Three-dimensional Ultrasonography and Power Doppler for Discrimination Between Benign and Malignant Endometrium in Premenopausal Women With Abnormal Uterine Bleeding

Mohamed El-Sharkawy; Akmal El-Mazny; Wafaa Ramadan; Dina Hatem; Aly Abdel-Hafiz; Mohamed Hammam; Adel Nada


BMC Womens Health. 2016;16(18) 

In This Article


This cross-sectional study was conducted at the Department of Obstetrics and Gynecology, Faculty of Medicine, Cairo University, during the period from August 2013 to May 2014. The study protocol was approved by the Research Ethics Committee, and informed verbal consent was obtained from all participants.

The study population consisted of 78 premenopausal women with abnormal uterine bleeding scheduled for hysteroscopy and endometrial curettage. They were subjected to detailed history taking, complete general and gynecological examination, routine pre-operative laboratory investigations, and preliminary transvaginal ultrasound. The exclusion criteria included uterine fibroids, adenomyosis, endometrial polyps, and any general diseases, hormones or medications that could potentially affect pelvic blood flow.

Transvaginal ultrasound (Voluson 730; Kretz, Zipf, Austria) examinations were performed within 24 h prior to surgery. Using ultrasound in the 2D mode, the endometrial thickness (ET) was measured as the thickest part (double layer) in the sagittal plane (Fig. 1). Then, color Doppler was activated and the flow velocity waveforms were obtained from the ascending main branch of the uterine artery on both sides of the internal os (Fig. 2). Three similar consecutive waveforms of good quality were analyzed, and the averaged right and left uterine artery pulsatility index (PI) and resistance index (RI) were calculated.

Figure 1.

Two-dimensional ultrasound measurement of endometrial thickness

Figure 2.

Two-dimensional color Doppler of uterine artery flow velocity waveforms

The ultrasound was then switched to the 3D mode with power Doppler. The setting conditions for this study were standardized using a frequency at 3–9 MHz, pulse repetition frequency at 0.6 kHz, gain at −4.0, and wall motion filter at low 1. The Virtual Organ Computer-Aided Analysis (VOCAL™) Imaging Program for the 3D power Doppler histogram analysis was used to measure the endometrial volume (EV) and 3D power Doppler indices within the endometrium (Figs. 3 and 4).

Figure 3.

Virtual Organ Computer-Aided Analysis of the endometrium

Figure 4.

Three-dimensional power Doppler flow indices of the endometrium

Vascularization index (VI) measures the ratio of the number of color voxels to the total number of voxels (%) and represents the presence of blood vessels (vascularity). Flow index (FI) measures the mean power Doppler signal intensity (0–100) and represents the average intensity of blood flow. Vascularization flow index (VFI) is calculated by multiplying VI and FI (0–100) and represents a combination of vascularity and flow intensity.

Hysteroscopic examination was performed routinely before endometrial curettage using a rigid 30° hysteroscope and a 4-mm-diameter diagnostic sheath (Karl Storz GmbH & Co KG, Tuttlingen, Germany). The hysteroscopic diagnosis was based on the following criteria: atrophic endometrium-thin and homogeneous in appearance; endometrial hyperplasia-thickened endometrium, easily indented with pressure, with or without multipolyp appearance; and endometrial carcinoma-irregular growth with or without abnormal vascularization.

Endometrial sampling was carried out by formal dilatation and curettage. The histopathological samples were examined by two senior pathologists who determined the final diagnosis. Ultrasonographic findings were compared with hysteroscopic and histopathologic findings.

Statistical Analysis

Data were expressed as mean ± SD or n (%) unless otherwise indicated. Continuous data were compared using Student t test or Mann-Whitney U test, as appropriate. Receiver-operating characteristic (ROC) curve analysis was used to evaluate the optimal cutoff value of ultrasound markers for prediction of malignant endometrial lesions; based on an equivalent sensitivity and specificity, and the highest value of the area under the curve (AUC). A P value <0.05 was considered statistically significant. The Statistical Package for the Social Science (SPSS Inc., Chicago, IL, USA), version 16.0, was used for data analyses.

Sample size calculation reveals that with a margin of error of 4.99 % and a response distribution of 50 %, the confidence level was 52 %; whereas with a margin of error of 9.92 % and a response distribution of 50 %, the confidence level was 84 %.