Background: Adrenal lesions represent a diverse group of pathologies ranging from benign adenomas to malignant or hormonally active tumors. With the increasing detection of adrenal incidentalomas, accurate imaging characterization is essential to differentiate benign from malignant lesions and guide management. Aim: To compare the diagnostic accuracy of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) in characterizing adrenal lesions. Methods: This cross-sectional comparative study included 100 patients with adrenal lesions evaluated using both CT and MRI at a tertiary care hospital. CT parameters such as unenhanced attenuation and contrast washout were compared with MRI parameters including chemical-shift imaging (CSI), T2 signal intensity, and apparent diffusion coefficient (ADC). Imaging findings were correlated with histopathological, biochemical, and clinical outcomes. Sensitivity, specificity, predictive values, and accuracy were calculated for both modalities, and ROC analysis was performed. Results: Among 100 cases, 72 were benign and 28 malignant. MRI demonstrated higher sensitivity (92.9%) and negative predictive value (96.9%) compared to CT (78.6% and 91.4%), while specificity remained comparable (CT 88.9%, MRI 87.5%). The overall diagnostic accuracy was 86.0% for CT and 89.0% for MRI. ROC analysis showed AUC values of 0.90 for CT and 0.93 for MRI (p=0.17). Mean unenhanced attenuation was significantly higher in malignant lesions (28.7±8.9 HU) versus benign (7.8±3.2 HU), while MRI showed markedly lower CSI signal drop (7.5±5.9% vs 32.6±8.7%) and ADC values (0.98±0.18 vs 1.42±0.21×10⁻³ mm²/s) in malignant lesions (p<0.001 for all). Conclusion: Both CT and MRI provide high diagnostic accuracy for adrenal lesion characterization. MRI offers superior sensitivity and tissue contrast, especially in lipid-poor or indeterminate lesions, while CT retains advantages in availability and structural delineation. The integration of CT and MRI parameters with biochemical and clinical data yields optimal diagnostic precision in adrenal pathology assessment.

Adrenal lesions, Computed tomography, Magnetic resonance imaging