A reprodutibilidade da medida do volume endometrial por meio do VOCAL - A importância do passo de rotação

Abstract

Purpose: to determine the intraobserver and interobserver reproducibility of endometrial volume measurements using the VOCAL® -imaging program (Virtual Organ Computer-aided AnaLysis). Methods: one three-dimensional (3-D) ultrasound dataset of the endometrium was obtained from each of five infertile women with different endometrial volumes. For each 3-D dataset, the endometrial volume was calculated by two different observers using the manual mode in four different rotational steps (30°, 15°, 9° and 6°). Ten measurements were obtained with each method and observer from each 3-D dataset. We have used one-way ANOVA and the Tukey post-test to verify the differences among means and the intraclass correlation coefficient to test reliability. Results: rotational methods employing a rotation step of 30° were associated with lower endometrial volume readings in 3 of the 5 patients. There were no significant differences between the means obtained by the 15°, 9° or 6° step rotation. No significant difference was found between the means obtained by the two different observers. The intraclass correlation coefficients were significantly lower with 30° (all under 0.984) than with the other step rotations (all above 0.996). Conclusions: the use of a rotational step of 15° or less provides reliable readings of endometrial volume: there were no significant differences between the means calculated by the two observers, associated with highintraclass correlation coefficient (>0.996). We recommend the 15° step rotation because it is quicker to be performed than 6° and 9°.