Learning objectives
The purpose of this exhibit is:
1.To review imaging of ectopic pregnancy with surgical specimen.
2.To show the pathologic findings corresponding to the imaging findings we interpret as ectopic pregnancy,
emphasizing the pathology of the gestational sac(GS)-like structure and differences between the corpus luteum cyst and the GS-like structure.
3.To show rare types of ectopic pregnancy; cervical pregnancy,
interstitial pregnancy,
ovarian pregnancy,
cesarean scar pregnancy,
abdominal pregnancy,
etc.
Background
Ectopic pregnancy is one in which the fertilized ovum implants in a site other than the endometrial lining of the uterus,
and it is the leading cause of pregnancy-related death in the first trimester even today.
The incidence of ectopic pregnancy is 1.5-2% of all pregnancies and has increased in the last few decades [1] probably due to increasing number of sexually transmitted disease and employment of assisted reproductive technology [2].
MRI is performed when transvaginal ultrasonography (TVUS) is inconclusive or more detailed information of...
Findings and procedure details
Normal pregnancy
MRI appearance of normal pregnancy at 5 weeks’ gestation is shown in figure 1,
and the corresponding TVUS image and anatomic scheme are presented in figure 2.
Tubal pregnancy
Tubal pregnancy is a pregnancy that occurs within the fallopian tube,
and it is the most common form of ectopic pregnancy,
accounting about 98% of all ectopic pregnancies.
The most common implantation site is the ampulla (75-80%),
followed by the isthmus (10-15%) and the fimbria (5%),
the interstitial (2-4%) (figure 3) [4,6].
There are...
Conclusion
The major teaching points of this exhibit are:
1: To get familiar with imaging findings of ectopic pregnancy including rare types of ectopic pregnancy.
2: To understand the pathological features of ectopic pregnancy.
3: To get to be able to diagnose cases of ectopic pregnancy confidently,
based on the understanding of the anatomy and pathology of ectopic pregnancy.
References
1.
Barnhart KT (2009) Clinical practice.
Ectopic pregnancy.
N Eng J Med 361:379-87
2.
Yoshigi J,
Yashiro N,
Kinoshita T,
O’Uchi T,
Kitagaki H (2006) Diagnosis of ectopic pregnancy with MRI: efficacy of T2*-weighted imaging.
Magn Reson Med Sci 5(1):25–32
3.
Parker RA 3rd,
Yano M,
Tai AW,
Friedman M,
Narra VR,
Menias CO (2012) MR imaging findings of ectopic pregnancy: a pictorial review.
RadioGraphics 32:1445-1460
4.
Tamai K,
Koyama T,
Togashi K (2007) MR features of ectopic pregnancy.
Eur Radiol 17: 3236-46
5.
Takahashi...