Significance and Diagnostic Accuracy of Resistive Index in Predicting Malignant Ovarian Masses Keeping Histopathology as Gold Standard

ABSTRACTOBJECTIVE This study aimed to determine the significance and diagnostic accuracy of the resistive index (RI) in predicting malignancy in ovarian masses, using histopathology as the gold standard. METHODOLOGY This prospective study was conducted at the Department of Radiology, Northwest General Hospital and Research Centre, Peshawar, from Jan 1 2024, to Jul 31 2025. A sample size of 159 was calculated using the WHO calculator. Patients were selected through convenience sampling. Trans-abdominal Doppler Ultrasound was performed using a 3.5 MHz transducer on a GE Logic 5 Doppler Ultrasound machine. The Resistive Index (RI) was calculated for each case, and a threshold of 0.6 was used to differentiate benign from malignant lesions. Data analysis was done using SPSS version 25. RESULTSThe sensitivity of the resistive index in predicting malignancy in ovarian masses was 75.2%, and the specificity was 63.2%. The positive predictive value of the RI was 86.7%, and the negative predictive value was 44.4% when histopathology served as the gold standard. The mean age of patients in our study was 48.3 ± 8.1 years. CONCLUSION Doppler ultrasound and the resistive index are pivotal non-invasive tools for predicting malignant risk in ovarian masses, with high diagnostic accuracy. It has not only dramatically improved our ability to differentiate benign from malignant adnexal masses but also helped surgeons with preoperative planning. Effect modifiers like patient body habits and the performing sonologist’s expertise. should be included in further studies to determine their effect on the diagnostic accuracy of RI.