Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

1,249 results found
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Crohn disease

Crohn disease, also known as regional enteritis, is an idiopathic inflammatory bowel disease characterized by widespread discontinuous gastrointestinal tract inflammation. The terminal ileum and proximal colon are most often affected. Extraintestinal disease is common. Epidemiology The diagnos...
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Croup

Croup, also known as acute laryngotracheobronchitis, is due to viral infection of the upper airway by parainfluenza virus or respiratory syncytial virus (RSV). Although imaging findings are not required for the diagnosis, classic findings of narrowing of the subglottic airway and dilatation of ...
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Crouzon syndrome

Crouzon syndrome is rare disorder characterized by premature craniosynostoses.  Pathology Features include: abnormal calvarial shape: in severe case can give a "cloverleaf skull"  shallow orbits with exophthalmos mid facial hypoplasia bifid uvula Genetics It carries an autosomal dominant...
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Currarino-Silverman syndrome

Currarino-Silverman syndrome, also known as pectus carinatum type 2 deformity, is a rare disorder. Clinical presentation Patients present with a high carinate chest deformity due to a premature fusion of the manubriosternal joint and sternal ossification centers. Congenital heart diseases have...
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Currarino syndrome

The Currarino syndrome is a complex condition variably comprised of characteristic congenital anomalies of the sacrum, anorectum and presacral soft tissues. It is also known as the Currarino triad or ASP triad, however, not all three features are always present 6.  anorectal malformation or con...
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Cyanotic congenital heart disease

A number of entities can present as cyanotic congenital heart disease. These can be divided into those with increased (pulmonary plethora) or decreased pulmonary vascularity : increased pulmonary vascularity total anomalous pulmonary venous return (TAPVR) (types I and II) transposition of the...
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CyberKnife

CyberKnife® is a stereotactic radiotherapy system which uses a compact linear accelerator mounted on a robotic arm, coupled with a digital x-ray image guidance system.  The robotic arm allows movement with many degrees of freedom compared to typical linear accelerators which only rotate around t...
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Cyclopia

Cyclopia refers to a rare fetal malformation characterized by a single palpebral fissure and a single midline orbit. This orbit may contain either a single globe or two separate globe. Epidemiology The condition is thought to affect approximately 1 in 40,000 to 95,000 births (inclusive of stil...
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Cystic fibrosis

Cystic fibrosis (CF), also called mucoviscidosis, is an autosomal recessive genetic disease that affects the exocrine function of the lungs, liver, pancreas, small bowel, sweat glands, and the male genital system 11. resulting in progressive disability and multisystem failure. This article is a ...
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Cystic fibrosis (pulmonary manifestations)

Pulmonary manifestations of cystic fibrosis are some of the best known in cystic fibrosis (CF). This is partly because the lungs are often severely affected and the cause of significant morbidity and mortality.  For general discussion of cystic fibrosis, and a discussion of its other manifestat...
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Cystic hygroma

Cystic hygroma, also known as cystic or nuchal lymphangioma, refers to the congenital macrocystic lymphatic malformations that most commonly occur in the cervicofacial regions, particularly at the posterior cervical triangle in infants. Terminology While these lesions are commonly known as cys...
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Cystic leukoencephalopathy without megalencephaly

Cystic leukoencephalopathy without megalencephaly, is an autosomal-recessive inherited condition that manifests in the early childhood with moderate to severe psychomotor retardation and spasticity. On imaging, it is characterized by bilateral anterior subcortical temporal lobe cysts and extens...
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Cystic lung lesions (pediatric)

Cystic lesions in pediatric patients are usually congenital lesions and, as such, can be seen antenatally and following delivery. Pathology Etiology Congenital These congenital lesions are predominantly covered by the overarching diagnosis of bronchopulmonary foregut malformation. This is a ...
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Cystic mass adjacent to the angle of mandible (differential)

The differential diagnosis of a cystic mass adjacent to the angle of mandible includes: 2nd branchial cleft cyst lymphatic malformation (lymphangioma) cystic lymphadenopathy from tuberculosis from metastatic squamous cell carcinoma  from metastatic papillary thyroid cancer See also cys...
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Cystic partially differentiated nephroblastoma

Cystic partially differentiated nephroblastomas are rare pediatric cystic renal tumors. They are distinct from pediatric nephromas although they have very similar imaging appearances. Terminology Evolving terminology regarding cystic nephromas and other cystic renal tumors reflects ongoing cha...
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Cystinosis

Cystinosis, also known as Abderhalden Kaufmann Lignac syndrome, is the most common hereditary cause of renal Fanconi syndrome. Cystinosis is one of the lysosomal storage disorders.  Epidemiology It has a reported incidence of 1:192,000 1. Cystinosis is typically diagnosed in infancy.  Clinica...
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Dacryocystocele

Dacryocystoceles are caused by obstruction of both the proximal and distal ends of the nasolacrimal duct. An imperforate Hasner valve causes the distal blockage, but the cause of proximal obstruction is less clearly understood but the Rosenmuller valve has been implicated.  Epidemiology Dacryo...
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Dandy-Walker continuum

Dandy-Walker continuum, also referred to as Dandy-Walker spectrum or Dandy-Walker complex, corresponds to a group of disorders believed to represent a continuum spectrum of posterior fossa malformations, characterized by inferior vermian hypoplasia and incomplete formation of the fourth ventricl...
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Danon disease

Danon disease is an X-linked dominant cause of debilitating cardioskeletal myopathy and is a lysosomal storage disorder. Epidemiology Although considered rare, the exact incidence is unknown 1. Clinical presentation Danon disease is characterized by the triad of 1-4: cardiomyopathy the mos...
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Delayed bone age

A generalized retardation in skeletal maturation has different causative or etiological factors, these can be classified as follows: chronic ill health congenital heart disease (especially cyanotic) chronic renal disease inflammatory bowel disease malnutrition: failure to thrive (FTT) rick...
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Delbet classification

The Delbet classification helps predict the risk of avascular necrosis of the femoral head in neck of femur fractures, as well as determine operative vs non-operative management.  Classification type I: trans-epiphyseal separation fracture through proximal femoral physis, and represents Salte...
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Delta resistive index

The delta resistive index (delta RI or Δ RI) is a measurement that can be made when performing Doppler ultrasound. In preterm babies who have hydrocephalus secondary to intraventricular hemorrhage, the delta RI can be used to determine whether decompression of the ventricular system with an...
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Dense metaphyseal bands (differential)

The differential diagnosis of dense metaphyseal bands is wide. Differential diagnosis Common chronic anemia, e.g. sickle cell disease, thalassemia chemotherapy, e.g. methotrexate growth acceleration lines following growth arrest due to systemic illness or stress in infancy or childhood, e.g...
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Desmoplastic infantile astrocytoma and ganglioglioma

Desmoplastic infantile astrocytoma and gangliogliomas are a rare intracranial tumor, which despite their aggressive appearances tend to have a good prognosis and are considered WHO grade I tumors.  Terminology Previously considered separate entities, desmoplastic infantile astrocytoma and desm...
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Developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH), or in older texts congenital dislocation of the hip (CDH), denotes aberrant development of the hip joint and results from an abnormal relationship of the femoral head to the acetabulum. Unlike CDH, developmental dysplasia of the hip is not confined to c...
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Diabetic embryopathy

Diabetic embryopathy refers to a spectrum of fetal anomalies that precipitate when the mother has background type I diabetes mellitus. The fetus may develop many of the fetal conditions associated with maternal diabetes although strictly speaking the anomalies should only include those that star...
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Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) (previously known as congenital hypoplastic anemia) is the primary congenital form of pure red cell aplasia. It is a rare sporadic genetic form of anemia that typically presents in the first few years of life, and usually only affects cells of the erythroid lineage ...
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Diastasis recti

Diastasis recti (rectus diastasis) or divarication of the recti is a stretching of the linea alba with abnormal widening of the gap between the two medial sides of the rectus abdominis muscle (increased inter-recti distance). The degree of widening needed for the diagnosis is controversial, wit...
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Diastematomyelia

Diastematomyelia, also known as a split cord malformation, refers to a type of spinal dysraphism (spina bifida occulta) when there is a longitudinal split in the spinal cord.  Terminology Although traditionally it has been distinguished from diplomyelia (in which the cord is duplicated rather ...
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DICER1 syndrome

DICER1 syndrome is a rare autosomal dominant disorder predisposing individual to the development of multiple tumor types. DICER1 is considered a tumor suppressor gene that encodes the endoribonuclease protein Dicer. The first association with pleuropulmonary blastoma was discovered in 2009. Ass...
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Diffuse brainstem gliomas

Diffuse brainstem gliomas, also known as diffuse intrinsic brainstem glioma (DIBG), is a term used to describe infiltrating astrocytomas, no longer recognized as a distinct entity in the 2016 update to the WHO classification of CNS tumors. It encompassed a variety of tumors, ranging from WHO gra...
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Disorders of gender development

Disorder of gender development refers to the spectrum of rare congenital conditions where there is an atypical development of chromosomal, gonadal, or anatomic sex. They can be classified broadly into four categories on the basis of gonadal histologic features which include: female pseudoherma...
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Divry van Bogaert syndrome

Divry van Bogaert syndrome is a familial juvenile-onset syndrome characterized by livedo racemosa, juvenile ischemic stroke, juvenile cerebral white matter disease leading to premature dementia, and epilepsy. Clinical presentation juvenile ischemic stroke epilepsy early-onset cognitive impai...
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Dorsal brainstem syndrome

Dorsal brainstem syndrome is a rare subset of hypoxic ischemic encephalopathy in neonates limited to the isolated involvement of the brainstem with sparing of the supratentorial brain. Due to its subtle imaging features, it is often undiagnosed. Clinical presentation Injuries involving the teg...
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Double bubble sign (duodenum)

The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally 2. Pathology Causes include 1,2: congenital obstruction duodenal web duodenal atresia duodenal stenosis...
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Double density sign (osteoid osteoma)

The double density sign, also sometimes clumsily referred to as the hotter spot within hot area sign, is a bone scan sign of an osteoid osteoma. It refers to a central focus of intense uptake (the nidus) within a surrounding lower, but nonetheless increased uptake, rim. See also double densit...
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Double lung point sign (Ultrasound)

The double lung point sign refers to a sharp boundary found between relatively aerated superior lung fields and coalescent "B‐lines" (representing interstitial edema) in the basal lung fields, with a reported sensitivity of 45.6%-76.7% and a specificity of 94.8%-100% 1,3 in diagnosing transient ...
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Double outlet left ventricle

Double outlet left ventricle (DOLV) is an extremely rare congenital cardiac anomaly where both the aorta and pulmonary trunk arise from the anatomical left ventricle. It is usually classified as a conotruncal anomaly and is often associated with a ventricular septal defect with normal continuity...
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Double outlet right ventricle

Double outlet right ventricle (DORV) is a congenital cardiac anomaly where both the aorta and pulmonary trunk arise from the morphologically right ventricle. It is reported to account for ~2% of congenital cardiac defects 1. It is usually classed as a conotruncal anomaly. There is almost always ...
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Double track sign (pyloric stenosis)

The double track sign is a radiological sign described in pyloric stenosis on various imaging modalities.  Barium study Double streaks of barium passing through the narrow pylorus 1. Ultrasound On fluid aided real-time examination, the pyloric fluid is compressed into smaller tracks as it is...
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Doughnut sign (disambiguation)

The doughnut sign can refer to a variety of different signs: doughnut sign (bone scan) doughnut sign (bowel) crescent in a doughnut sign (bowel) doughnut sign (chest) doughnut sign (orbit)
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Drash syndrome

Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of: Wilms tumor male pseudohermaphroditism progressive glomerulonephritis
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Dravet syndrome

Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a rare form of epilepsy usually presenting in the first 1-2 years of life. Clinical presentation The typical presentation occurs during the first six months to one year of life as tonic-clonic seizures in a fe...
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Duane radial ray syndrome

Duane radial ray syndrome (DRRS) (also known as the Okihiro syndrome) is a rare an autosomal dominant condition characterized by radial ray defects and a Duane anomaly (a form of strabismus with horizontal gaze palsy).
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Duane syndrome

Duane syndrome, also known as Duane retraction syndrome, is a rare congenital disease characterized by non-progressive strabismus. It is caused by a variable degree of abnormal development of one or both 6th cranial nerves (CN VI). Epidemiology It presents during childhood and it accounts for ...
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Dubowitz syndrome

Dubowitz syndrome (DS) is a rare genetic disorder with a wide clinical spectrum which includes: intrauterine growth restriction (IUGR) postnatal growth restriction microcephaly moderate intellectual disability  characteristic facial anomalies  telecanthus epicanthic folds blepharophimos...
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Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a dystrophinopathy and the most common muscular dystrophy. Epidemiology DMD has an incidence of 1 in 3500 to 5000 males 1,2. The condition is extremely rare in females due to its inheritance pattern, as discussed below 1. Clinical presentation The charact...
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Ductus arteriosus

The ductus arteriosum (DA) (or arteriosus) is the thick short conduit for blood to bypass the non-ventilated lungs in the fetus. It is located between and connects the proximal left pulmonary artery and the undersurface of the aortic arch distal to the origin of the last branch of the arch, at t...
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Ductus venosus

Ductus venosus (DV) is a narrow, trumpet-shaped vessel which is seen in the fetal liver connecting the umbilical vein directly to the caudal inferior vena cava. The vessel plays a critical role in the fetal circulation by shunting oxygenated and nutrient-rich umbilical venous blood from the plac...
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Duodenal atresia

Duodenal atresia results from a congenital malformation of the duodenum and requires prompt correction in the neonatal period. It is considered to be one of the commonest causes of a fetal bowel obstruction. Epidemiology The prevalence of duodenal atresia is ~1 in 5,000-10,000 newborns, and th...
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Duodenal web

A duodenal web, diaphragm or intraluminal diverticulum refers to a complete or incomplete obstruction at the duodenum due to a membranous web or intraluminal diverticulum. There is usually a small aperture at the center differentiating this from duodenal atresia.  Epidemiology Although they ar...
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Dysgenesis of the corpus callosum

Dysgenesis of the corpus callosum may be complete (agenesis) or partial and represents an in utero developmental anomaly. It can be divided into: primary agenesis: the corpus callosum never forms secondary dysgenesis: the corpus callosum forms normally and is subsequently destroyed Epidemiolo...
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Dysplasia epiphysealis hemimelica

Dysplasia epiphysealis hemimelica (DEH), also known as Trevor disease, is an extremely rare, non-hereditary disease that is characterized by osteochondromas arising from the epiphyses. Epidemiology The incidence is estimated at ~1:1,000,000 3. There is a recognized male predilection (M:F = 3:1...
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Ebstein anomaly

Ebstein anomaly is an uncommon congenital cardiac anomaly, characterized by a variable developmental anomaly of the tricuspid valve. Epidemiology The anomaly accounts for only ~0.5% of congenital cardiac defects 6,7, although it is the most common cause of congenital tricuspid regurgitation. T...
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Echogenic fetal bowel

Echogenic fetal bowel is an observation in antenatal ultrasound imaging, in which fetal bowel appears to be brighter than it is supposed to be. It is a soft marker for trisomy 21 and has several other associations. When observed, it needs to be interpreted in the context of other associated abno...
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Ectodermal dysplasia

Ectodermal dysplasia (ED) refers to a heterogeneous group of genetic disorders that cause abnormal ectoderm development. The effect is a non-progressive defect in the development of two or more tissues derived from embryonic ectoderm.  Epidemiology ED is rare with an estimated prevalence of 1:...
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Ectopia cordis

Ectopia cordis is an extremely rare congenital malformation where the heart is located partially or totally outside the thoracic cavity. The four main ectopic positions are: adjacent to the thorax: ~60% abdominal: 15-30% thoracoabdominal: 7-18%  cervical: ~3% Epidemiology The incidence is ...
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Ectopic ureter

An ectopic ureter is a congenital renal anomaly that occurs as a result of abnormal caudal migration of the ureteral bud during its insertion to the urinary bladder. Normally the ureter drains via the internal ureteral orifice at the trigone of the urinary bladder.  In females, the most common ...
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Ectrodactyly-ectrodermal dysplasia-clefting syndrome

Ectrodactyly-ectrodermal dysplasia-clefting (EEC) syndrome is a rare genetic syndrome that has high clinical variability but typically comprises of the triad of  ectrodactyly  +/- syndactyly 1 +/- polydactyly 5 ectrodermal dysplasia facial clefts: cleft lip and/or palate Pathology Genetics ...
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Edwards syndrome

Edwards syndrome, also known as trisomy 18, along with Down syndrome (trisomy 21) and Patau syndrome (trisomy 13), make up the only three autosomal trisomies to be compatible with extrauterine life in non-mosaic forms, albeit in the case of Edward syndrome only for a week or so.  Epidemiology ...
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Egg-on-a-string sign (heart)

Egg-on-a-string sign, also referred to as egg on its side, refers to the cardiomediastinal silhouette seen in transposition of the great arteries (TGA). The heart appears globular due to an abnormal convexity of the right atrial border and left atrial enlargement and therefore appears like an ...
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Eisenmenger syndrome

The Eisenmenger syndrome is a complication of an uncorrected high-flow, high-pressure congenital heart anomaly leading to chronic pulmonary arterial hypertension and shunt reversal. Epidemiology In general, the shunts that lead to Eisenmenger syndrome share high pressure and high flow 3. As su...
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Elbow ossification

Elbow ossification occurs at the six elbow ossification centers in a reproducible order. Being familiar with the order of ossification of the elbow is important in not mistaking an epicondylar fracture for a normal ossification center.  Appearance Order The order of appearances of the elbow o...
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Elbow ossification (mnemonic)

Mnemonics for elbow ossification include CRITOE and CRITOL. These are essentially the same, apart from the terminal letter which represents the External or Lateral epicondyle. Mnemonics CRITOE C: capitellum R: radial head I: internal epicondyle T: trochlea O: olecranon E: external epicon...
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Elbow series (pediatrics)

The elbow series for pediatrics is a set of radiographs taken to investigate elbow joint pathology, often in the context of trauma. It usually comprises an anteroposterior and lateral projection in order to minimize radiation dose to the patient. Depending on the department and clinical indicati...
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Embryonal rhabdomyosarcoma

The embryonal subtype of rhabdomyosarcoma is the most common variety of rhabdomyosarcoma, accounting for 50-70% of cases 1-2. It is typically seen in children below the age of 15. Pathology Embryonal rhabdomyosarcomas are further divided into three sub types 1: spindle cell rhabdomyosarcoma ...
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Embryonal tumors with multilayered rosettes (ETMR)

Embryonal tumors with multilayered rosettes (ETMR) are rare small round blue cell tumor of the central nervous system and are one of the most aggressive brain tumors usually encountered in children.  Terminology Previously embryonal tumors with multilayered rosettes (ETMR) were known as embryo...
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Encephalocele

Encephalocele, also known as meningoencephalocele, is a form of neural tube defect and a type of cephalocele where brain tissue and overlying meninges herniate out through a defect in the cranium.  Terminology It should be distinguished from cranial meningocele in which the lesion contains onl...
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Encephaloduroarteriomyosynangiosis

Encephaloduroarteriomyosynangiosis (EDAMS) is a surgical procedure performed most commonly in children with moyamoya disease or less commonly in individuals with intracranial atherosclerotic disease (ICAD) as a form of indirect revascularization to bypass the occlusive terminal internal carotid ...
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Encephalomyosynangiosis

Encephalomyosynangiosis (EMS) is a surgical procedure performed most commonly in children with moyamoya disease as a form of indirect revascularization to bypass the occlusive terminal internal carotid and/or circle of Willis vessels 1.  It entails dissecting strips of vascularized temporalis m...
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Enchondromatosis

Enchondromatosis, also known as Ollier disease (see Terminology section), is a non-hereditary, sporadic, skeletal disorder characterized by multiple enchondromas principally located in the metaphyseal regions. Terminology Some authors make a distinction between Ollier disease and enchondromato...
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Endocardial fibroelastosis

Endocardial fibroelastosis (EFE) is a rare cardiac condition which is classically described in the pediatric population (typically first two years). It is one of the causes in infants of unexplained heart failure. Epidemiology Associations mitral valve abnormalities: e.g mitral regurgitation ...
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Endochondral ossification

Endochondral ossification describes the process of ossification from mesenchymal cells (stem cells) with a cartilaginous template and is involved in the healing process of fractures. Bone formation occurs at ossification centers, which are either primary or secondary: primary ossification cent...
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Enterovirus 71

Enterovirus 71 is one of the viruses that causes hand-foot-and-mouth disease in children. It is an enterovirus, one of the picornaviruses. Infection with enterovirus 71 predominantly results in a vesicular rash of the hands and feet that follows a prodrome of symptoms including fever, vomiting ...
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Enterovirus rhombencephalitis

Enterovirus rhombencephalitis is the most common neurological complication of enterovirus infection 1. Clinical presentation Enterovirus rhombencephalitis causes acute and severe neurologic disorders such as ataxia, nystagmus, oculomotor palsies, or bulbar palsy. In some cases, neurologic affe...
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Ependymoma RELA fusion-positive

Ependymoma RELA fusion-positive is a recently accepted molecular variant of ependymoma, only recognized in the 2016 update to the WHO classification of CNS tumors. They are the most common type of supratentorial ependymoma in children, and not found in the posterior fossa or spinal cord.  Epide...
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Epicondyle fracture (elbow)

Epicondyle fractures are common injuries in children. They represent 10% of all elbow fractures in children and usually occur in boys after a fall on an outstretched arm. Medial epicondyle fractures comprise most of these injuries. They can usually be treated with splinting and early physiother...
Article

Epiglottitis

Epiglottitis, also known as supraglottitis, is a life-threatening condition caused by inflammation of the epiglottis and aryepiglottic folds 1,  which can lead to acute airway obstruction. Epidemiology The traditional age of presentation is in children of 3 to 6 years, although this has been c...
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Episodic spontaneous hypothermia with hyperhidrosis syndrome

Episodic spontaneous hypothermia with hyperhidrosis syndrome (ESHH) is a rare syndrome characterized by periodic hypothermia and hyperhidrosis. This occurs in the absence of agenesis of the corpus callosum, thus differentiating it from Shapiro syndrome 1. Epidemiology Episodic spontaneous hypo...
Article

Epispadias

Epispadias is a rare congenital anomaly that is almost always associated with bladder exstrophy.  Epidemiology It occurs in 1 in 30,000 births, with a male: female ratio of 3:1. Clinical presentation The roof of the urethra is absent and the urethra opens anywhere between the base and the gl...
Article

Erb palsy

Erb palsy, also known as brachial plexus birth palsy, is a form of obstetric brachial plexus injury as a result of complications during delivery.  Clinical presentation The most common cause is due to excessive lateral traction or stretching of the fetal head and neck in opposite directions du...
Article

Evaluation of endotracheal tube position

Endotracheal tubes (ETT) are wide-bore plastic tubes that are inserted into the trachea to allow artificial ventilation. Tubes come in a variety of sizes and have a balloon at the tip to ensure that gastric contents are not aspirated into the lungs. Adult tubes are usually approximately 1 cm in ...
Article

Ewing sarcoma

Ewing sarcomas are the second most common malignant primary bone tumors of childhood after osteosarcoma, typically arising from the medullary cavity with the invasion of the Haversian system. They usually present as moth-eaten destructive permeative lucent lesions in the shaft of long bones with...
Article

Ewing sarcoma family of tumors

The Ewing sarcoma family of tumors are a group of small round blue cell tumors that are closely histogenetically related, all demonstrating non-random t(11;22)(q24;q12) chromosome rearrangement resulting in the formation of the EWS-ETS fusion gene 1-3.  Terminology Although the literature is l...
Article

External beam radiotherapy

External beam radiotherapy (EBRT) (also known as teletherapy) is a form of ionizing radiation therapy delivered by a medical linear accelerator (or historically a cobalt-60 source) to a patient lying on a treatment bed. Megavoltage x-rays (4-25 MV) are the most commonly used. Alternative forms o...
Article

Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is used as a modified pulmonary or cardiopulmonary bypass technique in those with severe cardiac and/or respiratory failure refractory to conventional ventilatory support and medical intervention 1,3. There are two access paths for extracorporeal life s...
Article

Extrusion index

The extrusion index is a radiographic measurement of femoral head bony coverage by the acetabulum. It is useful in assessing for developmental dysplasia of the hip as well as femoroacetabular impingement. Measurement It is calculated by dividing the horizontal distance of the lateral femoral h...
Article

Exudative retinitis

Exudative retinitis, also known as retinal telangiectasis or Coats disease, is a rare congenital disease affecting the eyes and is a cause of leukocoria. Epidemiology It occurs predominantly in young males, with the onset of symptoms generally appearing in the first decade of life with a peak ...
Article

Facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a form of muscular dystrophy characterized by extremely variable degrees of facial, scapular and lower limb muscle involvement. Epidemiology It is considered one of the more common hereditary muscular disorders with a prevalence of ~1 in 8,000. ...
Article

Familial adenomatous polyposis syndrome

Familial adenomatous polyposis syndrome (FAPS) is characterized by the presence of hundreds of adenomatous polyps in the colon. It is the most common of the polyposis syndromes. Terminology Familial polyposis coli, attenuated familial adenomatous polyposis and Gardner syndrome are all variants...
Article

Familial Mediterranean fever

Familial Mediterranean fever (FMF) (also known as recurrent polyserositis) is a genetic autoimmune condition that is notable for its spontaneous self-limiting acute episodes of fever and serositis, especially peritonitis and synovitis. Epidemiology Familial Mediterranean fever tends to be ethn...
Article

Fatco syndrome

Fatco syndrome is a syndrome consisting of fibular aplasia tibial campomelia and oligosyndactyly. It is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance. Differential diagnosis Fuhrmann syndrome and Al-Awadi syndrome are said to be similar to FA...
Article

Faulty fetal packing

Faulty fetal packing, also known as congenital vault depression, is a congenital concave depression of the skull in a newborn. Epidemiology Occurs in 1 in 10,000 births 1.  Pathology This appearance is due to external compression on the skull from 1,2: fetal limb or twin uterine fibroid b...

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