Evaluation of early efficiency after high-intensity focused ultrasound operation on uterine fibroids by 3.0 T MRI-DWI

doi:10.3969/j.issn.1002-7386.2017.11.008

Abstract：Objective To use 3.0 T MRI diffusion weighted imaging (DWI) to evaluate the early efficiency of high-intensity focused ultrasound (HIFU) on uterine fibroids.Methods A total of 33 patients with uterine fibroids including 20 cases of solitary fibroids and 13 cases of multiple fibroids,with a total of 59 fibroids and patient's mean age being 34.3±8.7 years.All the patients underwent MRI scan,enhanced MRI scan,DWI scan before HIFU and on 1d after HIFU to observe and calculate quantitatively the signal value of enhanced T1WI and ADC value,the maximum ablation area of uterine fibroid after HIFU,and to evaluate its therapeutic effects.Results There appeared nonperfusion low signal ablation zone in T1 enhanced scan sequence after HIFU in 59 uterine fibroids,with ablation rate being 70.9%.After HIFU,the ablation zone displayed by DWI was closely correlated to that displayed by enhancement MRI scanning (r=0.97),moreover, the circular or curved strip DWI high signal was found around the ablation zone in 35 uterine fibroids,with ADC showing low signal.After HIFU, the central ADC value in ablation zone of uterine fibroids was increased,but there was no significant difference in ADC value (b=500s/mm2) before and after ablation (P>0.05).Among different b values,in ablation central part before and after operation, the ADC value of b=1 500s/mm2 was obviously lower than that of b=500s/mm2 (P<0.01).Conclusion The 3.0 T MRI diffusion weighted imaging can display objectively the ablation area of uterine fibroids before and after HIFU,which can reflect the physiological and pathological changes in the muscle wall of uterus and uterine fibroids after HIFU at molecular level.