Diagnostic Accuracy Of Resistive Index Of Doppler Ultrasound In Differentiating Malignant From Benign Breast Lesions Taking Histopathology As Gold Standard

Abstract

Introduction: Breast cancer remains one of the most prevalent and fatal malignancies in women worldwide, underscoring the need for diagnostic methods that are both rapid and accurate. Ultrasound, favored for its safety and accessibility, has become a primary tool for evaluating suspicious breast lesions. The addition of Doppler imaging, particularly the Resistive Index (RI), offers valuable insights into tumor vascularity, with elevated RI values often indicative of malignancy. Despite its potential, RI is underutilized in many clinical settings, where conventional grayscale ultrasound and mammography dominate. This study evaluates the diagnostic accuracy of RI against histopathological findings, aiming to reduce unnecessary biopsies and enhance the efficiency of breast cancer screening.

Objective: To determine the diagnostic accuracy of the Resistive Index (RI) on Doppler ultrasound in distinguishing benign from malignant breast lesions.

Methodology: This cross-sectional validation study was conducted at the Department of Radiology, Punjab Institute of Neurosciences, Lahore, over a six-month period from July 20, 2023, to January 20, 2024. A total of 209 female patients aged 25–60 years with clinically diagnosed breast lesions were enrolled. Patients were positioned supine oblique with the arm placed above the head during Doppler ultrasound examinations to assess lesion vascularity. For each lesion, three resistive index (RI) measurements were obtained, and their mean was recorded. Histopathological analysis served as the gold standard for diagnostic confirmation. Exclusion criteria included patients with comorbidities, those who had undergone mastectomy, and uncooperative individuals.

Results: All patient information was entered into SPSS Version 20 for detailed examination. Continuous variables, like patient age, are reported as mean ± standard deviation (SD) to show the average and how spreads out the ages are. Categorical factors-parity, lactation status, smoking, oral contraceptive use, and family history of breast cancer-are presented as counts and percentages so readers can see how common each one is in the group. To test how well the Resistive Index (RI) from Doppler ultrasound spots cancerous breast masses, several classic metrics were calculated. These included sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy. Each figure came from simple 2x2 tables that matched Doppler results against the final tissue diagnosis made by a pathologist. We considered results statistically significant when the p-value dropped below 0.05, meaning there is less than a 5% chance the findings happened by random fluctuation. To guard against confounding and examine test performance in patient subgroups, we divided the data by age, number of pregnancies, oral contraceptive therapy, smoking, family breast-cancer history, and whether the patient breast-fed. This step revealed how the relevance index varied from one demographic cluster to another.

Keywords:
Doppler Ultrasound, Resistive Index, Breast Lesions, Diagnostic Accuracy, Histopathology