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1,153 results found

Microgallbladder

Microgallbladder is a common abdominal manifestation of cystic fibrosis. It defines a gallbladder that has a length less than 2-3 cm and a width less than 0.5-1.5 cm on sonographic evaluation 1. Epidemiology The incidence of microgallbladder varies considerably in the literature, however most ...

Midaortic syndrome

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. Clinical presentation The onset of symptoms is usually during childhood or young adulthood 2: hypertension (most common) i...

Midface anomalies in children

Midface anomalies (craniofacial syndromes ) in children include Apert syndrome Crouzon syndrome Pfeiffer syndrome Treacher Collins syndrome Roberts syndrome Coffin-Lowry syndrome Saethre-Chotzen syndrome Noack syndrome Jackson-Weiss syndrome Carpenter syndrome Lowr...

Midgut volvulus

Midgut volvulus is a complication of malrotated bowel. It may result in proximal bowel obstruction with resultant ischemia if prompt treatment is not instigated. Epidemiology A midgut volvulus of malrotated bowel can potentially occur at any age but in approximately 75% of cases occur within a...

Miller-Dieker syndrome

Miller-Dieker syndrome (MDS) or is a rare chromosomal anomaly and is one of the conditions considered part of lissencephaly type I (classic) 6. It is the form of lissencephaly that is most recognizable on prenatal imaging due to its severity 5. Clinical presentation Features include: CNS ne...

Mineralizing microangiopathy

Mineralizing 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. Radiographic features Mineralizing microangiopathy can affect the brain widely, with typical sites i...

M-line of Cremin

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

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. Epidemiology Möbius syndrome is rare with an estimated incidence of ~1 case per 10...

Molybdenum cofactor deficiency

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. Epidemiology Less than 150 repo...

Monteggia fracture-dislocation

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. Mechanism ...

Morquio syndrome

Morquio syndrome (in older literature it is sometimes called Morquio-Brailsford syndrome) is an autosomal recessive mucopolysaccharidosis (MPS) type IV. Epidemiology Incidence estimated at ~1:40,000. Clinical presentation Many cases present at ~2 years of age and have normal intelligence. Cl...

Moyamoya disease

Moyamoya disease is an idiopathic, non-inflammatory, non-atherosclerotic progressive vasculo-occlusive disease involving the terminal supraclinoid internal carotid arteries and circle of Willis. Terminology The term moyamoya disease should be reserved for an idiopathic, sometimes familial, c...

Mucopolysaccharidoses

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

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

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. t...

Multicystic dysplastic kidney

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. Epidemiology Unilateral incidence is estimated at 1:2500-4000. There may be a predisposition for the left kidney, a slightl...

Multicystic encephalomalacia

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. Pathology It is a common feature observed in the neonatal h...

Multiple synostoses syndrome

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

Muscle-eye-brain disease is a congenital muscular dystrophy with associated progressive eye and brain abnormalities. Clinical presentation There is severe intellectual disability, in combination with seizures. Motor development is usually severely delayed. Eye abnormalities include choroidal h...

Mushroom sign (pyloric stenosis)

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. See also shoulder sign double track sign caterpillar sign string sign beak sign

Mustard repair

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 Rationale Transposition of the great arteries involves a discordance between the ven...

Myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome or ME/CFS, is a complex organic disorder, characterized by profound fatigue and associated marked impairment of both physical and mental functioning. Its underlying etiology is undetermined and a curative treatment remains elusive. Terminology ...

Myeloid sarcoma

Myeloid sarcomas, also called granulocytic sarcomas, chloromas, or extramedullary myeloid tumors, are rare extramedullary masses comprised of myeloid precursor cells. Most commonly, these tumors happen in association with acute myeloid leukemia (AML), but they may also occur with other myeloprol...

Myoclonic epilepsy with red ragged fibers (MERRF)

Myoclonic epilepsy with red ragged fibers (MERRF) is a rare, multisystem mitochondrial disorder. Clinical presentation Patients usually present in late adolescence or early adulthood with 1-3 myoclonus epilepsy cerebellar ataxia intellectual disability vision and/or hearing loss cardiom...

N-acetylaspartate (NAA) peak

N-acetylaspartate (NAA) is one of the more important compounds assessed on MR spectroscopy, and resonates at 2.0 ppm chemical shift (its concentration in healthy adults is 8-10 mM) 1. The synthesis of NAA, adenosine diphosphate-dependent, occurs in the neuronal mitochondria 2. NAA is the acetyl...

Nail-patella syndrome

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. Clinical presentation ...

Nasal encephalocele

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 glioma

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. Epidemiology Nasal gliomas are rare congenital lesions. These masses occur spora...

Necrotizing enterocolitis

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. Epidemiology ...

Necrotizing enterocolitis (staging)

Necrotizing enterocolitis (NEC) can be staged into three groups, to guide appropriate treatment based on the work of Bell et al. 1. In general, stage I and II are managed medically whereas stage III is managed surgically. stage I clinical signs lethargy, temperature instability, apnea, bradyc...

Necrotizing pneumonia

Necrotizing pneumonia refers to pneumonia characterized by the development of the necrosis within infected lung tissue. Terminology While the term has sometimes been used synonymously with cavitating pneumonia in some publications 2, not all necrotizing pulmonary infections may be complicated ...

Neonatal abdominal radiograph (supine view)

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. Patient position the patient is supine, lying on their back i...

Neonatal appendicitis

Neonatal appendicitis is rare, presumably in part due to the short funnel shape of the appendix at that age. Symptoms are non-specific and may mimic necrotizing enterocolitis.

Neonatal bilious vomiting

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 duodenal atresia jejunoileal atresia meconium ileus necrotizing entero...

Neonatal chest radiograph in the exam setting

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. Gestation First of all, have a look ...

Neonatal encephalopathy

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

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. Epidemiology The incide...

Neonatal hydronephrosis

Neonatal hydronephrosis is most commonly diagnosed antenatally as fetal pylectasis, and in the majority of cases is due to pelvi-ureteric junction (PUJ) obstruction. Pathology Etiology pelvi-ureteric junction (PUJ) obstruction (50% of cases 1,6) vesicoureteric reflux (~20% of cases 5) pos...

Neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy (HIE) is the result of a global hypoxic-ischemic brain injury in a term neonate, usually after asphyxia. Terminology 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

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 Nasogastric tube The NG tu...

Neonatal mastitis

Neonatal mastitis is rare and refers to infection of the breast tissue occurring in a neonate. Clinical presentation 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

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 localized in the adrenal gland. Epidemiology Neonatal neuroblastoma accounts for less than 5% of all cases and carries a f...

Neonatal pneumonia

Neonatal pneumonia refers to inflammatory changes of the respiratory system caused by neonatal infection. Epidemiology 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...

Neonatal pneumoperitoneum

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 Hirschsprung disease intestinal atresia or web peptic ulcer disease iatrogenic intubation...

Neonatal pneumothorax

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. Epidemio...

Neonatal respiratory distress (causes)

Causes of neonatal distress can be broadly split into intrathoracic, extrathoracic and systemic: Intrathoracic Medical respiratory distress syndrome (RDS) transient tachypnea of the newborn (TTN) meconium aspiration syndrome bronchopulmonary dysplasia (BPD) patent ductus arteriosus (PDA) ...

Neonate chest (supine view)

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

Nephroblastomatosis refers to diffuse or multifocal involvement of the kidneys with nephrogenic rests (persistent metanephric blastema). Epidemiology Nephrogenic rest are found incidentally in 1% of infants. Pathology Nephrogenic rests are foci of metanephric blastema that persist beyond 36 ...

Nephrotic syndrome

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. Clinical presentation Patients present with marked...

Neuhauser sign (distal ileum)

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...

Neurenteric canal of Kovalevsky

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.

Neuroacanthocytosis syndromes

Neuroacanthocytosis syndromes (NAS), previously known collectively as Levine-Critchley syndrome, are characterized by basal ganglia degeneration, acanthocytosis, and normal serum lipoprotein. There are four core NAS: chorea-acanthocytosis (ChAc) McLeod syndrome (MLS) Huntington disease-like ...

Neuroblastic tumors

Neuroblastic tumors arise from primitive cells of the sympathetic system and include the following entities: neuroblastoma ganglioneuroblastoma ganglioneuroma These entities represent a spectrum of disease from undifferentiated and aggressive (neuroblastoma) to the well differentiated and la...

Neuroblastoma

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...

Neuroblastoma (image-defined risk factors)

Image-defined risk factors are imaging features seen at the time of neuroblastoma diagnosis that confer a poorer prognosis. The International Neuroblastoma Risk Group (INRG) suggested an update (2009) to the neuroblastoma staging with a list of features that, if present, upstages a patient with ...

Neuroblastoma (staging)

There are two methods of neuroblastoma staging, one that is based on post-operative patients (INSS) and one developed for pre-treatment patients (INRGSS). Staging International Neuroblastoma Staging System (INSS) This staging system is for post-operative patients and mainly for prognosis 1: ...

Neuroblastoma vs Wilms tumor

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. Neuroblastoma calcification very common: 90% encases vascular structur...

Neurocristopathy syndromes

Neurocristopathy syndromes encompasses a group of conditions united by abnormal migration, differentiation, division or survival of neural crest cells 1. Examples include: Waardenburg-Shah syndrome Haddad syndrome MEN IIa neurofibromatosis type I (NF1) Sturge-Weber syndrome Bamforth-Lazar...

Neuroendocrine cell hyperplasia of infancy

Neuroendocrine cell hyperplasia of infancy (NEHI) is a rare interstitial lung disease of childhood that typically presents in the first year of life. Terminology Neuroendocrine cell hyperplasia of infancy was previously reported as persistent tachypnea of infancy until the disease was found to...

Neurofibroma

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

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) sever...

Niemann-Pick disease type B

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 includes hepatosplenomegaly, thrombocytopenia, and variab...

Niemann-Pick disease type C

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. Epidemiology NPD-C is inherited as an ...

Non-accidental injury

Non-accidental injuries (NAI) represent both ethical and legal challenges to treating physicians. Radiologists may be the first clinical staff to suspect non-accidental injuries when confronted with a particular injury pattern. Knowledge of these is essential if the opportunity to save a child ...

Non-decussating retinal-fugal fiber syndrome

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 fibroma

Non-ossifying fibromas (NOF) are the most common type of non-neoplastic fibrous bone lesion and are a larger version (>3 cm) of a fibrous cortical defect; both are encompassed by the term fibroxanthoma or metaphyseal fibrous defect. Epidemiology NOFs are very common in children and adolescents...

Non-tuberculous mycobacterial adenitis

Non-tuberculous mycobacterial adenitis refers to lymphadenopathy due to mycobacterial infection other than M. tuberculosis. Epidemiology Most cases occur in immunocompetent children younger than 5 years of age. Clinical presentation Patients present with a firm, painless mass that enlarges ...

Noonan syndrome

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. Epidemiology The estimated incidence is at ~1 in 1000-2500 10. As individuals have normal numbe...

Noonan syndrome with multiple lentigines

Noonan syndrome with multiple lentigines, previously known as LEOPARD syndrome (LS), is a rare autosomal dominant RASopathy that has many similarities to Noonan syndrome. Clinical presentation Despite a change in formal name, the 'LEOPARD' acronym is still useful to summarize the clinical feat...

Normal kidney size in children

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...

Normal myelination

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...

Normal pediatric imaging examples

This article lists examples of normal imaging of the pediatric patients divided by region, modality, and age. Chest Plain radiograph chest radiograph premature (27 weeks): example 1 6-year-old: example 1 12-year-old: example 1 CT CT chest: examples needed Abdomen Plain radiograph ab...

Norrie disease

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.

Nuchal fold

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. Terminology It shou...

Occipital horn syndrome

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

Octreotide scintigraphy uses 111In-labeled octreotide which is a somatostatin analog; it is also known as an OctreoscanTM, a brand name for 111In-labeled pentetreotide; pentetreotide is a DTPA-conjugated form of octreotide, originally manufactured by Mallinckrodt Nuclear Medicine LLC, which now ...

Odontohypophosphatasia

Odontohypophosphatasia is the mildest form of hypophosphatasia that manifests as tooth dysplasia and/or early loss of deciduous or permanent teeth. Pathology As with all forms of hypophosphatasia, the underlying abnormality is a mutation in the ALPL gene that encodes for tissue non-specific al...

OEIS complex

The OEIS complex refers to the combined occurrence of: an omphalocele bladder exstrophy / cloacal exstrophy an imperforate anus and spinal anomalies: e.g kyphoscoliosis hemivertebrae Epidemiology The estimated occurrence is at around 1-200,000 to 400,000 live births 1,8. Pathology Pos...

Esophageal atresia

Esophageal atresia refers to an absence in the continuity 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. Epidemiology It is thought to occur in ~1:3,000-4,500 live births 3...

Esophageal atresia (classification)

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%) ty...

Esophageal duplication cyst

Esophageal duplication cysts are a type of congenital foregut duplication cyst. Epidemiology Less common compared to other foregut duplication cysts. There may be an increased male predilection 5. Clinical presentation Patients are generally asymptomatic but may complain of dysphagia due to ...

Omega epiglottis

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. Differential diagnosis When seen on lateral neck radiograph, a...

Omega sign (disambiguation)

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)

Omphalocele

Omphaloceles, 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. Epidemiology The estimated occurrence can be up to 1:4000 of live births 3. Pathology Typic...

Opsomyoclonus

Opsomyoclonus (OMS), also known as dancing eyes-dancing feet syndrome and opsoclonus-myoclonus syndrome, is a clinical syndrome which has a strong association with neuroblastoma. Clinical presentation The “opso-“ refers to the presence of intermittent jerky eye movements (dancing eyes) and the...

Optic pathway glioma

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....

Oral-facial-digital syndromes

Oral-facial-digital syndromes (OFDS) are a group of rare genetic developmental disorder that affects the mouth, face, digits and also may cause some problems on the central nervous, kidney and the other organs. Classification Some publications have classified at least 13 forms of OFDS based on...

Ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency (OTCD) is a form of hyperammonemic encephalopathy. It can have variable levels of severity. Epidemiology It is considered the most common inborn error of metabolism of the urea cycle, with an incidence of one case per 14,000 live births. Pathology It is ...

Orthoroentgenogram

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

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. Epidemiology Osgood-Schlatter disease is seen in active adolescents, especially those who jump ...

Ossification centers of the elbow

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...

Ossification centers of the foot

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 Become ...

Ossifying renal tumor of infancy

Ossifying renal tumor of infancy (ORTI) is a rare renal tumor. Epidemiology extremely rare, <<1% of pediatric renal neoplasms (17 cases reported) 6 days - 3 months male predominant Pathology Histology reveals spindle cells and osteoblastic cells in a calcified osteoid matrix. It is thought...

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