.Macromolecules and lipids at 0.9, 1.3 and 2.0ppm (p≤0.05, p≤0.01 and p≤0.01, respectively) exhibited statistical differences in Short-TE MRS. Classification DiscussionThis is the first study of MRS as a non-invasive diagnostic aid in childhood brain tumo...

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Section: Discussionmentioning

confidence: 90%

Accurate classification of childhood brain tumours by in vivo 1H MRS – A multi-centre study

Vicente

Fuster–Garcia

Tortajada

et al. 2013

European Journal of Cancer

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“…Notably, several metabolites that are informative for neurodiagnostics and more broadly for cancer diagnostics, such as m-Ins, Lip, glutamate (Glu) and glutamine (Gln) 1 decay rapidly, such that they can be detected only at short echo times (TE) [22,23]. Due to high spectral density, fitting becomes even more problematic at short TEs.…”

Section: Ensuing Diagnostic Dilemmasmentioning

confidence: 99%

Iterative averaging of spectra as a powerful way of suppressing spurious resonances in signal processing

Belkić

2016

J Math Chem

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The fast Padé transform (FPT) was applied to magnetic resonance spectroscopic (MRS) time signals encoded in vivo on a 1.5 T scanner from the parietal-temporal brain region of a pediatric patient who had suffered cerebral asphyxia. An iterative averaging procedure was implemented to the 9th iteration, whereby spurious structures on the total shape spectra were effectively suppressed. The parametric and non-parametric FPT (±) were verified to reconstruct equivalent total shape spectra. Via the parametric FPT, the spectral region of interest was chosen to bypass the giant water resonance, automatically generating spectral envelopes without the need for windowing. The dense component spectra were reliably reconstructed by the FPT (+) , in the "usual" mode (mixture of absorption and dispersion components) and "ersatz" mode (reconstructed phases set to zero). Via the latter, interference effects were well-visualized for closely-overlapping and hidden resonances. The most stringent test was performed for the complex frequencies and associated complex amplitudes reconstructed by the FPT (+) . Exceedingly small variances were obtained for all four Padé-reconstructed parameters per genuine resonance, once convergence was achieved at the 7th to 9th iterated averages. This now fully-validated methodology can generate denoised spectra and accurate spectral parameters for in vivo MRS data encoded within neurodiagnostics. Such a multi-faceted Padé-based strategy for processing the dense spectra of the brain could vitally improve pediatric neurodiagnostics. A wider range of clinical applications becomes within reach, including areas of cancer diagnostics where the added value of in vivo MRS is urgently needed. The broad theoretical underpinnings of incorporating quantum mechanics into signal processing provide the basis for these innovative advances.

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“…Low levels of creatine, myo-inositol and taurine are the most relevant features of the in vivo MRS metabolic profile of pylocytic astrocytoma (6)(7)(8)(9)(10)(11)14). Overall, in vivo MRS biomarkers may help in the non-invasive diagnosis of paediatric brain tumours (6)(7)(8)(9)(10)(11)15). However, in vivo MRS of paediatric brain tumours still exhibits some limitations.…”

Section: Introductionmentioning

confidence: 99%

Comparative metabolic profiling of paediatric ependymoma, medulloblastoma and pilocytic astrocytoma

Cuellar-Baena

Morales²,

Martinetto³

et al. 2010

Int J Mol Med

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Abstract. Brain tumours are the most common solid tumours in children and a major cause of childhood mortality. The most common paediatric brain tumours include ependymomas, cerebellar astrocytomas and medulloblastomas. These brain tumours are highly heterogeneous regarding their histology, prognosis and therapeutic response. Subtle biochemical changes can be detected in intact tissues by High-Resolution Proton Magnetic Angle Spinning Spectroscopy (HR-MAS) revealing the status of tumour microheterogeneity and metabolic alterations before they are morphologically detectable. In this study, we present metabolic profiles by HR-MAS of 20 intact tissue samples from paediatric brain tumours. Tumour types include ependymoma, medulloblastoma and pilocytic astrocytoma. The metabolic characterization of paediatric brain tumour tissue by HR-MAS spectroscopy provided differential patterns for these tumours. The metabolic composition of the tumour tissue was highly consistent with previous in vivo and ex vivo studies. Some resonances detected in this work and not previously observed by in vivo spectroscopy also show potential in determining tumour type and grade (fatty acids, phenylalanine, glutamate). Overall, this work suggests that the additional information obtained by NMR metabolic profiling applied to tissue from paediatric brain tumours may be useful for assessing tumour grade and determining optimum treatment strategies.

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Short echo time 1 H magnetic resonance spectroscopy of childhood brain tumours

Cited by 31 publications

References 13 publications

Accurate classification of childhood brain tumours by in vivo 1H MRS – A multi-centre study

Accurate classification of childhood brain tumours by in vivo 1H MRS – A multi-centre study

Iterative averaging of spectra as a powerful way of suppressing spurious resonances in signal processing

Comparative metabolic profiling of paediatric ependymoma, medulloblastoma and pilocytic astrocytoma

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