Correlational Research On Different MRI Imaging With Effectiveness Of High Intensity Focused Ultrasound Ablating Uterine Fibroid

Objective：Uterine fibroids can be divided into different categories according tothe T2-weighted MR image and T1-weighted contrast-enhanced MR image.The objective of this study is to investigate the correlation on safety andefficiency of HIFU ablating uterine fibroids with MRI T2WI signal andenhancement type by comparing the ablation rate、irradiation time andenergy needed for the unit volume; Meanwhile, to analyze affecting factorsand to provide a basis for indications and optimal treatment of HIFU ablatinguterine fibroids.Methods：Patients with uterine fibroids were classified into three groups onpretreatment MR image: hypointense and hyperintense group on T2WI,homogenous and non-homogenous intense group on T2WI, lightenhancement and obvious enhancement group on T1-weightedcontrast-enhanced MR. After HIFU treatment, enhanced MRI were performed to evaluate non-perfused volume．Then compare the ablation rate,ablation efficiency between groups.Results:A total of72patients with72solitary uterine fibroids were treated withultrasound-guided HIFU. The average ablation rate of hypointense T2WIgroup was (88.85±9.32)%, while the hyperintense group’ was(79.67±10.38)%, which had significant difference (P<0.05). The averageablation rate of homogenous intense T2WI group was (83±10.98)%, thenon-homogenous ones’ was (81±12.81)%, there is no statistical difference.On the basis of contrast-enhanced T1-weighted images, ablation rate of lightenhancement group was (86.40±8.94)%, while the obvious group’ was(75.44±12.57)%, which had significant difference (P<0.05). Whenconsidering ablation efficiency, the dose and time that needed in per unitvolume of light enhancement ones’ was (3.42±2.29)J/mm3and(8.33±5.73)S/cm3respectively, which is statistically different from the othergroup’(6.85±5.14)J/mm3and (16.74±12.83)S/cm3.Conclusions：Uterine fibroids with hypointense on T2WI or light enhancement onT1WI can be considered as an indication of HIFU, which is much easier toachieve ideal ablation rate. At the same time，the light-enhanced ones wereimproved to need less energy and less time obviously, which is moreefficient. Meanwhile, MRI-T2WI combine dynamic contrast-enhanced MRI can predict the effectiveness and efficiency of HIFU ablating of fibroids.Which deserves further study.