Diagnostic Accuracy of MRI in Detecting Orbital Masses Keeping Histopathology as Gold Standard

Background: Orbital masses, encompassing a spectrum of benign and malignant lesions, pose significant diagnostic and therapeutic challenges. Magnetic resonance imaging (MRI) has been pivotal in the non-invasive evaluation of these lesions, owing to its superior soft tissue contrast and detailed anatomical resolution. The correlation between MRI findings and histopathological diagnosis remains crucial for accurate clinical decision-making. Objective: The study aimed to evaluate the diagnostic accuracy of MRI in identifying orbital masses, with a focus on differentiating between benign and malignant lesions, using histopathology as the gold standard. Methods: A prospective cross-sectional study was conducted at Jinnah Postgraduate Medical Centre (JPMC), Karachi, from January to December 2023. A total of 145 patients scheduled for surgery or biopsy, presenting with clinical symptoms indicative of orbital masses, were enrolled using a non-probability sequential sampling method. MRI evaluations were performed using a 1.5 Tesla machine. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of MRI in detecting orbital masses were calculated, comparing MRI findings with histopathological results. Results: Of the 145 patients, 55.2% were female, and 44.8% were male, with an age range predominantly between 18-30 years (87.6%). MRI identified 77.2% of cases as malignant and 22.8% as benign, whereas histopathology diagnosed 83.4% as malignant and 16.6% as benign. The diagnostic accuracy of MRI for benign masses showed a sensitivity of 81.82%, specificity of 96.43%, PPV of 87.10%, NPV of 94.74%, and an overall diagnostic accuracy of 93.10%. For malignant masses, MRI demonstrated a sensitivity of 90.16%, specificity of 86.90%, PPV of 83.33%, NPV of 92.41%, and a diagnostic accuracy of 88.28%. Conclusion: MRI exhibits a high diagnostic accuracy in identifying orbital masses, with excellent sensitivity and specificity. It proves to be a reliable diagnostic tool in differentiating between benign and malignant orbital lesions, supporting its integral role in the preoperative assessment and clinical management of patients with suspected orbital masses. Keywords: Orbital Masses, Magnetic Resonance Imaging, Diagnostic Accuracy, Histopathology, Benign Lesions, Malignant Lesions, MRI Sensitivity, MRI Specificity