Ultrasound, CT, and MRI for Orbital and Ocular Lesions: A Comparative Study in Nepal

Background Orbital and ocular lesions pose significant diagnostic challenges in resource-limited settings like Nepal, where accurate imaging is crucial for timely management. This study aims to evaluate and compare the performance of US, CT, and MRI in the detection and characterization of orbital and ocular lesions in a Nepalese hospital-based cohort. Methods This prospective study, conducted at B&C Teaching Hospital in Birtamode-5, Nepal, enrolled 130 patients with suspected orbital lesions or trauma, presenting with symptoms such as proptosis, vision loss, or pain. All patients underwent USG with a high-frequency linear probe; 85 received CT (Brivo 365, GE), and 45 underwent 1.5T MRI (Philips A series). Diagnostic accuracy was assessed against final diagnoses based on clinical findings, laboratory results, surgery, and histopathology. Metrics included sensitivity, specificity and accuracy across lesion types (tumors, trauma, infections, inflammation) and orbital compartments. Results The cohort (58.4% male, mean age 20–40 years) showed orbital tumors (33.0%), inflammation (20.7%), trauma (17.6%), and infections (13.8%) as primary conditions. MRI excelled in tumor characterization (100% intraocular, 98% intraconal) and inflammation (100% for optic neuritis/perineuritis). CT was superior for trauma (100% foreign body detection) and bony lesions. USG demonstrated 100% sensitivity for retinal detachment and vitreous hemorrhage but lower for deep tumors (50–55% characterization). All modalities achieved high accuracy for infections (90–100%). Conclusion US, CT, and MRI play complementary roles in orbital imaging, with USG ideal for initial screening, CT for emergencies, and MRI for complex soft tissue evaluation. A stepwise approach optimizes resource use in Nepal, enhancing diagnostic accuracy and patient outcomes.