The Diagnostic Value Of MRI In Determining Cesarean Scar Pregnancy And Retained Products Of Conception

Part Ⅰ The diagnostic value of magnetic resonance imaging of cesarean scar pregnancyObjective:To explore the imaging features of magnetic resonance imaging(MRI)of cesarean scar pregnancy(CSP).In 2016,the CSP diagnosis and treatment expert consensus has divided CSP into three types based on the growth direction of the gestational sac implanted in the scar and the thickness of the myometrium between the gestational sac and the bladder.To explore the diagnostic value of MRI in the three types(type Ⅰ,Ⅱ,Ⅲ)of CSP.Methods:185 women with surgically and pathologically confirmed CSP from June 2017 to June 2022 were retrospectively analyzed.The clinical,imaging and pathological data of CSP patients were collected,and all patients had pelvic cavity MRI examination.The imaging features of CSP were analyzed.The CSP had been divided into three types(type Ⅰ,Ⅱ,Ⅲ)based on the growth direction of the gestational sac implanted in the scar and the thickness of the myometrium between the gestational sac and the bladder.To compare the imaging characteristics of different types of CSP.The age,cesarean section frequency,amenorrhea days,serum β-human chorionic gonadotropin(β-hCG),maximum diameter of gestational sac,the length of the gestational sac and scar intersection,and vascular emptying signal around the gestational sac were analyzed using statistical software.Results:The MRI features of CSP are as follows:the part or whole of the gestational sac was located in the scar,the myometrium between the gestational sac and the bladder becomes thinner in varying degrees,the more vascular flow void signal can be seen in the muscular layer around the gestational sac,the uterus enlarged in various degrees,the endometrial thickness,and the effusion or hematometra of uterine cavity.185 cases of CSP were divided into 22 cases of type-Ⅰ(11.89%),144 cases of type-Ⅱ(77.84%),and 19 cases of type-Ⅲ(10.27%).The B-hCG concentration of type-Ⅱ CSP was greater than that of type I(P<0.05).Compared with type-I,type-Ⅱ and type-Ⅲ have longer maximum diameter of gestational sac,intersection length of gestational sac and scar,and the more vascular flow void signal around the gestational sac(P<0.05).The intersection length of the gestational sac and scar of type-Ⅲwas longer than that of type-Ⅱ(P<0.05).Conclusion:MRI can clearly show the scar of the uterus,pregnancy sac,decidua basalis,myometrium of the uterus,and blood flow void.MRI has high diagnostic value and clear classification for CSP,which is used to guid appropriatee clinical treatment options.MRI features,including the maximum diameter of gestational sac,the intersection length of the gestational sac and scar,the vascular flow void signal in the muscle layer around the gestational sac,and scar thickness are used to predict the risk of intraoperative bleeding and improve the clinical safety of surgery.Part Ⅱ The diagnostic value of magnetic resonance imaging of retained product of conception after cesarean scar pregnancyObjective:To explore the imaging features and diagnostic value of MRI for retained products of conception(RPOC)after cesarean scar pregnancy(CSP).Methods:57 women with suspected RPOC in our hospital from June 2016 to June 2022 were retrospectively analyzed.The clinical,imaging and pathological data of CSP patients were collected,and all patients had pelvic cavity MRI and ultrasonography examination.The pathologic results were regarded as the gold standard.To analyze and explore the MRI manifestations of RPOC after cesarean scar pregnancy.The specificity,sensitivity,positive predictive value,negative predictive value,misdiagnosis rate,and missed diagnosis rate of MRI and ultrasonography in RPOC patients were compared and analyzed.Results:The pathological diagnosis results were as follows:54 cases of RPOC and 3 cases of trophoblastic disease.54 cases of RPOC patients showed flake,nodular,and mass abnormal signals in the uterine scar area.T1WI was low mixed signals,T2WI and DWI were high and low mixed signals.The binding zone at the attachment of residual tissue was discontinuous.In 36 cases(66.7%),RPOC was indistinct with the myometrium,and 32 cases(59.3%)reached the serous layer of the uterus.In 34 cases(63.0%)of RPOC,there were obvious tortuous and thickened vessels between the residual tissue of pregnancy and the myometrium.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,positive predictive value,and negative predictive value of MRI examination for RPOC were 94.4%,66.7%,33.3%,5.6%,98.1%,and 40.0%,respectively.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,positive predictive value,and negative predictive value of ultrasonography examination for RPOC were 92.6%,33.3%,66.7%,7.4%,96.2%,and 20.0%,respectively.Conclusion:MRI findings of RPOC in uterine scar pregnancy have certain characteristics.MRI can clearly show the anatomical structure of the uterus,the extent of the lesion,and the relationship between the residue and adjacent tissues.The sensitivity,specificity,positive predictive value,and negative predictive value of MRI in diagnosing RPOC are higher than those of ultrasonography.The misdiagnosis rate and missed diagnosis rate of MRI in diagnosing RPOC are lower than those of ultrasonography.The study provides important information for optimizing the management strategies.