Using transvaginal ultrasonography and MRI to evaluate ovarian volume and follicle count of infertile women: a comparative study

Abstract

To compare two-dimensional (2D) transvaginal ultrasonography (TVUS) and 2D/three-dimensional (3D) magnetic resonance imaging (MRI) in estimating ovarian volume and follicle count. The ovarian volume (OV) and follicle count (FC) of 84 women with infertility were evaluated by 2D TVUS and 2D/3D MRI. Bland-Altman analysis was used for comparison. The OV from 3D MRI was 0.50 ml (95% confidence interval [CI], 0.25-0.74, p<0.001) smaller than that by 2D TVUS. OV from 2D MRI was 2.65 ml (95% CI, 2.36-2.95, p<0.001) and 3.15 ml (95% CI, 2.77-3.53, p<0.001) smaller than that from 3D MRI and 2D TVUS, respectively. The FC1-9 mm and total follicle count (tFC) estimated by 2D TVUS were 7.81 (95% CI, 6.96-8.66, p<0.001) and 7.82 (95% CI, 6.97-8.67) smaller than those from 2D MRI, respectively. Further analysis showed that 2D TVUS detected lower FC1-3 mm but higher FC4-6 mm than 2D MRI. No significant difference was shown in the results of FC7-9 mm and FC≥10 mm. In women with infertility, 2D MRI underestimated OV as compared with 2D TVUS. OV from 3D MRI was lower but very close to that from 2D TVUS. For patients unsuitable for TVUS, 3D MRI is recommended for OV evaluation. 2D TVUS underestimated FC1-9 mm and tFC compared with 2D MRI. In fertility counselling and research, 2D MRI is a useful alternative to TVUS when an accurate FC is needed.