The urinary tract dilatation (UTD) classification system is a proposed unified classification of urinary tract dilatation for prenatal and postnatal care. This classification was formed with the collaborations from eight societies (American College of Radiology (ACR), American Institute of Ultra...
The uterine artery is seen bilaterally and is a branch of the anterior division of the internal iliac artery.
It runs medially in the pelvis, within the base of the broad ligament, to the outer surface of the uterus. From lateral to medial it has a descending, transverse ...
Uterine artery embolization (UAE) is an interventional radiological technique to occlude the arterial supply to the uterus and is performed for various reasons.
Uterine artery embolization has been practised for more than 20 years for controlling hemorrhage following delivery/abortion,...
Uterine artery embolization (UAE) is used as an alternative to hysterectomy in selected patients and MRI assessment is key in allowing not only pre-procedure assessment but also assessing post-procedural outcome.
For a general discussion of the underlying condition refer to the article on ute...
Uterine artery flow notching refers to a phenomenon observed in uterine arterial Doppler ultrasound assessment.
The presence of notching after 22 weeks is associated with several other conditions including adverse pregnancy outcomes. These include
pregnancy induced hyp...
Uterine artery pseudoaneurysm (UAP) is a rare cause of secondary postpartum hemorrhage.
UAP usually presents as delayed (secondary) postpartum hemorrhage, that is per vaginal bleeding which occurs more than 24 hours and up to 6 weeks postpartum. However, some reported ca...
Uterine dehiscence is, usually, used to refer to the process of gradual myometrial rupture without a rupture of membranes. However, the term is used synonymously with uterine rupture by some authors. It is often described in the context of a C-section scar where it is also termed an incisional d...
Uterine duplication anomalies are a group of Müllerian duct anomalies where fusion of the Müllerian duct associated structures fail to some degree:
uterus didelphys: class III
bicornuate uterus: class IV (second commonest duplication anomaly)
septate uterus: class V (commonest duplication ano...
Uterine enlargement can occur in a number of situations from both diffuse and focal processes. These include:
gestation related events
normal intrauterine pregnancy
molar pregnancy - gestational trophoblastic disease
postpartum uterus - still larger than usual
Uterine inversion is a rare condition in which the uterus is essentially turned inside out. There are two types: "puerperal" (within six weeks of childbirth) and "non-puerperal". The reason for uterine inversion is unclear. In the puerperal form, it is theorized that excessive traction on the um...
Uterine perforation represents a serious complication that can occur as a result of any type of intrauterine procedure or implantation. Some authors use the term uterine rupture synonymously with the term uterine perforation.
IUCD insertion: IUCD related uterine perforation
Uterine rupture is a rare but nevertheless potentially catastrophic complication that can occur in pregnancy.
The incidence rate in pregnancy is 0.05% 6.
Uterine rupture is usually an acute presentation with hemodynamic instability and abdominal discomfo...
Uteroplacental blood flow assessment is an important part of fetal well-being assessment and evaluates Doppler flow in the uterine arteries and rarely the ovarian arteries.
In a non-gravid state and at the very start of pregnancy the flow in the uterine artery is of high pulsatility ...
The uterus is an extraperitoneal hollow, thick-walled, muscular organ of the female reproductive tract that lies in the lesser pelvis.
The uterus has an inverted pear shape. It measures about 7.5 cm in length, 5 cm wide at its upper part, and nearly 2.5 cm in thickness in adults....
VACTERL is an acronym that describes a non-random constellation of congenital anomalies. It is not a true syndrome as such and is equivalent to the VATER anomaly.
The estimated incidence is 1 in 10,000-40,000 births 3.
The acronym VACTERL derives from:
V: vertebral an...
The VACTERL-H association is a rare non-random association which bears the features of the standard VACTERL association with added fetal hydrocephalus.
Unlike the standard VACTERL association which is sporadic, the VACTERL-H is hereditary with both X-linked 3 and autosomal recessive 2 inheritan...
The vagina is a midline fibromuscular tubular organ positioned in the female perineum extending superiorly from the vulva, to the cervix and uterus in the pelvis.
The vagina is 6-8 cm in length, extending posterosuperior from the vestibule through the urogenital diaphragm to the...
There can be several variations with cord insertion into the placenta:
central insertion (~90%): normal situation
eccentric cord insertion: lateral insertion of the umbilical cord >2 cm from the placental margin
term sometimes used synonymously with marginal cord insertion
marginal cord inse...
There can be many variations in the fetal presentation which is determined by which part of the fetus is projecting towards the internal cervical os. This includes:
cephalic presentation: fetal head presenting towards the internal cervical os, considered normal and occurs in the vast majority o...
There can be several variations in placental morphology. These include:
single lobed discoid placenta (single disc): most common scenario
bilobed placenta: two near equal size lobes
succenturiate lobe(s): one or more smaller accessory lobes
circumvallate placenta: rolled placental edges with...
Vasa previa refers to a situation where there are aberrant fetal vessels crossing over or in close proximity to the internal cervical os, ahead of the fetal presenting part. These vessels are within the amniotic membranes, without the support of the placenta. Vasa previa is a rare but potentiall...
Vein of Galen aneurysmal malformations (VGAMs), probably better termed as median prosencephalic arteriovenous fistulas, are uncommon intracranial anomalies that tend to present dramatically during early childhood with features of a left-to-right shunt and high-output cardiac failure.
Velamentous cord insertion is a type of abnormal umbilical cord insertion into the placenta.
The estimated incidence is ~1% in singleton and 9-15% in twin pregnancies, respectively 11. It is also more common in placenta previa than in normally located placentas. The prevalence may...
The term venous lakes may refer to:
cutaneous venous lakes, often occurring on the lower lip 1
osseous venous lakes occurring in the skull 2
placental (venous) lakes 3
Ventricular septal defects (VSD) represent defects in the interventricular septum that allow a hemodynamic communication between the right and left ventricles. It typically results in a left-to-right shunt.
They represent one of the most common congenital cardiac anomalies and may...
Evaluation of vermian lobulation is essential in assessment of the vermian maturity. MRI is a useful tool in assessment of the fetal posterior fossa.
Normal vermian lobulation by weeks 1:
by 21 weeks: the prepyramidal fissure can be seen between the tuber and pyramis
Radiological evaluation of the posterior fossa is an essential part of the routine fetal assessment, including vermian maturity assessment.
Ultrasonography is a readily available diagnostic tool in the assessment of the fetal posterior fossa but is sometimes limited due t...
Vitamin B9 (folate or folic acid) is a water-soluble vitamin, part of the vitamin B complex, vital for the synthesis of several amino acids, the purines adenosine and guanine and the pyrimidine thymine (three of the four nucleotide bases and hence critical for the synthesis of nucleic acids).
Walker-Warburg syndrome (WWS), sometimes known as HARDE syndrome, is an extremely rare lethal form of congenital muscular dystrophy. It is primarily characterized by:
fetal hydrocephalus: almost always present
neuronal migrational anomalies: agyria (cobblestone lissencephaly / lissencephaly ty...
Wharton jelly refers to the gelatinous substance within the umbilical cord.
Wharton jelly is derived from extra-embryonic mesoderm and is largely made up of mucopolysaccharides (hyaluronic acid and chondroitin sulphate) while containing smaller amounts of fibroblasts and macropha...
Wolf-Hirschhorn syndrome (WHS) is an extremely rare chromosomal anomaly characterized by partial deletion of the p arm of chromosome 4 (4p16.3).
There is a large clinical spectrum:
agenesis of the corpus callosum
Yolk sac is the first anatomical structure identified within the gestational sac. It plays a critical role in embryonal development by providing nutrients, serving as the site of initial hematopoiesis, providing endocrine, metabolic and immunological functions and contributing to the development...
Zika virus infection is a zoonosis which is associated with congenital birth defects, with microcephaly the most widely known.
Zika was once isolated to Africa and Asia, however, it spread to the Americas in the last decade 1. There were thousands of cases confirmed in the America...