In pediatric imaging, the anteroposterior supine chest x-ray is beneficial for imaging unconscious or uncooperative patients. This view is preferred in infant and neonate imaging, whilst AP erect and PA erect views are ideal for children able to cooperate in sitting or standing 1.
As radiation ...
The clavicle is a unique bone and as such it often displays unique pathology. The following is an attempt to summarize pediatric clavicle abnormalities.
Pediatric bone tumors and tumor-like lesions of the clavicle
majority of clavicular tumors are malignant
Ewing sarcoma (most common)
The pediatric curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core pediatric knowledge.
Topics pertaining to pediatric radiology, including pediatric neuroradiology and fetal radiology, although there will be some cross coverag...
The pediatric cystic renal diseases comprises a group of conditions that are all either autosomal recessive or non-hereditary:
autosomal recessive polycystic kidney disease (ARPKD):
hyperechoic and enlarged kidney
multicystic dysplastic kidney (MCDK):
absence of functional parenchyma, ureter...
Pediatric elbow radiographs are commonly encountered in the emergency department and, when approached in a systematic fashion, are not as difficult to interpret as most people think!
Check that the ossification centers are present and in the correct position. Th...
The pediatric kidneys follow a growth curve. The measurements below are of the longest maximal dimension. Measurements in parentheses are one standard deviation.
0 months 1: female: 4.15 cm (0.35); male: 4.22 cm (0.32)
2 months: 5.28 cm (0.66)
6 months: 6.15 cm (0.67)
10 months: 6.23 cm (0....
The PRETEXT system proposed by the International Childhood Liver Tumors Strategy Group (previously called Société Internationale d’Oncologie Pédiatrique - Epithelial Liver Tumor Study Group - SIOPEL) aims for staging and risk stratification of liver tumors at diagnosis.
It is used to describe ...
Pediatric mediastinal masses are the most common chest masses in children, with the anterior mediastinum being the most common site 1.
As in adults, mediastinal masses are classified depending on anatomical sites:
anterior mediastinal masses
middle mediastinal masses
posterior mediastinal ma...
This classification system based on the embryology and anatomy of the nasal cavity, nasofrontal region, and nasolacrimal apparatus as well as anomalies associated with craniofacial syndromes.2
choanal atresia and stenosis
pyriform aperture stenosis
Pediatric nasal cavity masses can occur within the nose or the nasopharynx. These masses are often found incidentally on imaging but can be readily apparent clinically.
The clinical features of these lesions tend to mimic upper respiratory processes and may result in dela...
Tumors of the posterior fossa in children can be remembered using the mnemonic:
The mnemonic is not in order of prevalence; pilocytic astrocytomas are most common.
B: brainstem glioma
A: astrocytoma (pilocytic) (85%)
This is a basic article for medical students and other non-radiologists
Pediatric radiology curriculum for medical students covers the fundamental imaging modalities, conditions and presentations on children that require imaging.
As expected and of more importance compared to adults, when cons...
Pediatric renal tumors and masses are another group of diseases (just like cystic renal diseases in both the adult and child) that are bewildering in their number, nomenclature and overlapping findings.
Wilms tumor: common in older children 1-8 years old
There is a wide range of primary malignancies that results in pediatric skeletal metastases 1:
leukemia: although not truly metastases
clear cell sarcoma: Wilms’ variant
Ewing’s sarcoma: lung metastases much more common
Pediatric urinary tract infections are common and are a source of significant imaging in young children.
Pediatric urinary tract infections affect up to 2.8% of all children every year, with approximately 2% of boys and 8% or more of girls developing a urinary tract infection at s...
The British National Institute for Health and Care Excellence (NICE) published the “Urinary tract infection in under 16s: diagnosis and management” in 2007 as a guideline for pediatric urinary tract infection (UTI) management, including imaging, prophylaxis and follow-up 1.
This article intend...
Pallister-Hall syndrome is characterized by:
renal anomalies, e.g horseshoe kidney
The pancake adrenal gland or "lying down" adrenal sign refers to the flattened disk-like appearance of the adrenal gland in the renal fossa when the ipsilateral kidney is absent. When a pancake adrenal gland is present careful examination should be performed to exclude renal agenesis or renal ec...
Pancreatoblastomas are rare pediatric tumors of the pancreas. However, they are the most common pancreatic neoplasm of childhood and are often associated with a raised alpha-fetoprotein.
There is slight male predilection. Usually occurs in the first decade of life with a mean age ...
Panner disease is an osteochondrosis of the capitellum. It should be distinguished from osteochondritis dissecans of the elbow which also affects the capitellum.
Panner disease is typically seen in children (5-10 years of age), although it is also seen in throwers due to repeated...
A parachute mitral valve is a valvular congenital abnormality usually identified in infants or young children though is can present later in adulthood.
Parachute mitral valves occur when all the chordae tendineae are attached to a single papillary muscle origin. Unlike the normal sit...
Parapagus twins are conjoined twins that lie side-by-side with ventrolateral fusion.
This type of conjoined twins usually shares the umbilicus, abdomen, and pelvis. The conjoined pelvis may have a single symphysis pubis and one or two sacra.
The lower gastrointestinal tract (single colon and...
Parotid infantile hemangiomas are the most common parotid tumor of childhood. They usually run a characteristically benign course.
The median age at diagnosis is 4 months 1. There is female preponderance with a male:female ratio of 1:3.
Presents as en enlar...
Patau syndrome (also known as trisomy 13) is considered the 3rd commonest autosomal trisomy.
Patau syndrome along with Down syndrome (trisomy 21) and Edward syndrome (trisomy 18) are the only three trisomies to be compatible with extrauterine life. However, few infants live more than a few days...
Patellar sleeve fractures represent chondral or osteochondral avulsion injury at the inferior pole of the patella.
Patellar sleeve fractures occur in the pediatric population, typically between 8 and 12 years of age.
Unlike Sinding-Larsen-Johannson disease,...
Patent ductus arteriosus or arteriosum (PDA) is a congenital cardiac anomaly where there is persistent patency of the ductus arteriosus, a normal connection of the fetal circulation between the aorta and the pulmonary arterial system that develops from the 6th aortic arch.
A patent urachus is one of the spectrum of congenital urachal anomalies. It has occasionally been termed "urachal fistula".
A patent urachus is often diagnosed in neonates when urine is noted leaking from the umbilicus. The umbilicus may also have an abnormal appearance o...
Neonatal hypoxic ischemic brain injuries can manifest in different patterns of involvement depending on the severity and timing of the insult. When considering the perinatal maturation process of the brain and the severity of an insult, it is possible to understand the various manifestations.
The PECARN (Pediatric Emergency Care Applied Research Network) traumatic brain injury algorithm is a clinical decision rule that aims to identify children at very low risk of clinically important traumatic brain injury (ci-TBI) 1. This validated pediatric algorithm predicts likelihood of the abo...
Pectus carinatum, otherwise known as a pigeon chest, refers to a chest wall deformity in which the sternum protrudes anteriorly. It is less common than pectus excavatum.
scoliosis (common) 2
cyanotic congenital heart disease (uncommon)
Pectus excavatum, also known as funnel chest, is a congenital chest wall deformity characterized by concave depression of the sternum, resulting in cosmetic and radiographic alterations.
It is the most common chest wall deformity, accounting for approximately 90% of cases, occurs ...
The posteroanterior erect chest view is often performed in older pediatric patients; when the patient is able to cooperate with sitting or standing erect. This chest view examines the lungs, bony thoracic cavity, mediastinum and great vessels.
The PA erect view is often chosen over the AP erect...
Pelvic osteotomy relates to an orthopedic treatment for developmental acetabular dysplasia of the hip.
The main purpose of pelvic osteotomy is the prevention of early degenerative changes by stabilisation of the hip and redistribution of joint loading. It is obtained by surgical reshaping/remod...
PELVIS or LUMBAR syndrome is the combination of pelvic hemangiomas with other extracutaneous abnormalities. The syndrome may be incomplete.
external genital malformations
Pelviureteric junction (PUJ) obstruction/stenosis, also known as ureteropelvic junction (UPJ) obstruction/stenosis, can be one of the causes of an obstructive uropathy. It can be congenital or acquired with a congenital PUJ obstruction being one of the commonest causes of antenatal hydronephrosi...
The pentalogy of Cantrell is an extremely rare phenomenon with an incidence estimated at around 6 per million live births 3.
It encompasses the following 5 main features 1.
ectopia cordis (abnormal location of heart)
pericardial defect or sternal cleft
The pentalogy of Fallot is a variant of the more common tetralogy of Fallot, comprising the classic four features with the addition of an atrial septal defect or patent ductus arteriosus:
ventricular septal defect (VSD)
right ventricular outlfow tract narrowing or complete obstruction
Pepper syndrome is of interest only (the term is not readily used in day-to-day practice), and refers to primary adrenal neuroblastoma with extensive liver metastases 1. In essence, it refers to stage 4S neuroblastoma (see staging of neuroblastoma).
Pericallosal lipomas are fat-containing lesions occurring in the interhemispheric fissure closely related to the corpus callosum, which is often abnormal. It is the most common location for an intracranial lipoma.
On imaging, they can be identified in two different morphologies: tubulonodular, ...
Pericardial teratomas are type of primary pericardial tumor. They are usually diagnosed in infants and neonates. As with all teratomas, they are comprised of contain endodermal, mesodermal and neuroectodermal germinal layers. While they are usually benign tumors, they may be life-threatening du...
Perinatal lethal hypophosphatasia (PLH) is the most severe form of hypophosphatasia. If untreated, it is lethal in all cases.
The estimated incidence is at ~1:100,000 live births.
As with all hypophosphatasia cases, this is due to a mutation in chromosome 1q3...
Periosteal reaction in the pediatric population, also known as periostitis in children, is relatively common occurrence and can result from many causes.
The differential diagnosis for multiple bone periostitis include but not limited to the following:
Peripheral primitive neuroectodermal tumors (pPNET) tend to be large and aggressive retroperitoneal tumors.
The imaging characteristics of peripheral PNETs are nonspecific. However, they should be considered in the differential diagnosis of a large, aggressive retroperit...
Periventricular leukomalacia (PVL) or white matter injury of prematurity affecting the periventricular zones, and typically results in cavitation and periventricular cyst formation.
It is important to note that both periventricular and subcortical leukomalacia correspond to a continuous diseas...
One of the methods used for grading of periventricular leukomalacia based on sonographic appearances is as:
grade 1: areas of increased periventricular echogenicity without any cyst formation persisting for more than 7 days
grade 2: the echogenicity has resolved into small periventricular cyst...
Perkin line is a line drawn perpendicular to Hilgenreiner line, intersecting the lateral most aspect of the acetabular roof.
The upper femoral epiphysis should be seen in the inferomedial quadrant: it should lie below Hilgenreiner line, and medial to Perkin line. If the nucleus of the femoral ...
Persistent hyperplastic primary vitreous (PHPV), also known as the persistent fetal vasculature, refers to a rare congenital developmental malformation of the eye.
Clinically, this condition usually manifests as unilateral or bilateral leucocoria. Patients may also have p...
The most common cause of pulmonary hypertension in newborns is persistent pulmonary hypertension of the newborn (PPHN). It occurs in term or late preterms infants, where the fetal shunts persist after birth and fail to close. It falls under group 1.5 of the Dana Point classification system of pu...
A persistent right umbilical vein (PRUV) is an uncommon vascular anomaly which is often detected in utero.
The estimated prevalence is ~2 per 1000 births 1,2.
In the normal situation, the right umbilical vein begins to obliterate in the ~4th week of gestation and disap...
Perthes disease, also known as Legg-Calvé-Perthes disease, refers to idiopathic osteonecrosis of the femoral epiphysis seen in children. It should not be confused with Perthes lesion of the shoulder.
It is a diagnosis of exclusion and other causes of osteonecrosis (including sickle cell disease...
This is a basic article for medical students and other non-radiologists
Perthes disease is the name given to idiopathic AVN (avascular necrosis) of the femoral epiphysis in children. It most often occurs in children around the age of 5-6 years and is one of the common considerations when childr...
Pertussis, also known as whooping cough is a highly contagious, acute respiratory illness that is caused by the gram-negative bacterium Bordetella pertussis.
The incidence of pertussis in children has dramatically decreased since the introduction of pertussis vaccination. However,...
PHACE syndrome, also known as cutaneous hemangioma–vascular complex syndrome or Pascual-Castroviejo type II syndrome, is a phakomatosis that comprises of:
P: posterior fossa malformations (e.g. Dandy-Walker malformation)
A: arterial anomalies
C: coarctation of the aorta and ca...
Phenylketonuria (PKU) is an inborn error of metabolism resulting from abnormal metabolism of phenylalanine. If untreated, patients can develop central nervous system impairment.
PKU is inherited as an autosomal recessive disorder with an incidence of 1 in 10,000. It is more commo...
Phocomelia is an extremely rare congenital skeletal disorder that characteristically affects the limbs. It can affect either the upper limbs or lower limbs or both. Phocomelia is also a descriptive term to describe the characteristic limb anomalies occurring with its associated conditions.
Physeal bars are interruptions of the normal growth plate cartilage, due to the formation of a bony or fibrous bridge between the epiphysis and metaphysis. Left untreated, physeal bars can cause abnormal bone angulation or limb length discrepancies.
Physeal bars are not ...
Physeal fractures (also called Salter-Harris fractures) are important childhood fractures that involve the physeal plate. They are relatively common and important to differentiate from other injuries because the involvement of the physis (growth plate) may cause premature closure resulting in li...
Physiologic periostitis describes the normal presence of smooth bilateral diaphyseal periosteal new bone in the humeri, femora or tibiae of infants aged 1 to 6 months. It can be observed in both preterm and term infants. The etiology is unclear but may simply relate to rapid growth.
Pilocytic astrocytomas, also known as juvenile pilocytic astrocytomas, are low-grade, relatively well-defined astrocytomas that tend to occur in young patients. They are considered WHO grade I tumors in the current (2016) WHO classification of CNS tumors and correspondingly have a relatively goo...
Ping pong skull fracture or pond skull fracture refers to a depressed skull fracture of the infant skull caused by inner buckling of the calvarium. It is seen in newborns because of the soft and resilient nature of their bones (like greenstick fractures of long bones) and the fracture line is no...
Pink tetralogy of Fallot refers to a tetralogy of Fallot in which the degree of right ventricular outflow obstruction is minimal, resulting no significant right to left shunt, and therefore no cyanosis. Symptoms are mild and presentation may be delayed, even into adulthood.
Plagiocephaly refers to a type of craniosynostosis in which there is asymmetric premature closure of the coronal and/or lambdoid sutures. It can either involve single or asymmetric multiple sutures. Premature coronal suture closure is associated with the Harlequin eye deformity.
History and ety...
Platyspondyly is a radiographic feature and refers to flattened vertebral bodies throughout the axial skeleton.
Platyspondyly can be feature of many conditions which include:
severe Gaucher disease 1
Pleurisy (or pleuritis) refers to the disease entity characterized by inflammation of the pleura. It classically presents as pleuritic pain.
Pleurisy is often used by medical professionals and laypeople both to refer to the inflammation of the pleura and also the symptoms. Strictl...
Pleuropulmonary blastomas (PPB) are a rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the parietal pleura.
PPB is encountered in childhood, mostly in the first years of life (90% in th...
Pneumatosis coli is a descriptive sign presenting radiographically as intramural gas limited to the colonic wall.
There are different terminologies in the medical literature, such as pneumatosis intestinalis, pneumatosis coli, and pneumatosis cystoides intestinalis. Pneumatosis in...
Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as:
pre-axial polydactyly: extra digit(s) towards the thumb/hallux (radially)
post-axial polydactyly: extra digit(...
Polymicrogyria is one of many malformations of cortical development (see classification system for cortical malformations), and along with grey matter heterotopias, falls under a bewildering group of conditions characterized by abnormalities both in migration of neurons to the cortex and abnorma...
Porencephaly is a rare congenital disorder that results in cystic degeneration and encephalomalacia and the formation of porencephalic cysts. The term is used variably among radiologists with its broadest definition being a cleft or cystic cavity within the brain 9, and its more narrow definitio...
Portal hypertension is defined as portal venous pressure greater than 12 mmHg.
Causes can be split in their relation to the hepatic sinusoids:
portal vein thrombosis
extrinsic compression of portal vein
Schistosomiasis (S. mansoni or S. japonicum)
Positional plagiocephaly, also known as deformational plagiocephaly, refers to a calvarial deformation that results from external pressure after birth when an infant is consistently placed in the same position for rest and sleep. It can be marked in very premature infants, whose heads become fla...
Post-axial polydactyly refers to polydactyly where the additional digit is on the ulnar margin of the hand, or lateral to the 5th toe.
Post-axial polydactyly is more common than pre-axial polydactyly, with an estimated incidence of 1 in 3000.
The posterior fontanelle or occipital fontanelle (or fontanel) is the triangular soft membranous gap at the junction of the lambdoid and sagittal sutures. It persists until approximately 3 months after birth, after which it is known as the lambda. It can be used as an additional sonographic wind...
Posterior fossa astrocytomas, those arising either from the cerebellum or from the brainstem are most frequently seen in children. Approximately 60% of all pediatric astrocytomas are found in the posterior fossa (20% brainstem, 40% cerebellum).
Many types of astrocytoma are found in the posteri...
Posterior urethral valves (PUVs), also referred as congenital obstructing posterior urethral membranes (COPUM), are the most common congenital obstructive lesion of the urethra and a common cause of obstructive uropathy in infancy.
Posterior urethral valves are congenital and only...
The Potter sequence is a constellation of findings demonstrated postnatally as a consequence of severe, prolonged oligohydramnios in utero.
It consists of:
pulmonary hypoplasia: often severe and incompatible with life
growth restriction (IUGR)
abnormal facies (Potter f...
A helpful mnemonic to remember the common clinical features of Potter syndrome:
P: pulmonary hypoplasia
T: twisted skin (wrinkly skin)
T: twisted face (Potter facies: low set ears, retrognathia, hypertelorism)
E: extremity deformities (limb deformities: club hands...
Pott puffy tumor refers to a non-neoplastic complication of acute sinusitis. It is characterized by a primarily subgaleal collection, subperiosteal abscess, and osteomyelitis. It is usually related to the frontal sinus but is sometimes secondary to mastoid pathology.
Rarer etiologies include tr...
A Pott 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 descending thoracic aorta and the left pulmonary artery.
This does not relieve the right ventricular outflow obstructi...
Prader-Willi syndrome (PWS) is a rare genetic disorder. It is the most common cause of obesity caused by a genetic syndrome and is primarily characterized by:
sexual infancy: hypogonadism
there usually morbid obesity resulting from hyperphagia is amplified by decre...
Preauricular sinuses are common congenital abnormalities that are typically small blind-ended openings near the ascending limb of the helix. These can be a simple pit or have a sinus tract and/or cystic component.
They are most common in East Asian populations with an incidence of...
Pre-axial polydactyly refers to polydactyly where the additional digit is towards the first digit of the hand (radial side) or foot (medially).
Pre-axial polydactyly is less common than post-axial polydactyly, with an estimated incidence of 1 in 7000.
Premature closure of a growth plate subsequently results in a shortened bone, which can occur in a number of situations.
juvenile chronic arthritis
juvenile rheumatoid arthritis
Prenatal onset infantile cortical hyperostosis is a rare variant of infantile cortical hyperostosis, however, it is a more severe and lethal form and newborns die early postnatally.
Both sporadic and autosomal recessive inheritance have been suggested. A missense mutation in the gene...
Primary ciliary dyskinesia, also known as immotile cilia syndrome, is the result of a congenital defect in the ultrastructure of cilia that renders them incapable of normal movement. It is associated with a number of anatomic and functional abnormalities.
Primary ciliary dyskinesi...
Pediatric primary lung tumors are rare in children however they must be distinguished from locally aggressive inflammatory conditions and benign disease. 1
Primary lung tumors in the neonates and infants include:
pleuropulmonary blastoma (PPB)
infantile fibrosarcoma of the lung
fetal lung in...
Primitive neuroectodermal tumors (or CNS PNET) were considered aggressive neoplasms of the brain, most frequently encountered in the pediatric population. Importantly, the term no longer appears in the current WHO classification of CNS tumors 11-12.
Please refer to embryonal tumors with multil...
Propionic acidemia is a rare organic acidemia caused by a deficiency in the enzyme propionyl coenzyme A carboxylase.
Propionic acidemia has an incidence of around 1 in 150,000 in the general population 1.
Around 80% of children with propionic acidemia wi...
Proteus syndrome is a rare congenital, multisystemic, hamartomatous condition characterized by asymmetrical overgrowth of almost any part of the body and a broad spectrum of manifestations. It can affect tissue from any germinal layer. It is suspected to be a genetic condition, but a particular ...
Proximal femoral focal deficiency is a congenital partial absence of the proximal end of the femur with shortening of the entire lower limb. The diagnosis and classification have been based mainly on plain radiograph findings. This method does not permit definite classification during the first ...
A proximal radio-ulnar synostosis is an upper limb skeletal malformation characterized by bony fusion at the proximal aspect of the radius and ulna. Of the radio-ulnar synostoses, the proximal third is considered the most common site.
It is often congenital but can rarely result fol...
Prune belly syndrome, also known as Eagle Barrett syndrome 3 or triad syndrome, is a rare anomaly comprising a specific constellation of features. It consists of three major findings:
gross ureteric dilatation
anterior abdominal wall underdevelopment (resulting in the "prune belly" appearance)...
A pseudocyst is an abnormal fluid-filled cavity which is not lined by epithelium. It is this fact that distinguishes it pathologically from a cyst, which is lined by epithelium.
Examples of pseudocysts are:
pseudocysts of the germinal matrix