MRS study of meningeal hemangiopericytoma and edema: A comparison with meningothelial meningioma

Abstract

Intracranial hemangiopericytomas (HPCs) are rare tumors and their radiological appearance resembles that of meningiomas, especially meningothelial meningiomas. To increase the knowledge on the biochemical composition of this type of tumor for better diagnosis and prognosis, we performed a molecular study using ex vivo high resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) perfomed on HPC and peritumoral edematous tissues. Moreover, to help in the discrimination between HPC and meningothelial meningioma we compared the ex vivo HR-MAS spectra of samples from one patient with HPC and 5 patients affected by meningothelial meningioma. Magnetic resonance imaging (MRI), in vivo localized single voxel 1H-MRS was also performed on the same patients prior to surgery and the in vivo and ex vivo MRS spectra were compared. We observed the presence of OH-butyrate, together with glucose in HPC and a low amount of N-acetylaspartate in the edema, that may reflect neuronal alteration responsible for associated epilepsy. Many differences between HPC and meningothelial meningioma were identified. The relative ratios of myo-inositol, glucose and gluthatione with respect to glutamate are higher in HPC compared to meningioma; whereas the relative ratios of creatine, glutamine, alanine, glycine and choline-containing compounds with respect to glutamate are lower in HPC compared to meningioma. These data will be useful to improve the interpretation of in vivo MRS spectra resulting in a more accurate diagnosis of these rare tumors.

Non-invasive grading of astrocytic tumours from the relative contents of myo-inositol and glycine measured by in vivo mrs

“…The glycine and mI contents in Table V show a similar trend compared to other reported studies (43)(44)(45)(46)(47)(48): mI content decreased with astrocytic grade, albeit non-significantly, in agreement with (43)(44)(45)(46)(47)(48). Furthermore, gly content increases with grade, in agreement with previous studies (43,44,46,48) in (43)), and the same trend in gly increase with tumour grade was observed in (47 and 50) (HRMAS studies).…”

Proton Magnetic Resonance Spectroscopy of Focal Intracranial Lesions: Role in Clinical Practice

“…Unlike meningiomas, the level of the glutamine/glutamate complex is not high, alanine is not recognized, a "distinct peak" at 3.8 ppm is absent. Instead, hemangiopericytomas show high peaks at 3.56 ppm, and 3.4 ppm, attributed to myo-inositol/glycine, and glucose, respectively, by some authors [30,31]. However, according to Young-Dae Cho et al [32] these peaks should be classified as resonant frequencies of the "unknown molecule" because; in contrast to myo-inositol and glucose (that have T2 within 110 ms) both of these peaks are observed at long TE [32].…”

Applications of high‐resolution magic angle spinning MRS in biomedical studies II—Human diseases

“…While clinical MR investigations on brain tumors have inspired studies of ex vivo HRMAS MRS of tissue specimens to reveal tumor‐type‐specific metabolic structures and pathways, the most significant value of such ex vivo tissue analyses is in improving interpretation of different tumor types, grades, and progression potential for in vivo MRS. A study of 17 human astrocytomas (four Grade II, one Grade III and 12 Grade IV) has shown spectral similarities between in vivo and ex vivo results (Figure ), and highly significant correlations were found for eight out of the 13 measured metabolite concentrations, including creatine (Cr), glutamate (Glu), glutamine (Gln), myo ‐inositol ( myo ‐Ino), N‐acetylaspartate (NAA), scyllo ‐inositol ( scy ‐Ino), total choline (tCho), glycerophosphocholine (GPC), phosphocholine (PCho), and lipids/macromolecules (Lip/MM) . Similarities between in vivo and ex vivo MRS have also been reported for heterogeneous primary and secondary glioblastomas (GBMs), as well as for hemangiopericytoma and meningiomas, two less heterogeneous tumor types …”

“…40 In addition to metabolite overlaps, the detection of certain metabolites can also be field strength and sensitivity dependent. For instance, alanine (Ala) was detectable in an HRMAS spectrum at 9.4 T but not at 3 T during in vivo MRS. 31 Despite these technical challenges, the trend of increasing magnetic field strength of clinical MRI scanners means that the clinical translation of HRMAS MRS findings is increasingly possible.…”