Ex vivo HR-MAS MRS of human meningiomas: a comparison with in vivo 1H MR spectra.

We report on the magnetic resonance spectroscopy (MRS) characterisation of different human meningiomas. Three histological subtypes of meningiomas (meningothelial, fibrous and oncocytic) were analysed both through in vivo and ex vivo MRS experiments. The ex vivo high-resolution magic angle spinning (HR-MAS) investigations, permitting an accurate description of the metabolic profile, are very helpful for the assignment of the resonances in vivo of human meningiomas and for the validation of the quantification procedure of in vivo MR spectra. By using one- and two-dimensional experiments, we were able to identify several metabolites in different histological subtypes of meningiomas. Our spectroscopic data confirmed the presence of the typical metabolites of these benign neoplasms and, at the same time, that meningomas with different morphological characteristics have different metabolic profiles, particularly regarding macromolecules and lipids. The ex vivo spectra allowed a better understanding and interpretation of the in vivo MR spectra, showing that the HR-MAS MRS technique could be a complementary method to strongly support the in vivo MR spectroscopy and increase its clinical potentiality.

Magnetic resonance spectroscopy and high performance liquid chromatography of neoplastic human renal tissues.

BACKGROUND: The biochemical composition of human neoplastic and normal renal tissues. MATERIALS AND METHODS: Thirteen patients with nephrocarcinomas were examined: 24 samples, 13 from the nephrocarcinomas, 9 from the surrounding healthy parenchyma and 2 from the healthy cortex and medulla were extracted and analyzed by Magnetic Resonance Spectroscopy (MRS) and High Performance Liquid Chromatography (HPLC). RESULTS: MRS yielded information on renal osmolytes, whereas HPLC disclosed the amino acid pattern of tissue extracts. Significant biochemical differences were found between normal and pathological renal tissues: the osmolyte content decreases dramatically in nephrocarcinomas. CONCLUSION: We confirm that many osmolytes are present in the healthy kidney, with a different distribution between cortex and medulla, and can be considered markers of a physiological renal function. The marked decrease of these osmolytes is typical of cancer. A detailed knowledge of the biochemical composition of human renal tissues is required for the use of diagnostic methods, like in vivo MRS, the reliability of which is based on the detection of molecular markers. Useful information can also be obtained from the study of the amino acidic fraction.