2.4. B-Mode, Color-Flow Doppler and Pulsed-Wave Doppler Procedures

Transabdominal ultrasound evaluation was performed always by the same operator, with the use of a 5 MHz micro convex transducer (Mindray^® ultrasound M5Vet, Shenzhen, China) in a right and left lateral recumbence. Ultrasonographic examination was carried out daily during the 8 days of treatment, always before the therapeutic protocol. Transversal cross-sections of the uterine horns were made in B-mode as an ellipse, and the area was calculated by the following formula: R1 x R2 x π, considering R1 = uterine width/2 and R2 = uterine height/2 [24]. We always considered the uterine cross-section with the higher dimension for our data collection purpose.

For the qualitative evaluation of the endometrial vasculature, scanning of uterine horns was preferably carried out in B-mode cross-section, followed by Color flow Doppler. A score from 1 to 3 was adopted, considering score 1 as the minimum degree of endometrial vasculature and score 3, the maximum degree, according to classification proposed by Veiga et al. [8].

Dopplervelocimetry of the right and left uterine arteries were performed in longitudinal section at the lateral region of the uterine body, using the bladder as an acoustic window. Pulsed-wave Doppler was used to characterize the waveform and the following vascular parameters were measured: blood flow velocity (peak systolic velocity (PS), end diastolic velocity (ED) and time average maximum velocity (TAMAX))and hemodynamic indexes (resistance index (RI), pulsatility index (PI) and peak systolic: diastolic velocity (S/D)). Resistance index of the uterine artery was also used to classify the uterine horns as the most compromised and less compromised, i.e., the uterine horn containing the artery with the lowest RI value was considered the most compromised and, conversely, the contralateral uterine horn was classified as the less compromised [8].