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Potential of MR spectroscopy for assessment of glioma grading. Martin Bulik , Radim Jancalek , Jiri Vanicek , Antonin Skoch , Marek Mechl. Presented by: Jessica Hernandez 24 March 2014 -- CHEM 4200. Overview . Introduction Spectrum/Results Metabolites Glioma Grades Limitations
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Potential of MR spectroscopy for assessmentof glioma grading Martin Bulik, RadimJancalek, Jiri Vanicek, Antonin Skoch, MarekMechl Presented by: Jessica Hernandez 24 March 2014 -- CHEM 4200
Overview • Introduction • Spectrum/Results • Metabolites • Glioma Grades • Limitations • Advantages
Gliomas • 77% primary malignant brain tumors • Classified into 4 grades • Diagnosing: • (1) Surgical Procedures • (2) Magnetic Resonance Imaging (MRI) • (3) MR Spectroscopy (MRS)
Magnetic resonance Spectroscopy (MRS) • Measures signals emitted by proton nuclei • Spectrum are visual representation of results • Obtain Spectrum 2 ways • (1) Single Voxel Spectroscopy (SVS) • (2) Multiple voxel spectroscopy
Metabolites • Metabolites – substances formed in or necessary for metabolism • N- Acetyl asparate (NAA) • Choline (Cho) • Creatine (Cr) • Myo-inositol (mIns) • Lactate (Lac) • Lipids (Lip)
N-Acetyl asparate (NAA) • Acetyl aspartic derivative • Found in grey and white matter • N-acetylaspartylglutamate (NAAG) • Roles: • Facilitation of energy metabolism • Important for myelin lipid synthesis • Low NAA levels then higher grade glioma
Choline (Cho) • Metabolic marker of cell membrane density and integrity • Choline kinase is required for cancer cell growth • Phosphocholine (Pcho) • High Cho levels then higher grade glioma Choline kinase
Creatine (Cr) • Energy metabolism marker • Synthesized from amino acids • Lower Cr levels indicates higher grade gliomas • Cr used as reference for metabolite ratios
Myo-inositol (mins) • Simple sugar • Marker of astrocytes • High levels of mIns present in low grade gliomas • Low levels in high grade gliomas
Lactate (Lac) & lipids (lip) • Anaerobic metabolic markers • Lac only in unhealthy brain tissue • Ischemia-poor blood supply to brain tissue
MRS Limitations Advantages Non invasive diagnosing tool Highly sensitive • Heterogeneity of tumors • Magnetic field strength • Specificity • Has to be paired with other MR methods