Endometrial Volume and Vascularity Measurements by Transvaginal 3-Dimensional Ultrasonography and Power Doppler Angiography in Stimulated and Tumoral Endometria: An Interobserver Reproducibility Study

The purpose of this study was to evaluate interobserver reproducibility of endometrial volume and vascular indices of the endometrium and subendometrial area estimated by 3-dimensional power Doppler angiography (3D-PDA) using the Virtual Organ Computer-Aided Analysis program, determining the influence of the endometrial growth etiology on measurements. Forty women underwent 3D-PDA ultrasonography. Group A comprised 25 women scanned on the day after controlled ovarian stimulation with human chorionic gonadotropin. Group B comprised 15 patients who had uterine bleeding and questionable endometrial thickening. (Histologic evaluation revealed 10 endometrial cancers and 5 endometrial hyperplasias.) A single observer examined all patients and acquired all volume data sets. Forty volume data sets were then analyzed with the Virtual Organ Computer-Aided Analysis program by 2 different observers. Endometrial volume and vascularity indices (vascularization index [VI], flow index [FI], and vascularization flow index [VFI]) of the endometrium and subendometrium were manually calculated in the coronal plane with a 9 degrees rotation step. An intraclass correlation coefficient (ICC) was used to assess interobserver reliability. Endometrial volume was more reproducible in group A (ICC = 0.98) than in group B (ICC = 0.58) (P < .05). Endometrial and subendometrial VI, FI, and VFI also presented good reproducibility with ICC greater than 0.84. The ICC was not statistically different for endometrial and subendometrial VI, FI, and VFI according to patient group, although subendometrial VFI was less reproducible in group B (ICC = 0.53) than in group A (ICC = 0.88). Endometrial volume and endometrial and subendometrial 3D power Doppler indices have acceptable reproducibility. The interobserver reproducibility in tumoral endometrium was more similar than in stimulated endometrium. Our results indicate that 3D-PDA is a reliable method to evaluate physiologic and pathologic endometrial changes.