MIBG scan is a scintigraphic study that uses metaiodobenzylguanidine labeled to iodine-123 or iodine-131. It is indicated in the investigation of phaeochromocytoma.
MIBG is positive in:
olfactory neuroblastoma 1
carcinoid tumor 4
Microcephaly is a descriptive term meaning a small head and is associated with numerous disorders of diverse etiology. It is usually associated with microencephaly (small brain). For the purpose of this article the two will be used interchangeably.
As with most terms which describe...
Midaortic syndrome is an uncommon entity affecting children and young adults. It is characterized by progressive narrowing of the abdominal aorta and its major branches.
The onset of symptoms is usually during childhood or young adulthood 2:
hypertension (most common)
Midface anomalies (craniofacial syndromes ) in children include
Treacher Collins syndrome
Midgut volvulus is a complication of malrotated bowel. It may result in proximal bowel obstruction with resultant ischemia if prompt treatment is not instigated.
A midgut volvulus of malrotated bowel can potentially occur at any age but in approximately 75% of cases occur within a...
Miller-Dieker syndrome (MDS) or is a rare chromosomal anomaly and is one of the conditions considered part of lissencephaly type I (classic) 6.
neuronal migrational anomalies: lissencephaly type I
prominent subarachnoid spaces
widened cerebral v...
Mineralising microangiopathy is a condition characterized by parenchymal cerebral calcifications, and is usually seen in children as a complication of cranial radiotherapy and chemotherapy 1,2.
Mineralizing microangiopathy can affect the brain widely, with typical sites i...
M-line of Cremin is an imaginary line that can be used to determine the level at which the blind pouch ends in anal atresia, determining whether the anal atresia is a high or a low type.
The line is drawn perpendicular to the long axis of the ischium on the lateral view and passes through the j...
Möbius syndrome, also known as congenital facial diplegia syndrome, is a rare congenital condition characterized by the absence or underdevelopment of the abducens nerve (CN VI) and facial nerve (CN VII) nuclei.
Möbius syndrome is rare with an estimated incidence of ~1 case per 10...
Molybdenum cofactor deficiency (MCD or MOCD) is a very rare, lethal, genetic condition caused by a loss of function of molybdenum-dependent enzymes, manifesting as severe and rapid neurological deterioration. On imaging it mimics hypoxic-ischemic encephalopathy.
Less than 150 repo...
Monteggia fracture-dislocations consist of a fracture of the ulnar shaft with concomitant dislocation of the radial head. The ulnar fracture is usually obvious, whereas the radial head dislocation can be overlooked, with potentially serious functional and medico-legal ramifications.
Morquio syndrome (in older literature it is sometimes called Morquio-Brailsford syndrome) is an autosomal recessive mucopolysaccharidosis (MPS) type IV.
Incidence estimated at ~1:40,000.
Many cases present at ~2 years of age and have normal intelligence. Cl...
Moyamoya disease is an idiopathic, non-inflammatory, non-atherosclerotic progressive vasculo-occlusive disease involving the circle of Willis, typically the supraclinoid internal carotid arteries.
The term moyamoya disease should be reserved for an idiopathic, sometimes familial, ...
Mucopolysaccharidoses (MPS) constitute a group of hereditary disorders, one of a number of lysosomal storage disorders, having in common an excessive accumulation of mucopolysaccharides secondary to deficiencies in specific enzymes (lysosomal hydrolases) responsible for degradation of mucopolysa...
Multicentric carpal tarsal osteolysis is a rare skeletal disorder which is characterized by progressive osteolysis of the carpal, metacarpal and tarsal bones. It usually presents in early childhood with progressive pain and stiffness of the wrist, feet and elbow, clinically mimicking juvenile rh...
Multicentric ossification refers to normal, or variant of normal, ossification at more than one site within a single epiphysis or apophysis. It is important to be aware of common sites where multicentric ossification may occur, to avoid confusion with fracture, apophysitis and other entities.
Multicystic dysplastic kidney (MCDK) is a type of non-heritable pediatric cystic renal disease. It results in multiple cysts being formed in utero in the affected kidney.
Unilateral incidence is estimated at 1:2500-4000. There may be a predisposition for the left kidney, a slightl...
Multicystic encephalomalacia corresponds to a variant of encephalomalacia commonly seen in neonates in which numerous loculated lacy pseudocysts within the white matter and cortex are present as a result of an extensive brain insult.
It is a common feature observed in the neonatal h...
Multiple synostoses syndrome (SYNS), proximal symphalangism (SYM), tarsal-carpal coalition (TCC) syndrome, stapes ankylosis with broad thumbs and toes (SABTT), and brachydactyly B2 (BDB2) are overlapping autosomal dominant conditions united by typically displaying ankylosis of the proximal inter...
Muscle-eye-brain disease is a congenital muscular dystrophy with associated progressive eye and brain abnormalities.
There is severe intellectual disability, in combination with seizures. Motor development is usually severely delayed. Eye abnormalities include choroidal h...
The mushroom sign (also called umbrella sign) is a radiological sign described in pyloric stenosis on barium examination.
This sign refers to the impression made by the hypertrophic pylorus on the duodenal cap.
cervix sign of pyloric stenosis
target sign of pyloric st...
The Mustard repair is a technique to correct transposition of the great arteries (TGA), and involves:
resection of atrial septum
creation of an atrial baffle with pericardium (or rarely synthetic material) 1
Transposition of the great arteries involves a discordance between the ven...
Myeloid sarcoma (also called granulocytic sarcoma, chloroma, and extramedullary myeloid tumor) is a rare neoplasm comprised of myeloid precursor cells.
It is typically seen is in children with ~60% occurring in individuals less than 15 years of age. There is no recognized gender p...
Myoclonic epilepsy with red ragged fibers (MERRF) is a rare, multisystem mitochondrial disorder.
Patients usually present in late adolescence or early adulthood with 1-3
vision and/or hearing loss
Nail-patella syndrome (also known as Fong disease, osteo-onychodysostosis, Österreicher-Turner syndrome 10, Turner-Kieser syndrome, and Trauner-Rieger syndrome) is a rare autosomal dominant condition which results from symmetrical mesodermal and ectodermal abnormalities.
Nasal encephaloceles are in most cases a form of neural tube defect particularly common in Southeast Asia. They are are herniation of cranial content through a bony defect in the anterior skull base into the nasal area.
The term is variably used but generally encompasses both frontoethmoidal en...
Nasal gliomas, also know as nasal glial heterotopia, are a rare congenital lesion composed of dysplastic glial cells which have lost their intracranial connections and present as an extranasal or intranasal mass.
Nasal gliomas are rare congenital lesions. These masses occur spora...
Necrotizing enterocolitis (NEC) is the most common gastrointestinal condition in premature neonates. It is characterized by inflammation, ischemia, and permeability of the neonatal bowel wall to bacteria. It is potentially life-threatening with significant associated morbidity 1.
Necrotizing enterocolitis (NEC) can be staged into three groups, helping to guide appropriate treatment. In general, stage I and II are managed medically whereas stage III is managed surgically.
lethargy, temperature instability, apnea, bradycardia
emesis, abdominal di...
Necrotizing pneumonia refers to pneumonia characterized by the development of the necrosis within infected lung tissue.
While the term has sometimes been used synonymously with cavitating pneumonia in some publications 2, not all necrotizing pulmonary infections may be complicated ...
AP supine radiograph for neonates is a mobile examination performed on the neonatal unit. It can be taken as a standalone projection or as part of a series including a left lateral decubitus x-ray in cases of suspected perforation.
the patient is supine, lying on their back i...
Neonatal appendicitis is rare, presumably in part due to the short funnel shape to the appendix at that age. Symptoms are non-specific and may mimic necrotizing enterocolitis.
Neonatal bilious vomiting has a relatively narrow differential - those conditions that cause intestinal obstruction, but do so distal to the ampulla of Vater. As such, the list includes:
malrotation with midgut volvulus
The neonatal chest radiograph in the exam setting may strike fear into the heart of many radiology registrars, but it need not!
There are only a limited number of diagnoses that will be presented on such films and they are often highlighted by the history.
First of all, have a look ...
Neonatal encephalopathy is a clinical syndrome referring to signs and symptoms of abnormal neurological function in the first few days of life in a neonate born at or beyond 35 weeks of gestation. It is described as difficulty with initiating and maintaining respiration, depression of tone and r...
Neonatal herpes simplex encephalitis is caused by vertical transmission of infection during passage from birth canal with diffuse cerebral involvement within the first month after birth; in contrast to adult herpes simplex encephalitis, it is commonly related to HSV-2.
Neonatal hydronephrosis is most commonly diagnosed antenatally as fetal pylectasis, and in the majority of cases is due to pelvi-ureteric junction (PUJ) obstruction.
pelvi-ureteric junction (PUJ) obstruction (50% of cases 1,6)
vesicoureteric reflux (~20% of cases 5)
Neonatal hypoxic-ischemic encephalopathy (HIE) is the result of a global hypoxic-ischemic brain injury in a term neonate, usually after asphyxia.
It is important to remember that neonatal encephalopathy may result from a variety of conditions and hypoxic-ischemic brain injury is th...
Neonatal lines and tubes are widely used in the NICU (neonatal intensive care unit) in the management of critically ill neonates. Examples include:
nasogastric (NG) tube
endotracheal (ET) tube
central venous line
umbilical artery catheter
umbilical vein catheter
The NG tu...
Neonatal mastitis is rare and refers to infection of the breast tissue occurring in a neonate.
Patients may present with unilateral breast erythema and pain sometimes with associated nipple discharge and lymphadenopathy. It usually occurs in patients under five weeks of a...
Neonatal neuroblastoma is a type of congenital neuroblastoma, an embryonal tumor arising from the sympathetic nervous system. In the majority of cases (45%), the tumor is localised in the adrenal gland.
Neonatal neuroblastoma accounts for less than 5% of all cases and carries ...
Neonatal pneumonia refers to inflammatory changes of the respiratory system caused by neonatal infection.
It is one of the leading causes of significant morbidity and mortality in developing countries. Neonatal pneumonia accounts for 10% of global child mortality. At the time of w...
The causes of neonatal pneumoperitoneum are different from adult pneumoperitoneum and include:
perforated hollow viscus
necrotizing enterocolitis (NEC): most common
meconium ileus in cystic fibrosis
intestinal atresia or web
peptic ulcer disease
Neonatal pneumothorax describes pneumothoraces occurring in neonates. It is a life-threatening condition, associated with high morbidity and mortality. The diagnosis is a challenge especially when the amount of air is small and may accumulate along the anterior or medial pleural space.
Causes of neonatal distress can be broadly split into intrathoracic, extrathoracic and systemic:
respiratory distress syndrome (RDS)
transient tachypnea of the newborn (TTN)
meconium aspiration syndrome
bronchopulmonary dysplasia (BPD)
patent ductus arteriosus (PDA)
The supine chest view of the neonatal patient is a common radiographic examination when examining preterm patients 1. Although not overall technically demanding, the radiographer should allocate time to ensure little to no repeats are required.
Research surrounding the technical evaluation and ...
Nephroblastomatosis refers to diffuse or multifocal involvement of the kidneys with nephrogenic rests (persistent metanephric blastema).
Nephrogenic rest are found incidentally in 1% of infants.
Nephrogenic rests are foci of metanephric blastema that persist beyond 36 ...
Nephrotic syndrome results from loss of plasma proteins in the urine and characterized by hypoalbuminemia, hyperalbuminuria, hyperlipidemia, and edema. It may be caused by primary (idiopathic) renal disease or by a variety of secondary causes.
Patients present with marked...
Neuhauser sign refers to a soap bubble appearance seen in the distal ileum in cases of meconium ileus, related to the air mixed with meconium. It may be seen with barium enema if contrast passes beyond the ileocecal valve or with small-bowel follow-through.
Although classically described with m...
The neurenteric canal or canal of Kovalevsky is the transient communication of the amnion through notochordal canal to the yolk sac during notochordal formation at day 16-17.
Abnormalities during this stage produce the neurenteric cyst spectrum.
Neuroblastic tumors arise from primitive cells of the sympathetic system and include the following entities:
These entities represent a spectrum of disease from undifferentiated and aggressive (neuroblastoma) to the well differentiated and la...
Neuroblastomas are tumors 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 tumor after leukemia and b...
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 tumor 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 structur...
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 tumors usually solitary and sporadic, however, there is a strong association with neurofibromatosis type 1 (NF1). These tumors present as a well-defined hypodense mass with minimal or no contrast enhancement on CT. On MRI, they usually are T1 hypo...
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 fiber 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 heterogeneous 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 10. As individuals have normal numbe...
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 summarize 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 pediatric 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. Menkes disease is the severe form of this disease, with patients rarely surviving past 3 years of age. Occipital horn syndrome (also known as X-linked cutis laxa or Ehlers Danl...
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...
The OEIS complex refers to the combined occurrence of:
bladder exstrophy / cloacal exstrophy
an imperforate anus
and spinal anomalies: e.g
The estimated occurrence is at around 1-200,000 to 400,000 live births 1,8.
An esophageal atresia refers to an absence in the contiguity of the esophagus due to an inappropriate division of the primitive foregut into the trachea and esophagus. This is the most common congenital anomaly of the esophagus.
It is thought to occur in ~1:3000-4500 live births ...
Esophageal atresia is closely related to tracheo-esophageal fistula and can be divided into1:
type A: isolated esophageal 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%)
Esophageal 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 epiglottis is a variant configuration of the normal epiglottis in which the lateral folds are curled inwards. The configuration is not necessarily pathologic but has been associated with higher rates of laryngomalacia 3.
When seen on lateral neck radiograph, a...
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)
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 (OMS), also known as 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 an...
Optic pathway gliomas are relatively uncommon tumors, with a variable clinical course and usually seen in the setting of neurofibromatosis type I (NF1). Histologically the majority are pilocytic astrocytomas.
They are characterized by imaging by an enlarged optic nerve seen either on CT or MRI...
Orthoroentgenogram is a radiographic study used to evaluate anatomic leg length and calculate leg-length discrepancies. This study utilizes 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 centers of the elbow that appear and develop in a relatively reproducible fashion, and are key to assessment of the pediatric elbow radiograph. Timing of their appearance varies in the literature but an approximation is given below. A useful mnemonic to remember the or...
Primary ossification centers 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 centers developing after birth
Ossifying renal tumor of infancy (ORTI) is a rare renal tumor.
extremely rare, <<1% of pediatric renal neoplasms (17 cases reported)
6 days - 3 months
Histology reveals spindle cells and osteoblastic cells in a calcified osteoid matrix. It is thought...
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.
Osteogenesis imperfecta was initially classified by type according to a sche...
Osteoid osteomas are benign bone-forming tumors that typically occur in children (particularly adolescents). They have a characteristic lucent nidus <2 cm and a surrounding solid periosteal reaction which classically causes night pain that is relieved by the use of salicylate analgesia, e.g. asp...
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...