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Multiparametric differentiation of posterior fossa tumors in children using diffusion‐weighted imaging and short echo‐time 1 H‐MR spectroscopy
Author(s) -
Schneider J.F.,
ConfortGouny S.,
Viola A.,
Le Fur Y.,
Viout P.,
Bennathan M.,
Chapon F.,
FigarellaBranger D.,
Cozzone P.,
Girard N.
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21185
Subject(s) - medulloblastoma , pilocytic astrocytoma , effective diffusion coefficient , medicine , ependymoma , nuclear medicine , magnetic resonance imaging , glioma , diffusion mri , in vivo magnetic resonance spectroscopy , neuroradiology , astrocytoma , radiology , pathology , neurology , cancer research , psychiatry
Purpose To assess the combined value of diffusion‐weighted imaging (DWI) and proton magnetic resonance spectroscopy ( 1 H‐MRS) in differentiating medulloblastoma, ependymoma, pilocytic astrocytoma, and infiltrating glioma in a pediatric population. Materials and Methods A total of 17 children with untreated posterior fossa tumors (seven medulloblastoma, four infiltrating glioma, two ependymoma, and four pilocytic astrocytoma), were investigated with conventional MRI, DWI, and MRS using a single‐voxel technique. Within the nonnecrotic tumor core, apparent diffusion coefficient (ADC) values using a standardized region of interest (ROI) were retrieved. Quantification of water signal and analysis of metabolite signals from MRS measurements in the same tumorous area were reviewed using multivariant linear discriminant analysis. Results Combination of ADC values and metabolites, which were normalized using water as an internal standard, allowed discrimination between the four tumor groups with a likelihood below 1 × 10 –9 . Positive predictive value was 1 in all cases. Tumors could not be discriminated when using metabolite ratios or ADC values alone, nor could they be differentiated using creatine (Cr) as an internal reference even in combination with ADC values. Conclusion Linear discriminant analysis using DWI and MRS using water as internal reference, fully discriminates the four most frequent posterior fossa tumors in children. J. Magn. Reson. Imaging. © 2007 Wiley‐Liss, Inc.