Role of Magnetic Resonance Spectroscopy in the Evaluation of Ring Enhancing Lesions of the Brain

Abstract

Introduction: The ring enhancing lesions of the brain are a challenging group of lesions with the variable possibilities of diagnosis under conventional Magnetic Resonance Imaging (MRI). Employing advanced techniques such as Magnetic Resonance Spectroscopy (MRS) could increase the success rates of the diagnosis. Aim: To assess the role of MRS in evaluating varying ring enhancing lesions of the brain. Materials and Methods: This prospective observational study involved 50 patients aged between 3-82 years who were detected with ring enhancing lesions of the brain on contrast MR studies. The patients underwent MRS evaluation. Categorical data was represented as frequency (%). The metabolite peaks of choline, lipid, lactate, N-Acetyl Aspartate (NAA), succinate and amino acids were recorded. The choline/creatine ratio was calculated and associated with the type of lesion the patients exhibited. Results: Among the 50 patients screened, the most prevalent pathologies were tuberculoma (36%) and neurocysticercosis (22%). While the patients diagnosed with tuberculoma presented with higher peak level of lipids and choline/creatine ratio of >1-2. Increased lactate, succinate, choline peak concomitant with no or insignificant lipid peak, were noted in the cases of neurocysticercosis. Primary brain tumour showed high choline peaks and elevated choline/creatine ratio (>2). Metastasis showed increased choline peak. Cerebral abscess showed increased amino acids and lactate peak. Conclusion: The diagnosis of varying ring enhancing lesions of the brain was accurately investigated by MRS. This accuracy enables delineating a treatment plan void of any dilemma.