To Study Variation Of Normal Uterine Myometrium During Menstrual Cycle And Accuracy Of MRI Staging For Stage Ⅰ Endometrial Cancer

Objective:The staging of endometrial carcinoma by magnetic resonance imaging (MRI) can be benefit to clinical favourable treatment and assessing prognosis and survival. Junctional zone and outward myometrium are important structure in the preoperative evaluation of depth of myometrial infiltration in endometrial cancer.In this study,the thickness and signal intensity of junctional zone and outward myometrium were measured and analyzed during the normal menstrual cycle,and whether this would affect the accuracy of staging of endometrial carcinoma by MRI. Patients with stage I endometrial carcinoma were classified based on International Federation of Gynecology and Obstetrics (FIGO) 1988 or 2009 classification,and contrast to pathology, respectively.To study the value of which FIGO endometrial carcinoma classification was emploied to MRI staging systems.Materials and Methods:Our study were divided two parts.The first part:12 healthy, regular cycle,no using hormone women were studied during a single menstrual cycle. T2WI was performed to prospectively coincide with the menstrual phases, follicular phases, periovulatory phases, and luteal phases of the menstrual cycle, respectively.To measure the thickness and signal intensity of junctional zone and outward myometrium on the midsagittal and axis planes of uterus,in which the myometrium was the thickest.To compare the thickness and signal intensity of junctional zone and outward myometrium in the cycle, data of the front and back wall of uterus, data of midsagittal and axis of uterus,especially the thickness and signal intensity of junctional zone and outward myometrium in back wall, junctional zone to myometrium ratio of thickness in back wall.The second part:T2WI and T1WI enhancement of 111 patients with stage I endometrial carcinoma confirmed by pathology were analyzed. They were classified based on FIGO 1988 or 2009 classification,and contrast to pathology.To compare the accuracy of MRI staging between on the basis of FIGO 1988 or FIGO 2009 classification.Results:①The signal intensity of junctional zone was the most high in luteal phases,then menstrual phases and periovulatory phases, and it was the most low in follicular phases. The signal intensity of junctional zone varied according to menstrual cycle,but not outward myometrium.②The junctional zone was the thickest in menstrual phases,then luteal phases and periovulatory phases, and it was the thinnest in follicular phases. The thickness of junctional zone varied followed menstrual cycle,but not outward myometrium.③Junctional zone to myometrium ratio of thickness was the biggest in menstrual phases,then luteal phases and periovulatory phases, and it was the smallest in follicular phases. The ratio varied followed menstrual cycle.④Using FIGO 1988 or 2009 classification, the correlation between preoperative MRI staging and final histology was moderate with Kappa= 0.421 and Kappa=0.586, respectively.⑤The using of FIGO 2009 classification increases the accuracy of MR staging of endometrial carcinoma than using FIGO 1988 classification (p＜0.01).Conclusion:The thickness and signal intensity of junctional zone varied followed menstrual cycle,but not outward myometrium. The menstrual cycle and physiological state of patients shoud be considered in the preoperative evaluation of depth of myometrial infiltration in endometrial cancer. Both using FIGO 1988 and 2009 classification, the correlation between preoperative MRI staging and final histology was all moderate. The accuracy of MR staging using FIGO 2009 classification increased.Innovation:①All the volunteers were performed MRI scan prospectively coinciding with menstrual phases, follicular phases, periovulatory phases and luteal phases of menstrual cycle,respectively.To investigate junctional zone and outward myometrium dynamicly in menstrual cycle.And estimate the ratio of junctional zone thickness to myometrium thickness.②Using FIGO 1988 or 2009 classification, to evaluate the correlation between preoperative MRI staging and final histology staging.③To propose that FIGO 2009 classification is favourable for MR staging.