ALL EARS!DR BHAVANA K

MOUSE EAR SIGN

MOUSE EAR SIGN• Erosions will usually begin at

the peripheral articular surfaces and extend centrally.

• Marginal erosions and bony overgrowth at the interphalangeal joints can create an appearance which resembles "mouse ears".

BLADDER EARS• Normal protrusion of lateral

aspect of bladder is seen into the inguinal canal, called "bladder ears“

• Seen in infants.

DOG EAR SIGN

DOG EAR SIGN• Dog ear sign of fluid in the

pelvic peritoneal recess.• Supine abdominal radiograph

shows a full bladder which represents the face of the dog.

• The convex soft-tissue opacity representing blood in the left lateral pelvic peritoneal recess and separated from the bladder by a thin hyperlucent strip of extraperitoneal fat is the dog ear.

John H. Harris, Jr. Reflections: Emergency Radiology. Radiology 2001; 218(2): 309-316.

RABBIT EAR SIGN

RABBIT EAR SIGN• Bilateral subdural hematomas

may lead to slit like ventricles displaced medially.

• Also called squeezed ventricle or hare’s ears sign

INVERTED RABBIT EAR SIGN

INVERTED RABBIT EAR SIGN• Hyperintensities in the dorsal

column due to Vitamin B12 deficiency.

• About 50% resolve completely after vitamin B12 therapy

• Also called Inverted V sign

EARS OF THE LYNX SIGN

EARS OF THE LYNX SIGN• Periventricular cone shaped

hyperintensities near the frontal horn resembling the tuft of hair on the ears of the lynx.

EARS OF THE LYNX SIGN• Seen in hereditary spastic

paraplegia with thin corpus callosum and Marchiafava bignami.

Thank you!