In vivo magnetic resonance spectroscopy for the differential diagnosis of a cerebral mass in a boy with precocious puberty: a case report and review of the literature.

MRS is a state-of-the-art, non-invasive imaging technique that compares the chemical composition of normal tissue to that of abnormal regions by juxtaposing the frequency of measured metabolites. MRS, in combination with clinical evaluation and classic MRI, can provide identification of CNS masses, thus eliminating the need for an invasive biopsy.