Energy Status And Metabolism in Intracranial Space Occupying Lesions: A Prospective 31p Spectroscopic Study

Abstract

Aim: Intracranial space occupying lesions can be infective or tumour. There are various advanced Magnetic resonance imaging techniques like perfusion, diffusion and proton spectroscopy which can differentiate between them. However, 31 Phosphorus spectroscopy studies the energy status and the metabolism pattern of various tissues and can be used potentially to differentiate between them depending on their Metabolism pattern. Thus, we aimed to study energy status of various intracranial lesions and try to differentiate between them including grades of gliomas. Materials and Methods:31 PMRS was done in 1.5T MRI in 43 patients prior to surgery or through/via stereo-tactic biopsy, of which 25 were men and 18 women with mean age 41.34 y ranging from 7-71 y. Single voxel phosphorus spectroscopy was done from the solid portion of the lesions and data was analysed and post processed.Results: Study includes Lymphoma (n=6), Grade 1 and 2 glioma (n=5), grade 3 glioma (n=9), grade 4 glioma(n=6), metastases (n=5), tuberculoma (n=7) and pyogenic abscesses (n=5). The integral values of PME, Pi, PDE, γ-ATP, α-ATP, β-ATP with reference to the position of PCr were calculated along with various ratios. Integral values of Pi and PDE were significantly increased in metastases but decreased in gliomas grade 1-2 compared to other pathologic conditions. Mean integral values of LEP (low energy phosphates) and total phosphates were significantly decreased in gliomas grades 1 and 2 and increased in metastases when compared with other pathologic conditions. PCr /Pi was increased in glioma grades 1, 2 and 3 but decreased in metastases; the significance was observed only in gliomas grade 3 and metastases. Metabolic ratios of PDE/βATP and Pi/ βATP were decreased in glioma grades 1 and 2 and increased in metastases with statistical significance. Conclusion:31 PMRS may help in differentiating primary from secondary lesions and assess grades of gliomas. P MR spectroscopy (TR = 400ms, TE=1ms, 512 acquisitions) using intravoxel in-vivo spectroscopy localization method with head quadrature dual-tuned coil. Care was taken to include mainly the solid portion of the lesion in the MRS voxel which ranged from 2 cm 3 -4 cm 3 . The duration of spectroscopy examination was about 5 min. Spectroscopy data were transferred to an installed software programme (Numaris spectroscopy analysis package VB33A). All post-processing techniques like apodization, zero and first order phase corrections were performed and spectra were plotted, analyzed and fitted to Lorentzian lines shapes.The following well resolved phosphorus metabolite peaks were observed in all patients-Phosphomonoesters (PME), Inorganic phosphate (Pi), Phosphodiesters (PDE), Phosphocreatine (PCr), γ, β, and α resonances of adenosine triphosphate (ATP). The chemical

Phosphorous Magnetic Resonance Spectroscopy to Detect Regional Differences of Energy and Membrane Metabolism in Naïve Glioblastoma Multiforme

“…The table shows that the present results are in accordance with the literature if differences have been found. In one study, no "normal" values were presented, and GBM data was compared to nontumorous pathologies [22]. The units of the y-axis are 10 −3 mm 2 /s for ADC, s/mm 2 for b1000, and unitless for FA.…”

“…So far, there have only been a few studies that have investigated newly diagnosed GBM with 31P-MRS. In these studies, differences in energy metabolite and/or membrane metabolite ratios and differences in pH or Mg 2+ values between GBM and the contralateral brain or the brains of healthy volunteers have been described [20][21][22][23][24][25].…”

Phosphorus (P) magnetic resonance spectroscopy for evaluation of brain tissue metabolism and measuring non-invasive pH. A study involving 23 volunteers. Part I

“…Первым по шкале химического сдвига слева от пика PCr расположен пик фосфодиэфиров (PDE=3,6 м.д.). Главные составляющие этого пика (глицерофосфоэтаноламин и глицерофосфохолин) являются структурными компонентами клеточных мембран, а повышение значений PDE наблюдается в случае усиления деградации фосфолипидов клеточных мембран [12]. Затем следуют пики неорганического фосфата -Pi=5,3 м.д.…”

“…Например, в работе R. Kamble и соавт. [12] для получения фосфорного спектра использовался МР-томограф с напряженностью магнитного поля 1,5 Тл. К другим причинам могут относиться конструктивные особенности принимающих катушек и особенности настройки аппаратов с различными алгоритмами подавления помех и артефактов.…”

Use of Magnetic Resonance Spectroscopy of the Brain to Differentiate Low Grade Glioma and its Clinical Relevance

“…Other spectroscopically methods like 31 P Phosphorus spectroscopy using metabolites inorganic phosphates and Phosphocreatine seem to be an additional tool in assessing grades of gliomas [28].…”