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

Abstract

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 twodimensional 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.

Biochemical Alterations from Normal Mucosa to Gastric Cancer by Ex vivo Magnetic Resonance Spectroscopy

“…The analysis of these spectra permitted a direct identification of a lot of metabolites (8,(12)(13)(14), and their differences in percentage were obtained by the inspection of CPMG spectra reported in Fig. 2A to D. The spectrum representative of H. pylori -related gastritis (Fig.…”

“…Proton HR-MAS MRS was done with a Bruker Avance400 spectrometer equipped with a 1 H, 13 C HR-MAS probe operating at 400.13 and 100.61 MHz. Samples were spun at 4,000 Hz, and three different types of monodimensional proton spectra were acquired at 4jC to prevent tissue degradation processes, which were found to be more evident at room temperature (8,(12)(13)(14), using the following:…”

“…Twodimensional 1 H, 13 C-heteronuclear single quantum coherence spectra were acquired using an echo-antiecho phase-sensitive standard pulse sequence (hsqcedetgp), 0.5-s relaxation delay, 1.725-ms evolution time, 4-kHz spectral width in f 2 , 4k data points, 128 scans per increment, 17-kHz spectral width in f 1 , and 256 increments. The identification of >55 metabolites was done using bidimensional spectra (8,(12)(13)(14).…”

“…It is widely applied in biomedical research, with particular attention to molecular evaluations about diagnosis, treatment, and prognosis of human neoplasms (6,7). The metabolic profiles, associated with healthy and malignant human tissue, can be now established through ex vivo high-resolution magic angle spinning magnetic resonance spectroscopy (HR-MAS MRS) done directly on human tissue specimens without any pretreatment (8)(9)(10). This technique is a powerful tool to investigate the molecular composition of human tissue, potentially bridging the in vitro (on human tissues extracts) and in vivo (directly on patients) MRS.…”

Proton Magnetic Resonance Spectroscopy of the Central Nervous System

“…This chemical substance, resonated at 3.8ppm using short TE 1 H-MRS ( Figure 8) and according to the in vitro study of Tugnoli et al it might receive contribution from phosphoethanolamine (PE) and other amino acids such as Leukine, ALanine, Glutamate, Glutamine, Glutathione, Lysine, Arginine and Serine [110]. …”