Background: Differentiating between neoplastic, inflammatory, and infective brain lesions remains a diagnostic challenge using conventional MRI techniques, due to overlapping imaging features. Diffusion Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping provide microstructural insights into lesion characterization by assessing water molecule movement in tissues. Aim: To evaluate the role of DWI and ADC in differentiating neoplastic, inflammatory, and infective brain lesions, and to assess their sensitivity and specificity in lesion characterization. Methods: This prospective, correlational study was conducted at Sarojini Naidu Medical College, Agra, from February 2023 to July 2024, involving 220 patients with suspected brain lesions. MRI examinations were performed using a 1.5 Tesla PHILIPS machine. DWI signal intensity (hyper-, iso-, hypointense) and quantitative ADC values were measured across lesion types. Statistical analysis including ANOVA, t-tests, and Chi-square tests were employed to determine significance. Results: DWI patterns showed that neoplastic lesions were mainly hyper-or isointense, inflammatory lesions were largely isointense or hypointense, and infective lesions exhibited prominent hyperintensity. ADC values varied significantly among lesion types: infective lesions had lower values (mean ≈ 0.798), inflammatory lesions higher values (mean ≈ 1.253), and neoplastic lesions intermediate values (mean ≈ 0.995). ANOVA revealed highly significant differences (p < 0.001). Sensitivity was highest for neoplastic lesions (93%), followed by inflammatory (91%) and infective lesions (88%). Conclusion: DWI and ADC significantly enhance the ability to differentiate between neoplastic, inflammatory, and infective brain lesions. Their combined application increases diagnostic accuracy, aids in non-invasive lesion characterization, and guides appropriate clinical management, especially where conventional imaging may be inconclusive.

Diffusion weighted imaging, apparent diffusion coefficient, brain lesions, neoplastic, inflammatory, infective