Determination of sensitivity and specificity of Magnetic Resonance Spectroscopy (MRS) in evaluation of rim enhancing brain lesions

Open Access

Abstract

Background: Rim-enhancing brain lesions present a diagnostic challenge due to overlapping imaging features between neoplastic and non-neoplastic pathologies. Accurate preoperative differentiation is crucial for appropriate management. This study aimed to determine the sensitivity and specificity of Magnetic Resonance Spectroscopy (MRS) in differentiating high-grade gliomas from cerebral abscesses, using histopathology as the reference standard. Methods & Materials: A cross-sectional study was conducted at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, from July 2022 to June 2023. Twenty-nine patients with suspected rim-enhancing brain lesions underwent conventional MRI and single-voxel proton MRS. Metabolites including N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and lactate were analyzed. Histopathological examination of surgical specimens served as the gold standard. Diagnostic performance of MRS was evaluated using sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). Results: The mean age of participants was 41.23 ± 15.07 years, with a male predominance (55.2%). Headache, nausea, vomiting, and seizures were the most common presenting symptoms. High-grade gliomas constituted 51.7% and cerebral abscesses 48.3% of MRS diagnoses. MRS demonstrated elevated Cho/Cr ratios in gliomas (2.94 ± 1.83) and higher NAA/Cr ratios in abscesses (1.89 ± 0.69), both statistically significant (p < 0.05). Sensitivity, specificity, and accuracy of MRS were 100%, 82.2%, and 93.1% for cerebral abscesses, and 100% for all parameters in high-grade gliomas. Conclusion: MRS is a reliable, non-invasive adjunct to conventional MRI for differentiating rim-enhancing brain lesions, with excellent diagnostic accuracy. Incorporation of metabolite ratios enhances lesion characterization and guides clinical decision-making. Further multicenter studies with larger cohorts are recommended.