Researchers at Emory University in Atlanta said deep vein thrombosis is a blood clot that forms in a vein deep in the body, most often in the lower leg or thigh. A loose clot, or embolus, can break off and travel through the bloodstream to the lungs and block blood flow -- a life-threatening condition called pulmonary embolism.

Researchers treated 37 patients with the clot-dissolving drug tissue plasminogen activator while using ultrasound to loosen the proteins in their blood clots and send the drug into the clots faster. Of these 37, 16 had deep vein thrombosis and 21 had acute in-situ arterial thrombosis. All the patients with arterial thrombosis had their clots completely dissolved, and all but six of the deep vein thrombosis patients had theirs completely dissolved.

Four deep vein thrombosis patients had their clots partially dissolved and two saw no change. One of the 37 had a complication, a neck hematoma.

The study was presented at the annual VEITH symposium in New York.