Measurements of uterine volume: A comparison between measurements by ultrasonography and by water displacement

Abstract

The uterine volume was measured in 30 patients 24 hours before hysterectomy by ultrasonography using the prolate ellipsoid formula. At hysterectomy the volumes of the same uteri were measured again by water displacement. A comparison is made between the two methods of measurements. Although the correlation between the methods is high (r = 0.964) and the mean percentage bias very small (+2.0%), the agreement between the methods for 95% of subjects is between -33.6, 8% and +37.6%. This is a potentially large disagreement relative to the typical size of the uterus, indicating that ultrasonic uterine volume measurement by the prolate ellipsoid method is not adequately precise for clinical management of the individual patient.

Measuring uterine cavity volume with sonohysterography: A new objective method

“…This disagreement is attributed to the inaccuracy of the prolate ellipsoid method. 22 In our study, we noticed that determining the volume of the uterine cavity by measuring the volume of the fluid used to fill the balloon of the Foley catheter alone cannot be relied upon as a standard method. This emphasises our approach of coupling Foley catheter balloons and sonohysterography as a more accurate method for measuring uterine cavity volume.…”