Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Case 69 Physiologic pelvic intraperitoneal fluid
- Case 70 Avoiding missed injuries to the bowel and mesentery: the importance of intraperitoneal fluid
- Obstetrics and gynecology
- Case 71 Endometrial hypodensity simulating fluid
- Case 72 Pseudogestational sac
- Case 73 Cystic pelvic mass simulating the bladder
- Case 74 Ovarian torsion
- Case 75 Urine jets simulating a bladder mass
- Case 76 Extraluminal bladder Foley catheter
- Case 77 Missed bladder rupture
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Case 72 - Pseudogestational sac
from Obstetrics and gynecology
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Case 69 Physiologic pelvic intraperitoneal fluid
- Case 70 Avoiding missed injuries to the bowel and mesentery: the importance of intraperitoneal fluid
- Obstetrics and gynecology
- Case 71 Endometrial hypodensity simulating fluid
- Case 72 Pseudogestational sac
- Case 73 Cystic pelvic mass simulating the bladder
- Case 74 Ovarian torsion
- Case 75 Urine jets simulating a bladder mass
- Case 76 Extraluminal bladder Foley catheter
- Case 77 Missed bladder rupture
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Summary
Imaging description
A pseudogestational sac (also known as a pseudosac) presents as an oval fluid collection centrally located within the uterine cavity of a pregnant patient.
The earliest sign of an intrauterine pregnancy (IUP) is the intradecidual sign, a small fluid collection surrounded by an echogenic ring, eccentrically located within the endometrium (Figure 72.1) [1].
Soon after, a double decidual sac sign may be identified, which is a small eccentric fluid collection within the endometrium, partially surrounded by two layers of decidua.
In contrast, a pseudosac consists of fluid located centrally within the uterine cavity (not within the endometrium), and surrounded by only one layer of decidualized endometrium (Figure 72.2). A double decidual sac sign is absent [2, 3]. “Beaking” of the fluid collection is suggestive of a pseudosac, but a leiomyoma or focal uterine contraction can cause a similar appearance in an IUP [4].
Decidual cysts are thin-walled cysts, usually at the junction of the endometrium and myometrium. They are non-specific findings and are identified in non-pregnant patients, normal IUPs, and ectopic pregnancies [1].
Although the intradecidual and double decidual signs have been reported as accurate, if there is any question about the location of the fluid, it is prudent to take a more conservative approach and specify that findings could represent an early IUP or a pseudosac associated with ectopic pregnancy, to ensure that an ectopic pregnancy diagnosis is not missed, resulting in a potentially fatal outcome.
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- Pearls and Pitfalls in Emergency RadiologyVariants and Other Difficult Diagnoses, pp. 244 - 245Publisher: Cambridge University PressPrint publication year: 2013