Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Knuckle sign. The figure clearly shows evident blood clot (black arrows) due to pulmonary embolism causing abrupt interruption of pulmonary arteries—in a patient affected by deep vein thrombosis. The abrupt interruption evokes the appearance of a knuckle
