In radiology

Radiology

Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...

, the thumbprint sign is a finding on a lateral C-spine radiograph that suggests the diagnosis of epiglottitis

Epiglottitis

Epiglottitis is an inflammation of the epiglottis - the flap that sits at the base of the tongue, which keeps food from going into the trachea . Due to its place in the airway, swelling of this structure can interfere with breathing and constitutes a medical emergency...

. The sign is caused by a thickened free edge of the epiglottis

Epiglottis

The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. It projects obliquely upwards behind the tongue and the hyoid bone, pointing dorsally. The term, like tonsils, is often incorrectly used to refer to the uvula...

, which causes it to appear more radiopaque than normal, resembling the distal thumb

Thumb

The thumb is the first digit of the hand. When a person is standing in the medical anatomical position , the thumb is the lateral-most digit...

.

In an abdominal x-ray, thumbprinting (or the "thumb print sign") has similar appearance of thumbs protruding into the intestinal lumen, but are in fact caused by thickened edematous mucosal folds.. Abdominal thumbprinting is a sign of intestinal ischemia.

External links

• Thumbprint sign on plain film