'Semiology' - The Signs in Radiology

'A'

ABSENT BOW TIE SIGN
Seen in MRI Knee, in Bucket handle tear of meniscus.
In normal knee - the continuity of the anterior and posterior horns are seen in two contiguous sagittal images. If this is not seen in 2 contiguous sagittal images - it's called Bow tie sign - Absent.

ACCORDION SIGN
Seen due to marked submucosal edema of the colon.
Differentials include:
1. Ischemic Colitis.
2. Radiation Induced Colitis.
3. Infectious Colitis.
4. Typhilitis (Neutropenic Colitis).
5. Crohns and UC ( Only 2 conditions which result in wall thickness >10mm).


AIR CRESCENT SIGN
Seen in CXR or CT.
Seen mainly in Saprophytic Pulmonary Aspergillosis or in Angio-invasive form (after 2 weeks).
Crescent of air lining the fungal ball within a cavity gives the name.
 'The air-crescent sign consists of a nodular opacity that represents retracted, infarcted lung associated with crescentic or circumferential cavitation. Although this finding is not specific for angioinvasive aspergillosis, it is highly characteristic in the proper clinical setting. It is seen in nearly 50% of patients with invasive aspergillosis, particularly those in whom the initial lesion was consolidation or a mass.'

ANGIOGRAPHIC STRING SIGN
Seen in pre-occlusive atherosclerosis - ICA - bifurcation.
Can also be seen in post-radiation stenosis,  recanalization of ICA thrombus and also in ICA dissection.

 







APPLE CORE LESION 
Seen in Barium enema / CECT in Stenosing Ca.Colon. (See image below)

>>>>  The Apple Core !!!

 

 

 

'B'

BANANA SIGN
Seen in Antenatal USG - Appearance of cerebellum in fetal Arnold-Chiari II.


BARE ORBIT SIGN
Seen in Skull Radiograph AP view - Caused by Non-visualization of the innominate line (Sphenoid bone).
Differentials include Neurofibromatosis, Metastasis and Myeloma.

BAS RELIEF SIGN (Syn : RIGLER's SIGN)
Same as Rigler's Sign /Double wall sign / Ghost appearance of bowel - of pneumoperitoneum in supine abdominal radiograph.

BIRD OF PREY SIGN (Bird's beak appearance)
Seen in Barium enema of Sigmoid Volvulus.

BLACK EYEBROW SIGN
Seen in Skull radiograph in traumatic orbital emphysema.

BLACK PLEURA SIGN
Seen in Pulmonary Alveolar Microlithiasis.

BLADE OF GRASS SIGN
Syn : FLAME SIGN
'V' shaped diaphyseal lucency in early Paget's due to Osteolysis.
Usually seen in Tibia.
In calvarium osteolysis is called as Osteoporosis circumscripta.
(See image below; Ref : Radiology article, 2001)

BLIND VERTEBRA
Seen in AP Radiograph - in bilateral pedicular lytic lesions (metastasis).
(See 'One eyed pedicle sign' or 'Winking Owl Sign' also.)

BOOT SHAPED HEART = Coeur en Sabot
is seen characteristically in CXR of Tetralogy of Fallot patients.

BOWLER HAT SIGN
Seen in DCBE of Colonic Diverticulum (Outwards) or Polyp (inwards). 

BOX SHAPED HEART
Ebstein's Anomaly (Prominent RA, Dilated RVOT and small Aorta)

BRACKET CALCIFICATON
Seen in Calcified Corpus Callosal Lipoma in Skull frontal Radiograph resembling 'round brackets' ( ).

BRUSH SIGN
Seen  Moyamoya disease. Indicates 'severity' of the disease.

BUN SIGN ( Syn : SANDWICH SIGN, OREO/NABISCO Cookie sign)
Separation of fat stripes in Pericardial Effusion in lateral CXR ( Penetrated).

'C'

CARMAN MENISCUS SIGN
Seen in Malignant Gastric Ulcer in Barium study.
Large flat ulcer with heaped up edges trap Barium, with lenticular collection convex in relation to the lumen.

CLAW SIGN
Seen in Barium Enema in Intussusception.

CLOVER LEAF SIGN
Seen in Duodenal Ulcer (Barium Study).

CLOVER LEAF SKULL (Syn :  kleeblattschädel)
Refers to the shape of skull in severe craniosynostosis - due to premature closure of sagittal, coronal and lamboid sutures. Seen in association with Thanatophoric dysplasia (type I only), Severe Crouzon, Severe Apert etc.Clover leaf skull can be identified in utero.
 
COEUR EN SABOUT = See also 'Boot shaped Heart' - TOF.

COFFEE BEAN SIGN 
Characteristic finding of Sigmoid Volvulus.

(See below image; Ref : Radiology article, 2000,by Deborah Feldman, MD.)

Anteroposterior radiograph of the abdomen demonstrates the characteristic coffee
bean sign in sigmoid volvulus. The coffee bean is formed by grossly dilated and closely
apposed loops of bowel, which result from a closed-loop obstruction of the sigmoid colon.
There is an air-fluid level (black arrows) in each segment of dilated bowel. Note also the central
cleft (white arrow) of the coffee bean



COLON CUTOFF SIGN 
Is seen in acute pancreatitis. Refers to the abrupt cut off of the gas in the colon at the splenic flexure.
Occurs due to the spread of inflammation throught the phrenicocolic ligament in acute pancreatitis, which causes the spasm at the splenic flexure.


CONTINUOUS DIAPHRAGM SIGN
Seen in CXR of pneumomediastinum.

CREEPING FAT SIGN
Seen in CT Abdomen in ~40% of Crohns Disease.
Extensive proliferation of mesenteric fat separates the small bowel loops.

'D'

DANGLING CHOROID SIGN
Feature of fetal hydrocephalus in ultrasound.


DEEP SULCUS SIGN
Sign of pneumothorax in a supine radiaograph, with a deep costophrenic angle, due to air.
Also described in Lateral X Ray and MR Sagittal images of Knee joint in ACL tear.

DISAPPEARING BASAL GANGLIA SIGN
Seen in Acute MCA territory infarct. refers to the loss of delineation of basal ganglia structures -
syn : Lentiform Obscuration.

DOUBLE BRONCHIAL WALL SIGN
Seen in Pneumomediastinum.

DOUBLE BUBBLE SIGN
Seen in duodenal atresia,, stenosis, web, annular pancreas and malrotation during an antenatal USG. This appearance is due to the fluid filled stomach and proximal duodenum, appears like two bubbles!.

DOT IN CIRCLE SIGN
Seen in Mycetoma foot in T2 weighted MRI.
T2 weighted hyperintense lesions, representing granulation tissue surrounded by a low-signal-intensity rim representing intervening fibrous septa. Within many of these hyperintense lesions, there was a central low-signal-intensity dot, which gives rise to the “dot-in-circle” sign.

DOUBLE DECIDUAL SIGN
2 concentric echogenic lines surrounding the gestational sac. Decidua capsularis(inside) and Decidua parietalis(Outside).


DOUBLE DENSITY SIGN
Early sign of LA enlargement in CXR - frontal radiograph

DOUGHNUT SIGN
In Lateral CXR this refers to appearance caused by mediastinal lymphadenopathy. Normally in a lateral CXR the Aortic arch and the PAs form a Horse Shoe shape. The notch of the horse shoe, is obliterated in mediastinal lymphadenopathy -- resembling a 'doughnut'!.

In CT/US - Doughnut sign - sometimes refers to the appearance of a colonic carcinoma.

DROOPING LILY SIGN
IVP finding in Duplex renal system with proximal moiety hydronephrosis, displacing the opacified lower moiety calyces and ureter inferiorly, resembling a drooping lily.
(Radiopaedia) 


DUODENAL WINDSOCK SIGN
Seen in barium imaging of Duodenal Diverticulum.

DURAL TAIL SIGN
Feature of a Meningioma in CECT / CE-MRI

'E'

EGG ON A STRING APPEARANCE
Seen in TGA. Abnormal convexity of right atrium with narrow superior mediastinum.

EYE OF TIGER APPEARANCE
- Hallervorden-Spatz Syndrome. May be seen in other conditions like PSNP, Levodopa responsive Parkinsonism. Central high SI surrounded by low SI in Globus Pallidus due to intensified Iron deposition in T2WI MR images.

'F'

FAT C2 SIGN
Refers to the enlarged AP dimension of C2(Axis) Vertebra compared to C3, on a lateral cervical spine radiograph, due an oblique fracture of C2, which causes displacement of either or both of anterior / posterior surfaces.

FOOTBALL SIGN
Supine abdominal radiograph in child with pneumoperitoneum, with the distended abdomen resembling a football !!.

 

'G'

GOLDEN S SIGN
Central bronchogenic carcinoma causing right upper lobe collapse, with the mass causing a convex bulge in the medial aspect of lower border of the collapsed lung resembling a reverse S.

'H' 

HEAD CHEESE SIGN
Name given to mixed lung parenchymal attenuation in CT  with GGO, consolidation, normal lung, air trapping etc. Differentials include Extrinsic Allergic Alveolitis / Hypersensitivity Pneumonitis, Sarcoidosis, Atypical infections like Mycoplasma with associate bronchiolitis.

 

'I'

INSULAR RIBBON SIGN
Seen in CT Brain - in Acute MCA territory infarct.

'J'

'K'

'L'
LEPTOMENINGEAL IVY SIGN
Again a feature of Moya Moya disease, like in Brush sign mentioned before.
The ivy sign on FLAIR images was defined as a linear high signal intensity along the cortical sulci or brain surface in the cerebral hemisphere.

LUFTSICHEL SIGN
Seen in CXR or CT of Left upper lobe lung collapse.
Luftsichel is two German words - Luft(air) and sichel(sickle) - the superior segment of the lower lobe ascends up along the aorta, producing an air-crescent, thus likened to an 'air-sickle', in the region of aortic knob.

 

 

 

 

 

 

 

 

 

 

 

 

'M'

MEXICAN HAT SIGN
Described in Double Contrast Barium Enema (DCBE) in cases of Pedunculated polyps of the bowel. Central opacity is the stalk and margins are due the polyp itself.

 

'N'

'O'

ONE EYED PEDICLE SIGN 
Syn : Winking Owl Sign

Due to destruction of posterior vertebral body and adjacent pedicle on AP XR (Thoraco-lumbar spine).

Lytic lesion destroying the right pedicle, resembling the closed eye of an Owl !!!

The Winking Owl !!!

'P'

POPCORN APPEARANCE
MRI BRAIN T2WI : Cavernoma
CT CHEST : Hamartoma

 

'Q'

'R'

REVERSED HALO SIGN
Seen in CT. Central GGO surrounded by consolidation. Radiological reverse of CT Halo Sign.

The central area of the ground-glass attenuation corresponds histopathologically to alveolar septal inflammation and cellular debris in alveolar spaces and the crescent or ring-shaped peripheral air-space consolidation corresponds to granulomatous tissue within the distal air spaces .

hich gi

ves rise to the “dot-in-circle” sign


The sign was reported as a relatively specific finding for COP.
Also been described in various diseases, including pulmonary paracoccidioidomycosis, pulmonary zygomycosis, invasive pulmonary aspergillosis , lymphomatoid granulomatosis, Wegener's granulomatosis , lipoid pneumonia , pulmonary sarcoidosis , drug-induced interstitial pneumonitis  and cellular NSIP.

'S'

SNOWSTORM APPEARANCE
Seen in USG of Hydatidiform mole

 

'T'

TRIPPLE BUBBLE SIGN
Seen in Jejunal atresia.

'U'

 

'V'

V-sign of NACLEIRO
Sign of Pneumomediastinum.

'W'

WATERBOTTLE SIGN
Seen in Pericardial Effusion

'X'

 

'Y'

 

'Z'

to be continued...