1,830 results
Article
Tubal ring sign
The tubal ring sign, also referred to as a bagel sign or blob sign, is one of the ultrasound signs of a tubal ectopic pregnancy. It comprises an echogenic ring that surrounds an unruptured ectopic pregnancy. It is said to have a 95% positive predictive value (PPV) for ectopic pregnancy.
Differe...
Article
Renal dysgenesis
Renal dysgenesis is a very broad term which can include any form underdevelopment of the kidneys. The spectrum includes:
renal agenesis: complete lack of formation
renal hypoplasia: partial lack of formation
Some authors also classify any form of renal maldevelopment affecting size, shape of ...
Article
Cervical incompetence
Cervical incompetence refers to a painless spontaneous dilatation of the cervix and is a common cause of second trimester pregnancy failure.
Epidemiology
The estimated incidence varies geographically and generally thought to be around 1-1.5% of all pregnancies 1,15.
Clinical presentation
Typ...
Article
Echogenic fetal lung lesions
Echogenic fetal lung lesions on antenatal ultrasound can be detected in a number of situations. They include:
Airway obstructions: lung are often enlarged and echogenic bilaterally
congenital high airways obstruction syndrome (CHAOS)
tracheal atresia
congenital tracheal stenosis
laryngeal a...
Case
Club foot - antenatal ultrasound
![](https://prod-images-static.radiopaedia.org/images/22325960/552f72f7be98ad55f454e46747a625_thumb.jpeg)
Published
17 May 2016
72% complete
Ultrasound
Article
Myelomeningocele
Myelomeningocele, also known as spina bifida cystica, is a complex congenital spinal anomaly that results in spinal cord malformation (myelodysplasia).
Epidemiology
It is one of the most common congenital CNS anomalies and is thought to occur in approximately 1:500 of live births 5. There may...
Article
Transient abnormal myelopoiesis
Transient abnormal myelopoiesis (TAM) is a phenomenon that can happen in the fetuses or neonates with trisomy 21. The condition can mimic leukaemia.
Epidemiology
The estimated incidence is at ~10% of newborns with trisomy 21 3.
Radiographic features
Antenatal ultrasound
In the context of kn...
Article
Ampullary ectopic pregnancy
Ampullary ectopic pregnancy is the commonest type of tubal ectopic pregnancy and accounts for ~70% of such cases. According to one study, the disruption of the tubal wall was less than as in isthmic ectopic pregnancy 2.
Article
Isthmic ectopic pregnancy
An isthmic ectopic pregnancy is a subtype of tubal ectopic pregnancy an accounts for ~12% of such cases. According to one study, the rate of tubal wall disruption was higher than with an ampullary ectopic pregnancy, suggesting that in an isthmic ectopic pregnancy, the trophoblast penetrates the ...
Article
Hydranencephaly
Hydranencephaly is a rare encephalopathy that occurs in-utero. It is characterised by destruction of the cerebral hemispheres which are transformed into a membranous sac containing cerebrospinal fluid and the remnants of cortex and white matter 1.
Porencephaly is considered a less severe degree...
Article
Fetal ventriculomegaly (differential)
Fetal ventriculomegaly (ventricle width >10 mm) is an important finding in itself and it is also associated with other central nervous system abnormalities. For more information, see the main article fetal ventriculomegaly.
Differential diagnosis
Fetal ventriculomegaly can be thought of in ter...
Case
Right sided aortic arch - fetal ultrasound
![](https://prod-images-static.radiopaedia.org/images/60028280/193c172a1ccd3cd6a915b7ae28490154de21007ba0cee2ddb1eec9cd81b94310_thumb.jpeg)
Published
06 Nov 2022
79% complete
Ultrasound
Case
Pregnancy in subseptate uterus
Published
27 Dec 2011
50% complete
Ultrasound
Case
Failed early pregnancy
![](https://prod-images-static.radiopaedia.org/images/63909682/058c3a2386f3fc7334edd1d0506235ab4dac52d6316147b1bbe99f7740ff1c52_thumb.jpeg)
Published
08 Nov 2023
94% complete
Ultrasound
Article
Corpus luteum
The corpus luteum (plural: corpora lutea) is a temporary endocrine structure involved in ovulation and early pregnancy.
During ovulation, the primary follicle forms the secondary follicle and subsequently the mature vesicular follicle.
At ovulation the follicle ruptures expelling the ovum into...
Case
Dandy walker malformation with corpus callosum dysgenesis
![](https://prod-images-static.radiopaedia.org/images/52812972/05cdfb9d8519aca1f31bcf4f8573ec_thumb.jpeg)
Published
15 Jun 2020
95% complete
MRI
Article
Ovarian hyperstimulation syndrome
Ovarian hyperstimulation syndrome (OHSS) is a complication of controlled ovarian stimulation, which is an assisted reproduction technique used for in vitro fertilisation (IVF). Rarely, it may also occur spontaneously in pregnancy (see below). It consists of ovarian enlargement with an extravascu...
Article
Amniotic bands
Amniotic bands refer to free-floating blind-ending amnion with an intact chorionic membrane. In certain situations, they lead to amniotic band syndrome. They should not be confused with amniotic shelves which refer to the presence of amnion folding around pre-existing uterine adhesions. Some adv...
Case
Cyclopia
![](https://prod-images-static.radiopaedia.org/images/11208896/83ecc20b0c8e9912b720c3f3ec6babaadd4557fa35ecbef588454ff2af5710dd_thumb.jpeg)
Published
24 Feb 2015
69% complete
Ultrasound
Case
Pre-axial polydactyly
![](https://prod-images-static.radiopaedia.org/images/16577770/d94587d4fa9961c33596e0c9d88b89_thumb.jpeg)
Published
15 Oct 2015
66% complete
Ultrasound