Correlation Study Between Signal Characteristics Of Mr And Effect Of High-intensity Focused Ultrasound Ablation For Adenomyosis

Adenomyosis is a common gynecological disease caused by the invasion of endometrial glands and stroma into myometrium.The incidences of adenomyosis is about 8.8% to 31.0% and it? s clinical manifestations are progressive aggravation of dysmenorrhea,menstrual volume increase,infertility and so on.Magnetic resonance imaging(MRI)manifestation can show the pathological features of adenomyosis which include the enlargement of uterine volume,punctiform or flaky hyperintense foci in the lesions(ectopic endometrial tissue,endometrial cyst or hemorrhage).At present,the most effective treatment for adenomyosis is hysterectomy and still lack of effective conservative treatment in clinical.High intensity focused ultrasound(HIFU)is a kind of noninvasive thermal ablation technique developed rapidly in recent years.The application of HIFU in the treatment of adenomyosis was efficient,less side effect and with good repeatability.Previous studies have confirmed that the difficulty and effect of HIFU treatment were related to signal characteristics of MR.However,there is no acknowledged classification method of signalcharacteristics of MR T2 WI in adenomyosis.The objective of this study is to explore the relationship between signal characteristics of MR and the effect of HIFU ablation for adenomyosis by classifying and grouping signal characteristics of MR;to evaluate the effect of signal characteristics of MR T2 WI and different enhanced degree on dynamic contrast enhanced MRI on predicting HIFU treatment outcome for adenomyosis.We want to provide a basis for classification of signal characteristics of adenomyosis on MR T2 WI and optimization and standardization of HIFU treatment for adenomyosis.Objective1.To analyze signal characteristics of MR T2 WI in adenomyosis and to investigate the relationship between signal characteristics of MR T2 WI and HIFU treatment outcome for adenomyosis.2.To explore signal characteristics of MR T2 WI which were contributed to the effect of HIFU ablation for adenomyosis,to provide a basis for classification of MR T2 WI signal characteristics and to classify signal characteristics on MR T2 WI of adenomyosis.3.To investigate the effect of signal characteristics of MR T2 WI and different enhanced degree on dynamic contrast enhanced MRI on predicting HIFU treatment outcome for adenomyosis,to provide a basis for optimization and standardization of HIFU treatment for adenomyosis.Methods1.SubjectsFrom January 2012 to November 2016,502 patients with adenomyosis treated by HIFU in the First Affiliated Hospital of Chongqing Medical University were enrolled in the study.2.EquipmentsJC HIFU tumour therapeutic system produced by Chongqing HaifuMedical Tech Co.Ltd and Signa HD Excite 3.0T Magnetic resonance imaging system produced by GE.3.Methods3.1 Pretreatment magnetic resonance image evaluation:The plain and enhanced MRI scanning were performed in all patients before HIFU treatment to evaluate the size and position of uterus and the type,size,position,signal intensity of MR T2 WI and enhance degree on enhanced MRI of adenomyosis.According to the intensity of MR T2 WI,taken signal of normal uterine myometrium and uterine cavity as reference,hypointense was defined as the signal intensity of lesions was lower than that of normal myometrium,isointense was defined as the signal intensity of lesions was equal to that of normal uterine myometrium,slightly hypointense was defined as the signal intensity of lesions was higher than that of normal myometrium but lower than that of uterine cavity,extremely hyperintense11was defined as the signal intensity of lesions was higher than that of uterine cavity.3.1.1 According to signal characteristics of MR T2 WI,502 patients with adenomyosis were divided into group A(lesions with most hypointense and/or little isointense)and group B(lesions with most isointense and/or little hypointense).Each group was further subvided into subgroup A1/B1(without hyperintense foci in the lesions),subgroup A2/B2(with slightly hyperintense foci in the lesions)and subgroup A3/B3(with extremely and/or slightly hyperintense foci in the lesions),to search for the signal characteristics on MR T2 WI which were closely related to the effect of HIFU ablation for adenomyosis.3.1.2 According to signal characteristics of MR T2 WI which were closely related to the effect of HIFU ablation for adenomyosis,502 patients with adenomyosis were divided into group?(lesions without hyperintense foci)and group?(lesions with hyperintense foci).Each group was further subvided into subgroup?a/?a(slight enhancement),subgroup?b/?b(irregular enhancement)and subgroup?c/?c(significant enhancement),to study predictive effect of MR T2 WI combining dynamic contrast-enhanced MRI on high-intensity focused ultrasound treatment outcome for adenomyosis.3.2 HIFU ablation: HIFU ablation was completed by qualified physician from the First Affiliated Hospital of Chongqing Medical12University.3.3 Main outcome measures: treatment time,sonication time,sonication watt,sonication energy,non-perfused volume(NPV),non-perfused volume ratio(NPVR),energy efficiency factor(EEF),adverse effect and pain score.3.4 Posttreatment evaluation: The plain and enhanced MRI scanning was performed in all patients one day after HIFU ablation to measure NPV and caculate NPVR.3.5 Correlation analysis between MR T2 WI signal classification and the effect of HIFU ablation: based on HIFU treatment parameters and effect,analyze the classification of MR T2 WI signal which has clinical significance4.Statistical methodsStatistical analysis was performed using SPSS20.0 software.Results1.Among 502 patients with adenomyosis,258 cases with most hypointense of MR T2 WI were divided into group A and 244 cases with most isointense were divided into group B.1.1 NPV and NPVR of group A and group B were(62.1 ± 61.3)cm3,(68.3 ± 63.9)cm3,(45.3 ± 23.5)%,(46.3 ± 23.2)%,respectively,and there was no statistical difference of NPV and NPVR between group A and group B(all P>0.05);There was no statistical difference of sonication time,total ablation energy and energy efficiency factor(EEF)between group A and group B(all P>0.05).1.2 In group A,no statistical difference was found in NPV between subgroup A1,A2 and A3.NPVR of subgroup A1 was higher than that of subgroup A2 and subgroup A3,respectively(all P<0.05),there was no statistical difference of NPVR between subgroup A2 and subgroup A3(P>0.05).Sonication time,total ablation energy and EEF of subgroup A1 were lower than those of subgroup A2 and subgroup A3(all P<0.05)and no statistical difference was found in sonication time,total ablation energy and EEF between subgroup A2 and subgroup A3(all P>0.05).1.3 The results of subgroup B1,B2 and B3 from group B were the same as group A.2.Among 502 patients with adenomyosis,126 cases without most hyperintense foci on MR T2 WI were divided into group ? and 376 cases with hyperintense foci were divided into group ?.2.1 NPV of group? and group? were(68.8 ± 66.0)cm3,(62.6 ± 57.4)cm3,no statistical difference was found between these two group(P > 0.05).NPVR of group?was(55.2 ± 21.9)% which was higher than group?(P <0.05).The group? had significantly lower sonication time,total ablation energy and EEF than that of group?(P < 0.05).2.2 In group?,there was no statistical difference of NPV betweensubgroup?a,?b and?c(all P > 0.05).NPVR of subgroup?a,?b and?c were(70.4±21.8)%?(59.0±17.8)%?(44.5±18.6)%,respectively.NPVR of subgroup?a was higher than that of subgroup ?b,that of subgroup ?b was also higher than that of subgroup?c(all P < 0.05).EEF of subgroup?a and ?b were(3.8 ± 3.4)J/mm3,(3.5 ± 2.7)J/mm3,both them were lower than that of subgroup?c(all P < 0.05),no statistical difference was found in EEF between subgroup?a and subgroup?b(P >0.05).2.3 In group?,NPV and NPVR of subgroup?a were(80.5 ± 76.5)cm3,(58.7 ± 24.2)% which both were higher than that of subgroup?b and subgroup?c,NPVR of subgroup?b was higher that subgroup?c(all P <0.05).There was no statistical difference between subgroup ? b and subgroup?c in NPV(P > 0.05).EEF of subgroup?a,?b and?c were(9.3 ± 26.2)J/mm3,(9.6 ± 15.7)J/mm3,(13.3 ± 17.8)J/mm3,EEF of subgroup?a was lower than that of subgroup?b,and that of subgroup?b was also lower than that of subgroup?c,there were significant differences among three groups(all P < 0.05).Conclusion1.The presence or absence of hyperintense foci in adenomyosis on MR T2 WI is closely related to the difficulty and the effect of ultrasound ablation,so the classification of signal characteristics of adenomyosis onMR T2 WI which have the clinical significance are as follows: class ? :lesions without hyperintense foci,class ?: lesions with hyperintense foci.2.MR T2 WI combining dynamic contrast-enhanced MRI can be used as a predictor of HIFU treatment outcome for adenomyosis.Patients with adenomyosis which appear slight enhancement on dynamic contrast-enhanced MRI and without hyperintense foci on MR T2 WI have highest NPVR and for best treatment result,Patients with adenomyosis which appear significant enhancement on dynamic contrast-enhanced MRI and with hyperintense foci on MR T2 WI have lowest NPVR and are most difficult to ablation because it required the most of ultrasound energy to ablation per unit volume of lesions.