Obstetric Imaging
| Absent double decidual sign with MSD >10 mm | prediCtors of poor outCome in first trimester |
| Anterior uterine wall displaced away from fetal body | normal amniotiC fluid Volume Several methods are used for assessment of fluid; there is no evidence that any method is better than the other: • Subjective assessment (recommended by most sonographers) Anterior uterine wall displaced away from fetal body (good sign) |
| Banana sign (spina bifida) | Banana sign (spina bifida),
Posterior fossa Cerebellar view • Banana sign (Fig. 10-28): represents the cerebellum wrapped around the posterior brainstem secondary to downward traction of the spinal cord as part of Arnold-Chiari malformation • Most cases of spina bifida are suspected because of head abnormalities (e.g., banana sign). |
| Double decidual sac sign | Pregnancy? • Visualize gestational sac • Double decidual sac sign Double Decidual Sac Sign (Fig. 10-6) The double decidual sac sign is a useful early sign of IUP. It is based on the demonstration of three layers of different echogenicity: • Decidua parietalis (hyperechoic) • Fluid in the uterine cavity (hypoechoic) • Decidua capsularis (hyperechoic) The double-bleb sign refers to the presence of an amnion and yolk sac at 5 to 6 weeks. The embryo lies between these two structures. • Pseudogestational sacs have an absent double decidual sign. • No double decidual sign but rather a single rim of echoes around pseudogestational sac seen in ectopic pregnancy |
| Double Decidual Sac Sign | The double decidual sac sign is
a useful early sign of Intra uterine pregnancy. It is based on the
demonstration of three layers of different echogenicity: • Decidua parietalis (hyperechoic) • Fluid in the uterine cavity (hypoechoic) • Decidua capsularis (hyperechoic) |
| Double-bubble sign | • Double-bubble sign (can be
seen as early as 24th week of gestation) duodenal atresia |
| fluid around urinary bladder | US Features of Hydrops
Fetalis • Effusions Ascites (fluid around urinary bladder) is the first and most reliable sign. |
| Gross Polyhydramnios | Gross polyhydramnios has a higher association with fetal anomalies than mild polyhydramnios. Associated anomalies include anencephaly, encephalocele, GI obstructions, abdominal wall defects, achondroplasia, and hydrops (isoimmunization). |
| Interstitial line sign | Interstitial line sign:
hyperechoic endometrial line abuts but does not surround sac |
| Lambda sign | • Lambda sign: chorion extending
into intertwin membrane Dichorionicity |
| Lemon Sign | • Chiari II,
myelomeningocele • Encephalocele |
| Lemon sign (skull deformity) | • Lemon sign (skull
deformity) enCephaloCele Indirect signs • Lemon sign (Fig. 10-27): bifrontal indentation. In 90% of fetuses with spina bifida <24 br="" weeks.=""> In older fetuses (24 to 37 weeks), lemon sign disappears. Lemon sign is rarely seen in a normal fetus. spina bifida and myelomeningoCele Lemon Sign • Chiari II, myelomeningocele • Encephalocele |
| Oreo cookie sign | • Adrenal glands can be mistaken for kidneys (hypoechoic rim, echogenic center: Oreo cookie sign |
| separating amnion | • Failure to identify a separating amnion is not a reliable sign to diagnose monoamnionicity. |
| Spalding's sign | fetal death • No fetal heart beat • Absent fetal movement • Occasional findings: Overlapping skull bones (Spalding's sign) Gross distortion of fetal anatomy (maceration) Soft tissue edema: skin >5 mm |
| The double-bleb sign | The double-bleb sign refers to
the presence of an amnion and yolk sac at 5 to 6 weeks. The embryo lies between these two structures. |
| The double-bleb sign | The double-bleb sign refers to the presence of an amnion and yolk sac at 5 to 6 weeks. The embryo lies between these two structures. |
| Tubal ring sign (95% chance of ectopic | Tubal ring sign (95% chance of
ectopic): echogenic rim surrounding an unruptured ectopic pregnancy |
| Twin peak sign | Twin peak sign |
