title: First trimester caesarean scar ectopic pregnancy evaluation using MRI.
abstract: OBJECTIVE
  To determine the features of caesarean scar ectopic pregnancy (CSP) by using magnetic resonance imaging (MRI) in the first trimester.
  
  
  METHODS
  Thirty-nine women with CSP in the first trimester were initially selected and underwent transvaginal ultrasound and MRI examinations. Thirty-five patients with CSP were finally included in this study.
  
  
  RESULTS
  The CSPs were categorized into three groups: type I, in which a thin-walled diverticulum is present at the caesarean section scar (CSS) defect and the gestational sac (GS) is embedded in the diverticulum; type II, in which a thin-walled diverticulum is present at the CSS defect and the GS is partially embedded in the diverticulum; type III, in which a niche is present in the CSS defect and the GS is mainly embedded in the isthmus. Types I, II, and III CSP occurred in 40, 46, and 14% of the women, respectively. There was no significant difference between the three types in the minimum thickness of the CSS defect. In types I and II, there was a positive correlation in the maximum inlet diameter of the CSS defect and the approximate area of the GS.
  
  
  CONCLUSIONS
  Using MRI, most CSPs present as a diverticulum at the CSS defect, and the CSS defect becomes weaker with the growth of the GS. MRI showed detailed features of the CSP.
authors: Department of Radiology, Shenzhen NanShan People's Hospital, ShenZhen, China. Electronic address: pengkey@sina.com.
authors: K-W
authors: KW
authors: Peng
authors: Department of Ultrasound, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: Z
authors: Z
authors: Lei
authors: Department of Gynecology, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: T-H
authors: TH
authors: Xiao
authors: Department of Radiology, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: F-G
authors: FG
authors: Jia
authors: Department of Radiology, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: W-X
authors: WX
authors: Zhong
authors: Department of Internal Medicine, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: Y
authors: Y
authors: Gao
authors: Department of Radiology, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: B-X
authors: BX
authors: Shen
authors: Department of Radiology, Shenzhen NanShan People's Hospital, ShenZhen, China.
authors: J-W
authors: JW
authors: Xie
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects*; D002921:Cicatrix / Q000150:complications / Q000209:etiology / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011271:Pregnancy, Ectopic / Q000175:diagnosis*; D055815:Young Adult