Signrad

Front 1

“figure 3” sign

Back 1

notching that occurs at the site of coarctation of aorta
Dilation of the aorta proximal and distal to the coarctation results in the characteristic “figure 3” sign

Front 2

snowman heart

Back 2

TAPVR

Front 3

Egg on a side

Back 3

TGR

Front 4

boot shaped heart

Back 4

TOF

Front 5

double bubble sign can be seen in which diseases

Back 5

gas in stomach and duodenal bulb

duodenal atresia
annular pancreas
Ladd's bands
congenital duodenal web (or diaphragm)

Front 6

Brass Beaten Skull

Back 6

suggestive of long-standing hydrocephalus

corrugated appearance of the inner table of the skull

Front 7

Transependymal CSF flow

Back 7

often seen in acute hydrocephalus
in the frontal horns

Front 8

“insular ribbon sign”

Back 8

insular region is furthest from any potential collateral supply, probably explaining the early appearance of the edema that gives rise to the “insular ribbon sign”. Occurs in an MCA infarct

Front 9

light-bulb sign

Back 9

hyperintense signal on DWIs (“light-bulb sign”) precedes T2 hyperintensity, which typically develops at 6 to 12 hours postictal. earliest sign of ischemia

Front 10

empty delta sign

Back 10

The venous clot responsible may be seen indirectly as a filling defect in the superior sagittal sinus on contrast-enhanced CT, i.e., the “empty delta” sign (Fig. 4.30). The empty delta sign is usually present 1 to 4 weeks after sinus occlusion, but it may not be seen in the acute and chronic phases of the disease. Small venous occlusions are not reliably detected by CT. An appearance that mimics the empty delta sign has also been described in up to 10% of normal patients when CT scanning is delayed for more than 30 minutes after contrast infusion. This is probably a result of differential blood pool clearance and dural absorption of contrast, effectively highlighting the dural margins of a normal venous sinus.

Front 11

blueberry muffin sign

Back 11

raised, purple skin lesions

dermal metastases of neuroblastoma (stage IV-S)

Front 12

Carman meniscus sign

Back 12

semicircular (meniscoid) configuration of gastric ulcer seen in profile with compression

suggestive of malignancy
see: gastric ulcers

Front 13

chalice (Bergman) sign

Back 13

dilatation of ureter DISTAL to neoplasm

not seen with calculi or thrombi

Front 14

double bubble sign

Back 14

gas in stomach and duodenal bulb

duodenal atresia
annular pancreas
Ladd's bands
congenital duodenal web (or diaphragm)

Front 15

drooping lily sign

Back 15

appearance of renal pelvis with duplicated collecting system

upper pole moiety obstructs, becomes hydronephrotic
==> compresses lower-pole moiety and pushes it downward
see also: Weigert-Meyer rule

Front 16

epicardial fat sign

Back 16

two lucent lines on lateral CXR anterior to heart
subepicardial fat around LAD
anterior mediastinal fat

lines seen in 40% of all lateral CXRs

if separation > 2 mm ==> consider pericardial effusion or thickening

Front 17

Fleischner sign

Back 17

wide gap between thickened patulous ileocecal valve and narrowed ulcerated terminal ileum

"inverted umbrella" defect

associated with tuberculous involvement of the ileocecum

Front 18

football sign

Back 18

large pneumoperitoneum outlining entire abdominal cavity
falciform ligament = cross threads

Front 19

Frostberg inverted-three sign

Back 19

medial retraction of 2nd portion of duodenum

pancreatic Ca (<10% of Ca's)
acute pancreatitis
postbulbar ulcer disease

Front 20

halo sign

Back 20

narrow, radiolucent ring surrounding breast lesion
indicates benign tumor

rare exceptions:
intracystic carcinoma
papillary carcinoma
carcinoma arising in fibroadenoma


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Front 21

Hamman sign

Back 21

crackles heard in LEFT lateral decubitus position

indicates (+) pneumomediastinum

Front 22

knuckle sign

Back 22

seen in pulmonary embolism
abrupt tapering of an occluded vessel distally

Front 23

lambda sign

Back 23

small ascending aorta:
same size as right + left coronary aa.

hypoplastic left heart syndrome

Front 24

lemon sign

Back 24

concave frontal bones

suggests neural tube defect
also: "banana" sign

Front 25

melting sign

Back 25

regression of consolidation from periphery to center

seen in pulmonary infarction

appears within days to weeks

Front 26

Rigler sign

Back 26

bowel wall outlined by air on inside and outside
indicates pneumoperitoneum

Front 27

sandwich sign

Back 27

US: hypoechoic solid mass
around central linear hyperechoic area

CT: soft-tissue density surrounding bowel


==> lymphomatous involvement of mesentery

Front 28

snowman sign

Back 28

Supracardiac TAPVR
(total anomalous pulm venous return)

return to persistent left SVC
aka: "vertical vein"

Front 29

Spalding sign

Back 29

overlapping of fetal skull bones
suggests fetal demise

Front 30

Stierlin sign

Back 30

terminal ileum empties directly into stenotic ascending colon with non-opacification of the fibrotic and contracted cecum

associated with tuberculous involvement of the ileocecum

Front 31

Terry Thomas sign

Back 31

a gap between the scaphoid and the lunate bones suggesting a rupture of the scapho-lunate ligament

seen on x-ray, CT and MRI of the wrist
Terry Thomas was a British actor whose career was most active in the sixties.
the reference is to the prominant gap between his front teeth
many radiologists have taken to calling it the "David Letterman" sign for similar reasons

Front 32

trumpet sign

Back 32

enlargement of the nerve root secondary to edema

seen in disc herniation (HNP)

Front 33

V sign of Naclerio

Back 33

V-shaped collection of air

in mediastinum + along diaphragm
indicates pneumomediastinum + pneumothorax
seen in Boerhaave syndrome

Front 34

Westermark sign

Back 34

seen in 2% of pulmonary embolism
focal oligemia (vasoconstriction) distal to embolus

Front 35

Wimberger sign

Back 35

bilateral metaphyseal destruction in upper medial tibias

congenital syphilis

less likely:
bacterial osteomyelitis
hamartomosis
hyperparathyroidism

Front 36

String of Beads

Back 36

Fibromuscular Disease

Front 37

spider web pattern of intrahepatic venous collaterals

Back 37

budd-chiari

Front 38

spalding sign

Back 38

overlapping skull bones seen with fetal death

Front 39

Y-sign

Back 39

epidural lipomatosis
epidural fat compresses the thecal sac anchored to the osteofibrous walls of the spinal canal by meningovertebral ligaments.

Front 40

fluid sign

Back 40

csf signal intensity on T1 and STIR adjacent to a fractured endplate.

Front 41

halo sign

Back 41

is defined as an area of ground-glass attenuation surrounding a central pulmonary nodule or mass.

Front 42

air crescent sign

Back 42

results from air between an area of pulmonary consolidation and surrounding lung parenchyma. This can be seen in the later stages of invasive aspergillosis, where a central spherical area of lung has infarcted, leading to cavitation and retraction of the lung away from the surrounding parenchyma.

Front 43

signet ring sign

Back 43

occurs when a bronchus is larger than the adjacent pulmonary artery. This is seen in patients with bronchiectasis.

Front 44

signet ring sign

Back 44

occurs when a bronchus is larger than the adjacent pulmonary artery. This is seen in patients with bronchiectasis.

Front 45

comet tail sign

Back 45

refers to curvilinear opacities extending from a subpleural mass towards the hilum. This can be seen with round atelectasis and the comet tail represents distorted pulmonary vessels and bronchi pulled into the atelectatic lung.

Front 46

“Bowstringing”

Back 46

describes an appearance of the flexor tendon that is not flush with the underlying volar aspect of the phalanges. It is considered a secondary sign for underlying pulley injury

Front 47

cord sign

Back 47

is a specific indicator of venous thrombosis

Front 48

“curlicue” ureter sign

Back 48

a characteristic finding of ureterosciatic herniation on a retrograde uretergram

Front 49

colon cutoff sign

Back 49

can be used to describe abrupt cutoff of gas in the region of the splenic flexure, with emptying of the distal colon, on either radiography or CT.

Front 50

CT halo sign

Back 50

represents a central area of dense opacification (necrosis) surrounded by ground glass (hemorrhage).

Front 51

air crescent sign

Back 51

refers to a crescent of lucency formed by separation of devitalized tissue from surrounding lung parenchyma.

Front 52

Monad Sign

Back 52

Air may be seen between the dependent fungal mass and the cavity wall resulting in the Monad sign, differing from the air crescent sign in which there is no preexisting cavity.

Front 53

Falciform Ligament Sign

Back 53

The falciform ligament travels along the anterior margin of the abdomen from the liver to the umbilicus and is only visible on plain abdominal x-ray when surrounded by free intraperitoneal air.

Front 54

Double posterior cruciate ligament (PCL) sign

Back 54

double posterior cruciate ligament (PCL) sign indicates that a displaced intercondylar fragment lies inferior to the PCL, paralleling the orientation of this ligament. This finding has been reported only with medial meniscal tears.

Front 55

Anterior flipped meniscus sign

Back 55

anterior flipped meniscus sign refers to a bucket-handle tear that shows the peripheral posterior horn fragment displaced anteriorly, juxtaposed to the anterior horn. This finding is frequently accompanied by an absent bow tie meniscus sign.

Front 56

Squeeze Sign

Back 56

squeeze sign (change in size and shape with peristalsis), which is considered pathognomonic for a lipoma on barium enema.

Front 57

Molar Tooth Sign

Back 57

The molar tooth sign is a characteristic appearance of the midbrain in Joubert syndrome where the superior cerebellar peduncles become thin and parallel to each other. This gives a molar tooth appearance on axial images.

Front 58

Boomerang Sign

Back 58

The boomerang sign is hyperintense T2, FLAIR, or diffusion-weighted imaging signal in the splenium of the corpus callosum accompanying any number of insults, including, but not limited to, diffuse axonal injury, ischemia, multiple sclerosis, and posterior reversible encephalopathy syndrome. On a completely different front, a boomerang sign is also described on MRI in peroneus brevis split syndrome.

Front 59

Banana Sign

Back 59

A banana sign is an abnormal shape of a high-riding cerebellum typically seen by prenatal ultrasound or perhaps MRI in cases of Arnold Chiari II malformations.

Front 60

Pulvinar Sign

Back 60

The pulvinar sign refers to bilateral T2/FLAIR hyperintensities involving the pulvinar thalamic nuclei. It is classically described in variant Creutzfeldt-Jakob disease.

Front 61

Batwing Sign

Back 61

"batwing fourth ventricle sign," which refers to the morphology of the fourth ventricle in Joubert syndrome . With a hypoplastic vermis and apposed cerebellar hemispheres, the fourth ventricle gives an appearance suggestive of a bat with its wings outstretched. It is best demonstrated on axial imaging.