DIAGNOSTIC-ACCURACY OF TRANSVAGINAL ULTRASOUND IN DETECTING FREE PELVIC FLUID

OBJECTIVE: To evaluate the diagnostic accuracy of transvaginal ultraso nography in detecting and measuring free pelvic fluid. STUDY DESIGN: E ighty-two patients undergoing diagnostic or therapeutic laparoscopy at a tertiary care center were prospectively assessed before surgery by transvaginal ultrasound. Free pelvic fluid was measured in two ultraso nographic planes. These measurements were compared to the volume of fl uid aspirated during laparoscopy. RESULTS: The mean volumes reported f or transvaginal ultrasound were significantly lower than those observe d at laparoscopy (mean milliliters +/- SEM, 2.54 +/- 0.5 versus 9.42 /- 1.3, P < .001). The smallest volume of free pelvic fluid that was c onsistently detected by ultrasound was 8 mt. Whenever no fluid or <1 m t was detected by transvaginal ultrasound, a small volume of fluid was found at laparoscopy (mean milliliters +/- SEM, 1.6 +/- 0.47). The se nsitivity of transvaginal ultrasound was 83% and specificity teas 69%. CONCLUSION: Transvaginal ultrasound is a sensitive method of detectin g the presence of > 8 mL of free pelvic fluid and therefore is an impo rtant diagnostic tool in the assessment of pelvic pathology associated with increased peritoneal fluid.