SonoAVC: a novel method of automatic volume calculation

OBJECTIVES

To assess the ability of the new software SonoAVC to measure follicular volume and to compare these volume calculations with those made by conventional methods.

METHODS

Three-dimensional ultrasound imaging was used to acquire volumetric data from the ovaries of 51 women undergoing controlled ovarian stimulation as part of in-vitro fertilization treatment. All assessments were performed on the day of oocyte retrieval and the true volume of each follicle was ascertained by manual measurement of the follicular aspirate. SonoAVC was used to automatically measure the volume of follicles and to provide three perpendicular diameters (xyz diameters), which were used to estimate volume using the sphere formula. The sphere formula was also used to estimate the volume from manual measurements of follicle diameter derived from conventional two-dimensional (2D) displays. Virtual Organ Computer-aided AnaLysis (VOCAL) was also used to measure volume, and the validity of each technique was compared using limits of agreement.

RESULTS

Two hundred and twenty-four follicles with a mean follicular volume of 3.7 (range, 0.4-16.2) cm(3) were studied. SonoAVC provided highly accurate automatic follicular volume measurements in all cases. Volume estimations made from the automatic maximal follicular diameter measurements (xyz diameters) were less valid. VOCAL proved highly valid but was less accurate than SonoAVC. Volumes estimated from manually derived follicular diameter measurements were the least accurate.

CONCLUSIONS

SonoAVC provides highly valid, automatic measurements of follicular volume. These measurements are more accurate than volumes estimated from 2D manual measurements, automated measurements of follicular diameter and those calculated using VOCAL.