Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

991 results found
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Sinding-Larsen-Johansson disease

Sinding-Larsen-Johansson disease (SLJ), also known as Sinding-Larsen disease or Larsen-Johansson syndrome, affects the proximal end of the patellar tendon as it inserts into the inferior pole of the patella. It represents a chronic traction injury of the immature osteotendinous junction. It is a...
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Single umbilical artery

Single umbilical artery (SUA) results when there is a congenital absence of either the right or left umbilical artery. In the usual situation, there are paired umbilical arteries. For unknown reasons, the absence of the left umbilical artery is much more common (~70%). Epidemiology The estimat...
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Sinus pericranii

Sinus pericranii is a cranial venous anomaly in which there is an abnormal communication between intracranial dural sinuses and extracranial venous structures, usually via an emissary transosseous vein. It is considered a type of low flow vascular malformation. It occurs in close communication ...
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Situs classification

Situs classification can be a daunting topic, but it falls into three main groups : situs solitus: the normal configuration of thoracic and abdominal organs situs inversus: mirror image of normal situs ambiguus: an intermediate configuration with duplication (isomerism) Situs is best thought...
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Situs solitus

Situs solitus refers to the normal position of the thoracic and abdominal organs. Radiographic features Plain radiograph On plain radiograph, careful attention should be directed at the location of the aortic arch, gastric fundus, cardiac apex, pulmonary fissures and the branching pattern of ...
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Sitz marker study

The Sitz marker study is an older technique to estimate colonic transit time.  Indications In constipation it can help distinguish between slow colonic transit and a defecation disorder. Procedure The patient ingests a number of radio-opaque markers (plastic rings containing radio-opaque mat...
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Skeletal dysplasia

Skeletal dysplasia (also known as osteochondrodysplasia) refers to any abnormality in bone formation. There is a very wide clinicopathological spectrum and any part of the skeleton can be affected. Epidemiology The overall prevalence is estimated at ~2 per 10,000 live births 3. Pathology Typ...
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Slipped upper femoral epiphysis

Slipped upper femoral epiphysis (SUFE), also known as a slipped capital femoral epiphysis (SCFE), is a relatively common condition affecting the physis of the proximal femur in adolescents. It is one of the commonest hip abnormalities in adolescence and is bilateral in ~20% of cases. Epidemiolo...
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Slipped upper femoral epiphysis (summary)

This is a basic article for medical students and other non-radiologists Slipped upper femoral epiphysis (SUFE), also known as a slipped capital femoral epiphysis (SCFE),  is a relatively common condition affecting the physis of the proximal femur in adolescents. It is one of commonest hip abnor...
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Small bowel atresia

Small bowel atresia corresponds to malformations where there is a narrowing or absence of a portion of the small bowel, which includes: duodenal atresia jejunal atresia ileal atresia
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Small round blue cell tumors

A number of tumors share similar histology, composed of relatively uniform primitive small round blue cells. They also share many demographic, radiographic and clinical similarities. They include: Ewing sarcoma neuroblastoma embryonal rhabdomyosarcoma pineoblastoma Wilms tumor retinoblasto...
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Smith-Magenis syndrome

Smith-Magenis Syndrome (SMS) is a rare genetic syndrome which results from an interstitial deletion in chromosome 17p11.2. Terminology The condition is known by several other names which are all similar variants related to its underlying karyotype: 17p deletion syndrome, 17p11.2 monosomy, chro...
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Snowman sign (total anomalous pulmonary venous return)

Snowman sign refers to the configuration of the heart and the superior mediastinal borders resembling a snowman. This is seen in total anomalous pulmonary venous return (TAPVR) type I (supracardiac type). It is an abnormality of the fetal circulation wherein the entire pulmonary venous flow is ...
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Solitary sclerotic bone lesion

The differential diagnosis of a solitary sclerotic bone lesion is heavily influenced by the age of the patient, and includes: sclerotic metastasis solitary either because no others are present or no others have been imaged enostosis (bone island) osteosarcoma calcifying enchondroma osteobl...
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Sphenoidal fontanelles

The sphenoidal or anterolateral fontanelles (or fontanels) are paired bilateral soft membranous gaps at the junction of the coronal, sphenofrontal, sphenoparietal, sphenosquamosal, and squamosal sutures. Each mastoid fontanelle persists until approximately six months after birth, after which it ...
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Spinal dysraphism

Spinal dysraphism is a broad term given to a group of anomalies where there are malformations in the dorsum of the embryo. Neural tube defects come under this group as well.  Pathology There is often abnormal fusion of the midline embryonic neural tube leading to abnormal development of the ve...
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Spinal muscular atrophy

Spinal muscular atrophy (SMA) is a type of congenital neuromuscular disease affecting anterior horn cells of the brainstem and spinal cord. Epidemiology This disorder affects 1 in 6000-10000 infants 1. Clinical presentation The condition typically affects infants and young children, presenti...
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Spinal neurenteric cysts

Spinal neurenteric cysts are a rare type of foregut duplication cyst, accounting for ~1% of all spinal cord tumors. They are usually classified as spinal or intracranial and are associated with vertebral or CNS abnormalities respectively.  Pathology Neurenteric cysts result from incomplete res...
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Spleen size (pediatric)

The spleen size varies with a child's age. The three numbers below represent the 10th percentile, median, and 90th percentile for the long axis of the spleen (cm) 0-3 months: (3.3, 4.5, 5.8 cm) 3-6 months: (4.9, 5.3, 6.4 cm) 6-12 months: (5.2, 6.2, 6.8 cm) 1-2 years: (5.4, 6.9, 7.5 cm) 2-4...
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Spondylocostal dysostosis

Spondylocostal dysostosis (SCDO) is a rare condition characterized by short-trunk dwarfism secondary to developmental anomalies of the vertebrae and ribs. Previously the condition Jarcho-Levin syndrome (also known as spondylothoracic dysostosis) was grouped together with spondylocostal dysostosi...
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Spondyloepiphyseal dysplasia

Spondyloepiphyseal dysplasia is a type of skeletal dysplasia that mainly involves the spine and proximal epiphyseal centers.  Clinical presentation short neck short trunk with protruding abdomen  normal IQ spine atlanto-axial instability craniovertebral junction stenosis platyspondyly l...
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Sprengel deformity

Sprengel deformity, or congenital elevation of the scapula, is a complex deformity of the shoulder and is the most common congenital shoulder abnormality. An initial diagnosis can often be made on radiography, but CT or MRI is often necessary to evaluate the details of the abnormality. Clinical...
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Strawberry skull

Strawberry skull refers to the shape of the head on an antenatal ultrasound. Epidemiology Associations In general, strawberry skull is considered one of the non-specific 'soft markers' for abnormal fetal development. It is considered more closely associated with trisomy 18 (Edward syndrome). ...
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Stroke in children and young adults

Brain ischemia/infarction in children and young adults can result from several causes. embolic phenomena cyanotic heart disease cardiomyopathies mitral valve prolapse Osler-Weber-Rendu syndrome arterial dissection trauma spontaneous fibromuscular dysplasia Marfan syndrome Ehlers Danlo...
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Sturge-Weber syndrome

Sturge-Weber syndrome, or encephalotrigeminal angiomatosis, is a phakomatosis characterized by facial port wine stains and pial angiomas.  It is part of a wide spectrum of possible phenotypes included in the craniofacial arteriovenous metameric syndrome (CAMS). Epidemiology Sturge-Weber syndr...
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Subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE), also known as Dawson disease, is a rare chronic, progressive and fatal encephalitis that affects primarily children and young adults, caused by a persistent infection of immune resistant measles virus. Epidemiology  1 in 100,000 people infected with ...
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Subcortical leukomalacia

Subcortical leukomalacia corresponds to a continuous disease spectrum of periventricular leukomalacia (PVL) as the vascular border zones shift towards the periphery as the brain further matures. For this reason white matter lesions move from the periventricular to the subcortical zone. Please r...
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Subependymal hamartomas

Subependymal hamartomas are seen in patients with tuberous sclerosis. They are located along the ventricles and are mostly asymptomatic. As with other hamartomas, they grow at the same rate as the surrounding tissues. On imaging, they appear as small intraventricular mass, smaller than 1 cm, an...
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Subgaleal hematoma

Subgaleal hematoma describes scalp bleeding in the potential space between the periosteum and the galea aponeurosis. It is a rare but possibly lethal emergency. Epidemiology Moderate to severe presentations occur in 1.5 of 10 000 live births. It most commonly occurs after vacuum-assisted and f...
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SUFE grading

Grading of SUFE (slipped upper femoral epiphysis) can be made on both AP and true lateral projections.  On an AP radiograph a line along the superior margin of the femoral neck (line of Klein) should intersect the lateral corner of the epiphysis. As the epiphysis slips, the metaphysis can be d...
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Sunset eye sign

The sunset eye sign (also known as the setting sun phenomenon) is a clinical phenomenon encountered in infants and young children with raised intracranial pressure (seen in up to 40% of children with obstructive hydrocephalus and 13% of children with shunt dysfunction 1).  It consists of an up-...
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Supracondylar humeral fracture

Supracondylar humeral fractures, often simply referred to as supracondylar fractures, are a classic pediatric injury which require vigilance as imaging findings can be subtle. Epidemiology Simple supracondylar fractures are typically seen in younger children, and are uncommon in adults; 90% ar...
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Syndactyly

Syndactyly refers to a congenital fusion of two or more digits. It may be confined to soft tissue (soft tissue syndactyly / simple syndactyly) or may involve bone (bony syndactyly / complex syndactyly). Epidemiology The overall estimated incidence is at ~1 per 2,500 to 5,000 live births 6,8. T...
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Syphilis

Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.  Epidemiology Despite the discovery of penicillin...
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Takeuchi procedure

The Takeuchi procedure refers to a direct anastomosis of the anomalous left coronary artery from the pulmonary artery directly to the aorta was described in the 1970s and currently remains the procedure of choice. An intrapulmonary aortocoronary tunnel or baffle was performed by Takeuchi prior ...
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Tamm-Horsfall proteins

Tamm-Horsfall proteins, also known as uromodulin, may be a cause of echogenic renal pyramids in a neonate. Tamm-Horsfall proteins are physiologically excreted by the renal tubular epithelium. They are most often encountered on neonatal renal ultrasound, where the concentrated proteins in the re...
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Target sign (intussusception)

The target sign of intestinal intussusception, also known as the doughnut sign or bull's eye sign. The appearance is generated by concentric alternating echogenic and hypoechogenic bands. The echogenic bands are formed by mucosa and muscularis whereas the submucosa is responsible fo the hypoec...
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Target sign (pyloric stenosis)

The target sign of pyloric stenosis is a sign seen due to hypertrophied hypoechoic muscle surrounding echogenic mucosa, seen in pyloric stenosis. This is likened to that of a target. See also antral nipple sign cervix sign of pyloric stenosis shoulder sign of pyloric stenosis
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Taussig-Bing anomaly

Taussig-Bing anomaly is a rare congenital heart malformation and is one of the variants of double outlet right ventricle. It consists of transposition of the aorta to the right ventricle and malposition of the pulmonary artery with subpulmonary ventricular septal defect. History and etymology ...
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Tc-99m DMSA

Tc-99m DMSA (dimercaptosuccinic acid) is a technetium radiopharmaceutical used in renal imaging to evaluate renal structure and morphology, particularly in pediatric imaging for detection of scarring and pyelonephritis. DMSA is an ideal agent for the assessment of renal cortex as it binds to the...
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Tc-99m pertechnetate

Tc-99m pertechnetate is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach. Characteristics photon energy: 140 keV physical half-life biological half-life: 6 hours normal distribution: stomach, thyroid, salivary glands, (testicles) excretion: ...
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Technetium agents

Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. The radioactive technetium radiotracer can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise the functional imaging of various stru...
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Tectal beaking (midbrain)

Tectal beaking refers to the fusion of the midbrain colliculi into a single beak pointing posteriorly and invaginating into the cerebellum. It is seen with a Chiari type II malformation. Terminology The term bird beak sign is used in a number of other contexts: see bird beak sign (disambiguati...
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Tectal glioma

Tectal gliomas fall under the grouping of childhood brainstem gliomas and unlike the other tumors in that group they are typically low grade astrocytomas with good prognosis.  Epidemiology Tectal plate gliomas are encountered in children and adolescents 4. A male predilection has sometimes bee...
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Telephone receiver deformity

A telephone receiver deformity is a characteristic bowing of the shaft of the long bones, usually the humeri or femora, seen in thanatophoric dysplasia.
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Tension gastrothorax

Tension gastrothorax describes a rare life-threatening condition caused by mediastinal shift due to a distended stomach herniating into the thorax through a diaphragmatic defect.  Clinical presentation Presentation is generally with acute and severe respiratory failure, with clinical features ...
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Terminal myelocystocele

Terminal myelocystoceles are an uncommon form of spinal dysraphism representing marked dilatation of the central canal of the spinal cord, herniating posteriorly through a dorsal spinal defect. The result is a skin-covered mass in the lower lumbar region, consisting of an ependyma-lined sac.  E...
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Terminal zones of myelination

The terminal zones of myelination are located at the posterior aspect of the lateral ventricles (the peritrigonal regions) and are the only part of the cerebral white matter that may exhibit high T2 signal in a normal brain at 2 years of age, when myelination of cerebral white matter normally be...
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Tethered cord

Tethered spinal cord syndrome, also known as an occult spinal dysraphism sequence, is a neurological disorder caused by tissue attachments that limit the movement of the spinal cord within the spinal column. Clinical presentation The condition is closely linked to spina bifida, and as such pre...
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Tetralogy of Fallot

Tetralogy of Fallot (TOF) is the overall most common cyanotic congenital heart condition with many cases presenting after the newborn period. It has been classically characterized by the combination of ventricular septal defect (VSD), right ventricular outflow tract obstruction (RVOTO), overridi...
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Thalassemia

Thalassemia is an autosomal recessive hemoglobinopathy that originated in the Mediterranean region. The genetic defect causes a reduction in the rate of globin chain synthesis which causes the formation of abnormal hemoglobin molecules. The resultant microcytic anemia is the characteristic prese...
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Thalidomide embryopathy

Thalidomide embryopathy refers to a syndrome resulting from in utero exposure to thalidomide, and is characterized by multiple fetal anomalies. Fetal exposure to thalidomide occurred primarily from 1957 to 1961, when it was used as a treatment for nausea in pregnant women.  Epidemiology  Expos...
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Thanatophoric dysplasia

Thanatophoric dysplasia is a lethal skeletal dysplasia. It is the most common lethal skeletal dysplasia followed by osteogenesis imperfecta type II.  Epidemiology The estimated incidence is around 1:25,000-50,000 3. Pathology Genetics It results from a mutation coding for the fibroblast gro...
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Thiemann disease

Thiemann disease (also called familial osteoarthropathy of the fingers or osteonecrosis of the base of phalanx) is a non-inflammatory disorder of unknown etiology and refers to osteonecrosis of the epiphyses of the phalanges which leads to deformity of the fingers. Epidemiology Thiemann diseas...
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Thoracopagus conjoined twins

Thoracopagus conjoined twins are, as the name suggests, conjoined twins united at their thorax. Fusion is typically face-to-face, at the upper thorax to the umbilicus with a common sternum, diaphragm, and upper abdominal wall. Very often a common pericardial sac is present as well as a degree o...
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Thrombocytopenia with absent radius syndrome

Thrombocytopenia with absent radius (TAR) syndrome is primarily characterized by the following two features: fetal thrombocytopenia absent fetal radii (bilaterally) with the presence of both thumbs Epidemiology The condition is extremely rare with an estimated incidence of 0.4 per 100,000 bi...
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Thumb sign (epiglottitis)

The thumb sign in epiglottitis is a manifestation of an edematous and enlarged epiglottis which is seen on lateral soft-tissue radiograph of the neck, and it suggests a diagnosis of acute infectious epiglottitis. This is the radiographic corollary of the omega sign 1-3. See also Thumb sign is ...
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Thurstan Holland fragment

The Thurstan Holland fragment also known as the Thurstan Holland sign is an eponymous radiological sign depicting a triangular portion of the metaphysis remaining with the epiphysis in a physeal fracture. This fragment is one of the tell-tale signs of a type 2 Salter-Harris fracture 1. History ...
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Thymic hyperplasia

Thymic hyperplasia is a disorder whereby there is hyperplasia of the thymus gland.  Pathology Thymus hyperplasia can be subdivided into two forms:  true thymic hyperplasia lymphoid thymic hyperplasia Both true thymic hyperplasia and lymphoid hyperplasia manifest as diffuse symmetric enlarge...
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Thymic notch sign

The thymic notch sign represents the normal thymus in a newborn on a frontal chest radiograph. Interruption of the cardiac silhouette forms a notch, which may be seen on either side, but more frequently is seen on the left side. 
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Thymic sail sign

The thymic sail sign represents a triangular-shaped inferior margin of the normal thymus seen on a neonatal frontal chest radiograph. It is more commonly seen on the right side, but can also be bilateral. It is seen in 3-15% of all cases. This sign should not be confused with the spinnaker sail ...
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Thyroglossal duct cyst

Thyroglossal duct cysts (TGDC's) are the most common type of congenital neck cysts and pediatric neck masses. They are typically located in the midline and are the most common midline neck mass in young patients. They can be diagnosed with multiple imaging modalities, including ultrasound, CT, a...
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Tibia vara

Tibia vara (also known as genu varus and bow-leggedness) is a varus deformity with outward bowing at the knee and medial angulation (inward) of the lower leg in relation to the thigh's coronal axis. The differential of bow-legging in children is long, with common causes including Blount disease...
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Tibiotalar slant

Tibiotalar slant is the superolateral inclination of the tibial plafond, and results in an ankle valgus deformity. There are a number of causes 1: trauma, i.e. distal tibial fractures osteomyelitis and/or septic arthritis juvenile idiopathic arthritis haemophilic arthropathy sickle cell dis...
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Tight filum terminale syndrome

Tight filum terminale syndrome is caused by incomplete involution of the distal spinal cord during embryogenesis. This leads to development of an abnormally thickened filum terminale, which may be associated with lipomas or cysts within the filum. Tight filum terminale syndrome is always associ...
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Toddler fracture

Toddler fractures are minimally or undisplaced spiral fractures usually of the tibia, typically encountered in toddlers. It is a potentially difficult diagnosis to establish on account of both the symptoms and imaging findings being subtle. Terminology The term has sometimes also been used to ...
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Torsion of the appendix testis

Torsion of the appendix testis is the most common cause of an acute painful hemiscrotum in a child. The appendix testis is located at the upper pole of the testis (between the testis and the head of the epididymis). The normal appendix testis is 1 to 4 mm in length, and it is oval or pedunculat...
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Torticollis

Torticollis (wryneck) is a clinical finding of head tilt with or without rotational spinal malalignment. It is not a diagnosis in itself and there are a wide range of underlying conditions. It is most common in the pediatric age group.  Pathology Torticollis can be acute (<1 week) or chronic (...
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Torus fracture

Torus fractures, also known as buckle fractures, are incomplete fractures of the shaft of a long bone that is characterized by bulging of the cortex. They result from trabecular compression from an axial loading force along the long axis of the bone. They are usually seen in children, frequently...
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Total anomalous pulmonary venous return

Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart anomaly with an abnormal drainage anatomy of the entire pulmonary venous system. This contrasts with partial anomalous pulmonary venous return (PAPVR) where only part of the pulmonary venous anatomy is abnormal. In T...
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Total repair of tetralogy of Fallot

Total repair of tetralogy of Fallot is a corrective surgical procedure that involves closure of the ventricular septal defect (VSD) and relief of right ventricular outflow tract (RVOT) obstruction. Procedure Most patients with tetralogy of Fallot (TOF) undergo elective surgical repair between ...
Article

Townes-Brocks syndrome

Townes-Brocks syndrome (Renal-Ear-Anal-Radial (REAR) syndrome) is a rare autosomal dominant disease characterized by renal, anal, ear, and thumb abnormalities. Clinical presentation The major manifestations of this syndrome include: renal: displaced or rotated kidneys, horseshoe kidney, p...
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Tracheal buckling

Tracheal buckling is a normal finding in young infants when it is more flexible. There is typically deviation of the trachea anteriorly and to the right (up to 90°) and any other configuration (i.e. to the left or posteriorly) should raise the possibility of underlying pathology.  Practical poi...
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Tracheal stenosis

Tracheal stenosis is usually acquired following intubation or tracheostomy. It can also arise as part of the spectrum of tracheobronchial stenosis. Inflammation and pressure necrosis of the tracheal mucosa most commonly occur at either the tracheostomy stoma or at the level of the tube balloon....
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Tracheobronchial papillomatosis

Tracheobronchial papillomatosis refers to the occurrence of multiple squamous cell papillomas involving trachea and bronchi. It is an unusual manifestation of recurrent respiratory papillomatosis (RRP), itself a rare condition where HPV-associated papilloma form along the aerodigestive tract 8. ...
Article

Trampoline fracture

Trampoline fractures are transverse fractures of the proximal tibial metaphysis that occur in children while jumping on a trampoline (or inflatable castle). The fracture is thought to occur when a second, usually heavier individual causes the jumping surface to recoil upwards as the unsuspectin...
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Transient intussusception

Transient (non-obstructing) intussusception without a lead point is known to occur in both adults and children and occurs more frequently than was previously reported. Transient intussusception of the small bowel has been reported in adults with celiac disease and Crohn disease but is most freq...
Article

Transient synovitis of the hip

Transient synovitis of the hip refers to a self-limiting acute inflammatory condition affecting the synovial lining of the hip. It is considered one of the most common causes of hip pain and limping in young children. Over 90% of hip joint effusions in children tend to be due to transient synovi...
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Transient tachypnea of the newborn

Transient tachypnea of the newborn, also known as retained fetal fluid or wet lung disease, presents in the neonate as tachypnea for the first few hours of life, lasting up to one day. The tachypnea usually resolves by within 48 hours.  Epidemiology Transient tachypnea is one of the commonest ...
Article

Transposition of the great arteries

Transposition of the great arteries (TGA) is the most common cyanotic congenital cardiac anomaly presenting during the newborn period, with cyanosis in the first 24 hours of life. It accounts for up to 7% of all congenital cardiac anomalies 1  and can be assessed with echocardiography, gated car...
Article

Transverse vaginal septum

Transverse vaginal (transvaginal) septum (TVS) is a type of rare congenital uterovaginal anomaly (class II under the Rock and Adam classification). Epidemiology It is rare with a frequency of 1 in 70,000 females. Clinical presentation In the case of a complete septum, patients commonly prese...
Article

Treacher Collins syndrome

Treacher Collins syndrome, also known as mandibulofacial dysostosis, is an autosomal dominant genetic abnormality and results from bilateral malformations of 1st and 2nd branchial arches.  Epidemiology The incidence is estimated at approximately 1 in 50,000 live births, with 60% of cases being...
Article

Triangular cord sign (biliary atresia)

The triangular cord sign is a triangular or tubular echogenic cord of fibrous tissue seen in the porta hepatis at ultrasonography and is relatively specific for the diagnosis of biliary atresia 1,2. This sign is useful in the evaluation of infants with cholestatic jaundice, helping in the diffe...
Article

Tricuspid atresia

Tricuspid atresia is a cyanotic congenital cardiac anomaly which is characterized by agenesis of the tricuspid valve and right ventricular inlet. There is almost always an obligatory intra-atrial connection through either an ASD or patent foramen ovale (PFO) in order for circulation to be comple...
Article

Trident acetabulum

Trident acetabulum is an appearance which can be seen in several skeletal dysplasias 1. It is characterized by small bony spurs at the medial and lateral acetabular margins with a more subtle central spur, resembling a trident, the three-pronged spear of classical Greece 1. The trident is most ...
Article

Trident hand

A trident hand is a description where the hands are short with stubby fingers, with a separation between the middle and ring fingers.  The appearance mimics a trident, the three-pronged spear of classical Greece. The trident is most commonly associated with the sea god Poseidon in Greek mytholo...
Article

Trigonocephaly

Trigonocephaly refers to the triangular appearance of the frontal skull created by premature fusion of the metopic suture (metopic craniosynostosis) 2.  Trigonocephaly accounts for around 5% of all craniosynostosis cases. Pathology The metopic suture divides the frontal bones in the midline. I...
Article

Trilateral retinoblastoma

Trilateral retinoblastoma refers to the combination of retinoblastoma (usually bilateral) and pineoblastoma. This relationship highlights the close relationship between these highly aggressive small round blue cell tumors. It affects only a minority of patients with retinoblastoma (1.5-5%) and ...
Article

Triphalangeal thumb

Triphalangeal thumb is considered a form of pre-axial polydactyly. Epidemiology Triphalangeal thumbs have an incidence of 1 in 25,000 7.  Pathology A triphalangeal thumb, as the name implies, has three phalanges instead of the usual two. There is an autosomal dominant genetic transmission 8....
Article

Triplane fracture

Triplane or triplanar fractures are of the distal tibia only occurring in adolescents. As the physiological closure of the physeal plate begins medially, the lateral (open) physis is prone to this type of fracture. The name is due to the fact of the fracture expanding both in frontal and lateral...
Article

Triple bubble sign

The triple bubble sign is the classic radiographic appearance observed in jejunal atresia 1,2. The appearance is due to a proximal obstruction caused by the atretric jejunum. It is equivalent to the double bubble sign, but a third bubble is seen because of proximal jejunal distention.
Article

Triradiate cartilage

The triradiate cartilage is the Y- shaped epiphyseal plate that occurs at the junction where the ischium, ilium and pubis meet in the skeletally immature skeleton.   The vertical component of the "Y" is the meeting of the ischium and pubic bone, the anterior arm is the junction of the ilium and...
Article

Trisomies

Trisomies are chromosomal anomalies which usually occur due to non-disjunction. The vast majority of affected fetuses being spontaneously aborted, often very early during gestation. Only three are compatible with extra-uterine life (T13, T18, T21), and only one beyond early infancy (T21). In or...

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