The absent posterior limb sign is one of the main MRI findings of prognostic significance in term neonates with suspected hypoxic-ischemic brain injury. An absent posterior limb sign is defined as loss of the normally distinct hyperintensity on T1-weighted images in the posterior part of the pos...
The antral nipple sign refers to redundant pyloric mucosa protruding into the gastric antrum and is seen in hypertrophic pyloric stenosis on ultrasound examination.
cervix sign (pyloric stenosis)
target sign (pyloric stenosis)
Apple-peel intestinal atresia, also known as type IIIb or Christmas tree intestinal atresia, is a rare form of small bowel atresia in which the duodenum or proximal jejunum ends in a blind pouch and the distal small bowel wraps around its vascular supply in a spiral resembling an apple peel. Oft...
The banana sign is one of the many notable fruit inspired signs.
This sign is seen on axial imaging through the posterior fossa of fetuses with associated conditions such as Chiari II malformation and/or spina bifida.
In Chiari II malformation, the banana sign describes the way the cerebellum...
Bone within a bone is a descriptive term applied to bones that appear to have another bone within them. There are numerous causes including:
thoracic and lumbar vertebrae (neonates and infants)
growth recovery lines (after infancy)
cortical splitting and new periostitis
sickle cell d...
The bracket sign refers to a radiographic appearance seen with the tubulonodular variety of pericallosal lipoma. It reflects calcification seen at the periphery of the midline lipoma. It is best seen on coronal imaging and historically was identified on frontal radiographs.
It should not be con...
Butterfly vertebra is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them.
anterior spina bifida +/- anterior meningocele
can be part of the Alagille syndr...
The caterpillar sign is a radiological sign described in pyloric stenosis.
It refers to the appearance of the stomach on an upper gastrointestinal radiographic series or plain abdominal radiograph 1,2. On these imaging modalities in a patient with pyloric stenosis, the stomach appears distended...
Celery stalk appearance can refer to the following:
celery stalk anterior cruciate ligament
celery stalk metaphysis
The cervix sign of pyloric stenosis describes the indentation of the pylorus into the fluid-filled antrum, seen in pyloric stenosis on ultrasound examination.
antral nipple sign (pyloric stenosis)
target sign (pyloric stenosis)
The claustrum sign refers to the bilateral claustral involvement seen in febrile infection-related epilepsy syndrome (FIRES).
This sign is described in T2 and FLAIR sequences, seen as hyperintensity of both claustra during the acute phase and posterior hypointensity during the chronic phase if ...
Congenital hallux valgus is a very rare finding wherein a fetus or newborn shows lateral deviation of the first toe(s). When found on prenatal imaging, bilateral congenital/foetal hallux valgus is highly suggestive of fibrodysplasia ossificans progressiva 1,2.
Copper beaten skull, also known as beaten silver skull or beaten brass skull, refers to the prominence of convolutional markings (gyral impressions on the inner table of the skull) seen throughout the skull vault.
The appearance of a copper beaten skull is associated with...
The corkscrew sign describes the spiral appearance of the distal duodenum and proximal jejunum seen in midgut volvulus 1.
In patients with malrotation and volvulus, the distal duodenum and proximal jejunum do not cross the midline and instead pass in an inferior direction. These loops twist on ...
Coxa valga describes a deformity of the hip where there is an increased angle between the femoral neck and femoral shaft.
Coxa valga is often associated with shallow acetabular angles and femoral head subluxation.
neuromuscular disorders, e.g. cerebral palsy
The crescent in a doughnut sign refers to the transverse ultrasound appearance of intestinal intussusception, and is a variation of the target sign (which is also known as the doughnut sign)
The doughnut is formed by concentric alternating echogenic and hypoechogenic bands. The echogenic bands ...
The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally 2.
Causes include 1,2:
The double density sign, also sometimes clumsily referred to as the hotter spot within hot area sign, is a bone scan sign of an osteoid osteoma.
It refers to a central focus of intense uptake (the nidus) within a surrounding lower, but nonetheless increased uptake, rim.
The double lung point sign refers to a sharp boundary found between relatively aerated superior lung fields and coalescent "B‐lines" (representing interstitial edema) in the basal lung fields, with a reported sensitivity of 45.6%-76.7% and a specificity of 94.8%-100% 1,3 in diagnosing transient ...
The double track sign is a radiological sign described in pyloric stenosis on various imaging modalities.
Double streaks of barium passing through the narrow pylorus 1.
On fluid aided real-time examination, the pyloric fluid is compressed into smaller tracks as it is...
The doughnut sign can refer to a variety of different signs:
doughnut sign (bone scan)
doughnut sign (bowel)
crescent in a doughnut sign (bowel)
doughnut sign (chest)
doughnut sign (orbit)
Echogenic fetal bowel is an observation in antenatal ultrasound imaging, in which fetal bowel appears to be brighter than it is supposed to be. It is a soft marker for trisomy 21 and has several other associations. When observed, it needs to be interpreted in the context of other associated abno...
Egg-on-a-string sign, also referred to as egg on its side, refers to the cardiomediastinal silhouette seen in transposition of the great arteries (TGA).
The heart appears globular due to an abnormal convexity of the right atrial border and left atrial enlargement and therefore appears like an ...
The flat floor of fourth ventricle sign is useful in detecting a pontine mass and is a sign of mass effect. The normal floor of the fourth ventricle (remember that the floor is anterior) normally slopes upwards towards the midline, with the facial colliculi visible on either side.
It is a non-...
The fountain sign is a sonographic sign described in acute idiopathic scrotal edema (AISE).
It refers to the appearance of the pattern of vascularity seen during transverse color Doppler sonography of the scrotum with both testes together 1. In this transverse view, in patients with AISE, marke...
The Gage sign is a V-shaped lucent defect at the lateral portion of the epiphysis and/or adjacent metaphysis. It is pathognomonic for Legg-Calve-Perthes disease.
It may occur early in the disease and is one of the five indicators of a worse prognosis, which are:
Gallbladder ghost triad is a term used on ultrasound studies when there is a combination of three gallbladder features on biliary atresia:
atretic gallbladder, length less than 19 mm
irregular or lobular contour
lack of smooth/complete echogenic mucosal lining with an indistinct wall
Ghost vertebra is a sign, that is generally used synonymously with bone-within-a-bone vertebra, and as such, the causes form a subset of those causing bone within a bone appearance 2:
Thorotrast administration: bone within a bone appearance due to temporary growth arrest 1
A halberd pelvis refers to a pathognomonic appearance of the pelvis seen in metatropic dysplasia, a rare form of spondyloepimetaphyseal dysplasia.
hypoplastic ilia with narrow sacrosciatic notches
horizontal acetabular roofs with small associated notches superior to their lateral borders
The harlequin eye deformity is characterized by elevation of the superolateral corner of the orbit. It may be seen in unilateral (plagiocephaly) or bilateral (brachycephaly) coronal suture synostosis.
History and etymology
The term harlequin eye derives from the appearance of the eyes on a har...
The Harrison sulcus or Harrison groove refers to a groove at the lower end of the rib cage seen in young children/infants with abnormally weak bones (e.g. rickets) or chronic respiratory disease (e.g. severe asthma). The lower chest is drawn in with flaring of the rib margin. The exact cause is ...
The haystack sign on chest radiographs in pediatric patients is indicative of pneumomediastinum. The pediatric heart is surrounded above and below with gas, giving it an appearance of a haystack from Monet's paintings.
A J-shaped sella is a variant morphology of the sella turcica, whereby the tuberculum sellae is flattened, thus forming the straight edge of the "J". The dorsum sellae remains rounded and forms the loop of the "J".
Differential diagnosis for a J-shaped sella includes 1,2...
The keyhole sign is an ultrasonographic sign seen in boys with posterior urethral valves. It refers to the appearance of the proximal urethra (which is dilated) and an associated thick-walled distended bladder which on ultrasound may resemble a keyhole.
A Kirner deformity, also known as dystelephalangy, is characterized by a curvature of the distal phalanx of the 5th digit in both a palmar and radial direction.
The deformity typically presents in late childhood to early adolescence, although a mild deformity may be present at bir...
The medial stripe sign refers to an area of increased lucency at the interface of the medial lung and the mediastinum on a chest radiograph in a case of medial pneumothorax. A small pneumothorax generally accumulates anteriorly or medially which may be difficult to detect, hence this sign holds ...
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.
double track sign
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...
Platyspondyly is a radiographic sign and refers to flattened vertebral bodies throughout the axial skeleton.
Platyspondyly can be feature of many conditions which include:
severe Gaucher disease 1
The pseudokidney of intussusception is an ultrasound finding in some cases of intestinal intussusception. It refers to the longitudinal ultrasound appearance of the intussuscepted segment of bowel which mimics a kidney.
The fat-containing mesentery which is dragged into the intussusception, con...
The alphabet P sign, or just P sign, is a sonographic finding in acute epiglottitis. Using point of care ultrasound (POCUS), on a longitudinal view at the level of the thyrohyoid membrane, a P-shaped hypoechogenicity is apparent. The curved portion of the P is formed from the edematous epiglotti...
Pulmonary plethora is a term used to describe the appearances of increased pulmonary perfusion on chest radiographs. It is commonly used in pediatric radiology.
Usually a left-to-right shunt of 2:1 is required for pulmonary plethora to occur 2,3. Increased pulmonary perfusion occurs...
Pyrexia (or fever) is a clinical sign, indicated by an abnormally elevated core body temperature, which is defined by several medical societies as ≥38.3°C (≥≈101°F). The temperature elevation may be persistent or episodic. If the body temperature is greater than 41.5°C - a rare phenomenon - it i...
Raccoon eyes sign (or panda eyes in the UK and Ireland) refers to periorbital ecchymosis with sparing of the tarsal plate 3 and is a physical examination finding indicative of a base of skull fracture of the anterior cranial fossa.
However it is not pathognomonic for trauma, and there are sever...
Rachitic rosary refers to expansion of the anterior rib ends at the costochondral junctions and is most frequently seen in rickets as nodularity at the costochondral junctions.
Other causes of this appearance include:
the costochondral junction is more angular ...
The radiocapitellar line is one of the key lines used to assess alignment on the elbow radiograph. It is particularly useful in the pediatric setting.
A line drawn down the neck of the radius should intersect the capitellum. It is important to ensure that you draw the line down the ra...
The Scham sign of slipped capital femoral epiphysis is one of the subtle signs that may be seen on the AP view of an adolescent hip radiograph with early slip.
In the normal adolescent hip, an intra-articular portion of the diaphysis of the collum overlies the posterior wall of the acetabulum i...
The shoulder sign of pyloric stenosis is seen during barium examination and refers to the bulging of the hypertrophied pyloric muscle into the lumen of the antrum.
It is closely related to the cervix sign (pyloric stenosis).
cervix sign (pyloric stenosis)
target sign (pyloric steno...
The presence of intramuscular edema (increased high T2/STIR signal) on MRI carries an extremely broad differential. Potential diagnoses include:
effects of direct injury or tear
denervation injury: denervation changes in muscles
early myositis ossificans
Snowman sign, also sometimes referred to as a figure of 8 sign or dumbell sign, is a radiologic sign related to conditions that have a shape which resembles a snowman. This include:
snowman sign (total anomalous pulmonary venous return) 1
snowman sign (pituitary macroadenoma) 2,3
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 also referred to as the figure of 8 sign.
It is an abnormality of the fetal circulat...
Strawberry skull refers to the shape of the head on an antenatal ultrasound.
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).
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-...
Suspected physical abuse (SPA), also known as non-accidental injury (NAI) or inflicted injury, in infants and young children represents both ethical and legal challenges to treating physicians.
Radiologists may be the first clinical staff to suspect non-accidental injuries when confronted with ...
The tadpole sign, also known as the lollipop sign, refers to a characteristic morphology of post-traumatic bridging vein thrombosis with a rounded "head" and a tapering "tail". The finding demonstrates a high specificity for abusive head trauma, a sub-type of non-accidental injury, and should wa...
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 hypoechoic bands. The echogenic bands are formed by mucosa and muscularis whereas the submucosa is responsible fo the hypoechoi...
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.
antral nipple sign (pyloric stenosis)
cervix sign (pyloric stenosis)
shoulder sign (pyloric stenosis)
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.
The term bird beak sign is used in a number of other contexts: see bird beak sign (disambiguati...
A telephone receiver deformity is a characteristic bowing of the shaft of the long bones, usually the humeri or femora, seen in thanatophoric dysplasia.
The telltale triangle sign, also known as the triangle sign or telltale triangle, is a radiographic sign seen on plain abdominal radiographs in a supine, cross table lateral or decubitus view that signifies presence of pneumoperitoneum, of any cause 1,2.
It describes the appearance of a radiolu...
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.
Thumb sign is ...
The Thurstan Holland fragment (or 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 indicates that a type 2 Salter-Harris fracture has occurred 1.
History and etymology
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.
thymic sail sign
thymic wave 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 ...
Thymic wave sign refers to the indentation of the normal thymus in young children by the ribs, resulting in a wavy border on chest radiograph.
There are at least 3 described signs relating to a normal thymus in infants; thymic sail sign, thymic notch sign and thymic wave sign. Being able to id...
The tit sign of pyloric stenosis is seen on barium studies as an outpouching of the lesser curve of the stomach proximal to the impression of the hypertrophied pyloric muscle.
It represents the transient trap of contrast medium between a peristaltic wave and the thickened, hypertrophied pyloric...
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...
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 appearance has...
The trident appearance (or sign) can refer to a variety of entities:
trident sign (osmotic demyelination)
trident sign (persistent trigeminal artery)
History and etymology
The trident is a three-pronged lance employed for spearing fish, and in Classical myth...
A trident hand is a description where the hands are short with stubby fingers, with a separation between the middle and ring fingers. It may be used for the clinical appearance of the hand or the appearance on imaging, particularly reminiscent of a trident on fetal ultrasound 5.
It can be seen ...
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.
Wimberger ring sign, often simply just called Wimberger ring, refers to a circular calcification surrounding the osteoporotic epiphyseal center of ossification in scurvy, which may result from bleeding.
It must not be confused with Wimberger sign, pathognomonic for congenital syphilis.
The Wimberger sign, also called Wimberger corner sign, refers to localized bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis.
It must not be mixed up with Wimberger ring sign seen in scurvy, which is sometimes also confusingly re...
The zebra stripe sign occurs where children with osteogenesis imperfecta have been treated with cyclical bisphosphonate therapy, e.g. pamidronate. When the drug is delivered in cycles, dense bone is formed while treatment is being given. This results in dense stripes across the metaphyses of bon...