Best predictors of grayscale ultrasound combined with color doppler in the diagnosis of retained products of conception

OBJECTIVES: To determine the best predictors of the presence of retained products of conception (RPOC) on grayscale and color Doppler transvaginal sonographic examination. METHODS: This was a retrospective study of 91 consecutive patients who underwent transvaginal sonography (TVS) with color Doppler to evaluate for the presence of RPOC. The images of TVS studies were reviewed by two radiologists in consensus blinded to the final outcome. Data on a number of variables including endometrial measurable mass and focal increased color vascularity were collected as predictors of RPOC. The patients' ages ranged from 17 to 48 years (mean, 31.8 ± 6.8) and gestational age from 5 to 24 weeks (mean, 9.2 ± 3.8). Thirty-six were confirmed as RPOC by dilatation and curettage (D&C) and pathology. Fifty-five were considered negative, 9 based on D&C results and 46 on clinical grounds. RESULTS: Sensitivity, specificity, negative- and positive-predictive and accuracy values were 81% (CI: 68%-94%), 71% (CI: 59%-83%), 85% (CI: 74%-95%), 64% (CI: 50%-78%), and 75% (CI: 66%-84%) to detect RPOC when a mass was present. The corresponding numbers for the presence of focal color vascularity were 94% (CI: 87%-100%) (p = 0.07), 67% (CI: 55%-80%) (p > 0.05), 95% (CI: 88%-100%) (p = 0.1), 65% (CI: 52%-78%) (p > 0.05), and 78% (CI: 70%-87%) (p > 0.05). Of the patients with confirmed RPOC on pathology, five had focal increased vascularity and no massand none had a mass without focal increased vascularity. CONCLUSION: An area of focal increased vascularity with or without a mass is the best predictor of the presence of RPOC.