≤11 ribs is associated with a number of congenital abnormalities and skeletal dysplasias, including:
Down syndrome (trisomy 21)
asphyxiating thoracic dysplasia (Jeune syndrome)
short rib polydactyly syndromes
chromosome 1q21.1 deletion...
18q-deletion syndrome is a rare chromosomal anomaly where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as do their severity. Characteristic clinical features include short stature, intellectual disability, hypotonia, facial, and dist...
22q11.2 deletion syndrome, also known as the DiGeorge syndrome or velocardiofacial syndrome, is a syndrome where a small portion of the chromosome 22 is lost and results in a variable but a recognisable pattern of physical and behavioral features.
The estimated incidence is at ~ 1...
Aase-Smith syndrome (or Aase syndrome) is an extremely rare congenital disorder characterized by anemia and skeletal deformity.
Aase-Smith syndrome has a prevalence of less than 1 per 1,000,000 persons. There have only been 20 reported cases
The abdomen radiograph is a commonly requested examination in the pediatric patient. Children that present for abdominal x-rays are often very unwell, therefore specialized techniques and appropriate communication are essential for gaining the child's cooperation.
Abdominal migraine is a syndrome which presents as recurrent episodes of severe abdominal pain, coupled with vasomotor symptoms, nausea, and emesis. Historically it has tended to be a pediatric diagnosis, but it is now increasingly seen in adults. It is one of the functional gastrointestinal dis...
Abdominoschisis (plural: abdominoschises) refers to a split or defect in the abdominal wall. Some authors use the term synonymously with a gastroschisis. When the defect continues into the thoracic region it is termed a thoracoabdominoschisis. A large abdominoschisis is considered part of the li...
Aberrant left pulmonary artery, also known as pulmonary sling, represents an anatomical variant characterized by the left pulmonary artery arising from the right pulmonary artery and passing above the right main bronchus and in between the trachea and esophagus to reach the left lung. It may lea...
An absent septum pellucidum may rarely be an isolated finding, or more commonly be seen in association with a variety of conditions.
The septum pellucidum is partly or entirely absent in 2 or 3 individuals per 100,000 in the general population.
An absent septum pelluc...
An absent thumb can have many associations. They include:
Fanconi anemia (pancytopenia-dysmelia syndrome)
phocomelia (e.g. thalidomide embryopathy)
Poland syndrome (pectoral muscle aplasia and syndactyly)
Seckel syndrome ...
Abusive head trauma is a term that is used for inflicted head injury that has occurred by either shaking, impact head trauma, or both, as part of the spectrum of non-accidental injury (NAI).
Subdural hemorrhage in a child should be viewed with suspicion. Most o...
Accessory ossicles are secondary ossification centers that remain separate from the adjacent bone. They are usually round or ovoid in shape, occur in typical locations and have well defined smooth cortical margins on all sides.
In most cases, they are congenital in origin, although they may occ...
The parietal and occipital bones in particular are common regions for accessory sutures because of their multiple ossification centers.
It is important to know these anatomic variations, mainly on the head trauma image studies in children, where it could be difficult to differentiate non-depres...
The acetabular angle is a radiographic measurement used when evaluating potential developmental dysplasia of the hip (DDH). It is most useful in patients who have started to ossify the epiphysis since ossification diminishes the usefulness of ultrasound.
The angle is formed by a horizontal lin...
Achondroplasia is a congenital genetic disorder resulting in rhizomelic dwarfism and is the most common skeletal dysplasia. It has numerous distinctive radiographic features.
It occurs due to sporadic mutations in the majority of cases but can be inherited as an autosomal dominan...
Achondroplasia is the most common cause of short-limb dwarfism. (For a general discussion, see the generic article on achondroplasia.)
As the skull base forms by endochondral ossification whereas the skull vault by membranous ossification, there is a marked discrepancy in relative size as the s...
Acrania anencephaly sequence is the progression from a relatively normal-appearing exposed brain due to an absent cranium (acrania) to an amorphous brain mass (exencephaly) to no recognisable brain tissue (anencephaly) 1.
The acrania anencephaly sequence begins with acrania, which...
Acrocephalosyndactyly syndromes (ACS) are a rare group of disorders collectively characterized by:
calvarial anomalies, e.g. craniosynostoses
digital anomalies, e.g. syndactyly
While there can be some overlap in features, they can be primarily classified into the following maj...
Acromial apohysiolysis is a finding on shoulder MRI that may be encountered in patients with an unfused acromial apophysis. It is associated with athletes in throwing sports.
Presents with superior shoulder tenderness in a patient <25 years old, often in a young throwing ...
Acute abdominal pain is a common acute presentation in clinical practice. It encompasses a very broad range of possible etiologies and diagnoses, and imaging is routinely employed as the primary investigative tool in its modern management.
A subgroup of patients with acute abdomina...
Acute bronchitis (plural: bronchitides) refers to acute-onset, short-term bronchial inflammation. It is usually self-limiting and often the result of a viral infection. Chest radiography is rarely necessary.
Acute bronchitis can affect people of all ages, but it is commonest in ch...
Acute idiopathic scrotal edema (AISE) is a self-limiting condition characterized by marked edema of the skin and dartos fascia without involvement of the deeper layers, testes, or epididymis. It is an important condition to recognize in order to avoid unnecessary surgical exploration.
Acute mastoiditis refers to a suppurative infection of the mastoid air cells. It is the most common complication of acute otitis media.
In acute otitis media, an inflammatory middle ear effusion is present that can freely move into the mastoid air cells. Consequently, some authors ...
Acute necrotizing encephalopathy, also referred as acute necrotizing encephalopathy of childhood, is a rare type of encephalopathy characterized by multiple bilateral brain lesions, mainly involving the thalami, but also the putamina, internal and external capsules, cerebellar white matter, and ...
Acute pyelonephritis (plural: acute pyelonephritides) is a bacterial infection of the renal pelvis and parenchyma most commonly seen in young women. It remains common and continues to have significant morbidity in certain groups of patients.
The incidence of acute pyelonephritis p...
Acyanotic congenital heart disease comprises numerous etiologies, which can be divided into those with increased pulmonary vascularity (pulmonary plethora) and those with normal vascularity:
increased pulmonary vascularity
ventricular septal defect (VSD)
atrial septal defect (ASD)
The Adams-Oliver syndrome (AOS) is a rare disorder characterized by aplasia cutis congenita (missing hair and/or skin) and variable degrees of terminal transverse limb defects.
polymicrogyria: can be associated with a variant of Adams-Oliver syndrome 3
Adenoidal hypertrophy or enlargement in children is common and due to an increase in the size of the adenoids. For adenoidal enlargement in adults, which is much rarer and usually pathological, please see the separate article, adenoidal hypertrophy (adults).
Afibrinogenemia, also called congenital afibrinogenemia, is a rare autosomal recessive inherited blood disorder due to deficiency of the clotting protein fibrinogen. The disorder is associated with increased risk of spontaneous hemorrhage1.
Afibrinogenemia has an estimated prevale...
Aflatoxins are naturally-occurring mycotoxins that are produced by Aspergillus species, especially Aspergillus flavus. They are acutely toxic and carcinogenic.
High-level aflatoxin exposure can result in acute aflatoxicosis with acute hepatic necrosis, leading to cirrhosis, and ...
Aicardi-Goutières syndrome is a rare hereditary neurodegenerative disease which usually presents in early infancy with systemic and central nervous system inflammatory syndrome characterized by hepatosplenomegaly, vasculopathy and encephalopathy. Many of the features are similar to congenital TO...
Aicardi syndrome is a rare severe developmental disorder. It results from an X-linked genetic defect that is fatal in males and therefore only manifests in females (except for rare 47, XXY cases).
Note: Aicardi syndrome is distinct from Aicardi-Goutieres syndrome although both are named after J...
Acquired immunodeficiency syndrome (AIDS) embryopathy is characterized by a group of dysmorphic features, which manifests either before or after birth in offsprings of women who are infected by HIV virus. The diagnosis, however, is in disfavour according to some authors 2.
Airway foreign bodies in children are potentially fatal, which is why immediate recognition is important. Unfortunately, delayed diagnosis is common.
Children under the age of four years are at increased risk of foreign body (FB) aspiration, with a slight male predominance 1.
Alagille syndrome (also known as arteriohepatic dysplasia) is a congenital genetic multisystem disorder.
Infants typically present with symptoms relating to the liver where it is one of the most common causes of hereditary cholestasis.
Alagille syndrome is inhe...
Alexander disease, also known as fibrinoid leukodystrophy, is a rare fatal leukodystrophy, which usually becomes clinically evident in the infantile period, although neonatal, juvenile and even adult variants are recognized. As with many other diseases with variable age of presentation, the earl...
Alobar holoprosencephaly is a subtype of holoprosencephaly and is the most severe of the classical three subtypes, with both semilobar and lobar holoprosencephaly having less severe clinical manifestations.
For a general discussion of epidemiology, clinical presentation, and pathology, please r...
Alpers syndrome, also known as Alpers-Huttenlocher syndrome or progressive cerebral poliodystrophy, is a rare childhood neurodegenerative POLG-related disorder. Along with Leigh syndrome, it is one of the commonest childhood mitochondrial disorders 1.
Alpers syndrome is incredibl...
The alpha angle is a measurement used in the ultrasonographic assessment of developmental dysplasia of the hip (DDH).
The angle is formed by the acetabular roof to the vertical cortex of the ilium and thus reflects the depth of the bony acetabular roof. This is a similar measurement to the acet...
Alpha-fetoprotein (AFP) is an important plasma protein synthesized by the yolk sac and fetal liver. In adults its main utility is as a tumor marker, primarily for hepatocellular carcinoma or teratoma. Functionally it is the fetal homologue of albumin i.e. it acts as a major carrier protein in th...
Alternating radiolucent and radiodense metaphyseal lines can be seen with a number of conditions and the differential diagnosis is wide:
growth arrest lines
rickets: especially those on prolonged treatment, e.g. vitamin D dependent rickets
Anal atresia, or imperforate anus, refers to a spectrum of anorectal abnormalities ranging from a membranous separation to complete absence of the anus.
The estimated incidence is 1 in 5000 live births.
Clinically there is no anal opening. Subtypes can be classified in...
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
Aneurysmal bone cysts (ABC) are benign expansile tumor-like bone lesions of uncertain etiology, composed of numerous blood-filled channels, and mostly diagnosed in children and adolescents.
Aneurysmal bone cysts are primarily seen in children and adolescents, with 80% occurring in...
Anomalous left coronary artery from the pulmonary artery (ALCAPA), also known as Bland-White-Garland syndrome (BWG), is a rare congenital coronary artery anomaly and is considered one of the most severe of such anomalies.
There are two forms, based on onset of disease, each of which has differe...
Anoxic brain injury, also known as global hypoxic-ischemic injury, is seen in all age groups (from antenatal to the elderly) as a result of numerous etiologies. The pattern of injury depends on a number of factors including:
age of the patient (brain maturity)
neonatal hypoxic-ischemic encepha...
The anterior or frontal fontanelle is the diamond-shaped soft membranous gap (fontanelle) at the junction of the coronal and sagittal sutures. It persists until approximately 18-24 months after birth, after which it is known as the bregma. The precise timing of the anterior fontanelle closure is...
The anterior humeral line is key to demonstrating normal elbow alignment and should be used whenever reading a pediatric elbow radiograph to exclude a subtle supracondylar fracture.
A line drawn down the anterior surface of the humerus should intersect the middle third of the capit...
Anterior inferior iliac spine (AIIS) avulsion injuries are one of the six main types of pelvic apophyseal avulsion fractures. Subacute or chronic avulsion injuries can be mistaken for a pseudotumor.
As with many pelvic avulsion injuries, they most often occur in adolescents (most...
Anterior lenticonus is present when the anterior surface of the ocular lens assumes a conical shape.
It can be unilateral or bilateral. Bilateral anterior lenticonus is associated with Alport syndrome.
Decreased visual activity and irregular refraction that...
Anterior vertebral body beaking occurs in a number of conditions and may emanate from the central portion or the lower third of the vertebral body.
Morquio syndrome 1 (middle for Morquio)
Hurler syndrome 2
Antley-Bixler syndrome (ABS), also known as trapezoidocephaly-synostosis syndrome, is a rare autosomal dominant or recessive condition characterized by craniosynostosis and extra-cranial synostoses. Mid-facial hypoplasia is also common.
It is a very rare condition with only 50 cas...
The antral nipple sign refers to redundant pyloric mucosa protruding into the gastric antrum and is seen in hypertrophic pyloric stenosis on ultrasound examination.
cervix sign (pyloric stenosis)
target sign (pyloric stenosis)
Aorto-ventricular tunnel (AVT) is an extremely rare form of congenital heart disease, representing an anomalous extracardiac communication between the ascending aorta and the left or right ventricles.
In most cases the anomalous communication is between the aorta and the left ventr...
Apert syndrome (also known as type I acrocephalosyndactyly) is a syndrome that is predominantly characterized by skull and limb malformations.
The estimated incidence is 1 case per 65-80,000 pregnancies.
increased paternal age has been proposed 6
Apgar score was originally described by Virginia Apgar (American anaesthesiologist, 1909-1974) in 1952.
Helpfully, her surname is also a useful mnemonic for remembering the 5 factors: each is graded as 0, 1 or 2 with a total possible score of 10. The lower the score the worse the prognosis.
Apodia is a rare non-syndromic transverse terminal lower limb defect characterized by the congenital absence of the foot and ankle. The remainder of the lower limb is present including both the tibia and fibular epiphyses. It can be unilateral or bilateral.
Apophyseal avulsion fractures of the pelvis and hip are relatively common among physically active adolescents and young adults.
Pelvic and hip apophyseal injuries typically occur in the 14 to 25 year age range.
Kicking sports, such as soccer, and gymnastics are frequen...
The apophysis of the proximal 5th metatarsal (plural apophyses) lies laterally and is oriented longitudinally parallel to the shaft.
Apophysis of the fifth metatarsal base appears on plain radiographs at age 12 for boys and 10 for girls. Fusion of the apophysis to the metatarsal base usually oc...
Appendicitis is inflammation of the vermiform appendix. It is a very common condition in general radiology practice and is one of the main reasons for abdominal surgery in young patients. CT is the most sensitive modality to detect appendicitis.
Acute appendicitis is typically a d...
Apple-peel intestinal atresia, also known as type IIIb or Christmas tree intestinal atresia, is a rare form of small bowel atresia in which the duodenum or proximal jejunum ends in a blind pouch and the distal small bowel wraps around its vascular supply in a spiral resembling an apple peel. Oft...
Arrhythmogenic right ventricular cardiomyopathy (ARVC), also referred to as arrhythmogenic right ventricular dysplasia (ARVD) or simply arrhythmogenic cardiomyopathy, is a cardiomyopathy that is one of the more common causes of sudden cardiac death in young patients.
The arterial switch procedure, also known as the Jatene switch procedure, is an intervention designed to correct D-transposition of the great arteries (D-TGA) at the level of the aorta and main pulmonary artery. It is generally preferred over atrial switch procedures for simple D-TGA due to impr...
Ascariasis is due to infection with the Ascaris lumbricoides adult worm and typically presents with gastrointestinal or pulmonary symptoms, depending on the stage of development.
Ascaris lumbricoides is widely distributed in tropical and subtropical regions and in other humid ar...
Ascites (hydroperitoneum is a rare synonym) is defined as an abnormal amount of intraperitoneal fluid.
Ascites (plural is same word) tends to be reserved for relatively sizable amounts of peritoneal fluid. The amount has not been defined formally, however it is noted that physiolog...
The original description of the Askin tumor (by Askin and Rosai in 1979 1), and many studies following it have led to a great deal of confusion. Until recently it has been considered a separate entity or as a type of peripheral primitive neuroectodermal tumor, usually of the chest wall.
Asphyxiating thoracic dysplasia, also known as Jeune syndrome, is a type of rare short limb skeletal dysplasia, which is primarily characterized by a constricted long narrow thoracic cavity, cystic renal dysplasia and characteristic skeletal features. It is also sometimes classified as one of th...
Asplenia refers to absence of the spleen thereby leading to deficient splenic function.
Seen in 3% of neonates with structural heart disease and in 30% of patients who die from cardiac malposition. The male-to-female ratio is 2:1.
Asplenia can be classified into two t...
Asplenia syndrome, also known as right isomerism or Ivemark syndrome, is a type of heterotaxy syndrome.
There is an increased male predilection. Asplenia syndrome is usually diagnosed in neonates 4.
In contrast to polysplenia syndrome, most patients die bef...
Atelosteogenesis refers to a heterogeneous group of lethal skeletal dysplasias that are characterized by aplasia/hypoplasia of the humeri, femora and spine.
atelosteogenesis type I (boomerang dysplasia)
atelosteogenesis type II
atelosteogenesis type III 4
Athlete heart syndrome refers to adaptations in both cardiac structure and function seen in people engaged in high-performance and endurance physical exercise.
The prevalence of the condition has increased due to the increased popularity of recreational exercise, approx 3.6/100,00...
Atresia (plural: atresias) refers to a situation where there is absence, underdevelopment or abnormal closure, of a normal anatomical tubular structure or opening.
Contrast this with agenesis which refers to the complete absence of any anatomical structure including its primordial precursors.
Atrial septal defect (ASD) is the second most common congenital heart defect after ventricular septal defects and the most common to become symptomatic in adulthood.
They are characterized by an abnormal opening in the atrial septum allowing communication between the right and left atria. Due t...
Atrioventricular septal defects (AVSDs), also known as atrioventricular canal defects or endocardial cushion defects, comprise a relatively wide range of defects involving the atrial septum, ventricular septum, and one or both of the tricuspid or mitral valve. They can represent 2-7% of congenit...
Atypical callosal dysgenesis is a term used to denote an unusual pattern of dysgenesis of the corpus callosum.
The development of the corpus callosum occurs between the 12th and 16-20th weeks of gestation 2-3. It begins with the genu and then continues posteriorly along the body to the splenium...
Atypical teratoid/rhabdoid tumors (AT/RT) are an uncommon WHO Grade IV tumor, which in the vast majority of cases occurs in young children less than two years of age. It most frequently presents as a posterior fossa mass. AT/RT often resembles medulloblastoma by imaging and even H&E microscopy, ...
Autoimmune lymphoproliferative syndrome (ALPS) is a rare lymphoproliferative condition.
It presents with chronic lymphadenopathy, splenomegaly, and symptomatic multilineage cytopenias in an otherwise healthy child.
It represents a failure of apoptotic mechanis...
Infantile autosomal recessive osteopetrosis is a subtype of osteopetrosis, a bone disease of dysfunctional osteoclasts that results in the overgrowth of bone. It is a more severe form that tends to present earlier. Hence, it is referred to as "infantile" and "malignant" compared to its autosomal...
Autosomal recessive polycystic kidney disease (ARPKD) is one of many pediatric cystic renal diseases.
On imaging, it usually presents on ultrasound with enlarged echogenic kidneys with multiple small cysts. Liver involvement with coarse echotexture, biliary tract cystic changes, and portal hype...
Exudative tracheitis, also known as bacterial tracheitis, membranous croup or membranous laryngotracheobronchitis, is a rare, but potentially life-threatening cause of upper airway obstruction.
Typical age ranges from 6 to 10 years of age.
Clinically it pre...
The Bado classification is one of the more widely used classifications for Monteggia fracture-dislocations and mainly focuses on the radial component. Four types are recognized and are generally based on the principle that the direction in which the apex of the ulnar fracture points is the same ...
The banana sign is one of the many notable fruit inspired signs.
This sign is seen on axial imaging through the posterior fossa of fetuses with associated conditions such as Chiari II malformation and/or spina bifida.
In Chiari II malformation, the banana sign describes the way the cerebellum...
Band heterotopia, also known as double cortex syndrome, is a form of diffuse grey matter heterotopia affecting almost only women. Refractory epilepsy is present in nearly all affected patients, with partial complex and atypical absence epilepsy being the most common syndromes.
On imaging, this ...
Barium sulfate (BaSO4), often just called barium in radiology parlance, is an ionic salt of barium (Ba), a metallic chemical element with atomic number 56. Barium sulfate forms the basis for a range of contrast media used in fluoroscopic examinations of the gastrointestinal tract. Unlike barium ...
Barlow disease could refer to:
infantile scurvy - named after Sir Thomas Barlow (1845-1945) who demonstrated infantile scurvy to be the same disease as adult scurvy
Barlow disease - mitral valve: form of mitral valve prolapse - named after John Brereton Barlow (1924-2008) 2
Barth syndrome (BTHS), also known as 3-methylglutaconic aciduria type II, is an extremely rare X-linked multisystem disorder that is usually diagnosed in infancy.
Barth syndrome has an estimated prevalence of 1 in 300,000-400,000 live births.
It is characte...
Bartter syndrome is a rare inherited renal disorder.
Bartter syndrome is characterized by hyperplasia of the juxtaglomerular cells along with:
elevated plasma renin
Baumann angle, also known as the humeral-capitellar angle, is used for the evaluation of the displacement of pediatric supracondylar humeral fractures. It is measured on a frontal radiograph, with elbow in extension.
This angle is formed by the humeral axis and a straight line through the epi...
Becker muscular dystrophy (BMD) is a dystrophinopathy that is considered to be a milder form of Duchenne muscular dystrophy.
It may be present in 3 to 6 per 100,000 male births. The condition is extremely rare in females due to its inheritance pattern, as discussed below.
Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth disorder characterized by a unique set of features that can consist of:
macroglossia: most common clinical finding 4
otic dysplasia ref
localized gigantism / macrosomia
Benign enlargement of the subarachnoid spaces in infancy (BESS or BESSI) also known as benign external hydrocephalus (BEH) is, as per the name, a benign enlargement of the subarachnoid spaces in infants. It usually involves the frontal lobe subarachnoid spaces, and it is characterized clinically...
Bent bone dysplasias are a class of dysplasia included in a 2010 classification of genetic skeletal disorders 1.
kyphomelic dysplasias, a diverse class, including
congenital bowing of the long bones
cartilage-hair hypoplasia (CHH; metaphyseal d...
Bernese periacetabular osteotomy, also known as Ganz osteotomy, is an orthopedic procedure involving osteotomy surrounding the acetabulum and subsequent angulation to improve coverage of the femoral head by the acetabulum. It is performed in the context of hip dysplasia. There is an osteotomy th...