ULTRASONOGRAPHY VERSUS MRI IN DIAGNOSING MALIGNANT OVARIAN MASSES: DIAGNOSTIC ACCURACY IN A TERTIARY CARE SETTING

Abstract

Objective: To determine the diagnostic accuracy of ultrasonography in diagnosing malignant ovarian masses, using magnetic resonance imaging (MRI) as the gold standard.

Methods: This cross-sectional validation study was conducted in the Department of Radiology, CDA Hospital, Islamabad, from June 15 to December 14, 2024. A total of 150 female patients presenting with abdominal pain (VAS >3) and an incidental ovarian lesion >1 cm on ultrasonography were included. Patients with prior biopsy-proven malignancy, prior oncological treatment, contraindications to MRI, or chronic systemic illnesses were excluded. Pelvic ultrasonography was performed with a convex probe on a full bladder, and MRI was performed using a 1.5 Tesla GE scanner. Findings of ultrasonography were compared against MRI as the reference standard.

Results: The mean age of patients was 36.28 ± 8.54 years. On ultrasonography, 81 patients were diagnosed with malignant masses and 69 with benign lesions. MRI identified 78 malignant and 72 benign cases. Cross-tabulation showed 74 true positives, 65 true negatives, 7 false positives, and 4 false negatives. Ultrasonography demonstrated a sensitivity of 94.87%, specificity 90.28%, positive predictive value 91.36%, negative predictive value 94.20%, and overall diagnostic accuracy 92.67% (p=0.0001).

Conclusion: Ultrasonography showed excellent diagnostic accuracy for differentiating malignant from benign ovarian masses compared to MRI. Given its affordability and accessibility, ultrasonography should remain the first-line imaging modality, reserving MRI for indeterminate or complex cases