Ultrasound volume measurements comparing a prolate ellipsoid method with a parallel planimetric area method against a known volume

A comparison of a prolate ellipsoid method and a parallel planimetric area method for measuring volumes with ultrasound was made using phantom models of water‐filled balloons scanned under set conditions. Correlation with actual volumes was significantly better with the parallel planimetric area method (p < 0.02) with 93.3% of parallel planimetric area measurements being within 5% of the actual volume compared with only 33.4% of measurements obtained with the prolate ellipsoid method. For uterine volume measurements, a parallel planimetric area method is the more suitable.