Assessment of MRI Accuracy for Intra-Axial Glioma Diagnosis and Grading

Objective: To evaluate the diagnostic accuracy of MRI in detecting intra-axial gliomas and differentiating low- from high-grade tumors, using histopathology as the gold standard. Methods: A cross-sectional study of 226 patients aged 15-60 years undergoing brain MRI was conducted at Liaquat National Hospital, Karachi. MRI findings were compared with histopathology. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy were calculated, with stratification by age, gender, residence, symptom duration, and clinical features. Results: Mean age was 38.9 ± 9.8 years; 71.2% were male. MRI detected intra-axial gliomas in 58% of patients versus 60.6% confirmed by histopathology. For tumor detection, MRI sensitivity was 83.2%, specificity 80.9%, PPV 87%, NPV 75.8%, and accuracy 82.3%. For grading, MRI sensitivity was 90.1%, specificity 86%, PPV 91.4%, NPV 84.1%, and accuracy 88.6%. Accuracy was highest in females and patients over 35 years, and in those presenting with seizures or vomiting. Conclusion: MRI provides high diagnostic accuracy for detection and grading of intra-axial gliomas. Multiparametric MRI protocols, incorporating diffusion and perfusion metrics, enhance non-invasive tumor characterization and support clinical decision-making.