Application Of 2D Ultrasound, Color Doppler Flow Imaging And 3D Color Power Angiography In Efficacy Evaluation Of Uterine Leiomyomas Treated With High Intensity Focused Ultrasound: Comparison With Contrast-enhanced Ultrasound

Background and Objective High intensity focused ultrasound(HIFU),as a new minimally invasive technique,has been used successfully in treatment of uterine leiomyomas.The key to evaluating therapeuic efficacy is to identify lesion extent ablated.Although both CT and MRI were able to identify blood per fusion region in lesion,their usage were often limited due to radiation injury and large consume and so on.This aim of study was to evaluate two-dimensional ultrasound(2DUS), color Doppler flow imaging(CDFI)and three-dimensional color power angiography(3D-CPA)in therapeutic efficacy of uterine leiomyomas treated with high intensity focused ultrasound(HIFU).Contrast-enhanced ultrasound(CEUS), as a diagnostic technique,compared with other ultrasound imaging in this study. Methods Forty-seven patients with 52 leiomyomas were treated with HIFU. 2DUS,CDFI,3D-CPA and CEUS was performed and the echo and the blood flow was observed before and after HIFU treatment respectively within twenty-four hours,Taking myometrium echo as reference,leiomyomas were divided into hypoecho,isoecho,hyperechogenicity and hyperecho by 2DUS,and blood flow was divided into 0,Ⅰ,Ⅱ,Ⅲgrade by CDFI and 3D-CPA.The CEUS results were taken as criterion,the sensitivity and specificity of 2DUS,CDFI,3D-CPA were calculated to assess treatment efficacy.The efficacy standard:no contrast perfusion on CEUS,hyperechoic region on 2DUS and blood flow signs disappearing or on CDFI and 3D-CPA indicated HIFU therapy was effective. and leiomyomas' flow was classified by vascularity using 3D-CPA.Blood perfusion was observed with CEUS before and after HIFU treatment.Echo,blood flow,volumes of leiomyomas and symptoms were observed during 6 months of follow-up.Results Twenty in 52 leiomyomas treated with HIFU were demonstrated no blood flow,32 no blood flow in the center.Leiomyomas showed hyperecho in 2DUS,of which 25 showed hyperechogenicity while 27 showed hyperechogenicity with hypoecho.The sensitivity and spectivity of commenting survival focus was 65%and 62.5%,respectively.Blood supply was decreased completely or significantly in CDFI,25 appeared as no blood flow,27 survival blood flow,the sensitivity and spectivity was 75%and 68.8%.Twenty-four leiomyomas were detected no blood flow in 3D-CPA,28 were left blood flow,the sensitivity and specitivity was 80%and 75%.One leiomyoma's remained blood flow appeared as gradeⅡby CDFI and 3D-CPA in 24h post-therapy,which was proved abundant blood perfusion with CEUS.Although the volume of the leiomyoma was decreased during 3-month follow-up,the blood flow increased, thus another complementary HIFU was carried out.During the 6-month-follow-up,the echo of leiomyomas decreased gradually,blood flow showed no increase,the volume decreased by 21%～95%from(102.3±58.2)cm~3 before treatment to(42.5±28.3)cm~3 after treatment.The symptoms were disappeared in 16 cases and improved in 31 after HIFU treatment.No outstanding adverse event was in 42 cases,skin vesicles in 3 cases and local swelling at skin scar in 2 cases.Conclusions The ablation efficacy could be evaluated by echo intensity of 2DUS,by central and peripheral blood supply of CDFI.The sensitivity and specitivity of 2DUS and CDFI are lower than that of 3D-CPA.But it is much more economic and convenient of 2DUS and CDFI,which is of great importance to patients needed long-term followup or complementary HIFU treatment.3D-CPA could demonstrate the blood supply of uterine leiomyomas stereoly,differentiate blood flow inside leiomyomas from outside clearly,more sensitive and specitive than CDFI.As an easy-performed and effective method,3D-CPA would be a new method to evaluate uterine leiomyomas treated with HIFU.