MR Spectroscopic Imaging

Abstract

Abbreviations ATRTAtypical teratoid rhabdoid tumor BCNU Bis-chloroethylnitrosourea (carmustine) GBM Glioblastoma multiforme HIF1αHypoxia-inducible factor 1-alpha PFS Progression-free survival PNET Primitive neuroectodermal tumor PRESS Point resolved spectroscopy rGBM Recurrent glioblastoma multiforme STEAM Stimulated echo acquisition mode T Tesla MR spectroscopy (MRS) allows the noninvasive measurement of the concentrations from selected metabolites in vivo. Till now, MR spectroscopy is applied for specific purposes in brain tumor diagnostics. The metabolic profile of a brain tumor not only characterizes tumor entity, but it may also be crucial for prognosis and for therapeutic decisions. In the last decades, it has become evident that molecular genetic markers of a brain tumor may be prognostic or even predictive for a specific therapy (Weller et al. 2009;Reifenberger et al. 2012). Therefore, therapy of brain tumors is becoming increasingly complex, and histopathological features should not be the only aspect of establishing therapeutic decisions in the future. These molecular markers influence the metabolic profile and the micro milieu of the tumor. While MRI is considered as method of choice for diagnostic imaging of brain tumors, the method of MR spectroscopy, which is based on the same physical principles as MRI and can be performed with the identical setup, provides metabolic information, thereby offering a tool for studying the metabolic profile. In vitro MRS studies of tumor specimen and many in vivo studies have already shown that MR spectroscopy is able to detect these metabolic profiles or even the oncometabolites themselves (Constantin et al. 2012). Therefore, the role of MR spectroscopy may fundamentally change in the next

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