The Most Commonly Seen Metabolites in Intracranial Space Occupying Lesions - A Prospective Study
Background: Intracranial space occupying lesions are defined as lesions occurring within the cranial vault, which can be intra-axial or extra-axial. Magnetic Resonance Spectroscopy can be performed in 10 -15 minutes and combined with conventional imaging protocols. Thus MRS offers the possibility of not just visualization of the lesion but also biochemical characterization simultaneously. The present study was aimed at establishing the most commonly seen metabolites in the intracranial space occupying lesions. Methods: The present observational study was conducted in the Department of Radiodiagnosis, Ananta Institute of medical science and research Centre, Udaipur, Rajasthan, on a 1.5 Tesla Siemens MAGNETIC RESONANCE IMAGING equipment and 3.0 TESLA MAGNETIC RESONANCE IMAGING equipment. As reference standards, values of Cho/Cr > 1.5, NAA/Cr < 1.6, Cho/NAA > 0.8, Lactate >1.34, Lipids >1.4, Glutamate >2.5, Glutamine >2.38, Alanine >1.48 were taken as abnormal. Based on these the lesions were characterised as benign/ malignant and grades of malignancy was determined. The data was arranged in a tabulated version and analysed using SPSS software. Results: Mean Cho/ Cr ratio was high in gliomas, metastasis and meningiomas, while it was normal in DNETs and infections. Highest Mean Cho/Cr value was seen in metastasis (3.48). Abscesses showed presence of lactate, acetone and aminoacids peaks, while acetone and aminoacids were not seen in Tuberculosis or NCC. Lipid peaks were seen in 100% of the cases of Tuberculosis. Conclusions: From the above study, we can conclude that presence of alanine in 100% of meningiomas makes it a useful marker for these tumors. Tuberculomas showed intense signals from lipids, and hence could be separated from Neurocysticercal cysts.
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