2.6. Evaluation of the treatment effects

Contrast-enhanced Sonazoid-based CEUS (Fig. ​(Fig.1)1) or MRI (Fig. ​(Fig.2)2) was performed 1 day after HIFU therapy, and the images were used to measure the non-perfused volume (NPV), which was defined as the tumor coagulation volume. The NPV was calculated using the same equation as that for fibroid volume before treatment (i.e., V = 0.5233 × D1 × D2 × D3). The fractional ablation (FA) was defined as the NPV divided by the fibroid volume before HIFU therapy. All the images were evaluated by an experienced radiologist, who measured the size of the targeted fibroid and the non-enhanced regions.

Imaging data obtained from a 48-year-old patient with uterine fibroid who successfully underwent Sonazoid-based contrast-enhanced ultrasonography (CEUS) followed by high-intensity focused ultrasound (HIFU) ablation. A: Pre-treatment CEUS image showing perfusion of a fibroid. B: Pre-treatment US image of a fibroid (5.6 cm 4.9 cm 5.1 cm). C: HIFU sonication at 30 minute after administration of Sonazoid. Massive grey scale changes occurred at 35 second of sonication. The total sonication time for this fibroid was 677 second. D: CEUS image obtained 1-day after the completion of HIFU ablation showing no perfusion of the treated fibroid. E: US image obtained 1-day after the completion of HIFU ablation displaying the B-mode ultrasonographic image of the treated fibroid.

Successful treatment of a patient with uterine fibroid using Sonazoid to enhance high-intensity focused ultrasound treatment effects. A. Pre-treatment T1- weighted contrast-enhanced MR image illustrating perfusion of the fibroid. B. Post-treatment T1-weighted contrast-enhanced MR image showing that the fibroid was mostly ablated.

The HIFU-associated parameters included average sonication power (an average power during the HIFU treatment), duration of HIFU sonication defined as the total time of HIFU treatment (ultrasonic irradiation time), treatment time, duration of general anesthesia, total energy, energy efficiency factor (EEF), and occurrence rate of MGSCs describing changes in mass grayscale before and after HIFU treatment.