| Objective:To explore the correlation between the MRI characteristics of uterine fibroids and the effect of HIFU and to investigate the the influence factors of anterior abdominal wall injury caused by HIFU. Methods:50 patients with 60 uterine fibroids in total treated by HIFU were enrolled in this study. Their MRI images were retrospectively collected and recorded the type, position and MRI T2WI signal of the fibroids before HIFU ablation.26 patients among them were given dynamic enhance MRI(DCE-MRI). DCE-MRI semi-quantitative parameters in both fibroids tissue and myometrium including MSI(maximum slop of increase), PH(peak height), SER(signal enhancement ratio) at 30s, 60s,90s, and 120s after contrast agents administration and TTP(time to peak) were measured and calculated based on time-signal strength curve(TIC). The patients were divided into complete ablation group and partial ablation group according to the non-perfused volume ratio(NPVR) at the end of treatment. DCE-MRI parameters between two groups were compared and analyzed. The relationship between the measured volume of the abdominal wall edema and the treatment-related parameters and fibroid-related information were studied. Results:The NPVR were relatively higher in the uterine fibroids that were located at the anterior wall of the uterine and the same situation was showed on the fibroids that were hypointense signal in T2WI. DCE-MRI parameters were showed the difference in the SER60s and SERmax between partial ablation group and complete ablation group had statistical significance(P<0.05); SER30s, SER120s, MSI, PH and TTP the difference between the two groups were not statistically significant(P>0.05). By correlation analysis, the volume of anterior abdominal wall edema were positively correlated with exposure time, total treatment dose, sonication time per unit and the distance between the rear edge of fibroids and the anterior abdominal wall fibroids(r=0.423,0.452,0.373,0.389 respectively, P<0.05). Between the edema group and the normal group, there were statistically significant differences in the exposure time and total treatment dose(P<0.05). Conclusion:The therapeutic effect of HIFUA for uterine fibroids were related to the lesion location, the signal intensity on T2WI. DCE-MRI semi-quantitative parameters could help to predict the effect of HIFU. The exposure time and the total treatment dose of ultrasound were the influence factors of anterior abdominal wall injury caused by HIFUA in treatment of uterine leiomyoma. |
