Neuroblastomas are tumours of neuroblastic origin. Although they may occur anywhere along the sympathetic chain, the vast majority arise from the adrenal gland.
They represent the most common extracranial solid childhood malignancy and are the third commonest childhood tumour after leukaemia an...
There are two methods of neuroblastoma staging, one that is based on post-operative patients (INSS) and one developed for pre-treatment patients (INRGSS).
International Neuroblastoma Staging System (INSS)
This staging system is for post-operative patients and mainly for prognosis 1:
Both neuroblastoma and Wilms tumour occur in early childhood and typically present as large abdominal masses closely related to the kidneys. Distinguishing between the two is important, and a number of features are helpful.
calcification very common: 90%
encases vascular structu...
Neurocristopathy syndromes encompasses a group of conditions united by abnormal migration, differentiation, division or survival of neural crest cells 1.
neurofibromatosis type I (NF1)
Neurofibromas are benign peripheral nerve sheath tumours usually solitary and sporadic, however, there is a strong association with neurofibromatosis type 1 (NF1). These tumours present as a well-defined hypodense mass with minimal or no contrast enhancement on CT. On MRI, they usually are T1 hy...
Niemann-Pick disease (NPD) is actually a collection of a number of distinct autosomal recessive lysosomal storage diseases. They are divided into two groups of two based on the underlying metabolic deficiency:
deficiency of acid sphingomyelinase 1,3,4
Niemann-Pick disease type A (NPD-A)
Niemann-Pick disease type B (NPD-B), along with Niemann-Pick disease type A (NPD-A), is an autosomal recessive disorder due to acid sphingomyelinase deficiency resulting in abnormal storage of sphingomyelin.
Common manifestation of NPD-B include hepatosplenomegaly, thrombocytopaenia and variabl...
Niemann-Pick disease type c (NPD-C or just NPC) is an autosomal recessive lysosomal storage disorder classed under Niemann-Pick disease on account of clinical similarities, namely hepatosplenomegaly and variable involvement of the central nervous system.
NPD-C is inherited as a a...
Non-accidental injuries (NAI) represent both ethical and legal challenges to treating physicians.
Radiologists are often the first to suspect NAI when confronted with particular injury patterns, and a knowledge of these is essential if the opportunity to save a child from future neglect is not ...
Non-decussating retinal-fugal fibre syndrome (NRFFS), also referred to as achiasma, is the isolated congenital absence of optic chiasm with unremarkable rest of the optic pathway and midline structures. Clinically, it typically presents as seesaw nystagmus since childhood. Diagnosis is usually m...
Non-ossifying fibromas (NOF) are the most common of non-neoplastic fibrous bone lesions and are a larger version (>3 cm) of a fibrous cortical defect; both are encompassed by the term fibroxanthoma or metaphyseal fibrous defect.
NOFs are very common in children and adolescents, an...
Noonan syndrome (NS) is a genetically and phenotypically heterogenous non aneuploidic congenital RASopathy. Affected individuals can bear some clinical features similar to that of Turner syndrome.
The estimated incidence is at ~1 in 1000-2500 11. As individuals have normal number...
Noonan syndrome with multiple lentigines, previously known as LEOPARD syndrome (LS), is a rare autosomal dominant RASopathy that has many similarities to Noonan syndrome.
Despite a change in formal name, the 'LEOPARD' acronym is still useful to summarise the clinical feat...
The normal size of kidneys in children will naturally depend on the age and size of the child. Based on the children's ages normal average renal length on ultrasound are as follows:
0 to 2 months: 5 cm (approximately 2 inches)
2 months to 6 months: 5.7 cm
6 months to 1 year: 6.2 cm (2.5 inche...
After normal myelination in utero, myelination of the neonatal brain is far from complete. The first myelination is seen as early as the 16th week of gestation, in the column of Burdach, but only really takes off from the 24th week 1. It does not reach maturity until 2 years or so. It correlates...
This article lists examples of normal imaging of the paediatric patients divided by region, modality, and age.
premature (27 weeks): example 1
neonate: example 1
6-year-old: example 1
12-year-old: example 1
CT chest: examples needed
Norrie disease is a rare X-linked inherited cause of congenital bilateral blindness. It can present with a retinal mass (pseudoglioma) and cataracts. It is associated with developmental delay and hearing loss.
The nuchal fold is a normal fold of skin seen at the back of the fetal neck during the second trimester of pregnancy. Increased thickness of the nuchal fold is a soft marker associated with multiple fetal anomalies, and is measured on a routine second trimester ultrasound.
Occipital horn syndrome is a rare X-linked disorder of copper metabolism resulting in connective tissue abnormalities. The Menkes disease / kinky hair syndrome is the severe form of this disease, with patients rarely surviving past 3 years of age. Occipital horn syndrome (also known as X-linked...
Octreotide scintigraphy uses 111In-labelled octreotide which is a somatostatin analog; it is also known as an OctreoscanTM, a brand name for 111In-labelled pentetreotide; pentetreotide is a DTPA-conjugated form of octreotide, originally manufactured by Mallinckrodt Nuclear Medicine LLC, which no...
Odontohypophosphatasia is the mildest form of hypophosphatasia that manifests as tooth dysplasia and/or early loss of deciduous or permanent teeth.
As with all forms of hypophosphatasia, the underlying abnormality is a mutation in the ALPL gene that encodes for tissue non-specific al...
An oesophageal atresia refers to an absence in the contiguity of the oesophagus due to an inappropriate division of the primitive foregut into the trachea and oesophagus. This is the most common congenital anomaly of the oesophagus.
It is thought to occur in ~1:3000-4500 live bir...
Oesophageal atresia is closely related to tracheo-oesophageal fistula and can be divided into1:
type A: isolated oesophageal atresia (8%)
type B: proximal fistula with distal atresia (1%)
type C: proximal atresia with distal fistula (85%)
type D: double fistula with intervening atresia (1%)
Oesophageal duplication cysts are a type of congenital foregut duplication cyst.
Less common compared to other foregut duplication cysts. There may be an increased male predilection 5.
Patients are generally asymptomatic but may complain of dysphagia due to...
The omega sign can refer to a number of different anatomical structures or signs:
omega sign (epiglottitis)
omega sign (hand bump on the precentral gyrus)
The omega sign refers to the thickened aryepiglottic folds and epiglottis seen in epiglottitis, when the larynx is seen endoscopically or via laryngoscope, and not to the appearance on lateral plain films. CT would show the finding, but placing a child with epiglottitis supine to CT their neck i...
Omphalocoeles, or exomphalos, are congenital midline abdominal wall defects at the base of the umbilical cord insertion with herniation of gut (or occasionally other content) out of the fetal abdomen.
The estimated occurrence can be up to 1:4000 of live births 3.
Opsomyoclonus (dancing eyes-dancing feet syndrome) is a clinical syndrome which has a strong association with neuroblastoma.
The “opso-“ refers to the presence of intermittent jerky eye movements (dancing eyes) and the “myoclonus” to myoclonic jerks and cerebellar ataxia ...
Optic pathway gliomas are relatively uncommon tumours, with a variable clinical course and usually seen in the setting of neurofibromatosis type I (NF1). Histologically the majority are pilocytic astrocytomas.
They are characterised by imaging by an enlarged optic nerve seen either on CT or MR...
Orthoroentgenogram is a radiographic study used to evaluate anatomic leg length and calculate leg-length discrepancies. This study utilises a long ruler placed on the film, and three radiographs including bilateral hips, knees and ankles.
Similar studies used to evaluate true leg length include...
Osgood-Schlatter disease (OSD) is a chronic fatigue injury due to repeated microtrauma at the patellar ligament insertion onto the tibial tuberosity, usually affecting boys between ages 10-15 years.
Osgood-Schlatter disease is seen in active adolescents, especially those who jump ...
There are six ossification centres of the elbow that appear and develop in a relatively reproducible fashion, and are key to assessment of the paediatric elbow radiograph. Timing of their appearance varies in the literature but an approximation is given below. A useful mnemonic to remember the o...
Primary ossification centres present at birth
Visible on x-ray from birth:
calcaneus: 6 months in utero
talus: 7 months in utero
cuboid: 9 months in utero
metatarsals: 9 weeks in utero
phalanges: 3-10 months (proximal to distal)
Primary ossification centres developing after birth
Ossifying renal tumour of infancy (ORTI) is a rare renal tumour.
extremely rare, <<1% of paediatric renal neoplasms (17 cases reported)
6 days - 3 months
Histology reveals spindle cells and osteoblastic cells in a calcified osteoid matrix. It is thou...
Osteochondritis dissecans (OCD) is the end result of the aseptic separation of an osteochondral fragment with the gradual fragmentation of the articular surface. It is often associated with intraarticular loose bodies.
Onset is between childhood and middle age, with the majority o...
Osteofibrous dysplasia is a benign fibro-osseous cortical lesion that almost exclusively occurs in the tibia and fibula. It is most commonly seen in the mid-diaphysis of the tibia. Some consider it synonymous with ossifying fibroma because of histological similarities, but it is generally consid...
Osteogenesis imperfecta (OI) refers to a heterogeneous group of congenital, non-sex-linked, genetic disorders of collagen type I production, involving connective tissues and bones.
The hallmark feature of osteogenesis imperfecta is osteoporosis and fragile bones that fracture easily, as well a...
The several forms of osteogenesis imperfecta (OI) have been classified, representing wide variation in appearance and severity, and clinical features vary widely not only between types but within types.
OI was initially classified by type according to a scheme developed by Dr Da...
Osteoid osteomas are benign bone-forming tumours that typically occur in children (particularly adolescents). They have characteristic lucent nidus <2 cm and surrounding solid periosteal reaction and classically cause night pain that is relieved by the use of salicylate analgesia, e.g. aspirin.
Osteopathia striata with cranial sclerosis (OS-CS) is a clinically separate entity from osteopathia striata (Voorhoeve disease). Bony changes on their own are typically incidental and autosomal dominant, whereas OS-CS is a multisystem, X-linked dominant disorder.
OS-CS is extremel...
Osteopetrosis, also known as Albers-Schönberg disease or marble bone disease, is an uncommon hereditary disorder that results from defective osteoclasts. Bones become sclerotic and thick, but their abnormal structure actually causes them to be weak and brittle.
There are two separate subtypes o...
Oxycephaly (also known as turricephaly) is the most severe of the craniosynostoses and results from the premature closure of all sutures.
Characterised by a tower-like skull which may be associated with:
8th cranial nerve lesion
optic nerve compression
A number of paediatric cardiovascular procedures are encountered when reporting paediatric imaging. They include:
Blalock-Taussig (BT) shunt
classic: end to side subclavian to ipsilateral pulmonary arterial anastomosis
modified: graft anastomosis
Sano shunt: right ventricle ...
The differential diagnosis of paediatric cervical lesions is commonly encountered in practice, unfortunately, the list is long.
Most lesions tend to be inflammatory 3:
infected branchial cle...
The clavicle is a unique bone and as such it often displays unique pathology. The following is an attempt to summarise paediatric clavicle abnormalities.
Paediatric bone tumours and tumour-like lesions of the clavicle
majority of clavicular tumours are malignant
Ewing sarcoma (most common)
The paediatric curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core paediatric knowledge.
Topics pertaining to paediatric radiology, including paediatric neuroradiology and fetal radiology, although there will be some cross cov...
The paediatric 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, urete...
Paediatric 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 centres are present and in the correct position. T...
The paediatric 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 Tumours Strategy Group (previously called Société Internationale d’Oncologie Pédiatrique - Epithelial Liver Tumour Study Group - SIOPEL) aims for staging and risk stratification of liver tumours at diagnosis.
It is used to descri...
Paediatric 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 m...
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
Paediatric 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 del...
Tumours 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
Paediatric 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 con...
Paediatric renal tumours 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 tumour: common in older children 1-8 years old
There is a wide range of primary malignancies that results in paediatric skeletal metastases 1:
leukaemia: although not truly metastases
clear cell sarcoma: Wilms’ variant
Ewing’s sarcoma: lung metastases much more common
Paediatric urinary tract infections are common and are a source of significant imaging in young children.
Paediatric 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...
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 paediatric urinary tract infection (UTI) management, including imaging, prophylaxis and follow-up 1.
This article inten...
Pallister-Hall syndrome is characterised by:
renal anomalies, e.g horseshoe kidney
Pancreatoblastomas are rare paediatric tumours 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 ag...
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 haemangiomas are the most common parotid tumour 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 enl...
Patau syndrome (also known as trisomy 13) is considered the 3rd commonest autosomal trisomy.
This along with Down syndrome (T21) and Edward syndrome (T18) 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 paediatric 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 ischaemic 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 (Paediatric 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 paediatric algorithm predicts likelihood of the a...
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.
Patients may present with dyspnoea and exercise intolerance.
Pectus excavatum, also known as funnel chest, is a congenital chest wall deformity characterised 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 ...
Pelvic osteotomy relates to an orthopaedic 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/remo...
PELVIS or LUMBAR syndrome is the combination of pelvic haemangiomas 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 classical four features with the addition of an atrial septal defect or patent ductus arteriosus The five features therefore are:
ventricular septal defect (VSD)
right ventricular outlfow tract narro...
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, ...
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 paediatric 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 tumours (pPNET) tend to be large and aggressive retroperitoneal tumours.
The imaging characteristics of peripheral PNETs are nonspecific. However, they should be considered in the differential diagnosis of a large, aggressive retro...
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...
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 haemangioma–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 ...
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...
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 ...