Abstract:
|
[EN] H-1 MRS is becoming an accurate, non-invasive technique for initial examination of brain masses. We investigated if the combination of single-voxel H-1 MRS at 1.5 T at two different (TEs), short TE (PRESS or STEAM, ...[+]
[EN] H-1 MRS is becoming an accurate, non-invasive technique for initial examination of brain masses. We investigated if the combination of single-voxel H-1 MRS at 1.5 T at two different (TEs), short TE (PRESS or STEAM, 20-32 ms) and long TE (PRESS, 135-136 ms), improves the classification of brain tumors over using only one echo TE. A clinically validated dataset of 50 low-grade meningiomas, 105 aggressive tumors (glioblastoma and metastasis). and 30 low-grade glial tumors (astrocytomas grade II, oligodendrogliomas anti oligoastrocytomas) was used to fit predictive models based on the combination of features from short-TEs and long-TE spectra. A new approach that combines the two consecutively was used to produce a single data vector from which relevant features of the two TE spectra could be extracted by means of three algorithms: stepwise, reliefF, and principal components analysis. Least Squares support vector machines and linear discriminant analysis were applied to fit the pairwise and multiclass classifiers, respectively. Significant differences in performance were found when short-TE, long-TE or both spectra combined were used as input. In our dataset, to discriminate meningiomas, the combination of the two TE acquisitions produced optimal performance. To discriminate aggressive tumors from low-grade filial tumours, the use of short-TE acquisition alone was preferable. The classifier development strategy used here lends itself to automated learning and test performance processes, which may, be of use for future web-based multicentric classifier development studies. Copyright (c) 2008 John Wiley & Sons, Ltd.
[-]
|
Thanks:
|
This work was partially funded by the European Commission: eTUMOUR (contract no. FP6-2002-LIFESCI-HEALTH 503094). HealthAgents (contract no. FP6-2005-IST 027213), BIOPATTERN (contract no. FP6-2002-IST 508803); Programa de ...[+]
This work was partially funded by the European Commission: eTUMOUR (contract no. FP6-2002-LIFESCI-HEALTH 503094). HealthAgents (contract no. FP6-2005-IST 027213), BIOPATTERN (contract no. FP6-2002-IST 508803); Programa de Apoyo a la Investigacion y Desarrollo, PAID-00-06 UPV; Research Council KUL: GOA-AMBioRICS, Centers-of-excellence optimisation; Belgian Federal Government: DWTC, IUAPV P6/04 (DYSCO 2007-2011). Jan Luts is a PhD student supported by an IWT grant. We thank INTERPRET partners for providing data, in particular, C. Majos (IDI-Bellvitge), John Griffiths (SGUL), Arend Heerschap (RU), Witold Gajewicz (MUL), and Jorge Calvar (FLENI). We also thank Guillem Mercadal for his feedback about 1H MRS data processing.
[-]
|