What it means
The pulmonary arteries carry blood from the heart to the lungs to pick up oxygen. In a pulmonary embolism, a clot lodges in one of them. Most often it is a clot that formed in a deep leg vein (DVT) and broke loose. On a CT pulmonary angiogram, contrast dye makes the arteries bright, and a clot shows as a dark gap inside them. A V/Q scan instead compares airflow with blood flow in the lungs.
When it matters
A pulmonary embolism is usually treated straight away with blood thinners. Reports note where the clots sit, from the main arteries down to small branches, and whether the right side of the heart looks strained. That helps doctors judge how serious it is. A single small clot in a far branch (subsegmental) is sometimes only watched closely. Doctors also look for a cause, such as recent surgery, long travel or a clotting tendency.
Questions to ask your doctor
- Where are the clots, and is there any strain on the right side of my heart?
- How long will I need blood thinners, and what follow-up is planned?
- What likely caused the clot, and should I be tested for a clotting disorder?
