Undifferentiated embryonal sarcomas of the liver are rare, aggressive, and malignant liver tumors encountered in the pediatric population.
Approximately 90% of cases occur in patients under 15 years of age, most commonly between 6 and 10 years of age, but some cases have been rep...
Unicameral bone cysts (UBC), also known as simple bone cysts, are common benign non-neoplastic lucent bony lesions that are seen mainly in childhood and typically remain asymptomatic. They account for the S (simple bone cyst) in FEGNOMASHIC, the commonly used mnemonic for lytic bone lesions.
A unifocalisation procedure is a corrective surgical technique used in patients with complete pulmonary artery atresia with major aortopulmonary collateral arteries (MAPCAs). In this technique, the collateral vessels supplying blood from the aorta directly to the lungs are brought into continuit...
Urachal cysts are one of the manifestations of the spectrum of congenital urachal remnant abnormalities.
Urachal cysts usually remain asymptomatic until complicated by infection or bleeding.
An infected urachal cyst can occur at any age.
Urbach-Wiethe disease, also known as lipoid proteinosis or hyalinosis cutis et mucosae, is a rare autosomal recessive genodermatosis that primarily affects the skin, upper respiratory tract, and central nervous system (CNS).
Urbach-Wiethe disease is a very rare condition, with few...
Ureteric jets (or ureteral jets) are the visualization of the normal physiological periodic efflux of urine from the distal end of each ureter into the bladder.
When the urine passing down the ureter reaches the vesicoureteric junction it is forced out into the bladder via a strong...
Ureteroceles represent congenital dilatation of the distal-most portion of the ureter. The dilated portion of the ureter may herniate into the bladder secondary to the abnormal structure of vesicoureteric junction (VUJ).
Most ureteroceles are congenital, usually associated with ec...
There are numerous causes of urinary bladder diverticula:
Primary (congenital or idiopathic)
Hutch diverticulum (in paraureteral region)
bladder outlet obstruction
bladder neck stenosis
posterior urethral valve
prostatic enlargement (hypertrophy; carcinoma)
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...
Valvular heart diseases, or cardiac valvulopathies, describe any acquired or congenital disease affecting one or more of the four cardiac valves.
This is a general index article that classifies cardiac valvulopathies depending on which valve(s) is affected 1. See individual articles for in-dept...
van der Woude syndrome (VWS) is characterized by the association of congenital lower lip fistulae/pits with cleft lip and/or palate.
It is one of the most common clefting syndromes in humans 1 and affected individuals have a high prevalence of hypodontia.
It carries an aut...
Vascular rings and slings refer to the congenital vascular encirclement of the esophagus and/or trachea by anomalous/aberrant vessels.
Vascular rings are rare, occurring in <1% of patients 1. No gender or ethnic predispositions have been identified 3.
VATER (equivalent to VACTERL) is the non-random constellation of a number of congenital anomalies.
V: vertebral anomalies
A: anal atresia
TE: tracheo-oesophageal fistulas
R: radial ray hypoplasia, polydactyly and renal agenesis
The prevalence of at least 3/5 anomalies occurs...
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.
Ventricular septal defects (VSD) represent defects in the interventricular septum that allow a haemodynamic 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 ma...
The ventriculus terminalis or terminal ventricle of Krause, also known as the 5th ventricle, is an ependymal-lined fusiform dilatation of the terminal central canal of the spinal cord, positioned at the transition from the tip of the conus medullaris to the origin of the filum terminale.
Vesico-urachal diverticulum is one of the congenital urachal remnant abnormalities.
It is the proximal equivalent of a urachal umbilical sinus, representing a result of the failure of the urachus to close at the urinary bladder, forming an out-pouching of variable length from the...
Vesicoureteric reflux (VUR) is the term for abnormal flow of urine from the bladder into the upper urinary tract and is typically encountered in young children.
For grading of vesicoureteric reflux, please refer to vesicoureteric reflux grading.
The incidence of urinary tract in...
Vesicoureteric reflux (VUR) grading divides vesicoureteric reflux according to the height of reflux up the ureters and degree of dilatation of the ureters:
grade 1: reflux limited to the ureter
grade 2: reflux up to the renal pelvis
grade 3: mild dilatation of ureter and pelvicalyceal system
Vesicovaginal reflux is a well-known entity rarely encountered by radiologists. It is a behavioral disorder, a type of dysfunctional elimination syndrome commonly encountered in pre-pubertal girls. It is defined as reflux of urine into the vaginal vault either in supine or upright position durin...
Vitamin A (the retinoids) are a group of fat-soluble vitamins required for many physiological functions, mainly vision, reproduction and epithelial maintenance. In the retina, a specific retinoid, 11-cis-retinal, is formed by photoisomerisation within the rods and cones.
Vitamin B1 (thiamine) is a water-soluble vitamin that is an important coenzyme for two reactions in the citric acid cycle (Kreb cycle). It therefore is vital for cellular ATP production, particularly in the central nervous system.
Thiamine is the preferred official spelling, howeve...
Vitamin C (ascorbic acid) is a water soluble vitamin that is a coenzyme for the formation of the structure protein collagen, particularly creating cross-linking of collagen fibers which greatly increases its tensile strength. It also acts as an antioxidant.
Vitamin D (calciferol) is used to describe a group of five fat-soluble secosteroid vitamins required for the homeostasis of serum calcium and phosphorus. Vitamin D exists in two main forms (vitamers) in humans: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Vitamin D3 acts by re...
Vitamin E (the tocopherols) are a group of fat-soluble vitamins that act as antioxidants.
hypovitaminosis E is rarely seen outside premature infants
hypervitaminosis E is extremely rare as the toxicity of vitamin E is low except in chronic (usually >1 year) high doses. The commonest sequela is...
Vitamin K is a family of fat-soluble vitamins essential for normal blood-clotting function and comprises two vitamers that are found naturally: phytomenadione (also known as phylloquinone or K1) and menaquinone (or K2).
Menadione is a synthetic molecule which is occasionally called vitamin K3 h...
Voiding cystourethrography (VCUG), also known as a micturating cystourethrography (MCU), is a fluoroscopic study of the lower urinary tract in which contrast is introduced into the bladder via a catheter. The purpose of the examination is to assess the bladder, urethra, postoperative anatomy an...
Waardenburg syndrome is a rare congenital pigmentary disorder secondary to an abnormal distribution of neural crest-derived melanocytes during embryogenesis resulting in patchy areas of depigmentation. It is considered in the investigation of congenital sensorineural deafness.
The WAGR syndrome stands for:
Wilms tumors (greatly increased risk)
Occurs from a mutation related to chromosome 11p13 3 which is in close proximity to the WT1 gene.
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...
A Waterston shunt is a form of palliative surgery performed in patients with tetralogy of Fallot prior to the ability to repair the defect. It consists of a shunt formed between the ascending aorta and the right pulmonary artery.
This does not relieve the right ventricular outflow obstruction, ...
Weaver syndrome (WS) is a rare congenital disorder.
increased birth weight: fetal macrosomia
accelerated osseous maturation: increased bone age
typical facial features
Reporting a weightbearing foot series can be a daunting process if you are inexperienced and often results in the films being left for somebody else to report. This article attempts to demystify the whole process by providing a structured approach to their reporting.
Williams-Campbell syndrome (WCS) is a rare form of congenital cystic bronchiectasis, in which distal bronchial cartilage is defective.
It is thought to result from a deficiency of cartilage formation in the 4th to 6th order segmental bronchi.
Shows cystic ...
Wilms tumor, also known as nephroblastoma, is a malignant pediatric renal tumor.
Wilms tumors are the most common paediatic renal mass, accounting for over 85% of cases 1,8 and accounts for 6% of all childhood cancers 2. It typically occurs in early childhood (1-11 years) with pea...
Wilms' tumor staging is largely anatomical and relates to the invasion and spread of the tumor. Where there is invasion or metastasises, prognosis is poorer. Wilms tumor, is one of the more common childhood malignancies.
confined to kidney
complete resection possible
Wimberger ring sign , often simply just called Wimberger ring, refers to a circular calcification surrounding the osteoporotic epiphyseal center of ossification in scurvy, which may result from bleeding.
It must not be confused with Wimberger sign, pathognomonic for congenital syphilis.
The Wimberger sign, also called Wimberger corner sign, refers to localised bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis.
It must not be mixed up with Wimberger ring sign seen in scurvy, which is sometimes also confusingly re...
The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. In both the male and the female the Wolffian duct develops into the trigone of the urinary bladder.
In the female, in...
Wolf-Hirschhorn syndrome (WHS) is an extremely rare chromosomal anomaly characterized by partial deletion of the p arm of chromosome 4 (4p16.3).
agenesis of the corpus callosum
cleft lip + / - palate...
Wolman disease is a rare autosomal recessive inborn error of metabolism resulting in the deposition of fats in multiple organs.
Patients with Wolman disease typically present during the first two months of life with failure to thrive, diarrhea and vomiting. Abdominal dis...
Wyburn-Mason syndrome (also known as Bonnet-Dechaume-Blanc syndrome) is a rare, nonhereditary neurocutaneous disorder that typically presents with unilateral vascular malformations that primarily involve the brain, orbits and facial structures. It is currently classified as a craniofacial arteri...
The Yasargil classification is one of the two common systems for classifying vein of Galen malformations that is currently in use at the time of writing (mid 2016).
type I: small pure cisternal fistula between the vein of Galen (voG) and either the pericallosal arteries (anteri...
Yunis Varón syndrome is a rare skeletal dysplasia. It is thought to be autosomal recessive.
severe neurologic impairment
diastasis of sutures
absent thumbs and distal phalanges of fingers
The zebra stripe sign occurs where children with osteogenesis imperfecta have been treated with cyclical bisphosphonate therapy, e.g. pamidronate. When the drug is delivered in cycles, dense bone is formed while treatment is being given. This results in dense stripes across the metaphyses of bon...
The Zuelzer-Wilson syndrome (total colonic aganglionosis) is a subset of Hirschsprung disease, in which the whole colon is aganglionic. It is uncommon and accounts for 2-13% of cases of Hirschsprung disease 3. Multiple procedures have been devised to treat the condition, including proctocolectom...