Reproducibility of transvaginal three-dimensional endometrial volume measurements with virtual organ computer-aided analysis (VOCAL) during ovarian stimulation

Objective To calculate inter- and intraobserver reliabilities for three-dimensional endometrial volume measurements during in vitro fertilization using virtual organ computer-aided analysis (VOCAL(TM)). Patients and methods Three-dimensional ultrasound measurements of the endometrium using VOCAL software were performed on the day of oocyte retrieval in each of 79 consecutive patients undergoing in vitro fertilization or intracytoplasmic sperm injection. Endometrial volume was calculated every 15degrees and every 30degrees by two different observers in order to determine the reproducibility of the technique. Results Intraobserver reliability for the 15degrees measurements was 0.97 for both observers, for the 30degrees measurements, it was 0.93 for one observer and 0.96 for the other. Interobserver reliability was 0.80 for the endometrial volumes calculated every 15degrees and 0.83 for the volumes calculated every 30degrees The intra- and interobserver measurement agreement showed good reproducibility. However, the volumes calculated every 15degrees were more accurate because the means of differences were close to zero. Conclusion VOCAL provides a reproducible method for the estimation of the endometrial volume.